These circumstances made me desirous to try an experiment with some animals, in order to be convinced of the real effects of this poison; and as I had then two young puppies, I thought them the fittest objects for my purpose.  I accordingly procured with great difficulty some grains of Upas.  I dissolved half a grain of that gum in a small quantity of arrack, and dipped a lancet into it.  With this poisoned instrument I made an incision in the lower muscular part of the belly in one of the puppies.  Three minutes after it received the wound the animal began to cry out most piteously, and ran as fast as possible from one corner of the room to the other.  So it continued during six minutes, when all its strength being exhausted, it fell upon the ground, was taken with convulsions, and died in the eleventh minute.  I repeated this experiment with two other puppies, with a cat, and a fowl, and found the operation of the poison in all of them the same:  none of these animals survived above thirteen minutes.

I thought it necessary to try also the effect of the poison given inwardly, which I did in the following manner.  I dissolved a quarter of a grain of the gum in half an ounce of arrack, and made a dog of seven months old drink it.  In seven minutes a retching ensued, and I observed, at the same time, that the animal was delirious, as it ran up and down the room, fell on the ground, and tumbled about; then it rose again, cried out very loud, and in about half an hour after was seized with convulsions, and died.  I opened the body, and found the stomach very much inflamed, as the intestines were in some parts, but not so much as the stomach.  There was a small quantity of coagulated blood in the stomach; but I could discover no orifice from which it could have issued; and therefore supposed it to have been squeezed out of the lungs, by the animal’s straining while it was vomiting.

From these experiments I have been convinced that the gum of the Upas is the most dangerous and most violent of all vegetable poisons; and I am apt to believe that it greatly contributes to the unhealthiness of that island.  Nor is this the only evil attending it:  hundreds of the natives of Java, as well as Europeans, are yearly destroyed and treacherously murdered by that poison, either internally or externally.  Every man of quality or fashion has his dagger or other arms poisoned with it; and in times of war the Malayans poison the springs and other waters with it; by this treacherous practice the Dutch suffered greatly during the last war, as it occasioned the loss of half their army.  For this reason, they have ever since kept fish in the springs of which they drink the water; and sentinels are placed near them, who inspect the waters every hour, to see whether the fish are alive.  If they march with an army or body of troops into an enemy’s country, they always carry live fish with them, which they throw into the water some hours before they venture to drink it; by which means they have been able to prevent their total destruction.