SPICES 133 
Fic. 127.—Black Mustard (Brassica nigra, Mustard Family, Crucifere). 
Plant in flower and fruit, reduced. Pod. Seed, cut across showing 
the embryo with seed-leaves folded around the seed-stem, enlarged. 
(Britton and Brown.)—Annual, sometimes attaining a height of over 
2 m.; leaves becoming smooth; flowers bright yellow; pods smooth; 
i ai brown. Native home, north temperate regions of Old 
orld. 
Fic. 128.—White Mustard (Sinapis alba, Mustard Family, Cruciferae). 
Stem with leaves. Top showing flowers and fruit, reduced. Pod, 
about natural size. (Britton and Brown.)—Plant an annual about 
30-60 cm. tall; leaves hairy; flowers yellow; pod bristly; seeds light 
x abn Native home, temperate regions of Eurasia, and Northern 
rica. 
reported that the excessive use of this spice in India has re- 
sulted in dangerous, almost fatal consequences. In the small 
amounts necessary to give a mild and pleasant flavor to 
food all the spices in common use are not only wholesome 
to most persons but may be aids to digestion. Highly spiced 
food or strongly flavored confectionery, on the contrary, is 
apt to be unwholesome if much be eaten, and for young 
people positively injurious. 
It is a curious fact that the volatile oil to which mixed 
mustard owes its aroma and pungency does not exist in the 
seed itself, but is formed, during the process of mixing, from 
a tasteless substance through the action of an enzyme. Like 
diastase this enzyme acts only in the presence of moisture, 
and is destroyed by a temperature of 100° C. Hence, if dry 
mustard be sifted into boiling water no pungency is developed. 
