Page:Popular Science Monthly Volume 50.djvu/706

686 Isonandra gutta, of the order Sapotaceœ, which formerly abounded at Singapore and in all Malaysia, but which now tends to disappear under the ravages committed by gatherers. Gutta, in Malay, signifies gum or lime; percha signifies scrap. Incisions are made in the bark, as on rubber trees, and the liquor flows of perfect whiteness, darkening at contact of air. Coagulation takes place spontaneously in a short time. Like rubber, the liquid forms a film on top. This cream is removed, kneaded into a large lump and plumped into boiling water. Under the action of a high temperature it softens and forms the cake usually found in commerce. Other trees in Malaysia and Farther India, in Cambodia and Cochin China, produce good gutta. In Hindustan different grades are mixed by the natives. Chinese merchants, in their depots, mix and manipulate to give a good superficial appearance to the product, as the price is constantly advancing. As the gatherers also do not scruple to add vegetable débris, earth, or sand, it has become difficult to secure a pure article. An inferior quality is obtained from trees and climbers in Africa and Madagascar, and, with the development of those countries, more may be expected. For the present, the same ravaging system of gathering seems bound to prevail in these countries as that which the now indispensable gutta-percha and India-rubber growths are suffering in other countries. The valuable discovery of enormous supplies of gutta trees in the vast forests of Guiana was made about 1860. As might be expected, the rich flora of Brazil furnishes many varieties of the tree; one of which, the Mimusops elata, exudes a white liquid of an agreeable flavor, which is often used with tea or coffee. Other countries to be mentioned are Venezuela, Costa Rica, and Australia. (For the botany of India rubber and gutta-percha, the reader is referred to E. Chapel's comprehensive work, Le Caoutchouc et la Gutta-Percha.) Some growths produce caoutchouc gutteux, a substance of inferior quality, having the character of gutta-percha and India rubber.

The largest quantities of gutta-percha come from the Sunda Islands, Cochin China, Cambodia, and Hindustan. At first it was exported exclusively from Singapore, but now some shipments are made direct from the above-mentioned regions, from the island of Celebes and the Philippines; some going to the United States and the ports of Amsterdam and Rotterdam, but the greatest portion to England.

The different varieties in European markets are designated after their place of origin, the best being the Macassar, Java, Sumatra, Borneo, etc. The gutta-percha of the Orient is of various colors. The best grades are white or grayish, slightly rose-tinted, and generally contain very little foreign substance;