isoith Sulphurous Acid, SfC. 29 



or evaporation, without the use of the ammonia, the pro- 

 portion of sulphuric acid in the remaining oil was much 

 greater. 



By subjecting to the same process several essential oils, I 

 succeeded in obtaining as many liquids to which the above re- 

 marks were equally applicable. With some of the oils, how- 

 ever, similar results were, by this method, either totally or 

 partially unattainable, in consequence of their reaction with the 

 sulphuric acid being so energetic as to cause their decompo- 

 sition before any distillation could take place. No product 

 can be obtained by distillation with sulphuric acid and al- 

 cohol from the oil of cinnamon obtained from cassia. From 

 the oils of sassafras and cloves, but little can be procured. 



However, in one instance, by previously mixing the oil of 

 sassafras with the alcohol, in the manner described in the ac- 

 count given of the first experiment with the oil of turpentine, 

 I succeeded in obtaining in addition to a small quantity of the 

 heavy liquid containing sulphuric acid, a minute quantity of 

 a lighter one, devoid of that acid, which burned without 

 smoke, was insoluble in water, and very fluid. I am disposed 

 to consider the liquid thus procured as a hydrate of sassafras 

 oil, or sassafreine, as I would call it, being analogous to hy- 

 dric aether. 



The oil of sassafras, whether isolated or in combination, 

 possesses a remarkable property, which, I believe, has not at- 

 tracted sufficient observation: I mean that of producing an 

 intense crimson colour, when added, even in a very minute 

 quantity, to concentrated sulphuric acid. 



One drop of oil of sassafras imparted a striking colour to 

 forty-eight ounce measures of sulphuric acid, and appeared 

 perceptible when it formed less than a five millionth part. 

 This property was completely retained by the lighter liquid 

 above described as procured from oil of sassafras. 



I subsequently observed, that when sulphurous acid, whether 

 in the form of sulphurous aether, in that of a gas, or when in 

 union with water, was brought into contact with any of the 

 essential oils (including kreosote), which were subjected to 

 the experiment, they acquired a yellow colour, and a strong 

 smell of this acid. 



In the case of the yellow compound thus obtained from 

 any of the essential oils which I have tried, if the sulphurous 

 acid be removed by heat, the oil, by analysis, will be found 

 to yield sulphuric acid. That some acid of sulphur remains 

 in union must be evident, since washing with ammonia will 

 not entirely remove the power of yielding sulphuric acid ; and 

 the total absence of the sulphurous smell demonstrates that 



