44 H. ROSE ON THE COMBINATIONS OF THE 
against the view that oxygen can be replaced by chlorine in the 
so-called basic hydrochlorate salts, as well as in the combinations 
of acids with chlorides here in question ; and he retains the view 
relative to the latter compounds which I advanced when I made 
known the constitution of the chromate of the chloride of 
chromium *, 
If we combine two isomorphous acids with a base, or two 
isomorphous bases with an acid, it is always a like proportion of 
base or of acid which is taken up by the isomorphous substances. 
And if we were to mix the two isomorphous acids and isomor- 
phous bases in any proportion, the quantity of base or of acid 
which would combine with the mixture would always stand in a 
like proportion as the quantities which had been combined with 
the acids or bases separately. 
Among the bases ammonia possesses a peculiar character. It 
only appears as a distinct base when it has taken up water, 
or the constituents of it, in which case it has become converted 
into the oxide of ammonium, which is a base perfectly ana- 
logous in its properties to the other oxybases. In the combi- 
nations of ammonia with acids (the ammons), the ammonia re- 
mains, on treatment with water, either combined as such with 
the acid, as in sulphat-ammon and parasulphat-ammon, or it is 
converted by this treatment into the oxide of ammonium, as in 
the carbonat-ammon and other ammons which I have recently 
had occasion to examine. 
When two acids, which give isomorphous compounds with 
the same base, combine with ammonia to form neutral ammons, 
it is highly probable that each acid takes up an equal number 
of atoms of ammonia. Even when both acids have been mixed 
in different proportions, the ammonia taken up by this mixture 
must stand to them in the same proportion as to the individual 
acids. 
If, for instance, a portion of the sulphur in the anhydrous 
sulphuric acid were replaced by selenium, or even by chromium, 
the new acid, which might be regarded as a combination of se- 
lenic acid, or of chromic acid with sulphuric acid, must take up 
just as many atoms of ammonia as the latter alone. But the 
same should likewise be the case when in the sulphuric acid the 
other element, the oxygen, is replaced by chlorine, in a similar 
manner as the sulphur by selenium or chromium. 
* Annalen der Pharmacie, Bd. xxxi. p. 113. 
