EXHIBIT 8
 
                            [FORM OF TAX OPINION OF
               SKADDEN, ARPS, SLATE, MEAGHER & FLOM (ILLINOIS)]
 
                                                                         , 1996
 
Board of Directors
First Mississippi Corporation
700 North Street
Jackson, Mississippi 39215-1249
  Re: Distribution of [First Chemco, Inc.] and Merger of a wholly-owned
     subsidiary of Mississippi Chemical Corporation with and into First
     Mississippi Corporation
 
Gentlemen:
 
  We have acted as Special Counsel to First Mississippi Corporation, a
Mississippi corporation ("First Mississippi"), in connection with the
following contemplated transactions: (i) the complete liquidation of FirstMiss
Fertilizer, Inc. ("FirstMiss Fertilizer"), a Mississippi corporation and a
wholly-owned subsidiary of First Mississippi, through a statutory merger of
FirstMiss Fertilizer with and into First Mississippi (the "Liquidation"); (ii)
the transfer, assignment and conveyance of various assets by First Mississippi
to [First ChemCo, Inc.] ("New First Mississippi"), a Mississippi corporation
and a wholly-owned subsidiary of First Mississippi (the "Transfers"), pursuant
to Article IV of the Agreement and Plan of Distribution between First
Mississippi and New First Mississippi, dated as of           , 1996 (the
"Distribution Agreement"); (iii) the distribution of all the outstanding
shares of stock of New First Mississippi to the holders of shares of stock of
First Mississippi on a pro rata basis pursuant to the Distribution Agreement
(the "Distribution") and (iv) the merger (the "Merger") of MISS SUB, INC.
("Miss Sub"), a Mississippi corporation and a wholly-owned subsidiary of
Mississippi Chemical Corporation, a Mississippi corporation ("Mississippi
Chemical"), with and into First Mississippi pursuant to that certain Agreement
and Plan of Merger and Reorganization among Mississippi Chemical, Miss Sub and
First Mississippi, dated August 27, 1996 (the "Merger Agreement").
 
  All capitalized terms used herein, unless otherwise specified, have the
meanings assigned to them in the Proxy Statement/Prospectus, including Annex E
thereto, prepared in connection with the transactions contemplated by the
Merger Agreement and the Distribution Agreement (the "Proxy
Statement/Prospectus").
 
  In rendering our opinion, we have examined originals or copies, certified or
otherwise identified to our satisfaction, of the Merger Agreement, the
Distribution Agreement and the Proxy Statement/Prospectus and have relied upon
the accuracy and completeness of the statements, representations and covenants
contained therein. In addition, we have relied upon certain representations
made by officers and employees of First Mississippi, New First Mississippi and
Mississippi Chemical, including those contained in the certificates of certain
officers of First Mississippi, New First Mississippi and Mississippi Chemical
dated as of           , 1996. Where such representations are made to the best
knowledge and belief of the person making such representations, we have
assumed the facts to be as so represented. Our opinion is conditioned on the
initial and continuing accuracy of the statements, representations and
covenants referred to above and we have not independently verified the
accuracy or completeness of such statements, representations and covenants.
 
  In our examination of the documents referred to above and other documents we
have deemed necessary or appropriate to review as a basis for our opinion, we
have assumed the legal capacity of natural persons, the genuineness of all
signatures, the authenticity of all documents submitted to us as originals,
the conformity to original documents of all documents submitted to us as
certified or photostatic copies and the authenticity of the originals of such
latter documents. We have also assumed that the Liquidation, Transfers, Spin-
off and Merger will be consummated in accordance with the Merger Agreement,
the Distribution Agreement and as described in the Proxy Statement/Prospectus.
 
 
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  In rendering our opinion, we have considered the applicable provisions of
the Internal Revenue Code of 1986, as amended (the "Code"), Treasury
Regulations promulgated thereunder, pertinent judicial authorities,
interpretive rulings of the Internal Revenue Service and such other
authorities as we have considered relevant. It should be noted that statutes,
regulations, judicial decisions and administrative interpretations are subject
to change at any time and, in some circumstances, with retroactive effect. A
material change in the authorities upon which our opinion is based could
affect our conclusion.
 
  Based upon and subject to the foregoing, we are of the opinion that under
current law for U.S. Federal income tax purposes, (i) the Liquidation and
Transfers will qualify as one or more tax-free transactions under Sections
332, 351 or 368(a)(1)(D) of the Code, (ii) the Spin-off will qualify as a tax-
free distribution under Section 355 of the Code, and (iii) the Merger will
qualify as a tax-free reorganization within the meaning of Section 368(a) of
the Code.
 
