AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION
                                 ON JUNE 5, 2000

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

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Check the appropriate box:
      [__] Preliminary Proxy Statement
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           14a-6 (e) (2))
      [__] Definitive Proxy Statement
      [X ] Definitive Additional Materials
      [__] Soliciting Material Under Rule 14a-12

                               DEXTER CORPORATION

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                (NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

                      INTERNATIONAL SPECIALTY PRODUCTS INC.
                              ISP INVESTMENTS INC.

- --------------------------------------------------------------------------------
    (NAME OF PERSON (S) FILING PROXY STATEMENT, IF OTHER THAN THE REGISTRANT)

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                  computed pursuant to Exchange Act Rule 0-11 (set forth the
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                  was determined):



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         4)       Proposed maximum aggregate value of transaction:



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                                                                    June 5, 2000




Fellow Dexter Shareholder:

         ISP is proposing to purchase the shares of Dexter for $45 per share in
cash. This price represents a 38% premium over Dexter's closing price of $329/16
on December 13, 1999, the last trading day before the announcement of ISP's
proposal.

         Dexter's Board implemented sometime ago a "poison pill" provision which
makes it prohibitively expensive for ISP, or anyone else for that matter, to
acquire Dexter until the "poison pill" put into place by the current Board is
removed. Because of Dexter's "poison pill," we are asking you to elect our
nominees and approve several proposals intended to facilitate our $45 per share
proposal or a superior proposal.

         You should know that Dexter's Board rejected ISP's premium proposal
last December. And yet as of today, more than five months later, the Dexter
Board has failed to present Dexter shareholders with a single concrete,
creditable alternative. Instead, Dexter has repeatedly taken actions which we
believe are adverse to the interests of Dexter shareholders as previously set
forth in our May 24th letter to you.

         You should be aware of the fact that one of these actions involves the
grant of golden parachute, retention, and severance agreements, put into place
for the most part after we surfaced with our Dexter interest, which impose very
substantial costs, in the tens and tens of millions of dollars, on any acquirer!
You should also know that the cost associated with the golden parachute for
Dexter's current Chief Executive alone amounts to almost $3 million. THESE COSTS
COME OUT OF YOUR POCKET AS A DEXTER SHAREHOLDER AND MAKE DEXTER LESS VALUABLE TO
YOU AND ANY POTENTIAL ACQUIRER.

         Ask yourself: Do you really trust this Board to protect your interests
as a shareholder?


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                      VOTE TODAY TO PROTECT YOUR INTERESTS!

         We believe Dexter's Board and management have focused on preserving
their own interests to the detriment of Dexter shareholders. Utilizing their
classified Board charter provision, they have sought to entrench themselves by
denying shareholders the right to elect a majority of the Board at this year's
Annual Meeting. If Dexter's Board continues to block ISP's proposal, the "poison
pill" put into place by the current Board will make it impossible for ISP to
purchase Dexter shares. Moreover, there is no guarantee that your shares will
continue to trade at their current level. Remember, at the time ISP's $45 per
share proposal was first announced, Dexter stock traded at $ 329/16 .

         Rejecting ISP's proposal, Dexter has chosen instead to pursue its
"short term value maximization program." And while Dexter has continued, for
some months now, to issue optimistic prognostications to Dexter shareholders
concerning its "progress" with regard to this program ("29 [interested] third
parties" (March 23rd statement); results of first stage of program "very
positive," "several indications of interest in acquiring the entire Company,"
"we expect to be in a position to make a definitive announcement in the next few
weeks or so" (April 2nd statement); and "strong continuing interest in a
transaction involving all of Dexter," "received a number of significant
indications of interest for Dexter's wholly-owned businesses," "we are
proceeding expeditiously to develop those interests and to enter into contracts
providing for those sales as promptly as possible" (May 17th statement)), it has
not a single concrete result to show for its efforts.


   *                 *                *                 *                 *


         Dexter shareholders are faced at this point in time with a very
clear-cut choice. ISP has a $45 per share cash proposal on the table, which we
believe to be a very fair and full offer, vs. the Company's claim that it is
pursuing, in addition to a sale of the entire Company, a piecemeal liquidation
of the Company which is highly speculative, fraught with difficulties,
enormously tax inefficient, hard to value, and which has to be discounted for
risk, the time value of money, and finally how the money is going to be
delivered to shareholders.

         As you may be aware, Dexter's stock price has significantly lagged the
market since Dexter's current Chief Executive took office on December 29, 1989.
A $100 investment in Dexter stock on December 29, 1989 would have been worth
$144 on March 31, 1999 (the end of the month just prior to ISP's first
disclosure that it had acquired more than 5% of Dexter's shares), an increase of
only 44%. By comparison, a similar investment at the same time in the S&P 500


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Index would have been worth $364 on March 31, 1999, an increase of 264%, while
$100 invested in the Merrill Lynch Specialty Chemicals Universe on December 29,
1989 would have been worth $306 on March 31, 1999, an increase of 206%.

         As Dexter owners, you have the right to determine who should direct the
Company's affairs. ISP, Dexter's largest shareholder, and its nominees are
committed to pursue our $45 per share proposal or a superior proposal. Remember,
neither ISP, nor anyone else for that matter, can consummate an acquisition of
Dexter shares until the "poison pill" put in place by the current Board is
removed.

         VOTE IN YOUR OWN BEST INTERESTS! SEND A MESSAGE TO DEXTER'S CURRENT
DIRECTORS, BY SUPPORTING ISP'S NOMINEES AND ITS PROPOSALS, THAT YOU HAVE LOST
PATIENCE WITH THEIR DELAYING TACTICS AND DEXTER SHOULD BE SOLD PROMPTLY TO THE
HIGHEST BIDDER.

         TO PRESERVE YOUR OPPORTUNITY TO BENEFIT FROM THE ISP PROPOSAL OR A
SUPERIOR PROPOSAL, IT IS EXTREMELY IMPORTANT TO VOTE THE GOLD PROXY CARD TODAY.

         We urge you to carefully read the enclosed proxy materials and that you
act to protect your investment by signing, dating and returning the enclosed
GOLD proxy card today. If you have any questions or need assistance voting your
shares, please call Innisfree M&A Incorporated, toll-free at (888) 750-5834.

         Thank you for your support.







         /s/ Samuel J. Heyman                 /s/ Sunil Kumar
         Samuel J. Heyman                     Sunil Kumar
         Chairman of the Board                President and Chief Executive
                                              Officer




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        If you have any questions or need assistance voting your shares,
             Please call the firm assisting us in this solicitation:

                           INNISFREE M&A INCORPORATED

                           TOLL-FREE AT 1-888-750-5834

                (BANKS AND BROKERS CALL COLLECT AT 212-750-5833)

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