PRELIMINARY PROXY STATEMENT


              AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION
                                ON MARCH 20, 2001


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                            SCHEDULE 14A INFORMATION
                Proxy Statement Pursuant To Section 14(a) of the
                        Securities Exchange Act of 1934.

Filed by the Registrant [__]
Filed by a Party other than the Registrant [X]

Check the appropriate box:
            [X ] Preliminary Proxy Statement
            [__] Confidential, For Use of the Commission Only (as permitted by
                 Rule 14a-6 (e) (2))
            [__] Definitive Proxy Statement
            [__] Definitive Additional Materials
            [__] Soliciting Material Under Rule 14a-12

                              HERCULES INCORPORATED
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                (NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

                      INTERNATIONAL SPECIALTY PRODUCTS INC.
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    (NAME OF PERSON (S) FILING PROXY STATEMENT, IF OTHER THAN THE REGISTRANT)

PAYMENT OF FILING FEE (CHECK THE APPROPRIATE BOX):

            [X] No fee required.
            [_] Fee computed on table below per Exchange Act Rules 14a-6(I) (1)
                and 0-11.

1)                Title of each class of securities to which transaction
                  applies:



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2)                Aggregate number of securities to which transaction applies:



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3)                Per unit price or other underlying value of transaction
                  computed pursuant to Exchange Act Rule 0-11 (set forth the
                  amount on which the filing fee is calculated and state how it
                  was determined):



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NY2:\1026111\05\LZR305!.DOC\54104.0018


4)                Proposed maximum aggregate value of transaction:



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5)                Total fee paid:



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         [_] Fee paid previously with preliminary materials:


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         [_] Check box if any part of the fee is offset as provided by Exchange
Act Rule 0-11(a)(2) and identify the filing for which the offsetting fee was
paid previously. Identify the previous filing by registration statement number,
or the form or schedule and the date of its filing.

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                                       2



                PRELIMINARY PROXY MATERIALS DATED MARCH 20, 2001
                             SUBJECT TO COMPLETION


                    2001 ANNUAL MEETING OF THE STOCKHOLDERS

                            OF HERCULES INCORPORATED

                            ------------------------



                                PROXY STATEMENT

                    OF INTERNATIONAL SPECIALTY PRODUCTS INC.

                            ------------------------

                  We are sending this proxy statement to you as one of the
holders of common stock, $25/48 stated value per share, of Hercules
Incorporated, a Delaware corporation, in connection with our solicitation of
your proxy for use at the 2001 Annual Meeting of the Stockholders of Hercules
scheduled for 11:00 A.M., local time, on Thursday, April 26, 2001, at the
Delaware Art Museum, 2301 Kentmere Parkway, Wilmington, Delaware and at any
adjournments or postponements thereof. We are International Specialty Products
Inc., a Delaware corporation, and the largest stockholder of the Company,
beneficially owning approximately 9.9% of Hercules' outstanding shares of common
stock.

                  We are soliciting your proxy to vote at the 2001 Annual
Meeting for the election of our nominees, Samuel J. Heyman, Sunil Kumar, Gloria
Schaffer and Raymond Troubh, as directors of Hercules in the class with a
three-year term continuing until the 2004 Annual Meeting.

THIS PROXY STATEMENT AND THE BLUE PROXY CARD ARE FIRST BEING FURNISHED TO
STOCKHOLDERS ON OR ABOUT MARCH __, 2001.

WE URGE YOU TO SIGN, DATE AND RETURN THE BLUE PROXY CARD IN FAVOR OF THE
ELECTION OF OUR NOMINEES DESCRIBED IN THIS PROXY STATEMENT.

IF YOU HAVE ALREADY SENT A WHITE PROXY CARD TO THE HERCULES DIRECTORS, YOU MAY
REVOKE THAT PROXY AND VOTE AGAINST THE ELECTION OF HERCULES NOMINEES BY SIGNING,
DATING AND RETURNING THE ENCLOSED BLUE PROXY CARD. THE LATEST DATED PROXY IS THE
ONLY ONE THAT COUNTS. ANY PROXY MAY BE REVOKED AT ANY TIME PRIOR TO THE 2001
ANNUAL MEETING BY DELIVERING A WRITTEN NOTICE OF REVOCATION OR A LATER DATED
PROXY FOR THE 2001 ANNUAL MEETING TO GEORGESON SHAREHOLDER COMMUNICATIONS INC.
OR TO THE SECRETARY OF HERCULES, OR BY VOTING IN PERSON AT THE 2001 ANNUAL
MEETING. SEE "VOTING PROCEDURES" ON PAGE ___.



                                       3


                          REASONS FOR OUR SOLICITATION


                  We are the largest stockholder of the Company. As the owner of
more than 10.7 million shares of Hercules common stock, we have an investment of
$150 million at stake. Our interests are clearly aligned with yours. We want to
maximize value for all Hercules stockholders. Our four nominees for
directorships are committed, subject to their fiduciary duties if elected, to
urge Hercules Board to:

                  o        bring about the sale or merger of the Company, in the
                           most timely, effective and efficient manner possible;

                  o        remove barriers to offers for your shares, so that
                           you can make your own decisions; and

                  o        reverse the Company's position with regard to a
                           Hercules Bylaw which it claims requires the
                           affirmative vote of the holders of a majority of all
                           outstanding shares for the election of directors.

Our nominees, if elected, will not constitute a majority of the Board. As a
result, our nominees will not be in a position by themselves to cause the
Hercules Board to take the foregoing actions. However, we believe that the
election of our nominees will send a clear message to the remaining incumbent
directors that these actions are necessary and in the best interest of Hercules
stockholders.


THE COMPANY'S PERFORMANCE OVER THE LAST FIVE YEARS HAS, IN OUR OPINION, BEEN
DISASTROUS FOR STOCKHOLDERS.

                  When measured by virtually any financial yardstick, Hercules'
performance over the last five years, has, in our opinion, been disastrous for
the Company's stockholders. Consider the following:

                  o        Hercules' stock price in the last five years has lost
                           nearly 80% of its value since reaching its high of
                           $66.25 on March 19, 1996, wiping out more than $5.5
                           billion in stockholder value, notwithstanding one of
                           the greatest bull markets in the history of the
                           American stock market;


                  o        Based on total return to shareholders over the past
                           five years, Hercules was recently (February 26, 2001)
                           ranked by The Wall Street Journal as 6th worst out of
                           1,000 major public companies;


                  o        Hercules first cut and then totally eliminated your
                           dividend last year despite earlier assurances that
                           the dividend would be maintained;

                  o        Hercules' $3.1 billion acquisition of BetzDearborn in
                           1998 has been characterized by Paul Leming, an ING
                           Barings security analyst, as "one of the worst
                           acquisitions in the history of the chemical industry"
                           (July 18, 2000);



                                       4


                  o        You should know that all eight of the current
                           incumbent Hercules directors who served on the
                           Hercules Board at the time of the BetzDearborn
                           acquisition in 1998 voted to approve the transaction.
                           Three of the other current Hercules directors are
                           former BetzDearborn directors;


                  o        As a result of the BetzDearborn acquisition and the
                           poor operating performance of Hercules' businesses
                           since that time, the Company's debt, including
                           preferred stock, has increased eleven-fold over the
                           last five years - from less than $300 million, at the
                           end of 1995, to approximately $3.2 billion, at the
                           end of 2000. During that period of time, Hercules'
                           debt ratings have been reduced (six grade levels by
                           Moody's and seven at Standard and Poor's) to
                           non-investment grade - thereby severely impacting the
                           Company's borrowing costs;


                  o        Leslie Ravitz, a chemicals industry security analyst
                           at Morgan Stanley Dean Witter, referring to the
                           continued deterioration in Hercules' financial
                           performance, observed, "It just seems to get worse
                           and worse" (March 23, 2000). Since that time,
                           Hercules' performance has deteriorated even further;
                           and

                  o        Just this past February, Hercules reported fourth
                           quarter 2000 profit from operations of $68 million
                           and a net loss of $6 million, or $0.05 per diluted
                           share, excluding nonrecurring items. This result was
                           in sharp contrast to Hercules' own projection (off
                           more than 30%) given on October 26th, only two months
                           before the end of the quarter, that fourth quarter
                           profit from operations would be in the range of $100
                           million. The results also reflected a significant
                           decline from Hercules' fourth quarter earnings per
                           share of $0.46 in the previous year.

HERCULES HAS DISREGARDED, IN OUR VIEW, THE INTERESTS OF ITS STOCKHOLDERS BY
ERECTING A FORTRESS OF ANTI-TAKEOVER DEFENSES.


                  Hercules has erected over time a fortress of anti-takeover
defenses, which include a poison pill, staggered board, interpretation of a
Company Bylaw to require an affirmative vote of a majority of all outstanding
shares for election of directors, "blank check" preferred stock, an 80% super
majority vote requirement to amend certain Bylaws and charter provisions and
approve certain merger transactions, and the ability to add directors without
stockholder approval.


                  Consider the following examples of how the Hercules Board has
utilized these defenses in disregard, in our opinion, of the interests of its
stockholders:

                  (1) In October 2000, in order to increase our investment in
the Company, we proposed to purchase 25 million additional shares of Hercules
stock for $17.50 per share in cash, a premium of almost 50% over the closing
price on the day before our Hercules share ownership was first publicly


                                       5


announced. Parenthetically, we made this offer at the same time we recommended
that the Hercules Board entertain a sale of the Company. In so doing, we
acknowledged that "Hercules shares should be worth more in a sale of the
Company," and stated that the offer was an "expression of our confidence" in the
proposed sale course of action and was designed to "provide those Hercules
shareholders who wished to sell their shares now with an opportunity to do so at
a 25% premium above the current market price." However, because of the Company's
poison pill our offer required Board consent, and despite repeated requests that
Hercules permit us to proceed, the Board refused to do so.


                  You should know that the Hercules poison pill was adopted last
August notwithstanding the fact that Hercules stockholders have in the past
voiced their strong opposition to poison pills. In 1991, a non-binding proposal
to redeem Hercules' then-existing poison pill, or submit it to a stockholder
vote, was approved by stockholders. Despite this stockholder mandate, the
Hercules Board never put the redemption of the poison pill to a definitive vote
and refused to terminate the pill until three years later, allowing it to
terminate two years prior to its expiration.


                  With regard to the poison pill currently in effect at the
Company, which has a low 10% threshold, the Hercules Board rushed to adopt it
last year, without shareholder approval, less than two weeks after ISP had
publicly announced its ownership position in Hercules. When we later proposed a
compromise whereby the poison pill would be amended to permit anyone, including
ISP, to purchase up to 20% of the Company's outstanding shares (20% being a more
customary threshold for Companies with poison pills), our proposal was rejected
by the Board.


                  In its proxy statement, Hercules cites studies conducted by
J.P. Morgan & Co. in 1995 and 1997 that "show that companies with rights plans
receive higher takeover premiums than those without such plans and that rights
plans do not decrease the likelihood that takeover bids will be made or
completed." An IRRC publication "Corporate Governance Service 2000 Background
Report -- Poison Pills" published on March 6, 2000 discussed various poison pill
studies and noted that "[s]ome observers downplay the importance of the various
studies, saying that they provide generalized descriptions but that specific
companies use pills differently - sometimes for management entrenchment" and
that "some observers said their view of the studies depended in part on their
view of those producing them." We believe that the critical point here is that
because Hercules has reinstated its poison pill, its stockholders have been
deprived of the right to decide whether or not to accept offers for their
shares.


                  (2) Similarly, Hercules' disregard for the interests of the
Company's stockholders is demonstrated by a Hercules Bylaw which the Board
claims requires an affirmative vote of the holders of a majority of all
outstanding shares for the election of directors, instead of the greatest number
of votes actually cast at the 2001 Annual Meeting (a plurality vote). This would
mean, for example, that even if each ISP nominee receives 50,000,000 votes and
each incumbent director receives 10,000,000 votes, the incumbents would retain
their seats on the Board because our nominees would not have received a majority


                                       6


vote of approximately 108 million outstanding shares of Hercules common stock.