  Accordingly, based upon the foregoing opinions:
 
    1. A First Mississippi shareholder will not recognize any income, gain or
  loss as a result of the Distribution (except in connection with cash
  received in lieu of fractional share interests in New First Mississippi
  Common Stock). A First Mississippi shareholder who receives cash in lieu of
  fractional shares of New First Mississippi Common Stock will be treated as
  if such fractional shares had been received by the shareholder as part of
  the Distribution and then sold by such shareholder. Accordingly, such
  shareholder will recognize gain or loss equal to the difference between the
  cash so received and the portion of the tax basis in the New First
  Mississippi Common Stock that is allocable to such fractional shares. Such
  gain or loss will be capital gain or loss, provided that such fractional
  shares would have been held by such shareholder as a capital asset at the
  time of the Distribution.
 
    2. Following the Distribution, a First Mississippi shareholder will
  apportion his or her tax basis for his or her shares of First Mississippi
  Common Stock prior to the Distribution between such First Mississippi
  Common Stock and the New First Mississippi Common Stock received (or in the
  case of fractional shares, deemed received) in the Distribution in
  proportion to the relative fair market values of such First Mississippi
  Common Stock and New First Mississippi Common Stock on the Distribution
  Date.
 
    3. A First Mississippi shareholder's holding period for the New First
  Mississippi Common Stock received in the Distribution will include the
  period during which such shareholder held his or her First Mississippi
  Common Stock with respect to which the New First Mississippi Common Stock
  was received, provided that First Mississippi Common Stock is held as a
  capital asset by such shareholder at the time of the Distribution.
 
    4. No gain or loss will be recognized by First Mississippi as a result of
  the Transfers or the Distribution (other than income, if any, recognized by
  First Mississippi or its subsidiaries in connection with excess loss
  accounts under Treasury Regulation (S) 1.1502-19).
 
    5. No gain or loss will be recognized by First Mississippi shareholders
  whose shares of First Mississippi Common Stock are exchanged solely for
  Mississippi Chemical Common Stock pursuant to the Merger (except in
  connection with cash received in lieu of fractional share interests in
  Mississippi Chemical Common Stock). A First Mississippi shareholder who
  receives cash in lieu of fractional shares of Mississippi Chemical Common
  Stock will be treated as if such fractional shares had been received by the
  shareholder as part of the Merger and then sold by such shareholder.
  Accordingly, such shareholder will recognize gain or loss equal to the
  difference between the cash so received and the portion of the tax basis in
  First Mississippi Common Stock (as determined immediately following the
  Distribution) that is allocable to such fractional shares. Such gain or
  loss will be capital gain or loss, provided that such fractional shares
  would have been held by such shareholder as a capital asset at the
  Effective Time.
 
    6. The aggregate tax basis of the Mississippi Chemical Common Stock
  received (or, in the case of fractional shares, deemed received) by First
  Mississippi shareholders who exchange their First Mississippi Common Stock
  solely for Mississippi Chemical Common Stock in the Merger will be the same
  as the aggregate tax basis of the First Mississippi Common Stock (as
  determined immediately following the Distribution) surrendered in exchange
  therefor.
 
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    7. The holding period for the shares of Mississippi Chemical Common Stock
  received in the Merger will include the period during which the shares of
  the First Mississippi Common Stock surrendered in exchange therefor were
  held, provided that such shares of First Mississippi Common Stock were held
  as capital assets at the Effective Time.
 
    8. No gain or loss will be recognized by First Mississippi, Miss Sub or
  Mississippi Chemical as a result of the Merger (other than income, if any,
  recognized by First Mississippi or its subsidiaries in connection with
  excess loss accounts under Treasury Regulation (S) 1.1502-19).
 
  Except as set forth above, we express no opinion as to the tax consequences,
whether Federal, state, local or foreign, of the Liquidation, Transfers,
Distribution and Merger or of any transactions related thereto. This opinion
is solely for your benefit and is not to be used, circulated, quoted or
otherwise referred to for any purpose without our written permission. We
hereby consent to the filing of this opinion as an exhibit to the Proxy
Statement/Prospectus and to the use of our name in the Proxy
Statement/Prospectus under the heading "Certain Federal Income Tax
Consequences." In giving such consent, we do not thereby admit that we are in
the category of persons whose consent is required under Section 7 of the
Securities Act of 1933 or the rules and regulations promulgated thereunder.
 
                                          Very truly yours,
 
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