184 ODOROGRAPHIA. 
should alone consist. It is made up of 40 to 50 per cent. of the 
higher homologues of this series, the nitrotoluenes, particularly 
the metanitrotoluene and nitroxylols, of about 8 per. cent of 
benzene hydrocarbons which have escaped nitration, and 40 to 
45 per cent. of a residue boiling above 360°C. The indifference 
of this last constituent to powerful reagents, as well as the fact 
that a paraffinoid body was isolated from it, make it probable that 
we have here a mineral oil. The specimen is an instance of bare- 
faced and clumsy adulteration, and its value does not in the least 
correspond to the price at which it was bought.” It is added 
that “ Mirbane oils exist and circulateincommerce which practically 
contain no nitrobenzene at all.” A remark worthy of note. 
Pseudo-Mirbane. 
Nitrotoluene, C,H,(NO,)CHs, is obtained by dissolving toluene 
in fuming nitric acid and precipitating with water. It is a 
colourless liquid, boiling at 225°, possessing a smell of bitter 
almonds, and a very sweet, somewhat biting taste. At the same 
time, a small quantity of metanitrotoluene and the ortho- and 
para-compounds are formed*. ‘The relative quantities of the 
two chief products depend upon the concentration of the acid and 
the temperature at which the nitration is effected. When a very 
concentrated acid is employed, and the temperature allowed to 
rise, paranitrotoluene is chiefiy obtained, while the yield of the 
ortho-compound is greatly increased by employing a weaker acid 
and cooling the mixture well. 
The nitrotoluenes are manufactured on the large scale by 
mixing 10 parts of toluene with 1] parts of nitric acid sp. gr. 1°22 
and 1 part of sulphuric acid sp. gr. 1:33 with continual agitation, 
in the apparatus used for the manufacture of nitrobenzene; this 
mixture is then either cooled or kept warm, according to the product 
desired. The crude product is washed with water and caustic 
soda solution, freed from unattacked toluene by distillation with 
steam, and then distilled with superheated steam. The distillate 
is then repeatedly fractionated ; the larger portion of the fraction, 
distilling above 230°, solidifies on cooling, and the crystals, after 
purification by draining and pressing, yield pure. paranitrotoluene 
on distillation; the fraction boiling between 222°-223° consists 
* Ber. Deutsch. chem. Ges. xii. p. 445. 
