MISCELLANY. 
79 
into two aoids of another homologous series. Its density is 0.908, its 
taste insipid and irritating, its smell faint; it reddens litmus paper, and 
is very soluble in ordinary spirit even in the cold. It solidifies at 32° 
F. It is decomposed by sulphuric acid on the application of heat. 
M. Walter has verified the composition of this new acid by an analy- 
sis of the aethers it yields with alcohol and wood spirit. — lb., from 
Comptes Rendus. 
Experiments on the Absorption of Arsenic by Plants. By Dr. Herber- 
ger. — The experiments were made in the summer of 1843 in a loamy 
and in a sandy soil containing very little humus, with seeds of Triti- 
cum spelta which had been steeped in white arsenic. Although all the 
parts were examined both before the formation of stem, before flower- 
ing, and also just before ripening, not a trace of arsenic could be de- 
tected. In each experiment at least 250 grms. of the substance were 
carbonized with sulphuric acid, and then immediately tested according 
to Marsh's process, as well as by the method of Reinsch. — Ibid, from 
Jahrb. fiir Prakt. Phann. 
On the Purification of Mercury. By M. Ulex — In the distillation of 
mercury we are not only exposed to a very great loss, but the mercury 
is also not perfectly purified by it. This object is obtained, it is true, 
by digesting it with acids and perchloride of mercury; but it requires 
considerable time, as these agents are merely in contact with the sur- 
face of the mercury, and can only act upon all its particles by fre- 
quently repeated agitation. A solution of perchloride of iron alone 
possesses the property of dividing mercury to a very great extent. 
When, for instance. 1 lb. of mercury is treated with 3 drms. Liquor 
ferri muriatici, and the same quantity of water, and well shaken for 
half a minute, the entire mass is converted, with evolution of heat, 
into a dark gray mass. The perchloride of iron is reduced to the state 
of protochloride, while a portion of the mercury is convened into calo- 
mel, which latter prevents the globules of mercury running together. 
Tf the mercury contain any foreign metals in solution, they are more 
easily attacked by the chlorine than the mercury, and are either dis- 
solved or precipitated in a pulverulent form. To see whether mercury 
is contaminated with foreign metals, for instance with tin or lead, 
merely shaking with air suffices. Chemically pure mercury does 
not deposit any black powder in this operation, nor does it coat 
the sides of the glass vessel with a pellicle of mercury. The latter 
occurs even with _^.-J__th lead ; with --^-th, the mercury deposits, 
even after shaking it for three minutes, a black powder ; with T -J-^th 
lead such a mass of the black powder is obtained, that the surface of 
