MISCELLANY. 
On a new Method of detecting the Adulteration of Essential Oils. By M. 
Mero. — The sophistication of the different essential oils with oil of tur- 
pentine occurs daily in commerce, and no process capable of discover- 
ing the fraud with certainty is known ; the odour and the various che- 
mical tests have hitherto been insufficient. The essential oils of mar- 
joram, lavender, spikenard, sage, thyme, rosemary, wormwood, and 
peppermint are the most subject to this adulteration. 
In 1838, M. Mero discovered a method of detecting the presence of 
oil of turpentine founded on the circumstance that this oil dissolves the 
fixed oils with great facility, while the essential oils above mentioned 
do not. He considered therefore that it might serve to indicate the 
presence of oil of turpentine mixed with pure essential oils, whose 
powerful smell conceals that of the turpentine. 
After a great number of experiments, he found that the oil of poppies 
deserved the preference, because it always possesses the same consist- 
ence. It gave the most accurate results in the detection of the presence 
of oil of turpentine, in .small proportions, in the above-mentioned essen- 
tial oils. 
About 3 grms. of oil of poppies are poured into a graduated tube, and 
an equal quantity of the essential oil to be tested added; the mixture 
is then shaken, and should become of a milky white if the essential oil 
is pure, whilst it remains transparent if it contain any oil of turpentine. 
The value of this process may readily be ascertained, by first testing 
a pure essential oil, and then some essential oil of turpentine ) if the 
essential oil be then mixed with the oil of turpentine, even in propor- 
tions so small that no advantage could accrue to traders in mixing it, 
it is found to behave like the essential oil of turpentine itself, that is 
to say, the mixture is not rendered turbid. 
To make this experiment successfully, the mixture of the two essen- 
tial oils should be very intimate. The method employed in commerce 
for this purpose is this : — The pure essential oil, and the quantity of oil 
of turpentine which is to be added to it, are placed in a hot water-bath 
