282 Reaction of the Essential Oils with Sulphurous Acid. 
heat or evaporation, without the use of the ammonia, the proportion 
of sulphuric acid in the remaining oil was much greater. 
By subjecting to the same process several essential oils, I suc- 
ceeded in obtaining as many liquids to which the above remarks 
were equally applicable. With some of the oils, however, 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 decomposition before any distillation 
could take place. No product can be obtained by distillation with 
sulphuric acid and alcohol from the oil of cinnamon obtained from 
cassia. From the oils of sassafras and cloves, but little can be pro- 
cured. : 
However, in one instance, by previously mixing the oil of sassafras 
with the alcohol, in the manner described in the account given of 
the first experiment with the oil of turpentine, I succeeded in obtain- 
ing, 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. Tam disposed to consider the liquid thus procured as a hy- 
drate of sassafras oil, or sassafreine, as I would call it, being analo- 
_ gous to hydric ether. 
The oil of sassafras, whether isolated or in combination, possesses 
a remarkable property, which, I believe, has not attracted sufficient 
observation ; I mean that of producing an intense crimson color, 
when added, even in a very minute quantity, to concentrated sul- 
phuric acid. 
~ One drop of oil of sassafras imparted a striking color to forty-eight 
ounce measures of sulphuric acid, and appeared perceptible when 
it formed less than a five millionth part. This property was com- 
_ pletely 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 ether, in that of a gas, or when in union with 
water, was brought into contact with any of the essential oils (inclu- 
ding kreosote,) which were subjected to the experiment, they ac- 
quired a yellow color, 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 
