“ Undoubtedly, if there be a complete and adequate remedy at law in such a case as this, the remedy in equity will not be recognized. Assuming the tax to be void, equity will not restrain, by injunction, its collection, unless there be some other ground for equitable interposition. ”

“ The state board of equalization is one of the instrumentalities provided by the state for the purpose of raising the public revenue by way of taxation. In regard to corporations of the class of which the appellee and the other corporations involved here are members, it is the duty of that board to make an original assessment upon them. From the decision of the board in making such assessment no appeal is provided for, and each decision is therefore conclusive, except as proceedings for relief may thereafter be taken in the courts. ”

“ In all these cases, however, where there is jurisdiction to tax at all, equity will not grant an injunction to restrain the collection, even of an illegal tax, without the payment on the part of the taxpayer of the amount of a tax fairly and equitably due. ”

“ Those provisions relate to and cover all the instrumentalities by which the state acts, and so it has been held that whoever, by virtue of public position under a state government, deprives another of any right protected by that amendment against deprivation by the state, violates the constitutional inhibition ”

“ A system of valuation was adopted and applied to a large class of corporations, differing wholly from that applied to other corporations of the same class, and resulting in a discrimination against the appellee of the most serious and material nature. ”