OF BODIES CONTAINING NITROGEN. 241 



which contain nitrogen. In many of these com- 

 pounds, a transposition of their elements occurs 

 spontaneously as soon as they cease to form part 

 of a living organism ; that is, when they are drawn 

 out of the sphere of attraction in which alone they 

 are able to exist. 



There are, indeed, bodies destitute of nitrogen, 

 which possess a certain degree of stability only when 

 in combination, but which are unknown in an 

 isolated condition, because their elements, freed 

 from the power by which they were held together, 

 arrange themselves according to their own natural 

 attractions. Hypermanganic acid, manganic acid, 

 and hyposulphurous acid, belong to this class of 

 substances, which however are rare. 



The case is very different with azotised bodies. 

 It would appear that there is some peculiarity 

 in the nature of nitrogen, which gives its com- 

 pounds the power to decompose spontaneously 

 with so much facility. Now, nitrogen is known 

 to be the most indifferent of all the elements ; it 

 evinces no particular attraction to any one of the 

 simple bodies, and this character it preserves in 

 all its combinations, a character which explains the 

 cause of its easy separation from the matters with 

 which it is united. 



It is only when the quantity of nitrogen exceeds 

 a certain limit, that azotised compounds have some 

 degree of permanence, as is the case with melamin, 

 ammelin, &c. Their liability to change is also 



R 



