296 Dr. Murray on Muriatic Acid, [APRin, 
speculation with regard to the imaginary metallic base ammo- 
nium, and the existence of oxygen in ammonia and in nitrogen 
falls to the ground, while the anomaly presented by this alkali is 
removed. If the claim of the lately discovered principle in 
opium, Morphia as it has been named, to the distinction of an 
alkali be established, as from its origin it must probably have a 
compound base, it may, if it contain hydrogen, bear the same 
relation to the other alkalies that prussic acid does to the acids ; 
on it contain oxygen, it will be analogous to the vegetable 
acids. 
The fixed alkalies and the alkaline earths are considered as. 
containing water in intimate combination in a definite propor- 
tion; and it is doubtful if they can be obtained free from it in 
an insulated state, retaining at the same time their alkaline 
properties. It is obvious, however, that the elements of water 
may exist in combination with the base; that potash, for 
example, is not a compound of an oxide of potassium with 
water, but of potassium, oxygen, and hydrogen. Hence when, 
on adding water to peroxide of potassium, potash is produced, 
and oxygen gas is disengaged; this is not owing, as has been 
supposed, to the excess of oxygen in the peroxide being expelled, 
and the water taking its place; but to the water being decom- 
posed, and a portion of its hydrogen entering into the combina- 
tion, to form the alkali, while the corresponding oxygen is 
liberated. If hydrogen were brought to act on peroxide of 
potassium, the alkali would in like manner be formed. With the 
peroxide of barium, this very change, from the action of 
hydrogen, takes place ; the hydrogen, according to the usual 
explanation, combining with its cxygen, and forming water, 
which unites with the real earth, forming the hydrate ; in other 
words, and according to the strict expression of the fact, the 
hydrogen entering into the composition, and forming the barytes ; 
a result perfectly analogous to the formation of muriatic acid 
from oxymuriatic gas by the agency of hydrogen. 
The evidence in support of this doctrine, it is evident, is of 
the same kind as that with regard to the doctrine applied to the 
acids. There is the same superior probability in favour of 
the conclusion that the elements of water rather than water 
itself exist in these compounds, from the consideration that 
modifications of properties so important are more likely to arise 
from the agency of these elements than from any action which 
water can exert. And that water does not exist in them in 
consequence of the strength of attraction which the real alkali, 
as it has been considered, exerts towards it, is evident from this, 
that on the same principle ammonia ought to contain combined 
water in its insulated form, which is not the case. The combi- 
nation of water, therefore, or rather of its principles, in these 
compounds, depends on relations subsisting among the ultimate 
_ elements, not on an affinity exerted by the alkali itself; and this 
