Effective excise duty rate on coffee reduced to fixed per quintal level, limiting levy to that prescribed amount. Notification prescribes a fixed effective basic excise duty of Rs. 50 per quintal on coffee under sub headings 0901.11 and 0901.19 and, invoking the Central Excises and Salt Act, exempts from duty those amounts in excess of the duty calculated at that prescribed per quintal rate, applying the cap to all goods under the specified sub headings.