. The contents of the flask are then distilled, the
distillate saturated with barium carbonate, and the chloroform
distilled; the residue is evaporated to a small volume, the excess of
barium carbonate filtered off, and the filtrate evaporated to dryness
and weighed. The residue is dissolved in water, a few drops of nitric
acid added, and the solution divided into two portions. In the first
portion the barium is determined; in the second the barium chloride. The
total per cent. of barium minus that of barium chloride gives the amount
present as barium valerate, from which is calculated the per cent. of
amyl alcohol. By this process the author has determined one part of
fusel oil in ten thousand of alcohol. To detect very minute quantities
of fusel oil, the chloroform extracts are treated with several drops of
sulphuric acid and enough potassium permanganate to keep the solution
red for twenty-four hours. If allowed to stand in a test tube, the odor
of valeric aldehyde will first be noticed, then that of amyl valerate,
and lastly that of valeric acid.--_Amer. Chem. Journal._
[Footnote 8: Berichte d. Deutsch. Chem. Gesellsch., xv., 1,370
and 1,663.]
* * * * *
ON SILICON.
It is known that platinum heated in a forge fire, in contact with
carbon, becomes fusible. Boussingault has shown that this is due to the
formation of a silicide of platinum by means of the reduction of the
silica of the carbon by the metal.
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