Reaction of the Essential Oils ivith Sulphurous Acid. 283 



washing with ammonia will not entirely remove the power of yielding 

 sulphuric acid ; and the total absence of the sulphurous smell de- 

 monstrates that the sulphurous acid either enters into an intimate 

 combination with the oil, or acquires oxygen sufficient to convert it 

 into sulphuric or hyposulphuric acid. 



Those essential oils which contain oxygen, are most affected by 

 the action of sulphurous acid. 



Both the oils of cloves and cinnamon, after admixture with sul- 

 phurous ether and subsequent distillation, gave, on analysis, precipi- 

 tates of sulphate of barytes. In the case of cloves, the precipitate 

 amounted to one seventh of the whole weight. 



By distilling camphor with alcohol and sulphuric acid, I obtained 

 a yellow liquid, which, by washing with ammonia and evaporation, 

 in order to get rid of the sulphurous ether, yielded an oil. The oil, 

 by standing, separated into two portions, one solid, the other liquid. 

 The solid portion resembled camphor somewhat in smell, but differed 

 from it by melting at a much lower temperature, becoming com- 

 pletely fluid at 175°. 



I found that the essential oils of cinnamon and cloves possessed an 

 antiseptic power, quite equal to that of kreosote, and that their aque- 

 ous solutions, when sulphated, were even superior to similar solutions 

 of that agent. 



One part of milk mingled with four parts of a saturated aqueous 

 solution of the sulphated oil of cloves, remained after five days sweet 

 and liquid, while another portion of the same milk became curdled 

 and sour within twenty four hours. Having on the 2d day of July 

 added two drops of oil of cinnamon to an ounce measure of fresh 

 milk, it remained liquid on the 11th ; and, though it finally coagula- 

 ted, it continued free from bad taste or smell till September, al- 

 though other portions of the same milk had become putrid. A half 

 ounce of milk, to which a drop of sulphurous oil of turpentine had 

 been added, remained free from coagulation at the end of two days, 

 while another portion, containing five drops of pure oil of turpentine, 

 became curdled and sour on the next day. 



A number of pieces of meat were exposed in small wine glasses, 

 with water impregnated with solutions of the various essential oils. 

 Their antiseptic power seemed to be in the ratio of their acridity. 

 The milder oils seemed to have comparatively little antiseptic power, 

 unless associated with the sulphurous acid, which has long been 

 known as an antiseptic. 



