XXIII. On the oils produced by the action of sulphuric acid upon various classes of vegetables

Abstract

Nearly thirty years ago Döbereiner observed, when preparing formic acid by distilling 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 Döbereiner gave the somewhat fanciful name of “artificial oil of ants,” though the very limited quantity in which he was enabled to procure it pre­vented 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, chaff, &c., and was thus enabled to subject it to a more detailed examination. The oil, when analysed, was found to have the formula C 5 H 2 O 2 , or the triple of this, C 15 H 6 O 6 , 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.