282 A COMPENDIUM OF 
larva the gallis formed. When fully developed 
the insect escapes from the prison house, and 
the gall-nut of commerce is the result. There 
are several varieties, which are distinguished by 
the names of blue and white galls—these are 
from the Levant and are the officinal. The blue 
vary in size, and are usually gathered before the 
insect escapes from its interior. Some of the galls 
have more right to be called green than blue, 
from the fact that they have a greenish tinge. 
The white galls are so called because they are 
lighter in color, and are to be readily distin- 
guished by the hole in them by and through 
which the insect escapes. All the varieties of 
galls are-globular or sub-globularin shape, more 
or less; some smooth, others tuberculated, shin- 
ing, quite heavy and hard; when broken, the frac- 
ture is granular. The internal arrangement is 
of lighter color and moderately compact in char- 
acter, having a cavity in the centre, where we 
find the undeveloped remains of the insect. 
Galls have little or no odor, but a decided, strong 
astringent taste. The Mecca galls or Dead Sea 
apples are imported from Bussorah; whilst 
somewhat globular in shape, they have a num- 
ber of prominent projections, and are rarely 
found in this market. The other varieties of 
galls—such as the Chinese, Japanese, and Cali- 
fornian—are really nothing more than balls cov- 
ered by a thin fragile shell, inclosing the re- 
mains of many insects. Gall-nuts contain about 
5° per cent. of fannin and 2 or 3 per cent. of 
galtic acid, also starch, resin and sugar of the 
variety termed glucose. Gallotannic or digallic 
acid or tannin, as it is familiarly known, occurs 
