llJll] on New Onfunic Compounds of Nitro;im. 161 



organic azoimides have this in common, that they undergo chaiiire of 

 the first type — namely, loss of two-thirds the azidic nitrogen, when 

 treated with 80 per cent, sulphuric acid, or with various reducing 

 agents. Moreover, they are all extremely sensitive to the action of 

 light. As from time to time the marked analogy between the triazo- 

 complex and the halogens has been emphasized, it should be mentioned 

 that one complete contrast has lately been found. The halogen 

 derivatives of ethylamine are known to part so readily with halogen 

 hydride, that chloroethylamine and bromoethylamine cannot be 

 liberated from their salts without im media telv passing into di- 



methyleneimine, | /NH, isomeric with the unknown vinvlamine 



CH2/ 

 or aminoethylene. Salts of /8-triazoethylamine, on the other hand, 

 behave like salts of ethylamine itself, and so stable is the resulting 

 triazo-base that it may be distilled from solid potash under reduced 

 pressure without loss of hydrazoic acid. 



Many disappointments have occurred in studying the triazo- 

 group, and the most conspicuous one which I have to admit is the 

 failure to produce hexatomic nitrogen ; in view of the resemblance 

 between the complex in question and the halogens, and the associa- 

 tion of two atoms of the latter in their free molecules, it was to be 

 expected that a new modification of nitrogen might arise by linking 

 together two triazo-radicles. Experiments with this object have 

 failed, and if differently arranged efforts in the same direction are 

 also barren of result, the reluctance of the two nuclei to become 

 united may be regarded as having some bearing on the question of 

 the constitution and transformations of the triazo-group. To aid in 

 the elucidation of this is, indeed, the principal purpose of the fore- 

 going observations, in view of our present ignorance regarding the 

 disposition in space of the atoms or groups which are associated with 

 nitrogen in its organic derivatives. Such disposition or configura- 

 tion is fairly well understood with respect to carbon, the original 

 views of Kekule, as developed by van 't Hoff, having stood the test 

 of forty years' unceasing experimentation, but the efforts of chemists 

 to fathom the nature of combined nitrogen, and the arrangements in 

 space of its varying valency directions, have not been so successful. 

 Nitrogen remains a Sphinx among the elements, propounding riddles 

 to the inquiring chemist, although happily, unlike her prototype, she 

 does not annihilate those who fail to solve them. 



[M. 0. F.] 



Vol. XX. (No. 105) 



