SEEDS. 
115 
SIN APIS NIGRA (Black Mustard). 
The dried, ripe seeds of Brassica nigra (Fam. Cruci- 
ferse), an annual occurring much the same as Sinapis 
alba, and differing from it chiefly in peculiarities of 
the pod and color of the seed. 
Description. — Campy lotropous, ellipsoidal or ir- 
regularly spherical, 1 to T5 mm. in diameter ; exter- 
nally brownish-red, seed-coat membranaceous, finely 
pitted, hilum whitish, forming a conical projection, 
micropyle occurring as a slight depression ; internally 
without a reserve layer, hypocotyl curved, cotyledons 
conduplicate ; inodorous; taste pungent and acrid. 
Constituents. — Black mustard contains the same 
constituents as white mustard, save that it contains 
less of the ferment, myrosin, and the sinalbin is 
replaced by the glucoside, sinigrin (potassium myro- 
nate), which yields on interaction with the myrosin a 
light yellowish volatile oil (allyl isosulphocyanide or 
volatile oil of mustard), which has an acrid, burning 
taste, pungent odor, and also affects the eyes. 
Allied Products. — Of the seeds of the other Cruci- 
ferse which somewhat resemble black mustard, the fol- 
lowing may be mentioned : the seeds of field mustard 
or Sinapis arvensis, which are almost black and per- 
fectly smooth ; the seeds of sarepta mustard, or Sinapis 
juncea, which are smaller, dark brown and nearly 
smooth ; rape or colza seeds yielded by Brassica Napus, 
which are larger and of a bluish-black color; turnip 
seeds yielded by Brassica campestris, which are some- 
what larger but less acrid. 
STRAMONII SEMEN (Stramonium Seed). 
The ripe seeds of Datura Stramonium (Fam. Sola- 
nacese), an annual native probably of the regions of 
the Black and Caspian Seas and growing wild in 
