This peculiar principle is a product of the leaves and seeds of tobacco, by infusing them in acidulous water, adding lime, and distilling, and then washing the product with ether, when an ethereal solution of nicotine is obtained. One drop will kill a dog. It causes the pupil of the eye to contract, has a bitterish acrimonious taste, and a pungent smell, and on the whole, is one of the nastiest things in creation. It is composed of 73'26 per cent of carbon, 9'25 percent of hydrogen, and 17'09 per cent of nitrogen. It is related to a class of bodies called vegeto-alkalies, and is capable of uniting with an acid. On the human biain it produces a soothing effect, which is thought very pleasant, but can never be considered otherwise than unhealthy.