M. Fontana likewise observes, that this poison does not act on animals of cold blood. This poison likewise hinders the coagulation of the blood from those killed by it; but if introduced into the blood by the jugular vein, it produces death; and that it does not act on the nerves, but only on the blood.

SECTION IX.

[Phil. Trans. Pantolog.

Bohan, or Bohan-upas.

JAVA appears to be possessed of various trees, the juices of which are fatally poisonous. These vegetable poisons in the language of the country are called upases. In the first section of the present chapter we have noticed the destructive power of two of these upases -the upas tienté and the upas antiar. The tree named bohan, concerning which we have hitherto received no systematic description, produces a upas, or vegetable poison, of a still more active nature. Its effects indeed have been very unnecessarily exaggerated by many writers, but they are truly marvellous in the plain unvarnished fact.

The best and most satisfactory description we have hitherto received of the bohan tree, and its extraordinary and fatal secretion, has been communicated by M. Delille, a translation of whose paper in English was read in June, 1810, before the fellows of the Royal Society. M. Delille is a French physician, a member of the National Institute of Egypt, and transmitted this paper from the East Indies to the Royal Society, by means of an English lady. The botanical account of this poisonous plant he received from one of the French naturalists who accompanied Capt. Baudin, and who resided some time in Java; where he visited the interior of the country, and with much difficulty succceded in prevailing on the natives to show him the different poison-plants, which they carefully conceal in order to use them during war. Hence the reason of so many fables as have been repeated respecting the extraordinary destructiveness and influence of the upas, which in the language of the Javanese signifies vegetable poison, and is applied only to the juice of the bohan tree, and another twisted-stemmed plant.

The bohan is a large tree, which this writer considers a new genus: the other plant yielding an equally powerful poison, is of the woodbine genus. The upas, or poisonous juice, is extracted by an incision in the bark with a knife; and carefully collected and preserved by the natives to be used in their wars. As to its diffusing noxious effluvia in the atmosphere, and destroying all vegetation around it, the absurdity of these stories is best exposed by the fact, that the climbing species require the support of other plants to attain its usual growth. Dr. Delille made several experiments with the upas on dogs and cats. An incision was made in the thigh of a dog, and eight grains of upas dropped into it: shortly after the dog began to vomit, and continued vomiting at intervals, till he became convulsed, the muscles of his head greatly distorted, and he died in twenty minutes. Six grains were put into the thigh of another dog, which also vomited first his undigested food, next a white form, and died, contracted and convulsed, in fifteen minutes. A cat was also treated in like manner; but she was still sooner and more convulsed, and her muscles contracted: she continued leaping up for a few minutes, and fell down dead. All these animals died crying and in great agony. After repeating a number of experiments on the deleterious and prompt effects of this powerful poison, when applied externally, the author gave a grain and a half to a dog, which he took into his stomach, but it only produced a slight purging. To another four grains were given, which in about four hours produced both vomiting and purging, and the dog died in the course of half a day. On examining the bodies of these animals after death, no very extraordinary appearances were discovered; the ventricles of the heart were full of blood, and some slight traces of inflammation appeared in the stomach; but the derangement was not so great as might have been expected from such a violent and sudden death. From this circumstance, the author concluded that the absorbents had transmitted the poison to the nerves of the stomach, and that this peculiar vegetable poison acts exclusively on the nerves.

Messrs. Majendie and Delille have communicated to the class their experiments made on animals by means of the matter with which the natives of the isles of Java and of Borneo poison their

arrows.

M. Vauquelin has also made some experiments of this kind: at the end of his chemical analysis of the juice of the belladonna, he speaks of the effects of this substance on animals. Those which he forced to swallow it, fell down as if intoxicated, in a delirium precisely similar to that produced by opium.

M. Sage has reported on the same subject some more experiments, which chance threw in his way, or which he collected from others, and which confirm the action of this juice on the nervous system, and particularly on the brain.

A young practitioner in medicine, whose name has been mentioned in former annual reports, M. Nysten, has attempted to ascertain the effects of different gases injected into the blood-vessels of animals: he used the greater part of the gases with which we are acquainted. Atmospheric air, oxygen gas, the oxidulated azotic, carbonic acid; carbonic, phosphuretted and hydrogenated gases, &c. are in no respect deleterious. The oxy-muriatic, nitrous acid, and ammoniacal gases, seem to act by very violently irritating the right auricle and the pulmonary ventricle. The sulphuretted bydrogen, oxide of azote, and azotic gases, injure the contractile power of these parts others also change the nature of the blood so completely, that respiration can no longer convert it from venous blood into arterial, &c.

[Mem. de St. Instit. Nat. 1809.