                  This voting requirement, we believe, is not only highly
unusual but also disenfranchises stockholders and is inconsistent with good
corporate governance. We do not know of any other public company that has such a
provision. In our view, the Hercules Bylaw, as interpreted by the Company,
serves as a mechanism to entrench the current Board, because if no nominee
receives a majority vote of the outstanding shares, the incumbent directors
would remain in place beyond their three-year term, even if our nominees
received a plurality vote. We disagree with this interpretation and believe,
based on the reasons set forth under "Vote Required," that under Delaware law,
nominees for directorships should be elected if they receive the greatest number
of votes cast at the 2001 Annual Meeting - i.e., a plurality.


                  On February 7, 2001, we called Hercules' attention to this
obvious inequity, whereby a director-nominee could receive a majority of the
votes cast but nevertheless lose the election. On March 8, we requested that
Hercules take the necessary action to remedy this situation, but it has refused
to do so.

                  You should know that in a Delaware News Journal article (March
14, 2000) entitled, "Hercules' Election Method Is Fought", the Hercules voting
requirement provision prompted the following comments from a Wall Street analyst
as well as a corporate governance expert: Gary Hindes, Managing Director of New
York's Deltec Asset Management stated that, "These people [referring to the
Hercules directors] have managed to destroy what was a wonderful company," and
is further reported to have stated that Hercules should be asking for the
resignation of its directors, not supporting them for re-election; and Charles
Elson, Director of the Center for Corporate Governance at the University of
Delaware, characterized Hercules' voting provision as "highly unusual" and
further stated, "In all my years [of tracking corporate policies], I have not
seen that with the election of a board."


Ask yourself whether these devices are in your best interests. You do not need
to be "protected" from making your own decision to sell your shares. We believe
that it is paramount that YOU have the right to consider for yourself the merits
of offers for your shares, although some may argue that anti-takeover devices
such as those described above provide boards of directors with time to respond
to unsolicited bids and provide incentives for a potential bidder to negotiate
with the board. . Our nominees will advocate that the Board remove barriers to
offers for your shares, so that you can make your own decisions.


THE REVOLVING DOOR AT HERCULES- FOUR CHIEF EXECUTIVES IN A TWENTY-TWO MONTH
PERIOD AND NOW SEARCHING FOR A FIFTH.

                  One of the primary responsibilities of a Company's Board of
Directors is to choose, attract, evaluate, and properly motivate capable chief
executives and retain them for extended periods of time. By this standard of
measurement, in our opinion, the Hercules Board has been extremely unsuccessful,


                                       7


and we ask you to consider the recent record of chief executive turnover at
Hercules.


                  In 1996, R. Keith Elliott was elected Chief Executive of the
Company. In July, 1998, Elliott and the Hercules Board engineered the
BetzDearborn acquisition which, in our opinion, has been a disaster for the
Company and its stockholders. In October, 1998, William R. Cook, formerly Chief
Executive at BetzDearborn, was elected Hercules' Co-Chief Executive. Within two
months, in December, 1998, Cook abruptly resigned. As Leslie Ravitz, a chemicals
analyst at Morgan Stanley Dean Witter stated at the time, "operating with two
CEO's is a very inefficient strategy [for running] a company." Ravitz went on to
say that Cook and Elliott "were taking too long to make decisions."


                  Shortly thereafter, in May 1999, and less than one year after
the BetzDearborn acquisition, Elliott abruptly "resigned." Parenthetically, in
connection with Elliott's resignation after less than three years as Hercules'
Chief Executive, during which time the Company made the disastrous BetzDearborn
acquisition, he was given a severance package estimated to be worth more than
$14.25 million (not counting the value of accelerated vesting of stock options
and restricted stock grants). This consisted of promised payments of $462,500
per annum for the remaining years of his life plus an additional $500,000 per
annum for the next ten years.

                  Elliott was succeeded by Vincent Corbo who in turn resigned
less than sixteen months later in October, 2000. For Mr. Corbo's performance
during his short tenure as the Company's Chief Executive, Smart Money nominated
him to its "Underachievers Club". The Smart Money article (June 1, 2000),
entitled "Underachievers Club: Chief Executive Obstacle," had this to say about
Mr. Corbo and Hercules' performance on his watch:

                  "CEO Vincent Corbo took over on 7/1/99

                  Return since then: -62.2 percent

                  The facts: This Delaware-based firm has been suffering after
                  an acquisition binge drove debt up to 80 percent of its total
                  capital, nearly three times that of competitors. Corbo has
                  tried to cut the debt by selling off slow-growth divisions.
                  But he's had problems integrating Hercules's biggest
                  acquisition, BetzDearborn, a chemicals maker that until
                  recently used a separate financial tracking system. The
                  result? Confusion on Wall Street, earnings downgrades and
                  research reports with titles such as `More Bad News' and `When
                  Will It End?'

                  The response: `We have already announced significant actions
                  to improve the performance and the value of Hercules,' Corbo
                  says."

                  Thomas Gossage, who had retired as the Company's Chief
Executive in 1996, replaced Corbo last October as "temporary" Chief Executive.
At the time of Mr. Gossage's appointment, the Company announced that it had


                                       8


begun a nationwide search for a "permanent" Chief Executive with the assistance
of an outside search firm. Since that announcement almost five months ago,
Hercules stockholders have heard nothing further concerning the search for a
permanent chief executive.

                  While Mr. Gossage has, to be sure, immersed himself in the
Company's refinancing and restructuring activities, ask yourself whether
Hercules' operating businesses, with its more than 10,000 employees and 3
billion dollars of sales, could receive proper direction from a temporary chief
executive. Do you believe that the Hercules Board has properly discharged one of
its primary responsibilities - to choose, attract, evaluate, and retain able
chief executives?

                  Finally, chief executive turnover at Hercules has not been
without substantial cost to the Company and its stockholders. In addition to the
cost inevitably associated with extraordinary turnover, Hercules has incurred
costs, in the form of severance and pension payments, which we estimate will
exceed $30 million (not counting the value of pension enhancements, accelerated
vesting of stock options and restricted stock grants and other benefits and
perquisites), in connection with the resignations of four Hercules Chief
Executives in four years.

THE HERCULES BOARD, WE BELIEVE, MUST PROMPTLY SELL THE COMPANY IN ORDER TO
MAXIMIZE STOCKHOLDER VALUES.

                  Management wasted valuable time during the Corbo
administration, in our opinion, pursuing a flawed restructuring strategy. On
October 11, 2000, we wrote the Hercules Board stating that "it has become all
too apparent to us that the course Hercules is now pursuing will not enhance
shareholder value but erode it instead." We went on to recommend that "the
Hercules Board abandon its `too little, too late' approach and promptly
entertain a sale of the Company while the time is still propitious."

                  While shortly after our letter, Mr. Corbo resigned and
Hercules elected its current Chief Executive, Thomas Gossage, it was not until
late November that the Company implicitly acknowledged that we were right and
began to pursue a sale. A New York Times article, entitled "Hercules, a Chemical
Maker, to Sell All Its Businesses," observed, "the announcement was a tacit
acknowledgement that Hercules's original plan . . . was unlikely to work."


                  Notwithstanding the Company's October 27 announcement that it
had hired a financial advisor to advise it concerning a potential sale of the
Company, the Company's performance continues to deteriorate, and no sale of the
Company is in sight. What realistic expectation is there that the Hercules Board
is sufficiently committed to realizing the Company's underlying value when, in
our opinion, it has completely failed to do so over the last five years?

OUR INTERESTS ARE CLEARLY ALIGNED WITH YOURS. WE ARE COMMITTED TO MAXIMIZING
VALUE FOR HERCULES STOCKHOLDERS.




                                       9



                  ISP is the owner of more than 10.7 million shares of Hercules
common stock and has an investment of $150 million at stake. Our interests are
clearly aligned with yours. We want to maximize value for all Hercules
stockholders. Two of our nominees, Messrs. Heyman and Kumar, are ISP's Chairman
and its President and Chief Executive Officer, respectively, and accordingly
have a strong interest in maximizing the value of Hercules shares. In contrast,
the four incumbent nominee directors up for reelection this year have in the
aggregate purchased for full value only approximately 10,000 shares (the
Hercules nominees have acquired additional shares through outright grants and
Company subsidized stock purchases), worth approximately $137,000 at current
market prices.

                  We seek the opportunity for our nominees to participate
constructively as directors, and particularly with respect to any sale process
involving Hercules. We are not seeking to acquire or control the Company.
Rather, our concern is to safeguard stockholder interests and help ensure that a
sale be executed in an efficient and timely manner for the best price. In our
view, the performance of the current Board and its continued maintenance of a
wide variety of anti-takeover devices have not served the interests of the
stockholders and raise serious question as to whether the incumbent directors
can provide the best solution to the Company's problems. Their record speaks for
itself.

OUR NOMINEES WILL SEEK TO REMOVE ANTI-TAKEOVER DEVICES

                  If elected, our nominees will urge the Hercules Board to
remove the anti-takeover devices, which, in our view, threatens to
disenfranchise your voting rights and prevent you from making your own decisions
as to offers for your shares. Our nominees will seek, among other things, to:

                  o        redeem the poison pill rights plan adopted by the
                           Hercules Board last year;

                  o        urge the Board to reverse the Company's position with
                           regard to a Hercules Bylaw which it claims requires
                           the affirmative vote of the holders of a majority of
                           all outstanding shares for the election of directors;

                  o        present stockholders with the opportunity to opt out
                           of Section 203 of the Delaware General Corporation
                           Law (which generally prohibits certain business
                           combination transactions with a beneficial owner of
                           more than 15% of Hercules' voting stock for three
                           years unless Hercules' Board has previously approved
                           the business combination transaction or the initial
                           15% acquisition); and

                  o        resist the adoption of any other measures which could
                           deprive stockholders of the opportunity to make their
                           own decisions.

Our nominees, if elected, will not constitute a majority of the Board. As a
result, our nominees will not be in a position by themselves to cause the
Hercules Board to take the foregoing actions. However, we believe that the
election of our nominees will send a clear message to the remaining incumbent




                                       10



directors that these actions are necessary and in the best interest of Hercules
stockholders. Although it may be argued that anti-takeover devices such as those
described above provide boards of directors with time to respond to unsolicited
bids and provide incentives for a potential bidder to negotiate with the board,
we believe that you should be permitted to consider for yourself the merits of
offers for your shares.


                     --------------------------------------



         QUESTIONS AND ANSWERS ABOUT THIS PROXY SOLICITATION

Q:       WHO IS SOLICITING YOUR PROXY?

A:       We are International Specialty Products Inc. ("ISP"), a New York Stock
         Exchange listed, multinational manufacturer of specialty chemicals and
         mineral products. As of the date of this proxy statement, we are the
         largest stockholder of the Company and beneficially own 10,719,200
         shares of Hercules common stock, representing approximately 9.9% of the
         outstanding shares. For more information on the participants in our
         proxy solicitation, please see "Certain Information Concerning the
         Participants" on page ___.

Q:       WHO ARE THE ISP NOMINEES?

A:       In addition to Mr. Heyman, the Chairman of ISP's Board, and Mr. Kumar,
         President and Chief Executive Officer of ISP, our nominees include two
         independent persons who are not affiliated with ISP - Gloria Schaffer
         and Raymond Troubh. Gloria Schaffer has served in a number of high
         profile Government positions including the Secretary of State and the
         Commissioner of the Department of Consumer Protection of the State of
         Connecticut and a Member of the Civil Aeronautics Board. Mr. Troubh has
         broad financial experience, with over 25 years in financial consulting,
         which includes serving as a general partner at Lazard Freres & Co. Mr.
         Troubh also served as a governor of the American Stock Exchange. In
         addition, Mr. Troubh has served as a member of the Board of Directors
         of Time Warner, Inc., Becton, Dickinson and Company and America West
         Airlines, Inc. and currently serves as a member of the Board of
         Directors of eight public companies - including Starwood Hotels &
         Resorts, Inc., Health Net, Inc. and Diamond Offshore Drilling, Inc. If
         elected to the Hercules Board, each ISP nominee would act in accordance
         with his or her fiduciary duties to Hercules stockholders with respect
         to any action that he or she takes as a director. We have no reason to
         believe that any of our nominees will be disqualified or unable or
         unwilling to serve if elected. However, if any of our nominees are
         unable to serve or for good cause will not serve, proxies may be voted
         for another person nominated by ISP to fill the vacancy.



