NUX VOMIGA 171 



Description. The seeds have the shape of small discs, 20 to 25 mm. 

 in diameter and about 4 mm. thick, of an ash-grey or greenish grey 

 colour, and possessing a distinct sheen. They are usually not quite 

 flat, being a little depressed on one side and arched on the other, or 

 sometimes irregularly bent. They are covered with numerous, closely 

 appressed hairs, radiating from the centre to the circumference, to 

 which the satiny sheen of the seeds is due. The edge of the seed is 

 sometimes rounded, sometimes acute, according to the variety ; at 

 one point on the margin there is a distinct prominence (micropyle) 

 from which a raised line passes to the centre of the seed. This line 

 does not exist in the fresh seed, but makes its appearance during the 

 drying ; it has frequently been mistaken for the raphe. The hilum 

 is in the centre of either the raised or depressed surface, and may be 

 recognised by the scar left by the funicle. 



The dry seed is hard and horny, but softens when soaked in water ; 

 it can then easily be split into two thinner discs, exhibiting the small 

 embryo, consisting of a radicle and two leafy cotyledons, embedded in a 

 copious, grey, translucent, horny endosperm. 



The seeds are almost odourless, but have a persistent, intensely 

 bitter taste. 



The student should not fail to observe 



(a) The characteristic shape and satiny appressed hairs, 



(b) The horny endosperm and characteristic cotyledons. 



(c) The bitter taste. 



Microscopical Characters. The seed-coat is very thin and consists of a narrow 

 layer of brown, collapsed parenchyma covered with an epidermis, the cells of 

 which have developed into hairs. These are bent near the base and thus lie 

 close to the surface of the seed. The base is thick-walled and marked with 

 oblique pits ; above it passes into a tubular hair bearing longitudinal rod-like 

 thickenings. The endosperm consists of large cells with very thick walls which 

 swell in boiling water or in solution of potassium hydroxide. These cells contain 

 the alkaloids. 



In powdered nux vomica the hairs are broken up into the thick-walled bases 

 and rod-like fragments of the upper part. 



Constituents. The principal constituents of nux vomica are the 

 two alkaloids, strychnine and brucine, in addition to which they 

 contain a small percentage of a glucoside, loganin, which is much more 

 abundant in the pulp, and an acid that has been termed igasuric acid, 

 but is probably identical with caffeotannic acid. The alkaloid strych- 

 nicine which occurs in the leaves may also occur in minute quantity 

 in the commercial drug (Boorsma, 1902). An alkaloid, struxine, has 

 been obtained during the separation of strychnine from more or less 

 decomposed Cochin-China seeds ; it is probably not a normal con- 

 stituent of the seeds. 



The cell-wall of the endosperm, which is very thick, appears to 



