ON TINCTURE OP KINO. 
187 
The pure article ought to be a powder of greenish-yellow 
hue, possessing but litte taste or smell; insoluble in water, and 
totally vaporizable by heat; when pressed between the fingers 
it ought, even in small quantities, to communicate a sensation 
of harshness, arising from friction between the crystalline par- 
ticles, little to be expected from a powder apparently so 
minute. This latter circumstance will probably afford an easy 
means of detecting impurity, — as it cannot be much adulterat- 
ed when it communicates this sensation on pressure; for when 
equal parts of the pure and impure commercial variety are 
thoroughly mixed, by being shaken together, this is rendered 
almost imperceptible. 
The adulterated article is whiter than the pure, and yields 
no peculiar sensation on being pressed between the fingers, ex- 
cept when in a large lump, and even then the sensation is very 
slight. R. B. 
ART. XXVI. — ON TINCTURE OF KINO. 
By Augustine Duhamel. 
The article kino, as is well known, is disposed, when in 
alcoholic solution to become gelatinous. This, if not invari- 
ably, at least very generally happens by the ordinary method 
of making the tincture, which is by merely putting the allotted 
portion of kino in a bottle containing alcohol, which is then 
shaken a little and set aside for use. 
In about a month, or in less time, after this, the tincture 
will be perceived to have assumed a gelatinous form, unplea- 
sant to the eye, unfit for use, and not susceptible of filtration 
through paper. To prevent this, various means have been 
tried. Alcohol, in a diluted state, which was thought to ob- 
viate the change, proved of no avail to me. In the case of 
the exceptions from this change, the substances represented as 
kino may have been obtained from sources different from 
