ON KALMIA LATIFOLIA. 
263 
into a metallic still, with a sufficient quantity of water; a 
gradual heat was then applied until half a gallon had dis- 
tilled over. This was returned upon another portion of 
leaves, and again submitted to distillation, and the process 
continued until several pounds of the leaves were consumed. 
The distilled water was clear and transparent, and did not 
evince, in the slightest degree, the presence of a volatile oil, 
even after standing several weeks. 
13th. A decoction of the green leaves was treated with 
sub-acetate of lead to precipitate the gum tannin, and 
colouring matter, and after filtering to separate them, satu- 
rated with hydro-sulphuric acid to precipitate an excess 
of lead: the clear liquid was then boiled to expel the sul- 
phuretted hydrogen, and slowly evaporated. A reddish 
brown translucent extract was obtained, having a hot and 
acrid taste. A portion of this extract was dissolved in 
alcohol, boiled with animal charcoal, filtered, and allowed 
to evaporate, but without any thing farther being obtained. 
Another portion was dissolved in water, the acetic acid 
present saturated with magnesia, sulphuric ether added, and 
after repeated agitation allowed to separate; it was then 
decanted and spontaneously evaporated ; the product was a 
very small portion of straw coloured matter, which possessed 
the acridity of the extract and which seemed to be the acrid 
matter of the plant. It was but sparingly soluble in ether, 
for on re-evaporating the dissolved extract it was found to 
be still very acrid. In sensible properties, this substance 
resembled the acrid matter which exists in the Arum tri- 
phyllum ; it was not dissipated by boiling, although much 
injured, or even destroyed by long continued high temper- 
ature. Several attempts were made to obtain it in an iso- » 
lated condition, but without success, and consequently no 
satisfactory proof relative to its medicinal activity could be 
arrived at, but from its properties it was presumed that if 
taken into the system in sufficient quantity, it might, from 
