The aconite now used in medicine is derived from the _Aconitum napellus_, chiefly grown in Britain; it is also found in the mountainous districts of the temperate parts of the northern hemisphere. It grows on the Alps, the Pyrenees, the mountains of Germany and Austria, and also in Denmark and Sweden. On the Himalayas it is found at 10,000 to 16,000 feet above the sea level. Both the root and the leaves are used medicinally. The tap root of the aconite has been frequently eaten in mistake for horse-radish with fatal results. Aconite contains several active principles, all of which are powerful poisons. The chief of these is aconitine--probably the most deadly poison known--the fiftieth part of a grain of which has nearly caused death. Indian aconite, known as _Bish_, is chiefly derived from _Aconitum ferox_--a native of high altitude in the Himalaya regions--and is mentioned by the Persian physician, Alheroi, in the tenth century, also by many early Arabian writers on medicine. Isa Ben Ali pronounced it to be the most rapid of deadly poisons, and describes the symptoms with tolerable correctness. The chief symptoms of poisoning by aconite are heat, numbness and tingling in the mouth and throat, giddiness, and loss of muscular power. The pupils become dilated, the skin cold, and pulse feeble, with oppressed breathing, and dread of approaching death. Finally, numbness and paralysis come on, rapidly followed by death in a few sudden gasps. The poison being extremely rapid in effect, immediate action is absolutely necessary in order to save life.