ON THE VOLATILE OIL OP BETULA LENTA, ETC. 243 
compounds of oil of gaultheria and oxide of copper and of 
baryta, the addition of a dilute acid eliminated the oil appa- 
rently unchanged. 
Having given an outline of the principal results of M. 
Cahours, I wish in what follows to call the attention of 
chemists to the volatile oil of Betula lenta. The results of 
my experiments tend to prove — 
1st. The indentity of this volatile oil with the oil of Gaul- 
theria procumbens (salicylate of methylene.) 
2d. To the existence of a peculiar principle in the bark 
of the Betula lenta, which bears the same kind of relation 
to the oil of Gaultheria or Betula lenta, that amygdaline 
bears to the oil of bitter almond; and to which 1 have given 
the name of gaultherin, as it gives rise to the oil of Gaul- 
theria by its decomposition. The term betulin (perhaps 
more appropriate) has been already applied to another sub- 
stance. 
3d. That there exists in the same bark, associated with 
gaultherin, a substance enjoying the property of react- 
ing with the latter so as to produce the volatile oil, and 
which is analogous in its mode of operation to synaptase, or 
emulsin. 
The bark of the Betula lenta appears to be constituted 
much like that of the Cerasus serotina, (wild cherry.) It 
contains tannin, gum, saccharine matter, resin in consider- 
able quantity, gaultherin, fixed oil soluble in alcohol, &c. 
Oil of Betula lenta. The plant which yields this vo- 
latile oil is one of the most noble individuals of the Ameri- 
can forest, both as to its gigantic size and to the various 
economical uses to which its wood has been applied in 
cabinet work, &c. It attains the height of 80 feet; and grows 
abundantly in the middle and northern States, and in Canada, 
and is known under the various titles of sweet birch, black 
birch, cherry birch, and mountain mahogany. The bark and 
leaves are embued with the odor and taste of the Gaultheria 
procumbens, and this similarity in sensible properties sug- 
