By H. JAY.
It appears that every article manufactured with the aid of alcohol is
required on its introduction into France to pay duty on the supposed
quantity of this reagent which has been used in its preparation. Certain
transparent soaps of German origin are now met with, made, as is
alleged, without alcohol, and the author proposes the following process
for verifying this statement by ascertaining--the presence or absence of
alcohol in the manufactured article: 50 grms. of soap are cut into
very small pieces and placed in a phial of 200 c.c. capacity; 30 grms.
sulphuric acid are then added, and the phial is stoppered and agitated
till the soap is entirely dissolved. The phial is then filled up with
water, and the fatty acids are allowed to collect and solidify. The
subnatant liquid is drawn off, neutralized, and distilled. The first 25
c.c. are collected, filtered, and mixed, according to the process of MM.
Riche and Bardy for the detection of alcohol in commercial methylenes,
with ½ c.c. sulphuric acid at 18° B., then with the same volume of
permanganate (15 grms. per liter), and allowed to stand for one minute.
He then adds 8 drops of sodium hyposulphite at 33° B., and 1 c.c. of a
solution of magenta, 1 decigrm. per liter. If any alcohol is present
there appears within five minutes a distinct violet tinge. The presence
of essential oils gives rise to a partial reduction of the permanganate
without affecting the conversion of alcohol into aldehyd.
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