MISCELLANY. 
rated from the mother-ley, slightly washed, dissolved in a little boiling 
water, and set aside to crystallize. The crystallized acid is collected 
on a filter, rinsed once or twice with water, dried, then digested for 
several days with 3 oz. of alcohol and 1 oz. of purified animal charcoal, 
heated to boiling, filtered, and evaporated at a very gentle heat. The 
still slightly brownish crystals are again collected on a filter, rinsed 
with spirit, dissolved in 3 parts boiling water, and set aside to crystal- 
lize. The crystals obtained were now of a beautiful white colour, 
silky lustre, and perfectly pure. The mother-ley yielded on evapora- 
tion a small quantity of brownish-yellow crystals. The produce in 
beautiful white gallic acid amounted to 2£ oz. In another experi- 
ment, 3 lbs. of galls yielded 8 oz. — Chem. Gaz. from Archiv. der Pharm. 
Netv Test for Prussic Acid. — The following new method of testing for 
hydrocyanic acid is proposed by Mr. Richard Austin, jr., of this city. The 
precipitate of cyanide ofsilver, say £gr., obtained in the usual manner, 
is mixed with a small quantity of oxide of iron and carbonate of potash, 
and the whole fused together in an iron or platinum capsule. The 
fused mass is then dissolved in % oz. of distilled water, filtered, and 
rendered slightly acid by the addition of a few drops of hydrochloric 
acid. The liquid thus treated is next divided into two portions, to 
one of which a few drops of a solution of sulphate of copper is added, 
which immediately causes the evolution of the chocolate brown 
colour, so characteristic of the ferrocyanide of copper ; and to the other 
a few drops of the muriate tincture of iron, or any persalt of iron, when 
the solution becomes intensely blue by the formation of the ferrocyanide 
of iron, the ordinary prussian blue. 
In Mr. Aust'n's opinion, "these two tests, with the well-known 
odour of prussic acid, are, independent of all other s, sufficient to convince 
the medical jurist of the presence of free prussic acid.' 1 Mr. Austin 
adduces several arguments to show the superiority of this test over 
those already known to chemists, both in accuracy and facility of ap- 
plication, by persons not skilled in chemical manipulation. 
The precipitates above mentioned are very distinctly obtained with 
i gr. of cyanide of silver. — Dublin Hospital Gazette. 
Method of detecting very minute Quantities of Copper in Organic Fluids. 
By M. Filhol. — A very delicate test consists, according to Virgain, in 
immersing a piece of metallic iron in the fluid contained in a platinum 
crucible, when the copper is deposited on the platinum, and may then 
be dissolved with a few drops of nitric acid. The author proposes the 
following modification of this method : — He acidifies a large quantity 
of the fluid under examination in an evaporating dish, and then im- 
