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XXIII. On the Oils produced by the Action o/ Sulphuric Acid upon various Classes 
of Vegetables. By John Stenhouse, Esq., Ph.D., F.R.S. 
Received March 28, — Read April 18, 1850, 
Nearly thirty years ago Dobereiner observed, when preparing formic acid by di- 
stilling a mixture of starch, peroxide of manganese and sulphuric acid, that the liquid 
which passed into the receiver contained a small quantity of oil which rendered it 
turbid. To this oil Dobereiner gave the somewhat fanciful name of “ artificial oil of 
ants,” though the very limited quantity in which he was enabled to procure it pre- 
vented him from determining almost any of its properties. 
My attention was first directed to the subject in 1840, when I found that the oxide 
of manganese was quite unnecessary, and that this oil could be readily prepared by 
operating on most vegetable substances with slightly diluted sulphuric acid. In this 
way I succeeded in procuring considerable quantities of the oil from wheaten and 
oaten flour, from saw-dust, bran, chalf, &c., and was thus enabled to subject it to a 
more detailed examination. The oil, when analysed, was found to have the formula 
Cg Hg 0 . 2 , or the triple of this, Hg Og, presenting the remarkable circumstance of a 
volatile aromatic oil containing oxygen and hydrogen in the proportions to form 
water. This proved it to differ essentially from other known oils, all of which contain 
an excess of hydrogen. 
Dr. Fownes took up the subject in 1845, and made the interesting discovery, that 
when the oil was agitated with a considerable excess of aqueous ammonia and set 
aside for a few hours, it was converted into a bulky crystalline mass, becoming C^g 
Hg O 3 Nj by the absorption of one equivalent of nitrogen and the elimination of three 
equivalents of oxygen which had united with the hydrogen of the ammonia. To this 
compound Dr. Fownes gave the name of furfuramide, and to the oil itself that of 
furfurol. Dr. Fownes also made the still more important discovery, that when fur- 
furamide is boiled for a short time with dilute potash lye, it is without any alteration 
of its per-centage composition, but merely by a new arrangement of its component 
elements converted into a crystalline base, furfurine, the formula of which is C 30 
Oe N2. 
Furfurol was also examined in 1848 by M. Cahours, who, in addition to confirming 
Dr. Fownes’s discoveries, observed that when a stream of sulphuretted hydrogen is 
passed through an alcoholic solution of furfuramide, the half of the oxygen in that 
body is removed and replaced by sulphur. This new compound, which he called 
thiofurfurol, precipitates as a crystalline powder and has the formula C^g 83 O 2 . 
3 o 2 
