292 Dr. Murray on Muriatic Acid, (Apri, 
but it conforms to the general law, and forms a powerful acid 
with oxygen and hydrogen. Assuming the existence of a 
simple radical of muriatic acid, it resembles sulphur, phosphorus, 
and carbon, in forming an acid with oxygen, and one still more 
powerful with oxygen and hydrogen; but it differs in the pecu- 
liarity, 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 numerous propor- 
tions 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 compound of the 
radical with oxygen cannot be obtained in an insulated 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 sulphur, except that its 
binary compound with oxygen does not appear to have acidity, 
in which it approaches tothe 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 alkalies, and no other sub- 
stances give rise to both results; the greater number of the 
substances too, which form acids with oxygen or hydrogen, are 
evidently, from the smallness of their combining quantities, not 
of a metallic nature. Still the connexion between the two 
classes is in some measure established 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 diver- 
sity of products, which exist only in combination with those 
bodies by which their formation is determined, and, being modi- 
fied by any process causing their evolution, are not easily 
observed. It is doubtful if the same base in any case forms 
different acids by combination with oxygen in different propor- 
tions, or by combination with hydrogen in different proportions. 
But the example of the vegetable acids seems to show that this. 
may occur in the united action of oxygen and hydrogen ; carbon 
acidified by different proportions of these elements constituting 
the composition of these acids. Other bases may present similar 
results. The radical of muriatic acid may unite with other 
proportions of oxygen and hydrogen than those which form 
mvriatic acid ; and this might afford a solution of the theoretical 
difficulty of the production of water in the experiments in the 
