Concent. sulphuric acid, followed by bichromate of potash, gives with brucia a red-brown colour passing to green and yellow (Guy).
Whenever strychnia is found, brucia should also be looked for.
IGASURIA, a supposed third alkaloid of the Strychnos tribe, has been shown by Shenstone to be a mixture of strychnia and brucia (Chem. Soc. Journal, Sept. 1881, p. 457).
_Strychnic or Igasuric Acid_, obtained by Pelletier and Caventun from Nux Vomica and from St. Ignatius’ Bean, is probably identical with malic acid.
_Medicinal dose_ of strychnia 1/30 to 1/12 grain. _Fatal dose_: smallest recorded ½ grain (Dr. Warner, “Poisoning by Strychnia,” p. 138), ¼ grain (Guy; also case of Agnes Sennett, p. 121, _ante_), but a child of two or three years was killed by 1/16 grain (Christison): average for adults, ½ to 2 grains (Taylor).
_Recovery_ has taken place after 3 grains (Taylor), 4 grains (Lancet, 1863, i. 54), 3 to 7 grains (Husemann), 7 grains (Med. Gaz., xli., 305), “20 grains or more” (? Guy and Ferrier’s Forens. Med., 1881, p. 574), 40 grains (Med. Times and Gaz., 1865, p. 267). If these statements are correct, they must be accounted for either by vomiting, early and vigorous treatment, or impurity of the alkaloid.
Poisonous symptoms have sometimes occurred in adults, and frequently in children, from medicinal doses.
_Fatal close of nux vomica_: of the powder, 30 grains is the smallest (= ⅓ grain strychnia), (Hoffmann, Med. Rat. System, 2, 175), of the alcoholic extract, 3 grains (Christison on Poisons, p. 642).
_Brucia_ is not used in medicine. _Fatal dose_ rather uncertain, probably three to ten grains.
FATAL PERIOD FOR STRYCHNIA:—Shortest, five minutes (Dr. Gray on Strychnia, 1872, p. 55); longest, six hours after three grains (Taylor, Guy’s Hosp. Reports, Oct., 1857, p. 483); average, two hours. _For nux vomica_:—Shortest, fifteen minutes; longest, three hours or more (Guy); average, two hours (Taylor), one hour (Guy).
_Symptoms commence_ at various intervals after taking, according to dose, form, and constitution. The beginning may be (1) almost immediate (Mad. Merghelynk, 1870, Taylor’s Med. Juris., p. 408), (2) in five minutes (case of Dr. Warner, also Dr. Gray on Strychnia, 1872, p. 55), (3) in fifteen minutes (trial of Dove, p. 242), (4) about an hour (Palmer’s trial, p. 102), (5) forty minutes (Lond. Med. Repository, xix., 448), up to two and a half hours (Wormley, Microchemistry of Poisons, p. 538). Hence no conclusion can safely be drawn from this feature (see Dr. Letheby’s evidence in the Palmer trial, p. 166). Probably Dr. Todd’s statement in the same trial is the most correct average:—“Symptoms in ten minutes, if in solution and a large dose; otherwise in a half to one hour.”