* 
USEFUL PROPERTIES OF BENZOLE, ETC. 331 
It has an interest, too, as offering a cheap and ready 
source of many of the organic compounds of the benzoic 
series. Several beautiful bodies, which, from the compa- 
rative costliness of the parent materials, had only been ob- 
tained previously in very small quantities, may now be 
prepared in large bulk, such as nitrobenzole, nitraniline, 
&c. Dr. Hofman has recently used coal-tar benzole, pre- 
pared by a method which will be described below, as a 
convenient source of aniline, of which base he has thus 
produced a large quantity for some researches in which he 
has been engaged. 
The facility with which the vapor of benzole is taken up 
and retained by the air at its ordinary temperatures has 
been mentioned above. This property has been made to 
do service, with great success, in an apparatus for illumina- 
tion, in which a stream of air, having passed through a 
reservoir of the volatile hydrocarbon, is conducted through 
pipes to the burners, at which, being ignited like coal-gas, 
it yields a light of extreme brilliancy and whiteness. 
The property possessed by alcohol and pyroxylic spirit 
of burning with an almost lighlless flame, so opposite to 
that of the highly carbonized benzole, renders it easy, by 
properly adjusting a mixture of the volatile oil with either 
of these spirits, to obtain a fluid which shall be readily 
vaporized, and shall yield a flame of any required degree 
of whiteness. Thus a mixture of 1 part by measure of 
benzole and 2 parts of spirit of spec. grav. about 0.840 
forms an excellent fuel for a portable gas-lamp, which sup- 
plies itself with vapor by the heat which it generates in 
combustion. Any excess of spirit diminishes the lumi- 
nosity of the flame, while too much of the other causes a 
tendency to smoke. Similar mixtures may be made of 
benzole with acetone, or with other inflammable liquids 
poor in carbon. 
The inhalation of benzole vapors for the production of 
insensibility to pain is already on record as effectual. 
