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Dr. Hare on the Salt Radical Theory. | Sow 
the metal is not oxidized ; but even when present, hydrogen can- 
not be the cause or regulator of the affinity ; and to suppose that 
when absent, it imparts affinity or capacity, strikes me as unrea- 
sonable. Was there ever a greater heresy in science, than this 
idea, that thirty-six parts by weight of chlorine, combine with 
forty of potassium, not because it is the nature of these elements 
to unite in these proportions, but because one of them has been, 
is now, or may hereafter be united by a much more feeble affinity 
to one part of hydrogen, With all due deference for the author, 
the efficiency attributed to hydrogen, by him, appears to me as 
SS apaneg as it is anomalous 
. But is it with the dhiowide of hydrogen only that the bin- 
~ of mercury will yield a bichloride? May not this last 
mentioned compound, the well known corrosive sublimate, be 
obtained by sublimation of the sulphate or nitrate of the binoxide 
of mercury with various chlorides ? 
22. It is assumed, by Liebig, in his lecture above mentioned, 
to be a general law, that the number of equivalents of acid requi- 
site to saturate a base, is equal to the number of atoms of oxy- 
gen which it may contain. His words are: “ one equivalent of 
oxygen in a base sayin one equivalent of acid, two require 
two, three require three.” In the next paragraph the fact is 
cited, that protoxide of potassium will take only one equivalent 
of acid to saturate it. But if the preceding allegation be true, 
how does it happen that the peroxide of potassium does not take 
even one equivalent of acid, unless by being resolved into a pro- 
toxide, so that the addition of oxygen, instead of producing the 
result which flows from this general law, actually has an effect 
diametrically opposite? The same allegation may be truly made 
of the peroxides of each of the metals of the alkalies or of the 
alkaline earths. Yet the protoxides of potassium and sodium 
both unite with two equivalents of sulphuric acid. 
_ In the instances of lead, tin, antimony and manganese, 
the addition of oxygen beyond a certain amount, destroys the 
affinity for acids attendant on inferior degrees of oxidation, no 
less than in the instances above mentioned. 
24, Among the evidences adduced by Liebig, as justifying the 
law above mentioned, is the fact, that in the persulphates of iron 
and chromium, two atoms of metal, taking three of oxygen to 
form a sesquioxide, one atom of the sesquioxide requires for 
