482 ON THE PHYSIOLOGICAL ACTION OF CASCA BARK. 



the power of contracting the muscles throughout the body ; so 

 that, when the poison has fairly commenced its action, the 

 sufferer is incapable of standing or walking, and the head rolls 

 heavily about the breast and shoulders. 



Appearance of the Bark. — The pieces given to us by Mr. Mon- 

 teiro were from 8-12 inches long, about 4 inches broad, and 

 I of an inch thick, dark brownish-red in colour, and deeply 

 grooved externally. Their appearance agreed exactly with the 

 description given by C. A. Santos, in the American Journal of 

 Pharmacy, April 1849, p. 96, of the bark which he terms Saucy 

 bark, or Gidu. 



Chemical Reactions. — When treated with alcohol it yields a 

 -dark brownish-red tincture, and boiling water gives an infusion 

 of a similar colour, which deposits a pale brownish-red precipi- 

 tate on cooling ; but at the same time the supernatant fluid 

 remains turbid from suspended particles, which do not subside, 

 • and which are not removed by filtration. It becomes clear 

 when heated, but the turbidity returns on cooling. The tinc- 

 ture, when evaporated, leaves a resinous-looking extract, and 

 when mixed with water gives a pale brownish-red precipitate. 

 The watery solution of either the alcoholic or aqueous extract 

 ibecomes much darker in colour after exposure to air. 



An aqueous solution gives a brownish-black precipitate with 

 ferric perchloride, indicating the presence of some form of 

 tannin. It also gives a precipitate with tincture of galls or 

 tannic acid, mercuric chloride, stannic chloride, gold chloride, 

 silver nitrate, and lead acetate, either neutral or basic. If the 

 precipitate produced by neutral lead acetate be removed by 

 filtration, the addition of basic lead acetate to the filtrate causes 

 very little further turbidity. Platinum chloride causes little or 

 no precipitate. 



These reactions closely agree with those given by Santos and 

 Procter. 



Santos states that, by passing the dilute tincture through 

 animal charcoal, washing, drying, and boiling in absolute 

 alcohol, he obtained a crystalline substance which was poisonous ; 

 but Procter failed to obtain a poisonous substance, although he 

 got crystals which were non-poisonous. 



