FORMIC ACID IN STINGING NETTLES. 
181 
If valerianic acid is added to a solution of neutral acetate 
of potash, it instantly dissolves and in large quantity; in bin- 
acetate of potash the valerianic acid floats in oily drops upon 
the surface, and appears not to dissolve therein to a greater 
extent than in water. If a solution of neutral acetate of 
potash, to which an excess of valerianic acid has been added, 
is submitted to distillation, valerianic acid passes over, and 
the residue contains binacetate of potash together with valeri- 
anate of potash. If valerianic acid is added to binacetate of 
potash and the mixture distilled, valerianic acid passes over, 
and the binacetate is left in the retort free from valerianic 
acid. Butyric acid behaves precisely like valerianic acid. 
When therefore butyric or valerianic acid containing acetic acid 
is partially saturated wtih potash and distilled, either the whole 
of the acetic acid is left as an acid salt together with butyric 
acid, and in this case the acid which passes over is pure and 
free from acetic acid ; or only acetic acid is left in the residue, 
and in this case the distillate still contains acetic acid, which 
can be separated from the butyric or valerianic acid by a 
similar operation.— Chem. Gaz., January 15, 1850/ from 
Liebig's Annalen, Sept. 1849. r 
ART. XL VI.— ON THE OCCURRENCE OF FORMIC ACID IN 
STINGING NETTLES. 
By Dr. Gorup-Besanez. 
Some time ago, F. Will showed, by microchemical and 
microscopical experiments, that the fluid in the hairs of the 
so-called procession-caterpillar {Bornbyx processionaria,) 
which causes an inflammation of the skin, as well as the 
liquid in the poisonous organs of some insects, is nothing 
else than formic acid. It became highly probable therefore 
that formic acid would also occur in the vegetable kingdom 
already formed ; and the first class of plants which was 
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