JUDGMENT

FATHIMA BEEVI, J.:—These appeals by the Revenue under S. 35L of the Central Excises and Salt Act, 1944 involve the interpretation of the Notification No. 179 / 77 CE dated 18-6-1977. The Notification read thus:-

"In exercise of the powers conferred by subrule (1) of Rule 8 of the Central Excise Rules, 1944, the Central Government hereby exempts all goods falling under Item 68 of the First Schedule to the Central Excises and Salt Act, 1944 (1 of 1944) in or in relation to the manufacture of which no process is ordinarily carried on with the aid of power, from whole of the duty of excise leviable thereon."

2. Tariff Item 68 during the relevant period read

All other goods, not elsewhere specified, manufactured in a factory but excluding......

3. M/s. Rajasthan State Chemical Works, the respondents in Civil Appeals Nos. 3593-94 of 1989, are manufacturers of crude sodium sulphate. In the process of manufacture of common salt from brine, in the salt pans in which the process of evaporation takes place some quantities of sodium sulphate present in the brine also crystallise and settle at the bottom as crust. The sodium sulphate is thus obtained as a bye-product. For the purpose of th