                                       11


Q:       WHO CAN VOTE AT THE 2001 ANNUAL MEETING?

A:       If you owned Hercules shares on March 6, 2001 (the "Record Date"), you
         have the right to vote at the 2001 Annual Meeting. As of the close of
         business on the Record Date, we believe that there were 108,115,824
         shares of common stock of Hercules issued and outstanding and entitled
         to vote. Stockholders have one vote for each share of common stock they
         own with respect to all matters to be considered at the 2001 Annual
         Meeting.

Q:       WHAT SHOULD YOU DO TO VOTE?

A:       Sign, date and return the enclosed BLUE Proxy card TODAY in the
         envelope provided. For more information on how to vote your shares,
         please see "Voting Procedures" on page ___.

Q:       WHO DO YOU CALL IF YOU HAVE QUESTIONS ABOUT THE SOLICITATION?

A:       Please call Georgeson Shareholder Communications Inc. toll free at
         1-800-223-2064.





                                       12


--------------------------------------------------------------------------------
                                    IMPORTANT


                  PLEASE REVIEW THIS DOCUMENT AND THE ENCLOSED MATERIALS
CAREFULLY. YOUR VOTE IS VERY IMPORTANT, NO MATTER HOW MANY OR HOW FEW SHARES YOU
OWN.

1.       If your shares are registered in your own name, please sign, date and
         mail the enclosed BLUE Proxy Card to Georgeson Shareholder
         Communications Inc. in the postage-paid envelope provided today.

2.       If you have previously signed and returned a WHITE proxy card to
         Hercules, you have every right to change your vote. Only your latest
         dated card will count. You may revoke any WHITE proxy card already sent
         to Hercules by signing, dating and mailing the enclosed BLUE Proxy Card
         in the postage-paid envelope provided. Any proxy may be revoked at any
         time prior to the 2001 Annual Meeting by delivering a written notice of
         revocation or a later dated proxy for the 2001 Annual Meeting to
         Georgeson Shareholder Communications Inc. or the Secretary of Hercules,
         or by voting in person at the 2001 Annual Meeting.

3.       If your shares are held in the name of a brokerage firm, bank nominee
         or other institution, only it can sign a BLUE Proxy Card with respect
         to your shares and only after receiving your specific instructions.
         Accordingly, please sign, date and mail the enclosed BLUE Proxy Card in
         the postage-paid envelope provided, and to ensure that your shares are
         voted, you should also contact the person responsible for your account
         and give instructions for a BLUE Proxy Card to be issued representing
         your shares.

4.       After signing the enclosed BLUE Proxy Card, do not sign or return the
         WHITE proxy card unless you intend to change your vote, because only
         your latest dated proxy card will be counted.

                  If you have any questions about giving your proxy or require
assistance, please call:

                    Georgeson Shareholder Communications Inc.
                                 17 State Street
                               New York, NY 10004


                         Call Toll-Free: 1-800-223-2064

              Banks and Brokerage Firms Call Collect: 212-440-9800

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                                       13


                          BACKGROUND AND RECENT EVENTS

                  ISP began purchasing shares of Hercules common stock in
January 2000 because we believed that the shares of the Company were
substantially undervalued. On July 24, 2000, we filed a Schedule 13D with
respect to our beneficial ownership of approximately 9.98% of the outstanding
common stock of Hercules and informed the Company's former Chairman and CEO,
Vincent Corbo, that we wished to increase our ownership position and were filing
a Hart-Scott-Rodino application seeking permission to do so.

                  On August 1, 2000, Hercules released its second quarter 2000
earnings, which reported that net income had fallen 56% from the previous
quarter.

                  On August 4, 2000, less than two weeks after we filed our
Schedule 13D, the Hercules Board adopted the poison pill Rights Agreement. The
Board, in taking this action, defied the wishes of Hercules stockholders as
evidenced by the adoption of a non-binding proposal to redeem Hercules' previous
pill in 1992. The poison pill serves as a powerful anti-takeover device by
making it prohibitively expensive to acquire 10% or more of Hercules' common
stock without Board approval.

                  On August 25, 2000, Hercules announced that it was reducing
its quarterly dividend from $0.27 to $0.08 per share. The dividend was totally
eliminated on November 14, 2000.

                  On October 11, 2000, Mr. Heyman proposed that ISP commence a
tender offer for 25 million shares of Hercules common stock at $17.50 per share
in cash. This price represented a premium of over 22% based on the Hercules
closing price of $14.31 per share on October 10, 2000, and an almost 50% premium
over the Hercules closing price of $11.75 per share on July 21, 2000, the day
before our first public filing stating that we had acquired a 9.9% interest in
Hercules. In connection with ISP's proposal, Mr. Heyman delivered the following
letter to the Board on October 11, 2000, encouraging the Board to abandon
management's restructuring plan.

         Dear Hercules Board member:

                  As you no doubt are aware, Vince Corbo and I have had a number
         of discussions in recent weeks regarding Hercules' restructuring
         program. In this regard, I was surprised to learn from Vince yesterday
         that, notwithstanding the recent Moody's downgrade of the Company's
         debt as well as other developments referred to below, Hercules does not
         intend to alter its current course. Parenthetically, the downgrade,
         coming at a particularly turbulent time in the high yield market (I am
         enclosing an October 10th, The Wall Street Journal article entitled,
         "Junk-Bond Prices Shrink As Investor Caution Grows," regarding this
         subject), will now result in a very costly refinancing for the Company
         -- thereby making it impossible for Hercules to achieve anywhere near


                                       14


         the interest savings previously projected.

                  While Hercules' game plan may have made good sense when first
         adopted, we are convinced that adverse developments in recent months
         have now overtaken it. Accordingly, for Hercules to proceed now with a
         "too little, too late" program raises serious question as to whether
         the Company is pursuing a strategy which discriminates in favor of its
         creditors at the expense of its shareholders.

                  Consider these recent developments:

                  (1)      Significant delays in asset dispositions, including
                           the real possibility that FiberVisions will not be
                           sold at this time;
                  (2)      Decline in growth forecasts for core operations;
                  (3)      Reduction in size of acquisition program;
                  (4)      Significant decline in projected interest rate
                           savings;
                  (5)      Adverse impact of the euro, which is especially
                           significant for Hercules given its substantial
                           European presence;
                  (6)      Decline in overall earnings projections; and
                  (7)      Drastic dividend reduction.

                  In the face of these developments, it has become all too
         apparent to us that the course Hercules is now pursuing will not
         enhance shareholder value but erode it instead. What justification can
         there be for making asset divestitures which are earnings dilutive, and
         which in the end, because of the credit downgrade as well as other
         factors, will not be sufficient to enable Hercules to achieve
         sufficient financial flexibility to grow its remaining businesses at
         anywhere near the targets the Company established only several months
         ago? Under all the circumstances and given the fact that private sale
         values of specialty chemicals businesses are still robust and well
         above public trading values, we have come to the conclusion that the
         only practicable option for realizing Hercules' underlying values must
         involve the sale of the Company, in whole or in parts.

                  Also of serious concern to us is Hercules' apparent disregard
         for the interest of its shareholders, as demonstrated by its adoption
         of a "poison pill" on August 7th, which provides for a 10% trigger
         point. Significantly, the Board adopted this anti-shareholder provision
         little more than 2 weeks after we had notified Vince that we had
         acquired 9.9% of Hercules' shares, informing him at the same time that
         we wished to increase our ownership position and were filing a


                                       15


         Hart-Scott Rodino application seeking permission to do so. Moreover,
         Hercules' refusal to eliminate or modify its "poison pill" in the face
         of our offer of a standstill agreement is further indicative of
         Hercules' anti-shareholder bias.

                  We are therefore requesting that the Hercules Board abandon
         its "too little, too late" approach and promptly entertain a sale of
         the Company while the time is still propitious. And the timing here is
         all the more important in light of the fact that Hercules is about to
         embark on a major refinancing, which we anticipate could become
         extremely expensive to unwind should Hercules decide to pursue a sale
         of the Company at a later time.

                  In the meantime, as an expression of our confidence in this
         proposed course of action and to provide those Hercules shareholders
         who wish to sell their shares now with an opportunity to do so at a 25%
         premium above the current market price, we are prepared to commence a
         tender offer for 25 million shares of Hercules common stock at $17.50
         per share in cash. While we believe that Hercules' shares should be
         worth more, in a sale of the Company, than our tender offer price, this
         price represents an almost 50% premium over Hercules' closing price of
         $11.75 per share on July 21st, the day before ISP's 13D filing
         providing notice for the first time that it had acquired a 9.9%
         interest in Hercules. ISP's tender offer will not be subject to
         financing but will obviously require that the Hercules Board exempt our
         offer from the "poison pill" and approve ISP's purchase of shares for
         purposes of Section 203 of the Delaware General Corporation Law.

                  We are prepared to commence the tender offer promptly should
         you inform us that you will meet the above conditions. We would
         appreciate your timely response.

                                Sincerely,

                                /s/ Samuel J. Heyman

                  On October 11, 2000, Hercules issued a press release
indicating that it had received ISP's letter and that the Board would consider
ISP's proposal. Soon thereafter, on October 17, 2000, Vincent Corbo resigned as
Chairman and CEO of Hercules and Thomas Gossage was named its new Chairman and
CEO. Mr. Gossage stated that Hercules "will consider all strategic alternatives,
as well as the proposal made by Mr. Heyman, based on our considered view of what
is in the best interest of all Hercules shareholders." At the same time,
Hercules announced that it did not expect to meet analysts earnings estimates
for its third quarter ending September 30, 2000.



                                       16



                  On October 27, 2000, Hercules announced that it had retained a
financial advisor to assist Mr. Gossage and the Board in its evaluation of
various alternatives.


                  On November 28, 2000, Hercules announced that its Board had
decided to consider the sale or merger of the Company. Mr. Gossage stated that
"the best strategic path for the Company over the long-term is to become part of
a larger enterprise" and that "moving forward on this path provides the maximum
value and opportunity for our shareholders, employees and customers."


                  In mid-January 2001, ISP informed Hercules that it was not
interested in acquiring the Company and declined to receive confidential
information from Hercules in connection with its sale process.


                  On January 18, 2001, Hercules announced that it had ended
discussions on the sale of its FiberVisions Unit. Shortly thereafter, on January
23, 2001, Hercules debt was downgraded by Standard & Poor's.

                  After receiving no response to our proposal made on October
11, 2000, and in light of the adverse developments at the Company described
above, on January 23, 2001, ISP reiterated its proposal to make an offer to
purchase 25 million shares of Hercules common stock at a price of $17.50 per
share in cash if, as requested by Mr. Heyman, the Hercules Board would exempt
the offer from the poison pill and approve ISP's purchase of shares for purposes
of Section 203 of the Delaware General Corporation Law. In connection with ISP's
proposal, Mr. Heyman delivered the following letter to Mr. Gossage on January
23, 2001:

                  Dear Tom:

                        Confirming yesterday's telephone conversation, I have
                  reiterated ISP's interest in proceeding with its tender offer
                  first proposed to the Hercules Board last October.
                  Notwithstanding a number of adverse developments at the
                  Company, as well as the substantial deterioration of the U.S.
                  economy in recent months, we are still willing to proceed on
                  the same basis -- at the original price of $17.50 per share in
                  cash for 25 million shares of Hercules common stock.

                        Given the delay with respect to execution of the
                  Company's program and uncertainty as to its outcome, we
                  believe that a substantial number of Hercules shareholders may
                  very well wish to avail themselves of the opportunity to sell
                  their shares, or a portion thereof, at what amounts to a 30%
                  premium above the current market price and an almost 50%
                  premium over Hercules' closing price of $11.75 per share on
                  July 21st, the day before ISP's 13D filing providing notice
                  for the first time that it had acquired a 9.9% interest in
                  Hercules. As we have stated earlier, ISP's tender offer will
                  not be subject to financing but will obviously require that
                  the Hercules Board


                                       17


                  exempt our offer from the "poison pill" and approve ISP's
                  purchase of shares for purposes of Section 203 of the Delaware
                  General Corporation Law. We are prepared to commence the
                  tender offer promptly should you inform us that you will meet
                  these conditions.

