126 
DR. A. W. HOFMANN’S RESEARCHES REGARDING THE 
details I refer to Mr. Nicholson’s* paper on Cumidine, and to what I have stated 
about methylethylaniline {vide p. 114). The quantity of this substanee I had at my 
disposal was not sufficient for a determination of the boiling-point ; but if we recollect 
that ethylaniline boils at 204°, and that the introduction of methyl into aniline raised 
its boiling-point about 10°, it is evident that methylethylaniline cannot boil at a tem- 
perature much higher than 214°, i. e. eleven degrees below 225°, the boiling-point of 
cumidine observed by Mr. Nicholson. An account of the properties of xylidine has 
not yet been published ; however, I have not the slightest doubt that M. Cahours will 
find them widely differing from those of ethylaniline. 
Toluidine, xylidine and cumidine, resembling aniline, not only in their physical 
characters, but also in their origin from carbohyd rides, evidently belong to the class 
of alkaloids for which I have provisionally retained the name amidogen-bases, while 
the basic compounds derived from aniline are either irnidogen- or nitrile-bases. 
The difference of properties depends upon a difference in the molecular construction, 
as represented graphically by the following table : — 
H 
H N= Aniline. 
^12 Hj 
H 
H >N=Toluidine =Ci 4 Hg N=Methylaniline 
Cl4 H;. 
N. 
H |N=Xylidine =C 4 (,- N= Ethylaniline 
Ci6 H j 
f 1 
= C 4 H 'n. 
IC42 hJ 
H ) fEg Hg-j 
H N=Cumidine=Ci8 Hjg N=Methylethylaniline=i C4 H-In. 
C18 H J IC42 hJ 
These formulae assume the existence of a series of homologous radicals of com- 
pounds resembling in their chemical deportment, to a certain extent, the alcohols or 
the series Hn +2 O 2 . In a former paper-f-, I have shown how this resemblance be- 
comes more and more marked with every new investigation performed in this depart- 
ment of the science. A judicious application to these substances of the various 
methods hitherto employed in combining the radicals of the common alcohols with 
bromine or iodine, will probably enable us before long to obtain the corresponding 
products in the phenyl-, toluyl-, xylyl- and cumyl-series. The discovery of these sub- 
stances will furnish us at once with new processes for the production of the basic 
compounds in question, for it cannot be doubted that their aetion upon ammonia 
will give rise to the formation of the respeetive alkaloids with the same facility with 
which the treatment of ammonia with bromide and iodide of ethyl induces the form- 
* Loc. cit. p. 125. t Chem. Soc. Quart. Journ. ii. p. 329. 
