HISTORY. 
77 
1867 announced that, “If tannin is not a glucoside, it 
may perhaps be a digallic acid. The analyses of tan¬ 
nin and its salts agree with this composition as well as 
can be expected in the case of a substance which is so 
difficult to purify.” 
Lowe in 1872 contributed a paper on pure gallotan- 
nic acid, in which he described a method of purification 
by acetic ether, which will be more fully considered 
under the appropriate head. 
Notwithstanding the fact that most chemists at the 
present time devote themselves to the study of what 
may be termed artificial products, still those who have 
contributed to the literature of tannic acid during the 
last score of years could not be so much as mentioned 
in this brief history. During the past decade much 
time and earnest labor have been given to the endeavor 
to discover a universal method of estimating not only 
tannic acid but all tannins, and it is the intention that 
each author shall receive his full share of credit in the 
other parts of this work. 
7 * 
