The author commenced by referring to the first part of his paper, in which he had determined the existence, among the products of destructive distillation of animal substances, of picoline, which he had before obtained from coal-tar, and of a new base to which he had given the name of Petinine; and had also indicated the existence of certain other bases. On proceeding to the further investigation of these substances, he had been much impeded by deficiency in materials, and had, at length, been compelled to operate on no less than 250 gallons, or about a ton of bone oil.