TRANSACTIONS OF SECTION B. 621 



Ilinski bas proposed for his compound the formula 



.N— O 



CijHj. 



\n— o 



The formula 



.NO 





analogous to that of Bamberger's nitrosobenzene, is however also possible. No 

 conclusive argument can be adduced in favour of either of them, but, beyond all 

 doubt, our benzene derivatives must have the same constitution as Ilinski's 

 naphthalene compounds. The reaction then proceeds according to the equation 



N 





^\ 



Ortho-Bitrodiazobenzeneimide Ortho-dinitrosobenzene 



A convenient method of obtaining dinitroso derivatives from the corresponding 

 ortho-diazoimides consists in heating the latter in a solution of glycerine at tempera- 

 tures ranging from about 100° to 120°. When the evolution of nitrogen has 

 ceased, water is to be added and the nitroso-compound thus precipitated is filtered 

 off. By crystallisation from boiling alcohol it may be easily obtained in a state of 

 perfect purity. 



Ortho-dinitrosobenzene crystallises from its aqueous solution in needle-shaped 

 crystals, from alcohol in plates, fusing at 70°-71°. It is sparingly soluble in water, 

 easily in alcohol, ether, &c. 



It sublimes readily, and maybe volatilised in a current of steam. The odour of 

 its vapour is slightly irritating, and resembles in a dilate state that of nitrobenzene. 



"When heated, either with nitric acid of (55 per cent, on the water bath, or 

 treated with concentrated nitric acid at 0° in sulphuric acid solution, it yields a 

 mono-nitro derivative, crystallising in yellow needles ; fusing-point 143°. 



This mono-nitro derivative has the constitution 



NO 



/\no 



!Jno, 



as, by reduction, it yields the known 1. 2. 3, triamidobenzene. 

 We have also obtained an isomeric compound — 



NO 

 /^NO 



NOj 

 by decomposing the dinitrodiazobenzeneimide 



N<|| 

 I ^N 



r 



^NOj 



in the same manner. 



NO, 



