288 Dr. Murray on Muriatic Acid, [Aprit, 
action of a metal, its whole oxygen must be considered as 
retained, and its hydrogen is liberated. | any 
Nitric acid in its highest state of concentration is not a defi- 
nite compound of real acid with about a. fourth of its weight of 
water, but a ternary compound of nitrogen, oxygen, and 
hydrogen. Phosphoric acid is a triple compoand of phosphorus, 
oxygen, and hydrogen; and phosphorous acid is the proper 
binary compound of phosphorus and oxygen. The oxalic, 
tartaric, and other vegetable acids, are admitted to be ternary 
compounds of carbon, oxygen, and hydrogen; and are, there- 
fore, in strict conformity to the doctrine now illustrated. 
A relation of the elements of bodies to acidity is thus disco- 
vered different from what has hitherto been proposed. When a 
series of compounds exists, which have certain common charac- 
teristic properties, and when these compounds all contain a 
common element, we conclude with justice that these properties 
are derived more peculiarly from the action of this element. On 
this ground Lavoisier ferred, by anample induction, that oxygen 
is a principle of acidity. Berthollet brought into view the 
conclusion that it is not exclusively so, from the examples of 
prussic acid and sulphuretted hydrogen, In the latter, acidity 
appeared to be produced by the action of hydrogen. The disco- 
very by Gay-Lussac of the compound radical cyanogen, and its 
conversion into prussic acid by the addition of hydrogen, 
confirmed this conclusion ; and ‘the discovery of the relations of 
iodine still further established it. And now, if the preceding 
views are just, the system must be still further modified. While 
each of these conclusions is just to a certain extent, each of 
them requires to be limited in some of the cases to which they 
are applied; and while acidity is sometimes exclusively 
connected with oxygen, sometimes with hydrogen, the principle 
must also be admitted that it is more frequently the result of 
their combined operation. 
There appears even sufficient reason to infer that from the 
united aetion of these elements, a higher degree of acidity is 
acquired than from the action of either alone. Sulphur affords a 
striking example of this. With hydrogen it forms a weak acid. 
With oxygen, it also forms an acid, which, though of superior 
energy, still does not display much power. With hydrogen and: 
oxygen, it seems to receive the acidifying influence of both, and 
its acidity is proportionally exalted. : 
Nitrogen with hydrogen forms a compound altogether desti-’ 
tute of acidity, and possessed even of qualities the reverse. With 
oxygen in two definite proportions, it forms oxides; and it is: 
doubtful, if in any proportion, it can establish with oxygen an 
insulated acid. But with oxygen and hydrogen in union, ‘it. 
forms nitric acid, a compound more permanent, and of energetic 
action. 
Carbon with hydrogen forms compounds which retain inflam- 
