Tariff amendment adds pyrophillite blocks to customs table, specifying an ad valorem duty notation under the notification. The Central Government, under section 25(1) of the Customs Act, 1962, amends Notification No. 77/90-Customs by inserting a new Table entry under Chapter 69 for pyrophillite blocks with an ad valorem notation of forty percent, as effected by Notification No. 46/94-Cus dated 1-3-1994.