MOLECULAR CONSTITUTION OF THE VOLATILE ORGANIC BASES. 
99 
cold mixture of the two bodies be left for a few hours, it deposits crystals, which are 
much more definite than those obtained on the cooling of the hot solution. In either 
case the fluid assumes a deep amber colour which approaches brown, and the crystals 
are usually slightly yellow. These crystals vary in composition according to the pro- 
portions in which the two bodies have been mixed. If a very large excess of aniline 
has been used, they are of a prismatic character, and consist of pure hydrobromate 
of aniline. This compound was identified by analysis ; — 
0-0486 grm. of the crystals gave 0-0525 grin, of bromide of silver. 
Experimental percentage of bromine. Theoretical percentage of bromine in 
hydrobromate of aniline. 
45-88 45-97 
On the other hand, if the bromide of ethyl predominates to a considerable extent, 
the crystals are flat, four-sided tables, sometimes of considerable size. Several ana- 
lyses, the details of which will be found below, showed that they were the hydrobro- 
mate of a new base*, represented by the formula — 
i. e. of aniline in which 1 equiv. of hydrogen is replaced by 1 equiv. of ethyl, or am- 
monia in which 2 equivs. of hydrogen are replaced, the one by phenyl, the other by 
ethyl. The same base is contained in the free state, either alone or mixed with aniline 
in the mother-liquor of the crystals of hydrobromate of aniline, while the mother- 
liquor of the hydrobromate of the new base, especially if a large excess of the bromide 
has been employed, and after some days’ standing, consists of nearly perfectly pure 
bromide of ethyl, only a small quantity of the hydrobromate in question being kept 
in solution. 
The formation of the new basic compound, for which I propose the name Ethyl- 
aniline or Ethylophenylamine, takes place by the removal, from aniline, of 1 equiv. 
of hydrogen, in the form of hydrobromic acid, for which an equivalent of ethyl is 
substituted, the compound thus produced uniting with the hydrobromic acid. Hence 
the action of bromide of ethyl upon aniline may be represented by the following two 
simple equations: — 
Aniline. Bromide of Hydrobromate of Ethylaniline. 
Ethyl. Aniline. 
H; N-bC^ Hs Br=c,, N, H Br 
' ' ' ^ V ' 
Aniline. Bromide of Hydrobromate of 
Ethyl. Ethylaniline. 
* Frequently, as may be imagined, mixtures of the two hydrobromates are deposited according to the pro- 
l)ortion in which the constituents are mixed, 
o 2 
