M. RAMA JOIS, J. - In these writ petitions presented by Mangalore Metal House, Mangalore. the following question of law arises for consideration :

"Whether section 5(4) read with item 2 of the IV Schedule read with explanation-II thereto of the Karnataka Sales Tax Act ('the Act' for short) is violative of article 304(a) of the Constitution of India ?"

2. The question is raised on the basis of the following facts and circumstances. The petitioner is a registered dealer under the Act. He is dealer various items of iron and steel. In particular he is a dealer in M.S. rounds. The petitioner purchases M.S. rounds locally as well as in the course of inter-State trade and commerce. In respect of sale turnover of M.S. rounds, the provision, levying tax applicable, in view of explanation incorporated at the Fourth Schedule, is to the following effect :

(i) For the period from 1st October, 1957, to 31st March, 1978, though the tax on the first sale turnover of M.S. rounds is four per cent., if such M.S. rounds had been manufactured out of the scrap iron, on the sale or purchase of which tax had been paid to this State, no tax is payable.

(ii) For the period on and after 1st April, 1978