350 
MISCELLANY. 
names of Dr. Hodgkin, Mr. May, of Tottenham, and the late Dr. Sims, 
Physician to the Marylebone Infirmary. 
The following is a quotation from a communication with which Dr. 
Hodgkin had favored the author: — 
" The principal use to which I have applied the Bitter Almond Water 
has been as a means of allaying distressing itching, whether prurigo senilis, 
or the local varieties of the affection in which the itching is almost intole- 
rable. In some of these cases, and especially in prurigo ani, 1 have found 
it singularly useful. In employing it pretty extensively I have observed 
that whilst in some cases I obtained an immediate and gratifying effect, 
in some others it appeared to produce no benefit, but caused smarting and 
irritation. From this I was induced to believe that it affects different 
skins differently, as is the case with oil of turpentine, in consequence of 
peculiarities in individual sensibility. I have sometimes prescribed the 
Water of Bitter Almonds, diluted with distilled water, but never met with 
any inconvenience following the use of the former undiluted, except the 
smarting above mentioned." 
*• An efficient substitute may be obtained extemporaneously by having 
recourse to the essential oil. 
" The strength of wash employed by Edward May is a drop to the 
ounce, which is prepared by adding a solution of the oil in spirit to wa- 
ter. He keeps this solution of a known strength, one pari of the oil to 
seven of the spirit answers the purpose very well. He uses the same 
preparation as a substitute for hydrocyanic acid for internal administration; 
gives about half a drop for a dose, and finds that it has the advantage of 
being palatable as well as efficacious." 
Mr. Bell then proceeded to consider the constitution of the oil of bitter 
almonds, with a view to determine the nature of its properties as a medi- 
cinal agent. 
The oil of bitter almonds, of which the water is a saturated solution, 
has been minutely analysed by Robiquet, Pelouze, and other French 
chemists, and" a paper on the subject, written by MM. Wohler and Lie- 
big, is to be found in the Jlnnales de Chimie et Physique, Vol. LI. The oil 
which comes over in distillation is a compound of a peculiar essential oil 
with hydrocyanic acid. The acid may be separated by adding liquor 
potassse and protochloride of iron and re-distilling. The oil which is thus 
obtained is colorless, and has a specific gravity of 1.043. By exposure to 
the atmosphere or to oxygen, it is converted into benzoic acid ; which 
process depends on a change in the elements. The oil is a compound of 
benzule and hydrogen, one equivalent of each. It is, therefore, a hyduret of 
benzule, while benzoic acid is a compound of benzule and oxygen, or an 
oxide of benzule. 
M. Liebig thus explains the decomposition : — 
"When oil of bitter almonds is exposed to the air, it absorbs two equiv- 
