Reaction of the Essential Oils with Suiphurous Acid. 281 
wine, according to the nature of the process employed; and _ that 
the oil alluded to by Thenard and those procured by me by simple 
distillation, ebullition, or distillation with ammonia or potassium, are 
mixtures of the etherine with its sulphate in various proportions. As 
itis well known that the odor of the essential oils is rendered more 
active by dilution, the livelier smell of the solutions may be consist- 
ent with a diminished proportion of the odoriferous matter. 
Oil of wine cannot be distilled per se without partial decomposi- 
tion, which does not take place below the temperature of 300. 
When subjected to the distillatory process, over potassium, at a cer- 
tain temperature, a brisk reaction ensued, and the oil and metal 
agglutinated into a gelatinous mass. By raising the temperature 
the mass liquefied, and a colorless oil came over, which retained the 
odor of oil of wine. Meanwhile some of the potassium remained 
unchanged, and appeared within the liquid in the form of pure me- 
tallic globules. On pouring into a retort a portion of nitric acid, in 
order to remove the caput mortuum, ignition took place from the 
presence of the potassium. 
Arr. XII.— Of the Reaction of the Essential Oils with Sulphurous 
Acid, as evolved in union with Ether in the process of Etherifi- 
cation, or otherwise ; by R. Hare, M. D., Professor of Chemistry 
in the University of Pennsylvania. 
Havine mixed and subjected to distillation, two ounces of oil of 
turpentine, four ounces of alcohol and eight ounces of sulphuric acid, 
a yellow liquid came over, having all the appearance of that which 
is obtained in the process for making oil of wine, described in the 
preceding article. On removing, by means of ammonia, the sulphu- 
rous acid existing in the liquid, and driving off the ether by heat, a 
liquid remained, which differed from oil of turpentine in taste and 
smell, although a resemblance might still be traced. ‘This liquid 
was without any sensible action on potassium, which continued 
bright in it for many weeks. It proved, on examination, to contain 
a small quantity of sulphuric acid. ‘I ascertained, afterwards, that 
in order to produce these results, it was sufficient to pour oil of tur- 
pentine on the mass which remains after the termination of the or- 
dinary operation for obtaining ether, and apply heat. Subsequently 
it was observed that when the sulphurous ether was removed by 
Vou. XXXI.—No. 2 36 