                        Finally, ISP's proposed course of action is perfectly
                  consistent with Hercules' ongoing effort to maximize
                  shareholder values. In this connection, you can always rely on
                  the fact that we will be constructive with respect to any
                  actions favorable to all Hercules shareholders. Moreover, time
                  is of the essence here. As you know, Tom, we have been
                  extremely patient due in no small measure to your reassurance
                  to Hercules shareholders over recent months as well as our
                  desire to be constructive. Now, of course, Hercules' continued
                  optimistic prognostications over the past year have yet to be
                  realized, the economic environment deteriorates with each
                  passing day, and we must be allowed to proceed expeditiously
                  so that we can hold the price in place.

                        I would appreciate your prompt response.

                        All the best.

                                        Sincerely,

                                        /s/ Samuel J. Heyman

                  After still receiving no response to our tender offer proposal
made on October 11, 2000, and reiterated on January 23, 2001, Mr. Heyman
delivered the following letter to Mr. Gossage on February 7, 2001:

                  Dear Tom:

                        I am very disappointed that, notwithstanding our attempt
                  to impress upon you the urgency that ISP be permitted to
                  proceed with its tender offer, now more than two weeks later
                  we still have not received your Board's response. Apparently,
                  it has decided to await the results of Hercules' divestiture
                  program, which we believe is a serious mistake. Moreover, as I
                  indicated to you, it is just not realistic to expect us to
                  keep our offer in place indefinitely, especially when the
                  Company can clearly pursue its divestiture program while
                  permitting our offer to go forward at the same time.

                        Unless you promptly communicate that we can proceed with
                  the tender offer, we would now request that Hercules consider
                  an alternative ISP initiative - which would be to amend the
                  threshold for the Company's poison pill from the current 10%
                  to 20% (the latter being a more customary threshold for
                  companies with poison pills) and approve any party's purchase


                                       18


                  of shares up to the 20% threshold for purposes of Section 203
                  of the Delaware General Corporation Law. While you have
                  indicated that you share our philosophic opposition to poison
                  pills altogether, this more limited, compromise approach is
                  designed to hopefully elicit your Board's prompt affirmative
                  response and would at least permit ISP, or anyone else for
                  that matter, to make purchases up to a 20% limitation.

                        If the Hercules Board refuses to take this action
                  voluntarily, we intend to seek a vote of Hercules shareholders
                  at this year's Annual Meeting to repudiate the Company's
                  poison pill. In this connection, we believe that if the
                  Company will not act responsibly, its shareholders should be
                  able to decide. If you require us to proceed in this fashion,
                  we are requesting that the Hercules Board include the various
                  proposals in the attached letter in your proxy materials for
                  this year's Annual Meeting. Should the Board refuse this
                  request, the attached letter serves as formal notification
                  pursuant to Section 14 of the Securities Exchange Act of 1934,
                  which we have been advised must be provided no later than
                  today.

                        As you can see, we have included a proposal whereby
                  Hercules would opt out of the provisions of Section 203 of the
                  Delaware General Corporation Law, as well as various
                  housekeeping proposals, and have included a proposal relating
                  to the methodology used to elect directors. In this later
                  connection, we believe that Hercules Bylaws, which your
                  Company claims require "the affirmative vote of a majority of
                  the outstanding shares" to elect directors, is highly unusual
                  and serves no purpose other than as an entrenchment device.
                  Most companies require only a majority of the shares voted (a
                  plurality). Under your interpretation of the bylaws, a nominee
                  could receive a majority of the votes cast but nevertheless
                  lose the election.

                        All the best.

                                          Sincerely,

                                         /s/ Samuel J. Heyman

                  Just this past February, Hercules reported fourth quarter 2000
profit from operations of $68 million and a net loss of $6 million, or $0.05 per
diluted share, excluding nonrecurring items. This result was in sharp contrast
to Hercules' own projection (off more than 30%) given on October 26th, only two
months before the end of the quarter, that fourth quarter profit from operations
would be in the range of $100 million. The results also reflected a significant
decline from Hercules' fourth quarter earnings per share of $0.46 in the
previous year.



                                       19


                  On February 8, 2001, almost four months after our initial
proposal, Hercules said that it would consider ISP's tender offer "in due
course." Mr. Gossage also told analysts on February 8, 2001 that he was working
toward a sale of the Company by midyear, but declined to provide details on the
process.

                  In light of the Company's failure to respond to ISP's repeated
requests that the Company terminate its poison pill, or in the alternative amend
the poison pill's threshold from 10% to 20%, Mr. Heyman delivered the following
letter to Mr. Gossage on February 20, 2001:

                  Dear Tom:

                        Despite our repeated requests that Hercules eliminate
                  its poison pill (or, in connection with a proposed compromise,
                  at least increase its trigger point to 20%) to enable ISP (or
                  anyone else for that matter) to increase its ownership of your
                  Company's shares - which requests date back to September,
                  2000, and have been repeated in letters dated October 11,
                  January 23, and most recently on February 7 - we continue to
                  receive no response from you or your Board.

                        Since we became a shareholder early last year, the
                  Company and its shareholders have in our opinion paid a high
                  price for management's procrastination as well as its
                  continued flawed policies and poor execution. We are also
                  shocked and surprised by the Company's continued withholding
                  of information from its shareholders and what we consider to
                  be its remarkable indifference to their concerns - as was
                  plainly evidenced by the Company's recent conference call.

                        Under the circumstances, we believe that you have left
                  us no alternative but to wage a proxy contest at the Company's
                  Annual Meeting this Spring. In addition to the previous
                  notification we have given regarding proposals to be presented
                  for action at the Meeting, we will also be nominating a slate
                  of Directors to run for the four Board seats whose terms
                  expire this year, director-nominees who, I can assure you,
                  will be committed to the maximization of values for all
                  Hercules shareholders.

                                   Sincerely,

                              /s/ Samuel J. Heyman


                  Mr. Heyman stated in his February 20 letter that "[w]e are
shocked and surprised by the Company's continued withholding of information from
its shareholders" because on Hercules' February 8, 2001 conference call for
stockholders and analysts, the Company refused to entertain any questions
concerning the then-current state of the Company's business, the Company's



                                       20



prospects for the year, the status of the Company's sale process or the
proposals made by ISP. In addition, the Company even refused to disclose the
sale price for the Company's resins business, instead suggesting "you are
certainly free to speak to Eastman on that".


                  The Hercules Board failed to respond to ISP's repeated
requests (on October 11, 2000, January 23, 2001 and February 7, 2001) that
Hercules eliminate or revise its poison pill to enable ISP to promptly proceed
with its proposed tender offer.


                  On February 23, 2001, Mr. Gossage sent a letter to Mr. Heyman
stating that the Board had declined to amend the Hercules Shareholder Rights
Plan to permit an acquiror to purchase up to an additional 10% of the Company's
shares beyond the current 10% threshold. In addition, Mr. Gossage alleged that
"the progress of the Company's discussions with third parties could be very
negatively impacted by their perception of your activities." Mr. Gossage also
invited ISP to "submit a proposal to acquire the entire Company rather than a
proposal to purchase a significant minority interest."

                  In response to Mr. Gossage's February 23 letter, Mr. Heyman
reminded Mr. Gossage that ISP had already declined to take part in the auction
process, in large measure because ISP views its Hercules stake as an investment
and so that there could be no claim that ISP's participation, as the Company's
largest stockholder, would have a chilling effect on other interested bidders.
Mr. Heyman's message was contained in the following letter sent to Mr. Gossage
on February 28, 2001:


                  Dear Tom:

                        I was disappointed in your February 23rd letter and your
                  Board's decision to reject ISP's compromise proposal. Contrary
                  to your apparent belief, there is nothing inconsistent in our
                  view with a shareholder being permitted to underscore its
                  confidence in the underlying values of the Company by making
                  an additional investment on the one hand and your "on going
                  sale process" on the other.

                        We are concerned with what seems to us Hercules' narrow,
                  one-dimensional approach to maximizing shareholder values. If
                  Hercules is unable to sell the Company on an advantageous
                  basis, it will have needlessly deprived Hercules shareholders
                  of the opportunity to decide for themselves whether to accept
                  our previously proposed $17 1/2 tender offer or, under our
                  compromise approach, sell their shares in the open market to
                  ISP or any other shareholder wishing to acquire up to 20% of
                  the Company's shares. This position is especially surprising
                  given the multitude of takeover defenses the Company has
                  erected and the fact that we have always been willing to
                  address any of your legitimate concerns in the form of
                  reasonable conditions with respect to our ownership position.



                                       21


                        With respect to your reference to the withdrawal of our
                  proposed tender offer, as you know, the October offer expired
                  by its own terms on account of the fact that your Board had
                  refused to exempt it from its poison pill and related Delaware
                  statutory provisions. That is why we put forward the
                  compromise proposal to permit ISP to acquire up to 20% of
                  Hercules' shares rather than 35%. While we can only assume
                  that if your Board is unwilling to permit our acquisition of
                  up to 20% of Hercules shares, it would not have gone along
                  with our 35% proposal either - but if we are missing something
                  in this regard, please let us know.

                        With regard to the last point in your letter, your claim
                  that ISP's actions/statements are a hindrance to your efforts
                  is sheer nonsense, as in point of fact we have been very
                  patient and constructive shareholders for some time now. As
                  you will recall, it was ISP who first encouraged Hercules to
                  abandon its flawed restructuring strategy and sell the
                  Company. While it took Hercules quite some time to adopt this
                  strategy, we not only applauded the decision but have provided
                  assurances, whether we were a 10%, 20%, or 35% owner, that we
                  would support the sale of the Company at a fair price. In
                  fact, despite your invitation, we have refrained from taking
                  part in the auction process in large measure because we view
                  our Hercules stake as an investment and so that there could be
                  no claim that our participation, as the Company's major
                  shareholder, would have a chilling effect on other interested
                  bidders.

                        Tom, you know that we have a high conviction concerning
                  the way in which Hercules has conducted the Company's affairs
                  in recent years. In this connection, we intend to bring these
                  matters to the attention of Hercules shareholders at the
                  Company's upcoming Annual Meeting. Moreover, as owners of more
                  than 10.7 million Hercules shares, we will be seeking to elect
                  a slate of directors, with a strong ownership orientation
                  committed to the interests of Hercules shareholders, to
                  replace the four incumbent directors up for re-election this
                  year, who we understand (as of the last public filing) own in
                  the aggregate less than 50,000 shares.

                                          Sincerely,


                                          /s/ Samuel J. Heyman


                  On March 5, 2001, Mr. Heyman sent the following letter to
Mr. Gossage:


                  Dear Tom:



                                       22


                        Just a note to close the loop with you regarding the
                  discussions between our General Counsel, Rich Weinberg, and
                  your David Katz.

                        When I received your February 23rd letter, although I do
                  not believe for a minute that we are in any way hindering your
                  efforts to sell the Company, in an effort to bend over
                  backwards, I asked Rich to contact David to see whether there
                  was anything we could do to be helpful. Rich and David met on
                  February 26th and talked on the telephone several days later,
                  during which time we were requested to delay the filing of our
                  preliminary proxy materials.

                        We suggested, and quite appropriately I believe, that if
                  you wanted us to delay our filing for some period, we would be
                  willing to accommodate you so long as there was a similar
                  adjustment to the Annual Meeting date. Obviously, we cannot be
                  put in the position of delaying our filing and as a result SEC
                  clearance of our materials while at the same time Hercules
                  reserves its right to press forward with its April 26th Annual
                  Meeting date. And so we were completely floored when David got
                  back to us to indicate that this was apparently what you had
                  in mind.

                        Tom, we attempted to respond to your stated concerns,
                  but the upshot of these discussions is that you have left us
                  no alternative but to proceed with our filing, which should
                  take place later today.

