V. RAMASWAMI, J.

In these two tax revision cases, a common point is raised though the facts are slightly different. In the first case, Thermo Electrics is the assessee. It is a sole proprietary concern. The assessee was a dealer in heating mantles and was dealing in the purchase and sale of those articles. She was also manufacturing and selling standard cells (Toshnival Brand). Under an agreement Dt. 1st July, 1970, she agreed to give the standard cells to Thermo Electricals Madras Manufacturing, hereinafter referred to as TEMM, a firm of partnership, in consideration of a 10 per cent royalty on the net sale prices marketed by TEMM. Under the agreement, TEMM was given the exclusive right to manufacture and sell the standard cells in four States, namely Madras, Andhra, Kerala and Mysore. If TEMM wants to market the goods in other States, it would have to enter into a separate agreement with the assessee. As part of the agreement, the assessee sold all the raw materials which she had as listed in Appendix A to the agreement for the prices mentioned therein. Similarly, she sold to semi-finished products and finished products listed in Appendix B for the prices mentioned in