MOLECULAR CONSTITUTION OF THE VOLATILE ORGANIC BASES. 127 
ation of ethylamine ; we may hope moreover to form the imidogen- and nitrile-terms 
of these radicals, in the phenyl-series for instance : — 
H 1 C,2 H,. 
Ci2 H5 N, Diphenylamine and Hg N, Triphenylamine, 
C12 Hgj ‘ C ,2 H5J 
the production of which, as mentioned in the commencement of this paper, I have in 
vain attempted by the action of the phenyl-alcohol at high temperatures upon aniline. 
The view which I propose in the preceding remarks respecting the constitution of 
toluidine, xylidine and cumidine, must as yet be considered as a mere hypothesis. 
It will not however be difficult to establish it by facts. The action of bromide of 
ethyl upon these substances will at once decide this question. These bases, when 
subjected to the influence of the bromides, will give rise to the formation of a series 
of bases similar to those which I have obtained from aniline. I may mention that 
the deportment of toluidine and cumidine, in this respect, is now being studied by 
several of my pupils. There is no difficulty in introducing 1 equiv. of ethyl into tolu- 
idine ; the experiments are however not yet sufficiently advanced as to affirm also 
the insertion of the second equivalent. The alkaloid obtained by acting with bro- 
mide of ethyl upon toluidine is represented by the formula 
^18 ^13 
so that we are now in possession of three alkaloids of exactly the same composition, 
namely, ethylotoluidine, methylethylaniline and cumidine ; and here I cannot but 
allude to the wonderful variety of isomeric compounds to which a continuation of 
these researches must necessarily lead. We see at a glance that substances of the 
formula 
C18 Hi 3 N 
will also be obtained by inserting 1 equiv. of methyl into xylidine, by introducing 
2 equivs. of methyl into toluidine, or by fixing upon aniline the radical (propyl) 
belonging to the missing alcohol of propionic acid* (metacetic acid). We thus arrive 
at six alkaloids, having all the same numerical formulae, but widely differing in their 
construction. 
* A more appropriate name for metacetic acid, proposed by Dumas, Malaguti and Leblanc (Compt. Rend. 
XXV. 656), as it is the first acid of the series CnH„ O 4 that exhibits the character of a fatty acid, i. e. in being 
separated from solution as a layer of oil, and in forming salts with the alkalies that have a greasy appear- 
ance. 
