Mr. Stenhouse on Artificial Oil of Ants. 123 



a small quantity of oily matter which rendered it milky. To 

 this he gave the somewhat fanciful name of " artificial oil of 

 ants." From the extremely small quantity in which it is pro- 

 duced by this process, he did not succeed in collecting it, or 

 in determining its properties. 



In repeating Professor Emmet's process for formic acid, 

 which consists in distilling grain of various kinds with sul- 

 phuric acid, without any oxide of manganese, I observed that 

 under certain circumstances the liquid in the receiver con- 

 tained considerable quantities of this oil. After repeated trials 

 I succeeded in pretty easily preparing it. It is a constant 

 product, though in very different quantities, of the action of 

 sulphuric acid on vegetable substances, and it may be con- 

 veniently procured from grain of any kind, saw-dust, husks 

 of corn, &c. 



The process which I found to succeed best is the following. 

 Take equal weights of oatmeal or saw-dust and sulphuric 

 acid, diluted with its own bulk of water, and introduce the 

 mixture into a large copper still. As there is no oxide of 

 manganese present there is no frothing up of the liquid, so 

 that the still may be safely filled rather more than half-full ; 

 when the mixture has boiled some time and the meal is quite 

 charred, pour back the liquid which has distilled, adding the 

 same quantity of water as at first, and push the distillation 

 nearly to dryness. The liquid which passes over into the 

 receiver is slightly milky, owing to the presence of the oil, 

 and at the same time strongly acid from the sulphurous and 

 formic acid which it contains. It is to be neutralized with 

 slaked lime, when it becomes of a deep yellow colour, and is 

 again to be slowly distilled till about a fourth or fifth part of 

 it has passed over. This is to be mixed with a considerable 

 quantity of fused chloride of calcium, and subjected to a se- 

 cond distillation. The chloride of calcium retains a great 

 part of the water, in which the oil is pretty soluble : if too 

 much water still passes over after a second rectification, a 

 new quantity of chloride of calcium must be added, and the 

 distillation repeated a third time. The oil comes over mixed 

 with a litde water, and sinks to the bottom of the receiver; 

 about twelve pounds of meal yielded nearly one ounce of oil, 

 so that it is by no means an abundant product. 



Properties. — The anhydrous oil is transparent when newly 

 prepared, nearly colourless, having only a greenish-yellow 

 tinge, but when kept some time it becomes of a brownish-red, 

 from the formation of a resinous matter. Its taste and smell 

 are very pungent and aromatic, resembling oil of Cassia. It 

 stains paper, but not permanently. It catches fire very easily, 



