At the close of the preceding session, the Council of the Society did me the honour of entrusting me with the chemical examination of several articles sent not long ago to the Society by Mr Swinton, Secretary to Government at Calcutta. The articles in question are, 1. Specimens of the black varnish used in different parts of Hindostan and the Burmese territories, with specimens of the juices of which these varnishes are said to be compounded; 2. Specimens of naphtha from Persia, and of petroleum from Rangoon; 3. Specimens of wood-oil, a variety of fluid turpentine; 4. Specimens of crude caoutchouc, and of solutions of it in wood-oil.

The only one of these articles which has hitherto yielded results of such interest as to induce me to lay them before the Society, is the petroleum of Rangoon, which appears to contain a compound inflammable principle hitherto unknown.