RAJAGOPALA AYYANGAR, J.

The petitioners in this batch of revision cases are licensed tanners carrying on business in several places in the North Arcot District. Under rule 16(2) of the Turnover and Assessment Rules, these petitioners were assessed to sales tax on the total volume of their purchases. The assessments in dispute relate to the year 1951-52. The Assessing Officer as well as the Commercial Tax Officer on appeal had included in the taxable turnover, the purchases effected from "unlicensed" dealers, that is from those carrying on business outside the State. The Appellate Tribunal on appeal by these petitioners eliminated the last mentioned item in view of the decision of this Court in Hajee Abdul Shukoor v. State of Madras The petitioners, having obtained all the benefits derivable by them by virtue of the decision of this Court rendered up to that date, sought to challenge before the Appellate Tribunal the validity of the entire assessments, mainly on the ground that the provision, under which the petitioners applied for and obtained licences to deal in untanned hides and skins, was itself invalid. This attitude was adopted to obtain advantage from the decision of this Court in Noor Mohamed v. State of Madras which ruled that unlicensed dealers could not be assessed under rule 16 of the Turnover and Assessment Rules, under which alone a single point for leaving a tax on the sale of hides and skins had been fixed. This contention was negatived by the Tribunal, and in general the correctness of this contention was the only point which was urged before us in these several cases.

It would be necessary to set out some of the provisions of the Madras General Sales Tax Act and the Rules made thereunder in relation to the taxation of hides and skins and the decisions which have been rendered on the interpretation of these provisions in order to understand the arguments urged by learned counsel for the petitioners in support of his submission, that the sales tax levied upon licensed dealers is ultra vires and void.Section 3 of the Madras General Sales Tax Act, which is the charging provision of the enactment, lays a tax on every dealer on his total turnover for the year, which means that it is a multi-point tax. The question as to whether the turnover of a dealer is to be computed on the totality of his purchases or sales is to be determined by the rules, the only saving being that in respect of the same transactions of sale the buyer or the seller but not both shall be taxed. An exception is made in regard to this multi-point levy by section 5. The sales tax on hides and skins is governed by the provisions of this section, whose relevant words are :

"5. Subject to such restrictions and conditions as may be prescribed, including conditions as to licences and licence fees ........

(vi) the sale of hides and skins, whether tanned or untanned shall be liable to tax under section 3, sub-section (1), only at such single point in the series of sales by successive dealers as may be prescribed." *

"Prescribed", as usual, means "prescribed by rules made under the Act" and the rules which have been made are in two sets. The first is the Madras General Sales Tax (Turnover and Assessment) Rules, dealing with the determination of the turnover prescribing the person whose turnover is liable to be taxed and the fixation of the points at which transactions are liable to taxation in respect of commodities for which single point taxation is provided for in the Act. The second set of rules is the Madras General Sales Tax Rules, which lay down the procedure for applications for licences under the Act, the authorities which grant them, the conditions subject to which they are granted and held and the fees prescribed thereunder etc.

We shall now set out the relevant rules in regard to the taxation of hides and skins. Rule 4 of the Turnover and Assessment Rules prescribes :

"4. (1) Save as provided in sub-rule (2) the gross turnover of a deal