OF BODIES CONTAINING NITROGEN. 245 



pounds ; it is putrefaction in its simplest and most 

 perfect form, because the new products, the car- 

 bonic acid and ammonia, are incapable of further 

 transformations. 



Putrefaction assumes a totally different and 

 much more complicated form, when the products, 

 which are first formed, undergo a further change. 

 In these cases the process consists of several stages, 

 of which it is impossible to determine when one 

 ceases and the other begins. 



The transformations of cyanogen, a body com- 

 posed of carbon and nitrogen, and the simplest 

 of all the compounds of nitrogen, will convey a 

 clear idea of the great variety of products which are 

 produced in such a case : it is the only example of 

 the putrefaction of an azotised body which has been 

 at all accurately studied. 



A solution of cyanogen in water becomes turbid 

 after a short time, and deposits a black, or brownish 

 Hack matter, which is a combination of ammonia 

 with another body, produced by the simple union 

 of cyanogen with water. This substance is insoluble 

 in water, and is thus enabled to resist further 

 change. 



A second transformation is effected by the cya- 

 nogen being shared between the elements of the 

 water, in consequence of which cyanic acid is 

 formed by a certain quantity of the cyanogen 

 combining with the oxygen of the water, while 

 hydrocyanic acid is also formed by another portion 



