On the adulteration of certain Medicines. 13 
the circumstance of its being less soluble in alcohol of a mo- 
derate proof than most of the essential oils, furnishes a means 
of detection, if the experiment is conducted with care. Two 
samples of oil of peppermint were submitted for examina- 
ation and resulted in both cases alike. I put 20 minims of 
the suspected oil into a tall drop measure, with 20 minims of 
alcohol of 30 per cent, proof. They mixed freely, making a 
transparent solution, I then added two drops of water and 
shook up the mixtures, it subsided into two parts, showing 
ten minims of a transparent fluid in the bottom of the glass, 
and 32 minums of another transparent fluid, occupying the 
upper part of the glass; I then added 8 minims of water and 
shook up the mixture, which separated into 30 minims of a 
transparent fluid floating at top. My conclusion from this 
experiment is that the specimen of oil consisted of equal parts 
of spirits of turpentine and oil of peppermint, and that in the 
first instance the alcohol was of sufficient strength to dissolve 
this mixture; but on mixing it with two drops of water it 
dissolved only the oil of peppermint, rejecting the turpentine 
which subsided to the bottom, by its greater specific gravity. 
After being further diluted with 10 minims of water the alco- 
hol was too weak to dissolve the oil of peppermint, which 
again mixed with the turpentine, having greater affinity for 
it than for the diluted alcohol. This conclusion I have strength- 
ened by mixing various proportions of pure essential oil and 
spirits of turpentine, and by treating them as above detailed, 
have separated them again into their actual proportions. 
