370 
DR. A. W. HOFMANN’S RESEARCHES INTO THE 
requires the following values : — 
Theory. Mean of Experiment. 
1 equiv. of Tetrethylammonium . . . 
130-00 
9-37 
6 equivs. of Iodine 
758-16 
54-61 
53-76 
5 equivs of Mercury 
500-00 
36-02 
1 equiv. of Mercury-salt 
. 1388-16 
100-00 
The new oxide forms several other double compounds ; but as their analysis would 
have scarcely given additional elucidation to the subject, I have omitted to study 
them in detail. * 
The action of various chemical agents upon the con^pounds of tetrethylammonium 
gives rise to a series of very remarkable substances. Chlorine, bromine and iodine, 
convert the base into substitution-products, in which the basic character of the ori- 
ginal atom has disappeared ; of these the bromine-compound is distinguished by its 
splendid appearance, crystallizing as it does from alcohol in long magnificent orange- 
yellow needles. The iodine-compound, too, is very beautiful ; it forms either on addi- 
tion of iodine-solution to the base, or on evaporating a solution of the iodide exposed 
to the action of the air. In fact it is difficult to avoid the formation of this substance 
in recrystallizing iodide of tetrethylammonium. Cyanic acid yields with the base a 
crystalline compound, a sort of urea, which is remarkable for its composition, inas- 
much as it may be viewed as ordinary urea, in which the four equivalents of hydrogen 
are replaced by ethyl. I hope to communicate shortly a full account of these several 
substances. 
The preceding sketch, incomplete as it is, sufficiently exhibits the leading features 
of the new class of substances, of which tetrethylammonium and its compounds are 
the prototypes. It is at once evident that there is a marked difference between these 
latter and the bases which I have described in my former memoir. Irrespectively of 
the non-volatility of the new basic oxide, which forms in itself a line of demarcation, 
there are many other properties not less distinctive which attract our attention. The 
consecutive replacement of the several hydrogen-equivalents of ammonia induces a 
gradual change in the properties of the original atom ; ethylamine is almost as soluble 
in water as ammonia itself ; in diethylamine this property is less marked ; and finally, 
triethylamine is still less soluble. But another equivalent of ethyl being added, the 
substance changes altogether in property ; it becomes soluble in water in all propor- 
tions, in fact so soluble that it can scarcely be obtained in the dry state. A perfectly 
analogous, although reverse deportment, is exhibited by the platinum-salts of the 
various bases ; here we find that the solubility of the salts augments with the degree 
of ethylation, the salt of triethylamine being soluble in the extreme, while suddenly 
the tetrethylammonium-compound becomes not more soluble than the ammonium- 
compound itself. It is evident that ethylamine, diethylamine and triethylamine are 
compound ammonias ; the tetrethylated base is a compound oxide of ammonium. 
