FOODS AND DRUGS AND THEIR ADULTERANTS. 73 
channels (A, Fig. 29). The first two tissues appear, as a 
rule, as large opaque dark-brown masses, with the cell 
structure showing only at the edge. 
The detection under the microscope of other cell 
structures than’ those mentioned at once serves to indi- 
cate the presence of adulterants. Leach has pointed out 
that even a naked-eye examination sometimes reveals 
foreign substances. ‘‘The chicory grains are apparent 
from their dark and somewhat gummy appearance, and 
can usually be recognized by crushing them between the 
teeth. Their soft consistency and bitter taste are very 
distinctive. The dull surface of the outside of the 
crushed coffee-grains is in marked contrast to the pol- 
ished appearance of the surface of the broken peas or 
beans, often to be found as adulterants, while fragments 
of broken cereal grains are readily distinguished from 
coffee with a low-power magnifier, though perhaps not 
easily identified by the eye alone.” 
4. Chicory and other Adulterants of Coffee.—The 
roasted root of Cichorium Intybus is one of the substances 
most commonly found mixed with coffee. Its presence 
is at once betrayed by the appearance of masses of tissue 
made up of elongated cells of the type common to the 
stems of the higher plants. The outer layers are thin- 
walled and delicate, while the woody tissue proper contains 
large fusiform cells marked with fine scar-like cross- 
hatching, the ladder-cells of the fibro-vascular bundles. 
Occasionally, too, particles will be found which show the 
very peculiar branching, tubular structures of a homo- 
geneous dark color, which are known as the milk-tubes. 
