AND ON SOME SUBJECTS OF CHEMICAL THEORY. 319 
more powerful with oxygen and hydrogen ; but it differs in the 
peculiarity, that. the proportion of oxygen to the base in the 
binary combination is considerably larger than in the ternary, 
so that the addition of hydrogen converts the one into the 
other; and also in its combining apparently with more nume- 
rous proportions of oxygen than any of the other acidifiable 
bases,—two circumstances which, as well as the difficulty of 
effecting its decomposition, probably depend on the same 
cause, the strength of its attraction to oxygen. The fluoric are 
similar to the muriatic compounds, except that the binary com- 
pound of the radical with oxygen cannot be obtained in an in- 
sulated form, and that its combinations with oxygen are less 
numerous. ‘The relations of iodine or its radical are similar to 
those of the radical of muriatic acid, or perhaps rather to sul- 
phur, except that its binary compound with oxygen does not 
appear to have acidity, in which it approaches to the metals. 
The metals usually combine with oxygen so as to form oxides} 
some of them also form acids with oxygen, or with oxygen and 
hydrogen ; and these last usually also combine with hydrogen 
alone. This fact, of some of the metals forming acids, is so far 
an anomaly, since their compounds with oxygen rather form 
alkalis, and no other substances give rise to both results; the 
greater number of the substances, too, which form saad with 
oxygen or hydrogen, are evidently, from the smallness of their 
combining quantities, not of a metallic nature. Still the con- 
nection between the two classes is in some measure establish- 
ed on the one hand, by nitrogen, which with hydrogen forms 
an alkali, and on the other by iodine, which has properties and 
relations common to both. 
In some cases it is probable, that there is a variation in the 
proportions of these ternary combinations, giving rise to a di- 
versity of products, which exist only in combination with those _ 
bodies 
