Effective duty rate for bath oils limits excise liability to a specified ad valorem calculation reducing taxable excess. The notification, issued under sub rule (1) of rule 8 of the Central Excise Rules, 1944, exempts bath oils (thailams) under sub heading 3307.00 from so much of the excise duty leviable thereon as exceeds the amount calculated at a specified ad valorem rate, leaving only the duty equal to that ad valorem calculation chargeable.