On account of the difficulty of preparing the alcoholic extract of nu-r-roniiea of uniform strength, strychnia, or some of its soluble salts, is now generally substituted for it, as these admit of easy subdivision of the dose. Sulphate of strychnia has been used in some eases with great advantage (See Gaskoin, in Med. Gaz.,' vol. x., p. 316) ; so also the acetate; but a form of preparation which has proved of service in some long-standing and almost hopeless cases of paralysis, is the hydrio date of strychnia. (Sec Magcndie,' Formulaire.') Phosphate is also used ; and in Germany nitrate is much used.
Care must be taken that the strychnia be pure, as a spurious article is vended In France, which contains no trace of atrychnia. Bichloride of mercury is a good test for strychnia, but it causes no precipitate from the solution of the. acetate of strychnia; but the addition of hydrochloric acid causes a white crystalline precipitate. Sulpho cyanodide of potassium appears to be the best test for strychnia. (See ' British Annals of Medicine,' vol. i., p. 190.) Strychnia is prepared either from the iimr-romica seeds, in which case it is difficult and expensive to separate it from the brucia, or it is obtained from the St. Ignatius bean, in which it exists in about three times larger quantity than in nux-rontica. It is also, but rarely, pro cured from the Strychnos Colubrina. The purest and most easily obtained is furnished by the Slrychnos Ticute, but the rarity of this substance is a practical obstacle to its employment. Igasurina will probably be found to act like the others, but more mildly. • Snake-wood.—Many substances, in countries infested with serpents, are reputed to be efficacious in counteracting the poisonous bites of these reptiles : one of the most celebrated of these is the root of the Strychnos Cotabrina. The strychnia probably acts as an antagonist to
the stupifying effects of the poison of the snake, just as arsenic does to the poison of the Colaber carinatus of the West Indies. [At:BEN:el Strdstospotatorum, called also 8. Tatan Cottay, or Clearing-nut, is a native of India,and is a larger tree than any other species. It is devoid of noxious properties. The fruit, though when very young it is made into a preserve, and eaten, is reckoned emetic by the native doctors. The chief use made of it is to rub the seeds hard round the inside of an earthen pot, into which water is poured, and in a short time it becomes clear, tasteless, and wholesome, however muddy, brackish, or putrid it may have been : hence Its name of clearing-nut. Officers and soldiers, before setting off on a march, p--wide themselves with a et= of these, as water purified by such means is deemed more whole some than that clarified by alum.
Strychnos pseudo-china, Quina do Campo, or Field China, is a native of Brazil (St. Hilaire, Plantes Usuellea do t. I), and is devoid of atrychnia or brucia. It is a remedy of the Sertaneias, being pecu• liarly fitted for those cases to which the true cinchonas are unsuitable. The taste is at first faintly aromatic, then astringent, and at last slightly bitter. It has no odour. In its properties it resembles quassia, inenyantlies, or gentian more than the true cinchonas, with none of which, except the humalia bark, could it readily be confounded in its physical characters. Mr. Burchell says, however, that even in the proper localities of the cinchonas many etrychni are collected. LCINCIIONA, in NAT. HIST. Div., col. 10S1.1