396 
DR. A. W. HOFMANN’S RESEARCHES INTO THE 
for the disengagement of olefiant gas under the influence of heat proves to us that it 
is an ethyl-atom which in this compound occupies the supplemental position, if I 
may so call it, as represented in the formula 
C4 
C4 H5 
Cio 
and that the iodide, which is not likely to differ in its constitution from the oxide, has 
likewise to be represented by the formula 
C4 
C4 Hg 
CloH 
11 
N,C4Hg I. 
The preceding considerations clearly show, that, whatever the actual disposition of 
the molecules in ammonium or its congeners may be, the atoms re-arrange themselves 
whenever the fourth equivalent of hydrogen, or of its substitute, joins the compound. 
This re-arrangement, so evident in the ammonium-bases, containing various hydro- 
carbons, may be traced moreover in the lower ethyl-bases in a very obvious manner. 
For as long as there is any basic hydrogen present in the ammonia-skeleton, this 
hydrogen assumes what I have previously called the supplemental position, whenever 
the ammonia passes into the state of ammonium by the accession of a radical. Bromide 
of ethylammonium formed by the combination of ammonia with bromide of ethyl, 
when decomposed by a metallic oxide, yields ethylammonia, water and a metallic 
bromide, the oxide of ethylammonium formed in the first instance being decomposed 
like oxide of ammonium itself. It is this very transposition which we are in the habit 
of representing by the equation 
H3 N+C4 Hg Br=C4 Hg, H2 N, H Br. 
In the preceding pages I have stated some of the reasons which induced me to adopt 
the idea of an ammonium for the new class of compounds which I have had the 
honour to place before the Royal Society in the present memoir. I need scarcely 
mention, that such a step involves as a matter of necessity the assumption of a similar 
view for all the lower bases which form part of this investigation. It would be incon- 
sistent to speak any longer of hydrochlorate of ethylamine, of hydrobromate of 
diethylamine, &c. ; these salts have henceforward to be called chloride of ethylammo- 
nium, bromide of diethylammonium, &c., these compounds being nothing but interme- 
diate substitution-terms between the type and the last derivative. On considering 
the various chlorides from this point of view, we arrive at the following series: — 
Chloride of Ammonium H4 N Cl. 
Chloride of Ethylammonium 1 NCI. 
IC4 rlgj 
