668 
ME. P. G-EIESS ON A NEW SEEIES OE BODIES IN 
produce, such as is not met with in any other portion of the field of organic chemistry. 
When in the free state they are remarkable for their instability ; their compounds, how- 
ever, are somewhat more stable ; and it is for that reason that the latter have chiefly 
engaged my attention, and have been employed in the experiments to be described here- 
after. The very striking physical properties of these bodies, as well as' the large num- 
ber of products of decomposition to which they give rise, likewise deserve to be specially 
noticed. Altogether they may be looked upon as one of the most interesting groups of 
organic compounds. I have avoided, as much as possible, discussing their rational com- 
position, and have abstained from theoretical speculation. I have, however, come to the 
conclusion that the two atoms (or the molecule) of nitrogen, N 2 , they contain must be 
considered as equivalent to two atoms of hydrogen, and it is in accordance with this 
View that the names of the new compounds have been framed. 
PAET I.— COMPOUNDS OE DIAZOBENZOL. 
Nitrate of Diabenzol, G 6 H 4 N 2 , NHG 3 . 
This substance can be prepared in various ways ; most readily, however, by acting 
with nitrous acid upon a solution of nitrate of aniline. This salt of aniline is not very 
soluble in cold water ; therefore, in order to obtain a concentrated solution of the new 
compound, it is best to make a thick paste by grinding up a portion of the nitrate with 
water and submitting it to the action of the gas, when the undissolved portion of the 
aniline-salt rapidly disappears, and the whole is converted into the new body. The 
reaction being accompanied by considerable increase of temperature, it is necessary to 
keep the solution cool, and to guard against passing a too-rapid current of the gas. The 
temperature of the solution should not rise much above 30° C. The operation is inter- 
rupted as soon as the whole of the aniline has disappeared. This can be ascertained by 
adding a little strong solution of potassa to a portion of the liquid on a watch-glass, tvhen, 
if no more aniline is liberated, it may safely be inferred that the reaction is complete. 
The nitrate of diazobenzol is almost insoluble in ether, and even in ether mixed with much 
dilute alcohol, in consequence of which it may readily be obtained in a crystalline state 
thus: — the solution is first filtered, to remove traces of a brown resin, then mixed with 
about three times its volume of strong alcohol, and ether added until the precipitation is 
complete. The crystals are allowed to subside, and then filtered from the mother-liquor. 
The small quantity of the new body which remains in the mother-liquor may be neglected 
altogether, as its recovery is accompanied with great difficulty. To remove the last 
traces of colouring matter, the crystals are taken up with cold dilute alcohol and repre- 
cipitated by the addition of ether, when they are obtained as long white needles. 
Analysis, as will be shown further, proves that the new compound has the formula 
G 6 H 4 N 2 , NH9 3 . Its formation may be explained by the following equation: — 
€ 6 H 7 N, NHG 3 + NHG 2 = G 6 H 4 N 2 , NH0 3 + 2H 2 G. 
^ ^ \ ^ j - — , — - 
Nitrate of aniline. Nitrous acid. Nitrate of diazobenzol. Water. 