                                            Sincerely,

                                            /s/ Samuel J. Heyman


                  On March 8, 2001, Samuel J. Heyman sent the following letter
to Mr. Gossage:

                  Dear Tom:

                        Although I wrote you on February 7th regarding your
                  Company's director election by-law, which requires, according
                  to Hercules' interpretation, an affirmative vote of a majority
                  of the outstanding shares for election of directors, we have
                  received no response concerning this matter.

                        We have been advised that this by-law, as interpreted by
                  your Company, is to say the least highly unusual and indeed
                  may be unique in the annals of corporate governance. Moreover,
                  it could well operate to disenfranchise Hercules shareholders
                  by bringing about an unfair result whereby an ISP nominee, by
                  way of example, could receive votes representing 50 million
                  Hercules shares to 10 million shares for the incumbent, and


                                       23


                  under your Company's by-law, the incumbent would retain his or
                  her seat on the Board.

                        Tom, I think you would acknowledge that this would be an
                  outrageous result, and I would request that you and your Board
                  promptly take whatever action is necessary to remedy this -
                  thereby taking this issue off the table so that we can all
                  focus in our proxy contest on the real issues of concern to
                  Hercules shareholders.

                        Inasmuch as the Annual Meeting is scheduled to take
                  place in April, I would appreciate your prompt response.

                        Thank you for your anticipated cooperation in this
                  matter.

                                             Sincerely,

                                             /s/ Samuel J. Heyman

                  On March 12, 2001, Samuel J. Heyman sent the following letter
to Mr. Gossage:

                  Dear Tom:

                        We have not received a response to our February 7 and
                  March 8 letters concerning the director election Bylaw matter.
                  I can only assume that this matter has been referred to your
                  Board for its determination, and from past experience I must
                  tell you, quite frankly, that I simply have no confidence in
                  the willingness of the Hercules Board to do the right thing.

                        And this brings us to a second point. In reviewing past
                  actions of the Hercules Board, which in our opinion evidence a
                  clear disregard for the rights and interests of the Company's
                  shareholders, we simply cannot be sure that a favorable vote
                  on resolutions currently included in our Preliminary Proxy
                  Statement will be implemented by your Board without costly and
                  time consuming delay and even possible litigation. For
                  example, what possible explanation could there be for the
                  following:

                                    In 1992, a non-binding proposal to redeem
                           Hercules' then existing, 20% threshold poison pill or
                           submit it to a stockholder vote was approved by
                           stockholders. Despite this stockholder mandate, the
                           Hercules Board never put it to a definitive vote and
                           refused to terminate the pill for three years. And
                           then to add insult to injury, notwithstanding the
                           1992 stockholder vote, the Hercules Board implemented
                           just this past August, without notice or shareholder
                           approval, a new poison pill with a low 10% threshold.

                           In view of the above, we have decided to table our
                  other shareholder proposals in order to focus the proxy
                  contest on the election of our nominees. As a result, both


                                       24


                  sides will be able to address for shareholders, in a very
                  direct and clear cut way, the paramount issue - the Hercules
                  Board's record of corporate stewardship.

                                             Sincerely,


                                             /s/ Samuel J. Heyman




                  Mr. Heyman's statement in his March 12 letter that "we have
decided to table our other shareholder proposals" was intended to indicate that
except for the election of our four nominees, we do not presently intend to
raise any of our prior proposals (primarily relating to the Company's poison
pill and Delaware 203) at the 2001 Annual Meeting.



                              ELECTION OF DIRECTORS

                  We are soliciting your proxy for the election of the ISP
nominees as directors of the Company to serve until the 2004 Annual Meeting of
Stockholders and until their successors are duly elected and qualified.

                  In accordance with Hercules Restated Certificate of
Incorporation and Bylaws and the Delaware General Corporation Law, Hercules
Board of Directors is to consist of not less than seven and not more than
eighteen Directors, the exact number to be specified by the Board. The Directors
are to be divided into three classes as nearly equal in number as possible. At
each annual meeting of stockholders, members of one of the classes, on a
rotating basis, are elected for a three-year term. Based on information
contained in reports filed by the Company with the Securities and Exchange
Commission, thirteen directors currently serve on the Hercules Board. Four of
these directors have terms that expire in 2001 and, according to the Company's
proxy statement for the 2001 Annual Meeting, four directors are to be elected at
the 2001 Annual Meeting and one director, Robert G. Jahn, will be retiring upon
the expiration of his term. Messrs. Heyman, Kumar, Gloria Schaffer and Raymond
Troubh, if elected, would serve for terms expiring at the Company's annual
meeting of stockholders in 2004. If any additional directorships are to be voted
upon at the 2001 Annual Meeting, we reserve the right to nominate additional
persons to fill such positions. We do not expect that the ISP nominees will be
unable to stand for election but, in the event that any ISP nominee is unable to
do so, shares represented by BLUE proxy cards will be voted for the other ISP
nominees. In addition, ISP reserves the right to nominate substitute or
additional persons if the Company makes or announces any changes to its Bylaws
or takes or announces any other action that has, or if consummated would have,
the effect of disqualifying any of the ISP nominees.

                  If the ISP nominees are elected and take office as directors,
they intend to discharge their duties as directors of the Company in compliance
with all applicable legal requirements, including the general fiduciary


                                       25


obligations imposed upon corporate directors.

ISP NOMINEES

                  The information below concerning age, principal occupation and
directorships has been furnished by each respective nominee. The following
persons are our nominees for election as directors in the class whose terms
expire at the 2004 Annual Meeting of Stockholders:


                                                    Present Principal Occupation and Five Year
Name and Business Address            Age            Employment History                                  Class
-------------------------            ---            ------------------                                  -----
                                                                                                
Samuel J. Heyman                     62             Mr. Heyman has been a director and Chairman          2004
1361 Alps Road                                      of ISP since its formation and served as its
Wayne, New Jersey 07470                             Chief Executive Officer from its formation
                                                    until June 1999. He also has been a director
                                                    of GAF Corporation ("GAF") and its successor
                                                    by merger, G-I Holdings Inc. ("G-I
                                                    Holdings"), for more than five years and was
                                                    President and Chief Executive Officer of GAF
                                                    and certain of its subsidiaries and Chief
                                                    Executive Officer of G-I Holdings for more
                                                    than five years until September 2000. G-I
                                                    Holdings primary business is conducted
                                                    through Building Materials Corporation of
                                                    America ("BMCA"), an indirect, approximately
                                                    97% - owned subsidiary of G-I Holdings which
                                                    is primarily engaged in the commercial and
                                                    residential roofing business. In January
                                                    2001, G-I Holdings filed for protection
                                                    under chapter 11 of the United States
                                                    Bankruptcy Code as a result of its asbestos
                                                    liabilities. Mr. Heyman was a director and
                                                    Chairman of BMCA from its formation until
                                                    September 2000, and served as Chief
                                                    Executive Officer of BMCA from June 1996 to
                                                    January 1999 and from July 1999 to September
                                                    2000 and as the President of BMCA from July
                                                    1999 to February 2000. He is also the Chief
                                                    Executive Officer, Manager and General
                                                    Partner of a number of closely held real
                                                    estate development companies and
                                                    partnerships whose investments include
                                                    commercial real estate and a portfolio of
                                                    publicly traded securities.


                                       26



Sunil Kumar                          50             Mr. Kumar has been director, President and         2004
1361 Alps Road                                      Chief Executive Officer of ISP since June
Wayne, New Jersey 07470                             1999. Mr. Kumar has also been President and
                                                    Chief Executive Officer of certain
                                                    subsidiaries of ISP, including ISP
                                                    Investments Inc., since June 1999. Mr. Kumar
                                                    was a director, President and Chief
                                                    Executive Officer of BMCA from May 1995,
                                                    July 1996 and January 1999, respectively,
                                                    until June 1999. He was Chief Operating
                                                    Officer of BMCA from March 1996 to January
                                                    1999. Mr. Kumar also was President,
                                                    Commercial Roofing Products Division, and
                                                    Vice President of BMCA from February 1995 to
                                                    March 1996.

Gloria Schaffer                      70             Ms. Schaffer served as a Commissioner of the       2004
1211 Chapel St.                                     Department of Consumer Protection of the
New Haven, CT  06511                                State of Connecticut from 1991 to 1995, as a
                                                    Member of the Civil Aeronautics Board from
                                                    1978 to 1984 and as the Secretary of State
                                                    of the State of Connecticut from 1970 to
                                                    1978. Ms. Shaffer also previously served on
                                                    the Board of Directors of Amity Bank and
                                                    Amity Bankcorp, Mott's Inc. and Emery Air
                                                    Worldwide, and, since 1996, has served as a
                                                    partner at C.A. White, Inc., a real estate
                                                    development firm.

Raymond S. Troubh                    74             Mr. Troubh has been a financial consultant         2004
10 Rockefeller Plaza                                for more than five years. Prior to that he
Suite 712                                           was a general partner of Lazard Freres &
New York, New York 10020                            Co., an investment banking firm, and a
                                                    governor of the American Stock Exchange. Mr.
                                                    Troubh has served as a director of the
                                                    following public companies: Time Warner,
                                                    Inc., Becton, Dickinson and Company and
                                                    America West Airlines, Inc., and is a
                                                    director of ARIAD Pharmaceuticals, Inc., a
                                                    biopharmaceutical company, Diamond Offshore
                                                    Drilling, Inc., a contract drilling company,
                                                    General American Investors Company, an
                                                    investment trust company, Gentiva Health
                                                    Services, Inc., a healthcare provider,
                                                    Health Net, Inc., a managed healthcare
                                                    company, Starwood Hotels & Resorts, Inc., a
                                                    hotel operating company, Triarc Companies,
                                                    Inc., a holding company, and WHX


                                       27


                                                    Corporation, a steel products company. He is
                                                    also a trustee of Corporate Renaissance
                                                    Group Liquidating Trust, Inc., MicroCap
                                                    Liquidating Trust and Petrie Stores
                                                    Liquidating Trust.


                  Each of the nominees has consented to serve as a director
until the expiration of his or her respective term and until such nominee's
successor has been elected and qualified or until the earlier resignation or
removal of such nominee. We have no reason to believe that any of the nominees
named above will be disqualified or unable or unwilling to serve if elected.
However, if any of the nominees are unable to serve or for good cause will not
serve, proxies may be voted for another person nominated by ISP to fill the
vacancy.

                  The nominees understand that, if elected as directors of
Hercules, each of them will have an obligation under Delaware law to discharge
his or her duties as a director in good faith, consistent with his or her
fiduciary duties to Hercules and its stockholders.

                       WE STRONGLY RECOMMEND THAT YOU VOTE
                       "FOR" THE ELECTION OF OUR NOMINEES.


                         OTHER MATTERS TO BE CONSIDERED
                           AT THE 2001 ANNUAL MEETING

RATIFICATION OF APPOINTMENT OF INDEPENDENT AUDITORS

                  As set forth in Hercules' proxy statement, at the 2001 Annual
Meeting, Hercules stockholders will be asked to ratify the appointment by
Hercules Board of PricewaterhouseCoopers LLP as Hercules' independent auditors
for the year 2001. We are not making any recommendation on this proposal.

OTHER PROPOSALS

                  Except as set forth above, we are not aware of any proposals
to be brought before the 2001 Annual Meeting. However, we intend to bring before
the 2001 Annual Meeting such business as may be appropriate, including without
limitation nominating additional persons for directorships, or making other
proposals as may be appropriate to address any action of Hercules Board not
publicly disclosed prior to the date of this proxy statement. Should other
proposals be brought before the 2001 Annual Meeting, the persons named as
proxies in the enclosed BLUE proxy card will vote on such matters in their
discretion.



                                       28


                                VOTING PROCEDURES

                  In order to ensure that your views on the proposals are heard
by Hercules and your vote represented at the 2001 Annual Meeting, we urge you to
sign and date the enclosed BLUE Proxy Card and return it to Georgeson
Shareholder Communications Inc. ("Georgeson"), in the enclosed postage paid
envelope TODAY. Execution of the BLUE Proxy Card will not affect your right to
attend the 2001 Annual Meeting and to vote in person.

