Mississippi Constitution Art. 7, § 182

The power to tax corporations and their property shall never be surrendered or abridged by any contract or grant to which the State or any political subdivision thereof may be a party, except that the Legislature may grant exemption from taxation in the encouragement of manufactures and other new enterprises of public utility extending for a period of not exceeding ten (10) years on each such enterprise hereafter constructed, and may grant exemptions not exceeding ten (10) years on each addition thereto or expansion thereof, and may grant exemptions not exceeding ten (10) years on future additions to or expansions of existing manufactures and other enterprises of public utility. The time of each exemption shall commence from the date of completion of the new enterprise, and from the date of completion of each addition or expansion, for which an exemption is granted. When the Legislature grants such exemptions for a period of ten (10) years or less, it shall be done by general laws, which shall distinctly enumerate the classes of manufactures and other new enterprises of public utility, entitled to such exemptions, and shall prescribe the mode and manner in which the right to such exemptions shall be determined.