They contend that the Andhra (Madras) Act does not, in fact, impose a tax oh the Explanation sales, and that, in consequence, the Validation Act can have no effect on it; that the Validation Act is itself unconstitutional and void; that the Act even if valid, does not validate section 22 of the Andhra (Madras) Act; that it validates only levies and collections of tax already made, and does not authorise the initiation 1440 of fresh proceedings for assessment of tax or for realisa tion of the same; that even if the Act authorised fresh imposition of taxes, that could not be done without further legislation pursuant thereto by the State, and that no action could be taken on the basis of section 22 of the Andhra (Madras) Act, as, being unconstitutional when enacted, it was for all purposes non est ; that tax on the sale of yarn could under the Act be levied only at a single point and the State of Madras having imposed a tax on the sale of goods now proposed to be taxed, the Andhra State could not impose a tax once again on the sale of the self same goods, and that, further, the tax on yarn would, so far as the Andhra State is concerned, be bad as being hit by the Essential Commodities Act (52 of 1952), read with article 286 (3).