The tree[456] which produces these seeds grows in Ceylon, upon the coast of Coromandel, and in Malabar. The nux vomica is round and flat, about an inch broad, and nearly a quarter of an inch thick, with a prominence in the middle on both sides, of a grey colour, covered with a kind of woolly matter, but internally hard and tough. The kernel discovers to the taste a considerable bitterness, but makes little or no impression on the organs of smell. There is a popular belief that this substance is poisonous to all animals, except man. Instances, however, are not wanting to illustrate its deleterious effects upon the human species. It proves fatal to dogs in a very short period; it has also poisoned hares, foxes, wolves, cats, rabbits, and even some birds. _Loureiro_ relates that a horse died in four hours after taking a drachm of the seed in an half roasted state. Its effects, however, on different animals, and even on those of the same species, are somewhat uncertain, and not always in the proportion to the quantity given. With some animals it produces its effects almost instantaneously: with others, not until after the lapse of several hours, when laborious respiration, followed by torpor, tremblings, coma, and convulsions usually precede the fatal spasms, or _Tetanus_, which so especially distinguishes the operation of this poison. _Hoffman_ reports the case of a young girl of ten years of age, who, labouring under an obstinate quartan fever, took, at two doses, fifteen grains of nux vomica, and died very shortly afterwards. _MM. Pelletier_ and _Caventou_ have discovered in these seeds, a peculiar proximate principle, to which their virulence is owing; it was originally named _Vauqueline_, in honour of the celebrated French philosopher, but in deference to the opinion of the French Academy of Sciences, the discoverers have substituted the name _Strychnia_,[457] because “a name dearly loved, ought not to be applied to a noxious principle!” _Strychnia_ is highly alkaline, and crystallizes in very small four-sided prisms, terminated by four-sided pyramids; its taste is insupportably bitter, leaving a slight metallic flavour, and is so powerful as even to be perceptible when a grain is dissolved in eighty pounds of water;[458] it has no smell. So extreme is its activity upon the animal system, that in doses of half a grain it occasions serious effects, and in larger ones, convulsions and death. It is, perhaps, the most powerful, and, next to _hydro-cyanic acid_, the most rapid of poisons. _M. Majendie_ has killed a dog with one-eighth of a grain; and the editor of the _Edinburgh Medical and Surgical Journal_ has seen one die in two minutes after the injection of one-sixth of a grain into the cavity of the pleura.