The State is the appellant. The appeals are against the judgment of Veeraswami, J., by which he directed writs of mandamus to issue against the Commercial Tax Officer and the Deputy Commissioner for Commercial Taxes in the following circumstances. The two petitioners before the learned Judge, the respondents here, are manufacturers of vanaspati. The writ petitioner, the Mettur Chemical and Industrial Corporation, also manufactures soap. For the manufacture of either article groundnut oil is essential. In the case of certain commodities, sales of which are taxable under the Madras General Sales Tax Act at a single point, the Act provides that where any one of such articles is used as a component part in the manufacture of any other article liable to single point levy of tax, the sale of the first mentioned article shall be taxed at the concessional rate of 1 per cent only, instead of the rate specified in the First Schedule to the Act, which lists out articles liable to single point levy. Section 3 (3) of the Act, which provides for the lower rate of tax indicated, contains a proviso which is in these terms:

" Provided that the provisions of this sub-section shall not