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.
DOSES.
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.