from contract works for the purpose of assessment of r958 sales tax, to which the appellants replied by instituting Pandit Banarsi the proceedings, out of w ich h the present appeals arise. Das The appellant in Civil Appeal No. 253 of 1955 is a v. contractor doing business in the construction of build- The state of ings and roads for the Military and Public Works Madhya Pradesh Department in the State of Madhya Pradesh, and he filed M. P. No. 245of1954 challenging the validity of Ve;:;:~•7a the assessment which the respondents ,proposed to make, on two grounds: He contended ~,rstly, that the Provincial Legislature had authority under Entry 48, of List II, Sch. VII of the Government of India Act, 1935, to impose tax only on sale of goods, that th'.e' supply of materials in works contracts was not a sale within that Entry, and that the provisions of the Act, which sought to impose a tax thereon treating it as a sale, ·were therefore ultra vires; and secondly that he was entitled to exemption under item 33 in Sch. II to the Act as enacted by Act XVI of 1949, and that the notification of the Government dated September 18, 1950, withdrawing that exemption was unconstitutional and void. To appreciate this contention, it is necessary to refer to s. 6 of the Act, which is as follows:
