ANILINE. 129 



to ammonia, is produced; here we feel almost compelled to assume 

 that ammonia is formed from the cyanic acid just as from the free 

 acid, and that this ammonia is conjugated with the carbo-hydrogen 

 of the methyl or the ethyl, (C 2 H 2 or C 4 H 4 ,) and thus produces the 

 alkaloid. 



Urea presents perfectly similar reactions: when treated with 

 alkalies it developes ammonia ; and Wurtz* has shown that these 

 alkaloids may be prepared in such a manner that acetate of urea, 

 when heated with potash, shall yield the same alkaloid as is 

 obtained by the action of potash on cyanate of oxide of methyl, 

 namely C 2 H 5 N, while metacetonate of urea, similarly treated, gives 

 the same alkaloid as is obtained by the action of potash or cyanate 

 of oxide of ethyl, namely C 4 H 7 N. Although these substances may 

 either be regarded as pertaining to the class of ethers in which the 

 oxygen is replaced by amide, C 4 H 5 .Oc\}C 4 H 5 .H 2 N, or as ammonia 

 in which the. third atom of hydrogen is replaced by methyl or 

 ethyl, the most simple and probable explanation seems to be, that 

 they should be regarded as conjugated ammonia-compounds 

 = C 2 H 2 .H 3 N, and C 4 H 4 .H 3 N. 



As was already mentioned, we shall here only notice those alka- 

 loids which may be obtained from the decomposition of certain 

 animal matters. 



Many of these volatile alkaloids are liquid, like the nitriles, 

 but most of them are crystallisable. They have generally a nau- 

 seous odour and an acrid burning taste, are slightly soluble or alto- 

 gether insoluble in water, dissolve readily in alcohol, are most 

 soluble in ether and in fatty and volatile oils, and react on vege- 

 table colours. Their salts are, for the most part, crystallisable and 

 readily soluble ; but their combinations with bichloride of platinum 

 are nearly or entirely insoluble. 



ANILINE. C 12 H 7 N. 

 Chemical Relations. 



Properties. This alkaloid forms a colourless, strongly refract- 

 ing, oily fluid, with an aromatic odour; its specific gravity = 1'020, 

 it remains fluid at 20, evaporates very rapidly at an ordinary tem- 

 perature, begins to boil at 182, dissolves slightly in water, and in 

 every preparation in alcohol and ether, coagulates albumen, dis- 

 solves phosphorus and sulphur, and colours Dahlia (Georgina) paper 



* Compt. rend. T. 38, pp. 223-227. 



