ACTION OF ETHER ON GALLS. 
43 
respectively pure, colorless tannin from the former, and a 
green residue from the latter consisting of tannin, coloring 
matter, and other impurities. By this means about one half 
the tannin in the solution may be separated of the utmost pu- 
rity. The result is not the same with the solution from ordi- 
nary ether, the lower always retaining some portion of the 
brown coloring matter. 
Acting on galls by means of ordinary ether, to which 
water has been united by means of alcohol, there re- 
sults a liquid of which the brown hue increases in depth 
with the increase in the proportion of the alcohol and water. 
This liquid does not separate on standing, but when the alco- 
hol and water bear but a small proportion to the whole, the 
addition of water has the same result as with solution from 
ordinary ether; if, however, the latter liquid predominates, 
then this result is effectual by the addition of ether. The al- 
cohol does not act here as when hydrous ether is used, for 
both portions into which the liquid separates, contain much 
coloring matter, the green with part of the brown remaining 
in the upper portion, the under exhibiting a light yellow co- 
lor, and on evaporation yielding a yellowish product. 
The theories of Pelouze and Beral, which do not essentially 
differ, afford, with slight modifications, the explanation of the 
above results. The modifications necessary are to bring into 
view the relations in regard to the solubility of tannin, whether 
anhydrous or combined with ether and water, and of coloring 
matter with ether, alcohol, and water. Anhydrous tannin is 
freely soluble in water, less so in alcohol and in ether. When 
in contact with water and ether, combination takes place, 
which results in the formation of an oleaginous liquid, con- 
sidered by M. Beral to consist of definite proportions of each 
of its constituents. This compound is soluble in alcohol, ether, 
and water, but to much less extent than anhydrous tannin. The 
coloring matter existing in galls is of two kinds, a brown or 
deep yellow matter, insoluble in ether and soluble in alcohol 
and in water, but having a stronger affinity for the alcohol, and 
