Where the charter of a corporation provides for the payment by it of a state tax, and contains a proviso that “no other tax or impost shall be levied or assessed upon the said company,” the word “assessed” in the proviso cannot have the force and meaning of describing special levies for public improvements , but is used merely to describe the act of levying the tax or impost. New Jersey Midland R. Co. v. Jersey City, 42 N. J. Law, 97.