EMPYREU:\rATIC OILS, ETC. 387 



104-5 vols, at 47 '^ C. It is very volatile, evaporating perceptibly 

 at ordinary temperatures. 



When dropped on paper it makes a greasy stain, which quickly 

 disappears. It evaporates instantly on the skin, boils at 47^ C, 

 and distils unaltered. It is inflammable and burns with a smokeless 

 flame. It is insoluble in water, soluble in aqueous alcohol, but 

 mixes easily in absolute alcohol, ether and, oils both fixed and 

 volatile. It dissolves fats, camphor and similar substances with 

 facility, also caoutchouc when heated, the solution leaving a dry 

 varnish when evaporated. It dissolves resins for the most part 

 with difficulty and incompletely. Most alkaloids are quite insoluble 

 in it, even at the boiling point. 



Owing to its exceeding volatility, limpidity, and total absence of 

 unpleasant residue on evaporation, it is suggested that this liquid 

 would form a good solvent in the preparation of " concrete 

 essences, where a solvent of low boiling-point and pleasant odour 

 is desirable.* 



Furfurol, C^ H^ Oo. During the preparation of Formic acid 

 from a mixture of sugar or starch with dilute sulphuric acid and 

 peroxide of manganese, Doebereiner was the first to observe the 

 formation of this oily, aromatic liquid, which he designated by the 

 name of " Artificial oil of Ants."t 



The experiments of Doebereiner, repeated by Cahours, led to the 

 inference that this product was not obtained when the same bodies 

 were distilled with dilute sulphuric acid alone, without the peroxide 

 of manganese. Emmet, however, states having obtained it by 

 distilling sugar, starch, gum or wood with sulphuric acid in 

 sufficient state of dilution to prevent carbonisation : as soon as the 

 residue in the still became sufticiently concentrated to blacken the 

 material acted upon, nothing passed but formic acid. 



It was ascertained by the experiments of Stenhouse and of 

 Fownes, that the oily body known as Furfurol (from the Latin 

 furfur, bran, and oleum, oil) is always produced when dilute 

 sulphuric acid is distilled with bran, corn or oat flour, cocoa-nut 

 shell, the husk of linseed, or sawdust, particularly the sawdust of 

 mahogany. It was also found that hydrochloric acid could be 



* 1st Series, p. 63. 



t Doebereiner, Ann. Clieni. Pliarni., iii.,p. l-ll ; ibid., liv., p. 52 ; Pharm. 

 Journ. [i.], viii., p. 113. 



