On the Oxidation of Nitrobenzole and its Homologues. 177 
chromate of potassium and sulphuric acid, has been found in 
each case to yield benzoic acid. Cymole, on the other hand, the 
last member of the series, when treated in the same way, yields 
the insolinic acid discovered by Dr. Hofmann, and not the toluic 
acid which Mr. Noad obtained by acting upon this hydrocarbon 
with dilute nitric acid. Benzole remains wholly unacted upon 
when boiled for a very long period with bichromate of potassium 
and sulphuric acid. Not so, however, with nitrobenzole, which 
is slowly converted by this powerful oxidizing mixture into a 
soft, white, crystalline mass of intensely acid reaction. In the 
first experiment, I made use of a very excellent sample of com- 
mercial nitrobenzole, a portion of which seemed to be acted on 
with greater facility than the rest. An analysis of the acid 
thus formed gave numbers which indicated a mixture of nitro- 
benzoic and nitrophenoic acids: I propose the latter name for 
the new acid, which I believe to be the next lower homologue 
of the benzoic. The view that the acid burnt was a mixture, is 
confirmed by another experiment, to be related further on. In 
order to secure the absence of nitrotoluole from the nitrobenzole 
operated upon, I converted some benzole from benzoic acid into 
nitrobenzole, and repeated my experiments with this. The action 
of a most concentrated oxidizing solution was now found to be 
very much slower than in the former case; but after long diges- 
tion the nitrobenzole solidified in great measure on cooling the 
mixture, while from the solution itself numerous white crystalline 
~spangles separated. The liquid and solid parts were together 
poured into a funnel plugged with asbestos. To separate the 
unchanged nitrobenzole, the solid stopped by the filter was 
exhausted with boiling water, and the solution filtered twice 
through paper. When cold, the filtrate was full of large nacreous 
plates of a very pale straw colour, which by recrystallization 
became perfectly white. Having had but a few grains of this 
substance at my disposal, I have not yet made an accurate ex- 
amination of its physical properties. I found, however, that its 
reaction is strongly acid, that it is fusible without decomposi- 
tion, tolerably soluble in boiling water, and that it yields cry- 
stallizable salts. Not only does its origin and the method of 
its formation preclude the existence of more than twelve atoms 
of carbon in the new acid, but the following determination of 
silver in a carefully prepared specimen of its silver-salt points 
to the formula C!? H? Ag (NO*)O# for this compound, and to 
C!? H3 (NO‘) O# for the acid itself :— 
‘971 germ. of silver-salt gave ‘537 grm. of chloride of silver = 
"4041 grm. of silver, 
Phil. Mag. 8. 4. Vol. 21. No. 139. March 1861. = N 
