142 A COMPENDIUM OF 
and usually coated with a corky layer or epider- 
mis, rugged, wrinkled and frequently warty. 
Externally it presents a brick-red brown color, 
which assumes a shade deeper color internally; 
when broken shows a short fracture, with many 
fine fibres. The powder is of a red-brick color, 
peculiar odor, taste astringent and permanently 
bitter. The three varieties of the cinchonas 
mentioned are considered the best species, and 
are called officinal; from these the alkaloids of 
quinia, quinidia, cinchonia, cinchonidia and qui- 
nama are obtained, besides quite a number of 
allied radicals or alkaloids. For further account 
see United States Dispensatory. The cinchonas 
number thirty-six species, and about one-third 
of the number furnish the cinchona barks of 
commerce, all of which contain the alkaloids in 
a greater or lesser degree. Besides the afore- 
mentioned alkaloids the cinchonas contain kinic, 
kinovic and cincho-tannic acids, gum, sugar, wax, 
salts of lime and a volatile oil, “In preparing the 
alkaloids, or rather extracting them from the 
barks, the mother liquor contains a brown amor- 
phous substance known as chinoidine, which 
becomes soft under the heat of the hand, and is 
soluble in alcohol and ether. The cinchona 
pallida contains more cinchona and cinchonidia 
than guinine, and its infusions yield no precipi- 
tate with sodium sulphate. The yield of qui- 
nine depends upon the age of the tree and on the 
locality in which it grows. The spurious vari- 
eties of the cinchonas are not often found in 
rommerce as a specific adulterant of the genu- 
ine. They do, however, come to this country 
from the north Atlantic parts of South America, 