                  You are eligible to execute a BLUE Proxy only if you owned the
Common Stock on the Record Date. Hercules Board has set March 6, 2001 as the
Record Date for determining those stockholders who will be entitled to notice of
and to vote at the 2001 Annual Meeting. You will retain the right to execute a
proxy card in connection with this proxy solicitation even if you sell your
shares after the Record Date. Accordingly, it is important that you vote the
Shares held by you on the Record Date, or grant a proxy to vote such Shares on
the BLUE proxy card, even if you sell such shares after the Record Date.

                  As of the close of business on the Record Date, we believe
that there were 108,115,824 shares of common stock of Hercules issued and
outstanding and entitled to vote. Stockholders will have one vote for each share
of common stock they own with respect to all matters to be considered at the
2001 Annual Meeting.

                  In order for your views on the above-described proposals to be
represented at the 2001 Annual Meeting, please sign and date the enclosed BLUE
proxy card and return it to Georgeson in the enclosed prepaid envelope TODAY.
Execution of the BLUE proxy card will not affect your right to attend the 2001
Annual Meeting and to vote in person. Any proxy may be revoked at any time prior
to the 2001 Annual Meeting by delivering a written notice of revocation or a
later dated proxy for the 2001 Annual Meeting to Georgeson or the Secretary of
Hercules, or by voting in person at the 2001 Annual Meeting. Only your latest
dated proxy will count.

                  Unless otherwise indicated, the BLUE Proxy authorizes the
persons named in the proxy to vote, and such persons will vote, properly
executed and duly returned proxies FOR the ISP nominees. If no marking is made
on your BLUE Proxy with respect to the ratification of the appointment of
Hercules' independent auditors, you will be deemed to have given a direction to
abstain from voting on such matter.

                                  VOTE REQUIRED

                  Based on currently available public information, a quorum will
exist at the 2001 Annual Meeting if holders of not less than a majority of the
shares of Hercules common stock outstanding and entitled to vote at the 2001
Annual Meeting are present in person or by proxy. If a quorum is present, the
election of directors requires the following vote:



                                       29


o        ELECTION OF DIRECTORS: Hercules claims that its Bylaws require that in
         order to be elected, nominees for director must receive the affirmative
         vote of a majority of all outstanding shares. We disagree with its
         interpretation and believe, based on the reasons set forth below, that
         under Delaware law our nominees should be elected if they receive the
         greatest number of votes cast at the 2001 Annual Meeting.

                  Our view that, under Delaware law and the Hercules Bylaws, our
nominees should be deemed elected if they receive the greatest number of votes
cast at the 2001 Annual Meeting is supported by the following legal analysis:

                  Section 216(3) of the Delaware General Corporation Law
provides that in the absence of specification in the certificate of
incorporation or bylaws of a corporation, "[d]irectors shall be elected by a
plurality of the votes of the shares present in person or represented by proxy
at the meeting and entitled to vote on the election of directors." Delaware case
law has established that in order to overcome this voting rule, the certificate
of incorporation or bylaw provision must "not be couched in ambiguous language,
rather the language employed must be positive, explicit, clear and readily
understandable and susceptible to but one reasonable interpretation, which would
indicate beyond doubt that the rule was intended to be abrogated." Standard
Power and Light Corp. v. Investment Associates, Del. Supr., 51 A.2d 572 (1947).

                  Article II, Section 2 of Hercules Bylaws currently provides
that "[a]t each annual meeting, there shall be elected by ballot, by the
majority vote of the stock then issued and outstanding and entitled to vote
thereat, the number of directors necessary to fill the class of those whose term
then expires." The subordinate clause "by the majority vote of the stock then
issued and outstanding and entitled to vote thereat", we believe, should not be
interpreted as requiring that the winner obtain the affirmative vote of the
holders of a majority of the shares issued and outstanding. Such an
interpretation of the subordinate clause is disfavored because it deviates from
the "fundamental principle of majority rule." Centaur Partners, IV v. National
Intergroup, Inc., Del. Supr., 582 A.2d 923, 927 (1990). It also creates a
conflict with the rest of the sentence. Absent the subordinate clause, the
remainder of the sentence requires that a class of directors "shall be elected"
at the annual meeting. A construction that would require the winner to obtain
the affirmative vote of the holders of a majority of the shares issued and
outstanding, we believe, creates the possibility that in a contested election no
candidate will obtain the requisite number of votes, in which event no
successors would be elected at the annual meeting as the By-laws require and the
incumbent directors would continue to hold their seats even though their
three-year terms have expired and indeed, even though the incumbent directors
had received fewer votes than the other candidates or even no votes at all.

                  The Delaware Supreme Court has interpreted a similar bylaw in
a manner that avoids this same problem. In Standard Power, the Court was asked
to interpret the following provision in a certificate of incorporation:

         The holders of the Common Stock Series B shall have the right by the
         vote of a majority in number of shares of the Common Stock Series B
         issued and outstanding to elect a minority in number of the full Board


                                       30


         of Directors of the corporation, such minority to consist of the
         largest number of Directors which will constitute a minority in number
         of such full Board of Directors, and the directors so elected shall be
         known as Class B directors.

The Court declined to interpret the highlighted phrase as requiring a contestant
to obtain the votes of a majority of the outstanding shares because that result
"would be inequitable, unusual and such as reasonable men would not likely
intend." Id. at 577. The Court ruled that the provision "should be construed to
mean that a majority in number of the issued and outstanding Series B shares
must be voted, and that this is the full extent of the charter requirement in
this regard." Id. At 578. The court accepted that construction even though a
separate provision in the certificate of incorporation "requir[ed] the presence
for quorum purposes of a majority in number of the shares of the Series B stock
before the stockholders are entitled to vote for the election of Class B
directors[.]" Id. At 577.

                  The clause "by the majority vote of the stock then issued and
outstanding and entitled to vote thereat", we believe, should be interpreted in
identical fashion as the phrase from Standard Power: "by the vote of a majority
in number of shares of the Common Stock Series B issued and outstanding." The
reasons for our interpretation include the following:

         o        The language of the Hercules Bylaw closely tracks the language
                  of the bylaw interpreted in Standard Power.

         o        The Standard Power construction avoids the policy problems of
                  holdover directors and the possible disenfranchisement of a
                  plurality or even majority of those voting. These policy
                  considerations are of particular concern in this case, because
                  Hercules has a classified board.

         o        The Standard Power construction avoids creating an internal
                  inconsistency in Article II, Section 2.

         o        The language of Article II, Section 2 does not track the clear
                  language of Article I, Section 6: "the affirmative vote of the
                  holders of a majority of the shares present in person or by
                  proxy." If the drafters of the Bylaws wanted to deviate from
                  the default rule in Article I, Section 6, they knew how to
                  clearly draft such language (e.g., "election of a new director
                  shall require the affirmative vote of the holders of a
                  majority of the shares issued and outstanding").

                  Furthermore, the interpretation by the Company is not
consistent with the scheme of Section 141(d) of the Delaware General Corporation
Law, which establishes the conditions for a classified board of directors. The
statute permits, by the certificate of incorporation or a by-law adopted by the
vote of the stockholders, division of the directors into one, two or three
classes. The term of the first class shall expire at the next annual meeting,
the second class the year thereafter and the third class two years thereafter.
The statute further provides "... and at each annual election held after such


                                       31


classification and election, directors shall be chosen for a full term, as the
case may be, to succeed those whose terms expired." Should the Company's
interpretation be adopted and a class of directors not be elected in a
particular year, the incumbent directors would remain in office since their
successors would not be elected and qualified. We believe that this result,
which should be impermissible in any event as a matter of good corporate
governance, also runs contrary to New York Stock Exchange policy, as Section
304.00 of the NYSE Listed Company Manual specifies that "... directors' terms of
office should not exceed three years." There are no mechanics in the By-laws to
establish how many classes of directors would be elected in the second year and
third year and the term of each class. While this is also true should a
plurality not elect the new members of the class, the higher voting requirement
makes this a greater likelihood, particularly in the case of a proxy contest.

                  Our proxy statement and a form of proxy will be delivered to
holders of at least the percentage of the Company's common stock required under
applicable law to carry the Proposals.

                         WE STRONGLY RECOMMEND THAT YOU
                    VOTE "FOR" THE ELECTION OF OUR NOMINEES.

                            METHOD OF COUNTING VOTES

                  The holders of not less than a majority of the number of
shares of Hercules common stock outstanding and entitled to vote at the 2001
Annual Meeting must be represented in person or by proxy in order to constitute
a quorum for the transaction of business. Abstentions and broker non-votes will
be included for purposes of determining whether a quorum exists. Broker
non-votes occur when brokers do not receive voting instructions from their
customers on non-routine matters and consequently have no discretion to vote on
those matters. If your Hercules shares are held in the name of a brokerage firm,
bank nominee or other institution, you should contact the person responsible for
your account and give instructions for a proxy card to be issued so that your
shares will be represented at the 2001 Annual Meeting.

                  After a quorum is determined to exist at the 2001 Annual
Meeting, under our interpretation of Hercules director election Bylaw,
abstentions and broker non-votes will have no effect on the outcome of the
election of directors. Under Hercules' interpretation of that Bylaw, however,
abstentions and broker non-votes will be counted as votes cast against the
election of directors.


                  USE OF PREVIOUSLY PUBLISHED MATERIAL

                  This proxy statement includes quotations from previously
published material contained in periodicals, newspapers and analyst reports, the
source of which has been cited when used. We did not seek the consent of the
author or publication to the use of any such material as proxy soliciting
material. We have not directly or indirectly paid or proposed to pay any
consideration in connection with the publication or republication of such
material.




                                       32


                             ADDITIONAL INFORMATION

                  The principal executive offices of Hercules Incorporated are
at Hercules Plaza, 1313 North Market Street, Wilmington, Delaware 19894.
Hercules manufactures chemical specialties used in a variety of home, office and
industrial products including process paper chemicals, water treatment
chemicals, water-soluble polymers, food ingredients, resins and polypropylene
and polyethylene fibers. Hercules' primary markets include pulp and paper,
petroleum refineries, food processors and manufacturers, construction materials,
adhesives, pharmaceutical companies and personal care product manufacturers.
Except as otherwise noted herein, the information concerning Hercules has been
taken from or is based upon documents and records on file with the SEC and other
publicly available information. Although we do not have any knowledge that would
indicate that any statement contained herein based upon such documents and
records is untrue, we do not take any responsibility for the accuracy or
completeness of the information contained in such documents and records, or for
any failure by Hercules to disclose events that may affect the significance or
accuracy of such information.

                  The principal executive offices of ISP are at 300 Delaware
Avenue, Wilmington, Delaware 19801. We are a manufacturer of specialty chemicals
and mineral products.

                  We are subject to the informational requirements of the
Exchange Act, and, in accordance with the Exchange Act, file reports, proxy
statements and other documents with the SEC relating to our business, financial
condition and other matters. These reports, proxy statements and other documents
can be inspected and copied at the public reference facilities of the SEC at 450
Fifth Street, N.W., Washington, DC 20549, and at the regional offices of the SEC
located at Seven World Trade Center, 13th Floor, New York, New York 10048 and
Citicorp Center, 500 West Madison Street, Suite 1400, Chicago, Illinois 60661.
Copies of ISP's filings with the SEC can also be obtained by mail for a fee by
writing to the SEC's principal office at 450 Fifth Street, N.W., Washington, DC
20549. You can also get electronic copies of our filings with the SEC for free
on the SEC's Internet web site at http://www.sec.gov. Copies of our filings with
the SEC are also be available for inspection at the offices of the New York
Stock Exchange, 20 Broad Street, New York, New York 10005.

                          PROXY SOLICITATION; EXPENSES

                  Executed proxies may be solicited in person, by mail,
advertisement, telephone, telecopier, telegraph or similar means. Solicitation
may be made by directors, officers, investor relations personnel and other
employees of ISP and their affiliates, none of whom will receive additional
compensation for such solicitation. Proxies will be solicited from individuals,
brokers, banks, bank nominees and other institutional holders. We have requested
banks, brokerage houses and other custodians, nominees and fiduciaries to
forward all solicitation materials to the beneficial owners of the shares they
hold of record. We will reimburse these record holders for their reasonable
out-of-pocket expenses.



