Kaolin occurs abundantly in the Federated Malay States in connexion with granite, and is certainly formed on a large scale by weathering. The purest kaolin in large quantity, however, is found as veins in clay above limestone at Gopeng and elsewhere in Kinta, and in quartzite and shales near Tanjong Malim and Kerling. The purity of these veins and the information obtained about those in Kinta when traced down to limestone, lead to interesting considerations about their origin, and the nature of the material in the limestone is a matter of importance in connexion with the possibility of establishing a kaolin industry.