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NOTE UPON TANNIN. 
ART. XLIV.— NOTE UPON TANNIN. 
By M. Beral. 
Liquid tannin, that is to say, that which is obtained direct- 
ly from nut galls by hydrated sulphuric ether, is different 
from solid tannin. The latter is a pure immediate principle, 
the other is composed of tannin, water, and sulphuric ether, 
in proportions not correctly determined, but which I believe 
to be constant; or at most, susceptible of slight variations. 
The following facts permit us, at least in my opinion, to adopt 
the following conclusions. 
1st, Liquid tannin is very little soluble in water saturated 
with sulphuric ether, yet when tannin is added to hydrate 
of ether it is soluble to a marked degree. 
2. When the watery solution of nut galls is saturated with 
sulphuric ether, the tannin contained in it is transformed into 
liquid tannin, and this is separated from the remainder of the 
liquid. 
3. Tannin dissolved in water is affected in the same way, 
when ether is mixed with it. By standing, the mixture is 
separated into three strata, the first, or that at the bottom, is 
liquid tannin, the second is etherealized water, and the third 
is ether. This experiment succeeds best when the solution 
is concentrated. 
The property recognised in tannin of being little soluble in 
hydrate of ether is interesting, as it led me to suspect the 
possibility of extracting from the diluted tincture of nut galls, 
a part of the tannin which it contains, an extraction which, 
up to this time, had been considered as impossible. In fact, 
in the memoir upon tannin published by M. Pelouze in the 
Annals de Chimie et de Physique, we read the following: 
" Tannin is one of the most easily altered substances known, 
and it is besides accompanied in vegetables with coloring 
matters, of which it is extremely difficult, perhaps impossible, 
to free it completely, when the solution is at the same time 
effected." 
