18 BULLETIN 350, U. S. DEPAKTMENT OF AGKICULTURE. 
In order to obtain the maximum yield it is very important that the 
maceration of the ground material be made with lukewarm water, 
as the reaction between the constituents, with the formation of oil, 
takes place most expeditiously at that temperature. It is also neces- 
sary to conduct the maceration in a closed vessel, preferably in the 
still itself, in order to avoid the loss of oil by evaporation. 
As a preliminary experiment, a quantity of ground pits was treated 
according to this method and distilled in a still consisting essentially 
of a still body and a condenser. Live steam was passed into the 
macerated mixture, and the distillate collected in a receiving vessel 
of glass, from which the aqueous distillate was easily decanted. The 
oil accumulated on the bottom, and the final separation was made by 
means of a separatory funnel. After cohobation of the distillate, 
which consists in redistilling by direct application of heat, the yield 
of oil was found to be 0.1 per cent. 
By careful manipulation a yield of 0.95 per cent of volatile oil was 
obtained from the press cake which remained after the extraction 
of the fixed oil from the kernels. This is equivalent to nearly 1 pound 
of oil from every 100 pounds of press cake, 
It is recommended that the volatile oil be extracted from the ker- 
nels rather than from the pits direct, both from an economical stand- 
point and from the ease of manipulation, since much loss is avoided 
in working with the smaller volume of material in the form of the 
press cake than with the much larger bulk of ground pits. 
PHYSICAL AND CHEMICAL PROPERTIES OF THE VOLATILE OIL. 
The physical and chemical properties of the volatile oil were deter- 
mined and together with the yields were tabulated with other kernel 
oils, which included several market samples of bitter-almond oil. 
According to the United States Pharmacopoeia, bitter-almond oil is 
designated as being derived from bitter almonds and " other seeds 
containing amygclalin." 1 Cherry kernels contain amygdalin, and 
cherry oil should therefore belong to the same class as bitter- 
almond oil. 
The data obtained from the physical and chemical examination of 
the volatile oils are presented in Table VII. 
An examination of Table VII shows that the yield of cherry oil 
was somewhat less than that of the other oils. This is explained by 
the fact that the kernels used in the experiment were from pits which 
had been in the laboratory for a considerable length of time and had 
undoubtedly deteriorated. The yield of oil from fresh kernels would 
very probably be higher. However, the yield obtained was sufficient 
to justify the use of cherry kernels for the production of oil. 
1 The Pharmacopoeia of the United States . . . Eighth decennial revision, p. 306. Phil- 
adelphia, 1907. 
