CRUDE DRUGS. 437 



Description. — Orbicular, compressed, concavo-convex, some- 

 times irregularly bent, margin acute or rounded, 17 to 30 mm. in 

 diameter, 3 to 5 mm. thick ; externally grayish-yellow or grayish- 

 green, covered with long hairs giving the seed a satiny luster, 

 sometimes with adhering dark-brown fragments of the fruit pulp, 

 hilum near the center of one side, and a more or less distinct 

 ridge resembling a raphe extending from it to the micropyle ; very 

 hard when dry, tough when damp ; internally whitish, horny, endo- 

 sperm in two more or less regular concavo-convex halves, embryo 

 small, situated near the micropyle, and with two heart-shaped 

 cotyledons; inodorous; taste intensely and persistently bitter. 



Inner Structure. — See Figs. 122, C; 283, B ; 318. 



Constituents. — Ash i to 4 per cent. ; igasuric acid, which is 

 related to tannic acid, gives a green color with ferric salts and 

 exists in the see;ds in combination with the alkaloids; 1.5 to 5 per 

 cent, of alkaloids consisting of strychnine and brucine, the former 

 comprising from one-third to one-half of the total amount. 

 Strychnine crystallizes in rhombic prisms and gives with con- 

 centrated sulphuric acid, in connection with potassium dichromate, 

 a blue or violet color. Brucine forms rectangular octohedra and 

 gives a deep-red color with nitric acid. A glucoside, loganin, is 

 present in the seeds in small amount, but it is found in the pulp of 

 the fruit to the extent of 5 per cent. The alkaloids are probably 

 distributed in both the cell-contents and cell wall. Their presence 

 in the wall is shown by the use of iodine solution and in the con- 

 tents by the use of potassium dichromate and sulphuric acid. The 

 thick cellulose walls give the hard, horny character to these seeds 

 (Fig. 122, C), as also the date seed. A small amount of starch is 

 found in the fragments of adhering pulp. The seeds are some- 

 times made to look fresh by the use of a blue dye which is soluble 

 in dilute alcohol. 



Allied Plants. — The seeds of Strychnos Ignatii, a woody 

 climber of the Philippine Islands, contain about the same amount 

 of total alkaloids as nux vomica, of which one-third to two-thirds 

 is strychnine. The seeds are irregular, somewhat oblong or ovoid, 

 pebble-like, 20 to 30 mm. long, grayish or brownish-black, more 

 or less translucent, and are nearly free from lignified hairs, such 

 as are found in nux vomica. 