                                       33


                  In addition, ISP has retained Georgeson to solicit proxies on
our behalf in connection with the 2001 Annual Meeting. Georgeson will employ
approximately [75] people in its efforts. We have agreed to reimburse Georgeson
for its reasonable expenses and to pay to Georgeson fees not to exceed $225,000.

                  The entire expense of our proxy solicitation is being borne by
ISP. In the event that our nominees are elected to Hercules Board, we may seek
reimbursement of such expenses from Hercules. ISP does not intend to seek
reimbursement for the stipend it pays to its nominees and does not intend to
seek stockholder approval of reimbursement of its other expenses. In addition to
the engagement of Georgeson described above, costs related to the solicitation
of proxies include expenditures for printing, postage, legal and related
expenses and are expected to be approximately $__________. Total payment of
costs to date in furtherance of our proxy solicitation is approximately
$__________.

                 CERTAIN INFORMATION CONCERNING THE PARTICIPANTS

                  ISP, our nominees for directorships and the following officers
of ISP may be deemed to be "participants" (as defined in Instruction 3 to Item 4
of Rule 14a-101 of the Exchange Act) in this proxy solicitation: Richard A.
Weinberg, Executive Vice President, General Counsel and Secretary; Randall R.
Lay, Executive Vice President and Chief Financial Officer; Susan B. Yoss,
Executive Vice President and Treasurer; Stephen R. Olsen, Senior Vice
President-Corporate Development; Jared Landaw, Vice President-Law; and Ben
Stoller, Director-Corporate Finance and Investments. Information relating to the
beneficial ownership of common stock of Hercules by the participants in this
solicitation and certain other information relating to the participants is
contained in Annex V to this proxy statement and is incorporated in this proxy
statement by reference. Except as set forth in Annex V, none of the participants
in this solicitation are party to any commercial dealings with Hercules or its
subsidiaries required to be discussed pursuant to Schedule 14A promulgated under
the Exchange Act, which governs the disclosure contained in this proxy
statement.

                     CERTAIN INTERESTS IN THE PROPOSALS AND
                     WITH RESPECT TO SECURITIES OF HERCULES

                  To the knowledge of ISP, there are no contracts, arrangements,
understandings or relationships (legal or otherwise) among ISP or its associates
with respect to any securities of Hercules.

                  Gloria Schaffer and Raymond Troubh, each in his or her
capacity as a nominee for election to the Hercules Board, will receive a stipend
of $25,000 from ISP for his or her service as a nominee. This stipend is not
refundable in any manner in connection with the outcome of our proxy
solicitation or otherwise. The Nominees are each party to an indemnity agreement
with ISP (the "Director Indemnity Agreements"). In accordance with the terms of
the Director Indemnity Agreements, ISP has agreed to indemnify and hold harmless
each of the nominees from and against, among other things, all expenses,
liabilities and losses, including reasonable attorney's fees, related to any


                                       34


action, suit or proceeding to which such nominee is made a party or threatened
to be made a party by reason of such nominee's action or inaction while serving
as a nominee.
















                                       35


                         SECURITY OWNERSHIP OF DIRECTORS
                           AND MANAGEMENT OF HERCULES

                  The following table presents, as of March 6, 2001, based
solely on information contained in Hercules' 2001 proxy statement, the common
stock beneficially owned (as that term is defined by the SEC) by all directors
and named executive officers of Hercules, and the directors and executive
officers of Hercules as a group.

                  Except as otherwise noted in a footnote below, each director,
nominee and executive officer has sole voting and investment power with respect
to the number of shares of common stock set forth opposite his or her name in
the table.


                                                     Shares                  Options
                                                  Beneficially             Exercisable        Restricted          Percent of
            Name                                    Owned (1)             Within 60 Days      Stock Units           Shares
-----------------------------------------------------------------------------------------------------------------------------------
                                                                                                         
DIRECTORS AND OFFICERS
Thomas L. Gossage, Director and
Officer (2)                                             129,003               264,000                 0              *
J. Barry, Officer                                        71,954                 7,200                 0              *
D. W. DiDonna, Officer                                   44,637               148,100                 0              *
J. G. Drosdick, Director                                  9,423                 6,000             1,100              *
R. M. Fairbanks, III, Director                           12,088                21,000             1,253              *
I. J. Floyd, Officer                                     65,944                71,800                 0              *
A. R. Hirsig, Director                                    6,554                 6,000             1,100              *
E. E. Holiday, Director                                   3,999                18,000             1,376              *
R. G. Jahn, Director                                     14,236                27,000                 0              *
G. N. Kelley, Director                                    9,744                27,000             2,185              *
R. L. MacDonald, Jr., Director                           15,421                27,000             1,928              *
G. MacKenzie, Officer                                   125,997               170,280             1,299              *
H. E. McBrayer, Director                                 77,324                24,000             1,527              *
P. McCausland, Director                                   7,784                 9,000             1,100              *
J. A. H. Shober, Director                                 5,250                 6,000             1,100              *
P. A. Sneed, Director                                    11,925                18,000             1,253              *
V. J. Corbo, Director and Officer (3)                   109,119               275,200                 0              *
H. J. Tucci, Officer (4)                                 53,231               209,200                 0              *
ALL DIRECTORS AND OFFICERS AS A GROUP                   773,633             1,448,520            15,221              2%


*        Less than 1% of Hercules' outstanding shares of common stock.

(1)      Includes shares, as of December 31, 2000, in the Savings and Investment
         Plan as follows: J. Barry, 2,351; D. W. DiDonna, 1,276; I. J. Floyd,
         1,372; and G. MacKenzie, 3,421; and all directors and officers as a
         group, 8,420. Includes shares with restrictions and forfeiture risks as
         specified under the Long-Term Incentive Compensation Plan: T. L.
         Gossage, 128,003; J. Barry, 38,000; D. W. DiDonna, 39,747; G.
         MacKenzie, 76,270; I. J. Floyd, 45,910; H. J. Tucci, 1,821; and all
         directors and officers as a group, 274,956. Owners have the same voting
         and dividend rights as other shareholders of Hercules, except for the
         right to sell or transfer. Included in the non-employee directors'
         totals is a one-time equity award. Mr. Kelley's total includes 1,594
         shares that he holds jointly with his spouse.

(2)      Named Chairman and Chief Executive Officer on October 17, 2000.



                                       36


(3)      Resigned as President, Chairman and Chief Executive Officer on October
         17, 2000.

(4)      Retired as officer on December 1, 2000.













                                       37


                       PRINCIPAL STOCKHOLDERS OF HERCULES

                  The following table sets forth, based solely, except as
otherwise described herein, on information contained in Hercules' 2001 proxy
statement, the number and percentage of outstanding shares of common stock
beneficially owned by each person known to ISP as of such date to be the
beneficial owner of more than five percent of the outstanding shares of common
stock.

                                                Shares
                                              Beneficially      Percent of
            Name                                 Owned            Shares
-------------------------------------------------------------------------------

5% SHAREHOLDERS
International Specialty Products, Inc.          10,719,200        9.9%(1)
ISP Investments Inc.
ISP Opco Holdings Inc.
c/o ISP Management Company, Inc.
1361 Alps Road
Wayne, New Jersey  07670

T. Rowe Price Associates, Inc. (2)
100 E. Pratt Street
Baltimore, Maryland  21202                       7,198,428        6.7%

Mario J. Gabelli and related                     6,707,400        6.23%
entities (3)
c/o Gabelli Asset Management Inc.
One Corporate Center
Rye, New York  10580


(1)      ISP Investments Inc. (through ISP Investments Grantor Trust) has the
         sole power to vote, direct the voting of, dispose of and direct the
         disposition of the shares. ISP Opco Holdings Inc., by virtue of its
         indirect ownership of all of the outstanding capital stock of ISP
         Investments Inc., may be deemed to own beneficially (solely for
         purposes of Rule 13d-3) the shares. ISP, by virtue of its ownership of
         all of the outstanding common stock of ISP Opco Holdings Inc., may be
         deemed to own beneficially (solely for purposes of Rule 13d-3) the
         shares. Samuel J. Heyman, by virtue of his beneficial ownership (as
         defined in Rule 13d-3) of approximately 79% of the capital stock of
         ISP, may be deemed to own beneficially (solely for purposes of Rule
         13d-3) the shares.

(2)      Share holding as of March 6, 2001, as reported on Schedule 13G most
         recently filed by such shareholder.

(3)      Share holding as of March 6, 2001, as reported on Amendment No. 1 to
         the Schedule 13D filed by such shareholder.




                                       38


              STOCKHOLDERS' PROPOSALS IN HERCULES' PROXY STATEMENT

                  Pursuant to Rule 14a-8(e)(2) under the Exchange Act, any
proposal by a stockholder at the 2001 Annual Meeting, to be included in
Hercules' proxy statement, must be received in writing at Hercules' principal
executive offices not less than 120 calendar days in advance of the date of
Hercules' proxy statement released to security holders in connection with its
2000 Annual Meeting of Stockholders. However, if the date of the meeting is
changed by more than 30 days from the date of the previous year's meeting, then
the deadline is a reasonable time before Hercules begins to print and mail its
proxy materials.

                  Proposals should be addressed to the Corporate Secretary,
Hercules Incorporated, Hercules Plaza, 1313 North Market Street, Wilmington,
Delaware 19894.

WE URGE YOU TO SIGN, DATE AND RETURN THE BLUE PROXY CARD IN FAVOR OF THE
ELECTION OF OUR NOMINEES DESCRIBED IN THIS PROXY STATEMENT.

Dated:  __________ __, 2001

                                Sincerely,

                                Your Fellow Stockholder:

                                INTERNATIONAL SPECIALTY PRODUCTS INC.






                                       39


                 INFORMATION CONCERNING INTERNATIONAL SPECIALTY
                      PRODUCTS INC. AND OTHER PARTICIPANTS
                               IN THE SOLICITATION

                  Information is being given herein for (i) International
Specialty Products Inc., a Delaware corporation ("ISP"), (ii) Samuel J. Heyman,
a natural person and nominee for the Board of Directors of the Company, (iii)
Sunil Kumar, a natural person and nominee for the Board of Directors of the
Company, (iv) Gloria Schaffer, a natural person and nominee for the Board of
Directors of the Company, (v) Raymond Troubh, a natural person and nominee for
the Board of Directors of the Company, (vi) Richard A Weinberg, Executive Vice
President, General Counsel and Secretary of ISP ("Weinberg"), (vii) Randall R.
Lay, Executive Vice President and Chief Financial Officer of ISP ("Lay"), (viii)
Susan B. Yoss, Executive Vice President and Treasurer of ISP ("Yoss"), (ix)
Stephen R. Olsen, Senior Vice President-Corporate Development of ISP ("Olsen"),
(x) Jared Landaw, Vice President-Law of ISP ("Landaw") and (xi) Ben Stoller,
Director-Corporate Finance and Investments of ISP ("Stoller" and together with
Weinberg, Lay, Yoss, Olsen and Landaw, the "ISP Participants"), who are each a
"participant in a solicitation" as defined under the proxy rules (collectively,
the "Participants").

                  Information is also given for each of the entities listed on
Schedule A to this Annex V, each of which is an "associate", as defined under
the proxy rules, of ISP.

                  ISP is a Delaware corporation. ISP has its principal place of
business at 300 Delaware Avenue, Wilmington, Delaware 19801. The business
address of each of the ISP Participants is c/o ISP Management Company, Inc.,
1361 Alps Road, Wayne, New Jersey 07470. The address of each of the entities
listed on Schedule A to this Annex VI is c/o ISP Management Company, Inc., 1361
Alps Road, Wayne, New Jersey 07470.

                  The Participants may be deemed to have beneficial ownership of
Hercules Common Stock as set forth immediately below. Except as set forth below,
no associates of any of the Participants owns any Hercules Common Stock.




