290 A COMPENDIUM OF 
counter irritant. Dose, 2or 3 grains mixed with 
syrup. Cowage is rarely, if ever, found in the 
stores, and should not be kept, on account of its 
power to torment, for cases have been known 
of its pernicious influence in the hands of the 
practical joker. 
Amylum, Starch; obtained from the Common 
Wheat, Triticum Vulgare.—Natural order Gram- 
inacez. It is also found to exist as a constitu- 
ent inall kinds of grain, rhizomes, tubers, and 
acorns. The principal source of the commercial 
starch is from the wheat, potato, and corn, the 
latter starch usually occurring in packages and 
sold for culinary purposes. Starch varies as to 
the size of its granules, rice yielding the smallest 
and the tuber of the canna edulis (which is cul- 
tivated in the West Indies) yielding the largest. 
Amylum, as it occurs in commerce, is white 
opaque, occurring in column-like masses, easily 
pulverized, and producing a peculiar sound of 
its own kind when rubbed between the fingers. 
The granules of starch have a lens-like form, in 
the centre of which is a small dot termed a hilum. 
The arrow-root and potato starches present an 
appearance of small shells with many concentric 
rings ; they are larger granules than those exist- 
ing in the wheat or corn starch. To examine 
these minute objects it requires a powerful mi- 
croscope. Starch has neither taste nor odor, 
and is insoluble in cold water, alcohol, and 
ether, but when boiled in water the granules are 
broken up and dissolve. On cooling, a mucila- 
ginous compound.or jelly is the result, which 
turns blue by adding the smallest quantity of 
iodine. By dry, intense heat starch is converted 
