242 ON THE VOLATILE OIL OP BETULA LENTA, ETC. 
M. Cahours further observes that the compound resulting 
from the action of fuming nitric acid on oil of Gaultheria, 
has the composition of indigotate of methylene, (C 14 H 4 N 
O 9 x C 2 H 3 0) and that chlorine and bromine appear to 
act on that portion of the oil constituting the methylic base. 
In a subsequent paper* M. C. has given the results of his 
observations on the ammoniacal compound of oil of Gaul- 
theria, which are full of interest. By distilling that sub- 
stance he obtained a product having the composition of sali- 
cylamid, which under the influence of strong acids and 
bases, regenerates ammonia and salicylic acid, and has an 
acid reaction. 
When oil of Gaultheria is dropped on finely pulverized 
caustic baryta, considerable elevation of temperature occurs 
and a well defined crystalline compound is formed. If the 
baryta be in great excess, and the mixture be submitted to 
dry distillation, an oily matter passes over into the recipient, 
which is but partly soluble in a solution of potash. This 
substance, when purified by washing with alkaline water 
and dried over chloride of calcium, has the composition of 
anisole, a substance formed by the action of caustic baryta 
on crystallized anisic acid. 
M. Cahours observes, "although presenting the compo- 
sition of a neutral ether, the oil of Gaultheria behaves like 
a true acid. Thus treated with caustic potassa, or soda, it 
forms crystalline compounds, soluble in water and in alcohol; 
the addition ^of an acid separates the oil unchanged; it is 
only in the course of a day that the whole is converted into 
salicylic acid." In my experience it has taken a much 
longer period before the alkaline compounds of oil of Gaul- 
theria would cease to yield that oil on the addition of an 
acid. Some specimens kept more than twelve months, how- 
ever, were wholly changed, salicylic acid being precipitated 
by a dilute acid. In the case of some specimens of the 
Comptes Rendus, July 3d. 
