Reaction of the Essential Oils with Sulphurous 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 

 it is 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. Meanwhil-e 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. 



Art. XII. — Of the Reaction of the Essential Oils with Sulphurous 

 Acid, as evolved in union with Ether in the process of Ether if - 

 cation, or otherwise ; by R. Hare, M. D., Professor of Chemistry 

 in the University of Pennsylvania. 



Having 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 sufScient 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 



Vol. XXXI.— No. 2. 36 



