SATYANARAYANA RAO, J.

The assessees are licensed tanners and they were taxed on a purchase turnover of Rs. 9, 83, 438-13-3 under rule 16 of the Madras General Sales Tax (Turnover and Assessment) Rules. The contention before the Appellate Tribunal was that after tanning the skins, such tanned skins were exported outside the Indian Union and, therefore, they were entitled to exemption under Article 286 of the Constitution. This contention was rightly rejected by the Appellate Tribunal, and it is not now persisted in. But the short point, that has been raised by the learned counsel for the assessees, is that under rule 16 a tanner may be taxed on the purchase price only if his purchase was from a licensed dealer of untanned hides and shins, and if his purchase was only for the purpose of tanning by him. Until these two conditions were satisfied, the levy of the tax by the department could not be justified. As regards the second of the two conditions, it is stated that the language of the rule "sold to the tanner" and the language of the return Form A-4 prescribed by the rules in which the assessee is required to state the amount for which hides and skins were purchased for