( 1 ) THESE Tax Revision Cases were referred to a Full Bench by a Division Bench consisting of two of us (Basi Reddy and Mohamed Mirza, JJ.) because it was contended with some plausibility that the ruling of a Division Bench of this Court composed of Chandra Reddy, C. J. and Krishna Rao, J. in Berar Oil Industries v. Deputy Commissioner of Commercial Taxes, (1959) 10 STC 199 (AP), negativing the challenge based upon Article 14 of the Constitution as to the validity of a Government notification dated 9/11/1951, --amending Rule 5 (1) (k) of the Madras General Sales Tax (Turnover and Assessment) Rules, by the addition of the words "other than refined groundnut oil" and adding Sub-rule (5) to Rule 18 of the said Rules, the effect of which was the withdrawal of the benefit of the deduction of the purchase price of groundnut or kernel which went into the manufacture of refined oil, from the sale turnover of such oil, required reconsideration, in the light of certain observations of the Supreme Court in Tungabhadra Industries Ltd v. Commercial Tax Officer (1960) 11 STC 827; (AIR 1961 SC 412 ). Before dealing with this point and some other points which were urged before us,