DESTRUCTIVE DISTILLATION OF ANIMAL SUBSTANCES. 221 



bitter almonds. After the action has ceased, the fluid becomes muddy when 

 mixed with water, and a thick reddish-yellow oil is deposited, which has exactly 

 the odour of nitrobenzide, and resembles it in many of its properties. The quan- 

 tity of this substance produced is by no means large, and it is evidently mixed 

 with some resinous substance. Owing to this circumstance I have not been able 

 to submit it to purification and analysis, so as to ascertain whether it really is 

 nitrobenzide ; but though that substance has not yet been obtained by a similar 

 action on pure aniline, it is quite possible that it may be produced, and the reason 

 why it has not hitherto been observed, is probably because no one has had occasion 

 to sacrifice large quantities of aniline in this manner. The acid solution of the un- 

 decomposed base is passed through a wet filter, in order to separate the oil, and the 

 fluid boiled for some time to expel the last traces. On saturation with potash, 

 and distillation, an oily base passed over with the water, and collected on the 

 surface. This base, on being converted into a platinum salt, was found still to 

 give a result greatly above that required by theory for the substance of which I 

 was in quest. On submitting it to distillation, it was found to commence boiling 

 at about 320°, and hence to contain a large quantity of lutidine ; and it was only 

 the very last portion which gave a platinum salt corresponding with theory. It 

 was clear that a large quantity of lutidine had been retained at a boiling point 

 above that which naturally belonged to it, by the presence of aniline, and that 

 substance being destroyed, it came over at its natural boiling point. The higher 

 fractions of the oil containing aniline were therefore treated in a similar manner, 

 and the undecomposed bases, which amounted to from a half to two-thirds of the 

 original quantity acted on by nitric acid, were submitted to fractionated distillation. 

 The product was found to spread over a considerable number of degrees, and a 

 quantity of that collected between 340° and 345° was converted into a platinum 

 salt and analysed, but the results indicated the presence of much lutidine. 

 The product being still obviously impure, was submitted to a systematic frac- 

 tionation, and it was observed that the thermometer remained remarkably steady 

 about 354°. The portion boiling between 350° and 360° was collected apart, and 

 after several rectifications, a fraction was obtained, which distilled entirely be- 

 tween 352° and 356°, and proved to be the pure base, to which I gave the name 

 of collidine. 



Collidine. 



Collidine is obtained in the form of a transparent and colourless oil, which may 

 ! be preserved for a long time in bottles only partially filled with it, without acquir- 

 ' ing colour. A rod dipped in hydrochloric acid brought in contact with it, gives 

 i abundant white fumes. It is insoluble in water, and floats on its surface, with- 

 out undergoing diminution. It dissolves a small quantity of water, which is readily 

 separated by caustic potash. It is highly soluble in alcohol, ether, and the fixed 



