To the tongue of a young and rather less than half-grown cat, a drop of the oil of tobacco was applied. In fifteen seconds the ears were thrown into rapid and convulsive motions,--thirty seconds fruitless attempts to vomit. In one minute convulsive respiration; the animal fell upon the side. In four minutes and twenty seconds violent convulsions. In five minutes the breathing and the heart's motion had ceased. There was no evacuation by the mouth or otherwise. The vital powers had been too suddenly and too far reduced to admit of a reaction. The tremors, which followed death, subsided first in the superior extremities, and in five minutes ceased altogether. The muscles were perfectly flaccid. EXPERIMENT 5. In the tip of the nose of a mouse, a small puncture was made with a surgeon's needle, bedewed with the oil of tobacco. The little animal, from the insertion of this small quantity of the poison, fell into a violent agitation, and was dead in six minutes. EXPERIMENT 6. Two drops of the oil were rubbed upon the tongue of a red squirrel. This animal, so athletic as to render it difficult to secure him sufficiently long for the application, was in a moment seized with a violent agitation of the whole body and limbs, and was perfectly dead and motionless in one minute. EXPERIMENT 7. To the tongue of a dog rather under the middle size, five drops of the oil of tobacco were applied. In forty-five seconds he fell upon the side, got up, retched, and fell again. In one minute the respiration was laborious, and the pupils were dilated. In two minutes the breathing was slow and feeble, with puffing of the cheeks. In three minutes the pupils were smaller but continually varying. The left fore leg and the right hind leg were affected with a simultaneous convulsion or jerk, corresponding with the inspiratory motions of the chest. This continued for five minutes. In nine minutes alimentary evacuations; symptoms abated; and the animal attempted to walk. At ten minutes two drops of the oil were applied to the tongue. Instantly the breathing became laborious, with puffing of the cheeks; pupils much dilated. The convulsive or jerking motions of the two limbs appeared as before, recurring regularly at the interval of about two seconds, and exactly corresponding with the inspirations. In twelve minutes the pupils were more natural; slight frothing at the mouth, the animal still lying upon the side. At this time a drop of the oil was passed into each nostril. The labor of the respiration was suddenly increased, the jaws locked.