                                     A-I-1



                                               NUMBER OF SHARES                      APPROXIMATE MARGIN
                                                 OF HERCULES                     INDEBTEDNESS WITH RESPECT
NAME                                             COMMON STOCK                         TO COMMON STOCK
----                                             ------------                         ---------------
                                                                                      
ISP Investments Inc.                              10,719,200                                (2)
                                            (direct ownership)(1)
ISP Opco Holdings Inc.                            10,719,200                                (2)
                                           (indirect ownership)(1)
International Specialty Products Inc.             10,719,200                                (2)
                                           (indirect ownership)(1)
Samuel J. Heyman                                  10,719,200                                (2)
                                           (indirect ownership)(1)
Sunil Kumar                                           0                                     $ 0
Gloria Schaffer                                       0                                     $ 0
Raymond Troubh                                        0                                     $ 0
Richard A. Weinberg                                   0                                     $ 0
Randall R. Lay                                        0                                     $ 0
Susan B. Yoss                                         0                                     $ 0
Stephen R. Olsen                                      0                                     $ 0
Jared Landaw                                          0                                     $ 0
Ben Stoller                                           0                                     $ 0



(1)      ISP Investments (through ISP Investments Grantor Trust) has the sole
         power to vote, direct the voting of, dispose of and direct the
         disposition of the Hercules Common Stock. ISP Opco Holdings Inc. ("ISP
         Opco"), by virtue of its indirect ownership of all of the outstanding
         capital stock of ISP Investments, may be deemed to own beneficially
         (solely for purposes of Rule 13d-3) the Hercules Common Stock owned by
         ISP Investments. International Specialty Products Inc. ("ISP"), by
         virtue of its ownership of all of the outstanding common stock of ISP
         Opco, may be deemed to own beneficially (solely for purposes of Rule
         13d-3) the Hercules Common Stock owned by ISP Investments. Mr. Heyman,
         by virtue of his beneficial ownership (as defined in Rule 13d-3) of
         approximately 79% of the capital stock of ISP, may be deemed to own
         beneficially (solely for purposes of Rule 13d-3) the Hercules Common
         Stock owned by ISP Investments.

(2)      In the ordinary course of its business, ISP Investments Inc. purchases
         securities for its investment portfolio with funds obtained from the
         working capital of ISP Investments, loans from affiliates and
         borrowings pursuant to standard margin arrangements. Because the
         securities from multiple investments are pooled in one account, the
         amount of margin indebtedness incurred by ISP in connection with its


                                     A-I-2


         purchases of Hercules Common Stock, which purchases were numerous and
         made over several months, is impossible to determine with any degree of
         certainty.

                  To the best of the knowledge of the Participants and their
associates, none has been, within the past year, a party to any contract,
arrangement or understanding with any person with respect to any securities of
Hercules, including but not limited to joint ventures, loan or option
arrangements, puts or calls, guarantees against loss or guarantees of profits,
division of losses or profits, or the giving or withholding of proxies.

                  No Participant or associate owns any securities of the Company
of record but not beneficially.

                  ISP does not have any special arrangements with any of the ISP
Participants in connection with this proxy solicitation.

                  None of the Participants and none of their associates has any
arrangement or understanding with any person with respect to (i) any future
employment with Hercules or (ii) any future transactions to which Hercules or
any of its affiliates may be a party. ISP and certain of its subsidiaries
purchase and sell certain chemical products to Hercules and/or certain
subsidiaries or affiliates of Hercules in the ordinary course of business in an
aggregate amount per year that does not exceed $500,000. No family relationships
exist among the Participants' nominees or between any Hercules director or
executive officer and any of the Participants' nominees.

                  The following is a summary of all transactions in Hercules
securities by the Participants over the last two years.

 DATE OF TRANSACTION      NATURE OF TRANSACTION         NUMBER OF SHARES
-------------------------------------------------------------------------------
      01/28/00                  Buy                         21,700
      03/01/00                  Buy                        196,000
      03/02/00                  Buy                      1,030,000
      03/03/00                  Buy                      1,200,000
      03/09/00                  Buy                         60,000
      03/13/00                  Buy                         35,000
      03/14/00                  Buy                         11,800
      03/15/00                  Buy                         45,000
      03/20/00                  Buy                        150,000
      03/22/00                  Buy                         65,000
      03/23/00                  Buy                         13,000
      03/28/00                  Buy                        200,000
      03/29/00                  Buy                        106,000
      03/31/00                  Buy                         55,000
      04/03/00                  Buy                         35,000
      04/04/00                  Buy                         62,600


                                     A-I-3


 DATE OF TRANSACTION      NATURE OF TRANSACTION         NUMBER OF SHARES
-------------------------------------------------------------------------------
      04/07/00                  Buy                          2,500
      04/10/00                  Buy                        102,000
      04/12/00                  Buy                        151,000
      04/13/00                  Buy                        165,500
      04/14/00                  Buy                        102,000
      04/17/00                  Buy                         55,000
      04/18/00                  Buy                         63,000
      04/19/00                  Buy                         60,000
      04/20/00                  Buy                        370,000
      04/24/00                  Buy                         34,900
      04/25/00                  Buy                        100,000
      04/26/00                  Buy                         81,500
      04/28/00                  Buy                          7,500
      05/01/00                  Buy                            200
      05/02/00                  Buy                         35,000
      05/03/00                  Buy                        135,000
      05/04/00                  Buy                         95,000
      05/05/00                  Buy                         50,000
      05/08/00                  Buy                         35,000
      05/09/00                  Buy                         35,000
      05/10/00                  Buy                          1,000
       6/5/00                   Buy                         14,100
       6/6/00                   Buy                         41,200
       6/7/00                   Buy                         35,000
       6/8/00                   Buy                         14,400
       6/9/00                   Buy                         16,000
      6/19/00                   Buy                         70,000
      6/20/00                   Buy                         50,000
      6/22/00                   Buy                          2,500
      6/23/00                   Buy                         25,000
      7/10/00                   Buy                         35,000
      7/11/00                   Buy                         35,000
      7/12/00                   Buy                         11,800
      7/14/00                   Buy                      5,355,000
      7/17/00                   Buy                         40,000
      7/20/00                   Buy                          3,000
      7/21/00                   Buy                          4,000



                                     A-I-4


                                                           SCHEDULE A TO ANNEX I


               Associates of International Specialty Products Inc.
               ---------------------------------------------------


ISP Acquisition Corp.
ISP Investments Inc.
ISP Opco Holdings Inc.
Belleville Realty Corp.
ISP Alginates Inc.
ISP Management Company, Inc.
ISP Chemicals Inc.
ISP Minerals Inc.
ISP Technologies Inc.
ISP Mineral Products Inc.
ISP Environmental Services Inc.
Bluehall Incorporated
ISP Realty Corporation
ISP Real Estate Company, Inc.
International Specialty Products Funding Corporation
ISP Newark Inc.
ISP Van Dyk Inc.
ISP Fine Chemicals Inc.
ISP Freetown Fine Chemicals Inc.
Verona Inc.
ISP Global Technologies Inc.
ISP International Corp.
ISP Marl Holdings GmbH
ISP Holdings (U.K.) Ltd.
ISP Ireland
ISP (Puerto Rico) Inc.
ISP Marl GmbH
ISP Acetylene GmbH
ISP Alginates (U.K.) Ltd.
ISP (Great Britain) Co. Ltd.
ISP Andina, C.A.
ISP Argentina S.A.
ISP Asia Pacific Pte Ltd.
ISP (Australasia) Pte Ltd.
ISP (Belgium) N.V.
ISP (Belgium) International N.V.
ISP do Brasil Ltda.
ISP (Canada) Inc.
ISP Ceska Republika Spol S.R.O.


                                     A-I-5


ISP (China) Limited
ISP Colombia Ltda.
ISP Freight Service N.V.
ISP Global Operations (Barbados) Inc.
ISP Global Technologies (Germany) Holding GmbH
ISP Customer Service GmbH
ISP Global Technologies Deutschland GmbH
International Specialty Products ISP (France) S.A.
ISP (Hong Kong) Limited
ISP (Italia) S.r.l.
ISP (Japan) Ltd.
ISP (Korea) Limited
ISP Mexico, S.A. de C.V.
ISP (Norden) A.B.
ISP (Osterreich) GmbH
ISP (Polska) Sp.z. o.p.
ISP Sales (Barbados) Inc.
ISP Sales (U.K.) Limited
ISP (Singapore) Pte Ltd.
ISP (Switzerland) A.G.
ISP (Thailand) Co., Ltd.
Chemfields Pharmaceuticals Private Limited
Kelp Industries Pty Ltd
Arramara Teoranta
Thorverk Hf




                                     A-I-6


                               [PRELIMINARY COPY]

PROXY

                              HERCULES INCORPORATED

              PROXY SOLICITED ON BEHALF OF INTERNATIONAL SPECIALTY
           PRODUCTS INC. AND THE OTHER PARTICIPANTS IDENTIFIED IN THE
        PROXY STATEMENT FURNISHED HEREWITH ("ISP") FOR THE ANNUAL MEETING
                  OF STOCKHOLDERS, APRIL 26, 2001 AT 11:00 A.M.

The undersigned stockholder of Hercules Incorporated ("Hercules") hereby
appoints Samuel J. Heyman and Sunil Kumar and each of them, as attorneys and
proxies, each with power of substitution and revocation, to represent the
undersigned at the Annual Meeting of Stockholders of Hercules Incorporated to be
held at the Delaware Art Museum, 2301 Kentmere Parkway, Wilmington, Delaware on
April 26, 2001 at 11:00 A.M., local time, and at any adjournment or postponement
thereof, with authority to vote all shares held or owned by the undersigned in
accordance with the directions indicated herein.

                  Receipt of the Proxy Statement furnished herewith is hereby
acknowledged.

THIS PROXY WHEN PROPERLY EXECUTED WILL BE VOTED IN THE MANNER DIRECTED BY THE
UNDERSIGNED STOCKHOLDER. ON MATTERS FOR WHICH YOU DO NOT SPECIFY A CHOICE, YOUR
SHARES WILL BE VOTED IN ACCORDANCE WITH THE RECOMMENDATION OF ISP. YOU MAY
APPROVE OR VOTE SEPARATELY ON ANY OR ALL OF THE PROPOSALS.





                (CONTINUED AND TO BE SIGNED ON THE REVERSE SIDE)





                                     A-I-7


             ISP RECOMMENDS A VOTE "FOR" THE NOMINEES LISTED BELOW.
                                       ---



           Election of Directors



                                                                 
FOR all nominees listed on the right     WITHHOLD AUTHORITY to vote    NOMINEES: Samuel J. Heyman, Sunil Kumar, Gloria
(except as marked to the contrary        for all nominees listed to    Schaffer, Raymond Troubh
hereon).                                 the right.                    (Instructions:  To withhold authority to vote for
                                                                       any individual nominee, write that nominee's name in
               [_]                                   [_]               the space provided below.)

                                                                       -----------------------------------------------------





                         ISP MAKES NO RECOMMENDATION ON
                       THE FOLLOWING MATTER TO BE VOTED ON
                           AT THE 2001 ANNUAL MEETING


                                                                          FOR           AGAINST         ABSTAIN
RATIFICATION OF INDEPENDENT AUDITORS                                      [_]             [_]             [_]







IN THEIR DISCRETION, THE PROXIES ARE AUTHORIZED TO VOTE UPON SUCH OTHER BUSINESS
AS MAY PROPERLY BE PRESENTED TO THE MEETING OR ANY ADJOURNMENT OR POSTPONEMENT
THEREOF.



P                Dated: _____________, 2001


R                -------------------------------------------
                          (Signature)

O
                 -------------------------------------------
                          (Signature if held jointly)
X
                 -------------------------------------------
                 Title:
Y

                 Please sign exactly as name appears hereon.
                 When shares are held by joint tenants, both
                 should sign. When signing as attorney,
                 executor, administrator, trustee, or
                 guardian, please give full title as such.
                 If a corporation, please sign in full
                 corporate name by president or other
                 authorized officer. If a partnership,
                 please sign in partnership name by
                 authorized person. The signer hereby
                 revokes all proxies heretofore given by the
                 signer to vote at the 2001 Annual Meeting
                 of Hercules Incorporated and any
                 adjournment or postponement thereof.