EXHIBIT (A)(6)
 
                     [LETTERHEAD OF GOLDMAN, SACHS & CO.]
 
PERSONAL AND CONFIDENTIAL
 
October 9, 1997
 
Board of Directors
Melamine Chemicals, Inc.
39041 Highway 18 West
Donaldsonville, LA 70346
 
Gentlemen:
 
  You have requested our opinion as to the fairness from a financial point of
view to the holders of the outstanding shares of Common Stock, par value $.01
per share (the "Shares"), of Melamine Chemicals, Inc. (the "Company") of the
$20.50 per Share in cash proposed to be paid by MC Merger Corp. ("Merger
Sub"), a wholly-owned subsidiary of Borden Chemical, Inc. ("Buyer"), in the
Tender Offer and Merger (as defined below) pursuant to the Agreement and Plan
of Merger dated as of October 9, 1997 among Buyer, Merger Sub and the Company
(the "Agreement"). The Agreement provides for a tender offer for all of the
Shares (the "Tender Offer") pursuant to which Merger Sub will pay $20.50 per
Share in cash for each Share accepted. The Agreement further provides that
following completion of the Tender Offer, Merger Sub will be merged into the
Company (the "Merger") and each outstanding Share (other than Treasury Shares,
Parent Shares and Dissenting Shares (each as defined in the Agreement)) will
be converted into the right to receive $20.50 in cash.
 
  Goldman, Sachs & Co., as part of its investment banking business, is
continually engaged in the valuation of businesses and their securities in
connection with mergers and acquisitions, negotiated underwritings,
competitive biddings, secondary distributions of listed and unlisted
securities, private placements and valuations for estate, corporate and other
purposes. We are familiar with the Company, having acted as its financial
advisor in connection with, and having participated in certain of the
negotiations leading to, the Agreement. We also have provided certain
investment banking services to Borden Inc., parent of Buyer, from time to
time, including having acted as the sole underwriter in sales of common stock
of RJR Nabisco Holdings Corporation sold by Borden Inc. in February and March
of 1995, and may provide investment banking services to Buyer or Borden Inc.
in the future. In addition, we have provided in the past, and may provide in
the future, various investment banking services to Kohlberg Kravis Roberts &
Co., an affiliate of the principal shareholder of Borden Inc.
 
  In connection with this opinion, we have reviewed, among other things, the
Agreement; the Tender Agreement dated as of October 9, 1997 among Buyer,
Merger Sub and ChemFirst, Inc.; Annual Reports to Stockholders and Annual
Reports on From 10-K of the Company for the five fiscal years ended June 30,
1997; certain interim reports to stockholders and Quarterly Reports on Form
10-Q of the Company; certain other communications from the Company to its
stockholders; and certain internal financial analyses, replacement cost
estimates and forecasts for the Company prepared by its management. We also
have held discussions with members of the senior management of the Company
regarding its past and current business operations, financial condition and
future prospects. In addition, we have reviewed the reported price and trading
activity for the Shares, compared certain financial and stock market
information for the Company with similar information for certain other
companies the securities of which are publicly traded, reviewed the financial
terms of certain recent business combinations in the commodity chemicals
industry specifically and performed such other studies and analyses as we
considered appropriate.

 
  We have relied upon the accuracy and completeness of all of the financial
and other information reviewed by us and have assumed such accuracy and
completeness for purposes of rendering this opinion. In addition, we have not
made an independent evaluation or appraisal of the assets and liabilities of
the Company or any of its subsidiaries and we have not been furnished with any
such evaluation or appraisal. Our advisory services and the opinion expressed
herein are provided for the information and assistance of the Board of
Directors of the Company in connection with its consideration of the
transaction contemplated by the Agreement and such opinion does not constitute
a recommendation as to whether or not any holder of Shares should tender such
Shares in connection with such transaction.
 
  Based upon and subject to the foregoing and based upon such other matters as
we consider relevant, it is our opinion that as of the date hereof the $20.50
per Share in cash to be received by the holders of Shares in the Tender Offer
and the Merger is fair from a financial point of view to such holders.
 
Very truly yours,
 
/s/ GOLDMAN, SACHS & CO.
- -----------------------
(GOLDMAN, SACHS & CO.)