228 Selected Articles. 
Veget. alkalies. 
Pure tannin. 
Effect. 
Gallic acid. 
Quinine, 
White precipitate. 
.002 
No precipitate. 
Cinchonine, 
do. 
.002 
do. 
Morphine, 
do. 
.09 
do. 
Codeine, 
do. 
.09 
do. 
Narcotine, 
do. 
.002 
do. 
Strychnine, 
do. 
.002 
do. 
Brucine, 
do. 
.002 
do. 
Ematine, 
do. 
do. 
Veratrine, 
do. 
do. 
Delphine, 
do. 
do. 
Atropine, 
do. 
do. 
Aconitine, 
do. 
do. 
Coneine, 
do. 
do. 
Observations.— Ammonia gave no distinct precipitate in a 
solution containing .002 of some of the alkaloids, and .09 of 
others, whilst the effect of the tannin was very sensible. 
The action of tannin on the organic salifiable bases is analo- 
gous to that exercised by it on the metallic oxides, that is, it 
combines with them and produces true salts. 
These saline compounds may be analyzed either by means 
of gelatine, or by double decomposition with the salts of lead, 
tin, antimony, peroxide of iron, or which is better, by barytes, 
lime or magnesia. With either of these, the tannin is set at 
liberty and combines with the animal matter or the metallic 
oxides, whilst the freed alkaloid either remains in an isolated 
state, or unites with the acid of the decomposed metallic salt. 
At the same time I must admit, that the decomposition is 
rarely easy by the gelatine or the inorganic salts. It was 
only by means of barytes or lime that I was always able to 
effect a ready and prompt decomposition of the vegetable tan- 
nates. By using these in the state of hydrates and of a soft 
or gelatinous consistence, and mixing them with one of the 
alkaline oxides spoken of above, a blueish green colour is 
produced, which gradually passes to a reddish brown; if the 
mixture be dried at 100° C. till it becomes pulverulent, and 
the powder treated with boiling alcohol, this fluid will dissolve 
