110 REFUTATION OF THE SALT RADICAL THEORY, 
16. I trust that sufficient reasons have been adduced, to 
make it evident that the common result of the extrication 
of hydrogen, during the reaction of zinc or iron with sul- 
phuric or chlorohydric acid, is not a competent ground for 
assuming that there are, in amphide salts, "compound radi- 
cals" playing the same part as halogen bodies. 
17. Let us, in the next place, consider the argument in 
favor of the existence of such radicals, founded on the simi- 
litude of the haloid and amphide salts, which is stated by 
Dr. Kane in the following words: — 
" It had long been remarked as curious, that bodies so different in 
composition as the compound of chlorine with a metal, on one hand, 
and of an oxygen acid with the oxide of the metal on the other, should 
be so similar in properties that both must be classed as salts, and should 
give rise to a series of basic and acid compounds for the most part com- 
pletely parallel." — Elements, p. 681. 
18. Upon the similitude and complete, parallelism of 
the amphide and haloid salts, thus erroneously alleged, the 
author proceeds to argue in favor of the existence in the 
former, of compound halogen bodies, analogous in their 
mode of combination to chlorine or iodine. 
19. I presume it will be granted, that if similitude in 
properties be a sufficient ground for inferring an analogy in 
composition, dissimilitude ought to justify an opposite infer- 
ence. And that if, as the author alleges, certain bodies 
have been classed as salts, on account of their similarity in 
this respect, when dissimilar they ought notlo be so classed. 
Under this view of the question, I propose to examine how 
far any similitude in properties exists between the bodies 
designated as salts by the author or any other chemist. 
20. The salts, hitherto considered as compounds of acids 
and bases, are by Berzelius called amphide salts, being pro- 
duced severally by the union, of one or other of his am- 
phigen class, comprising oxygen, sulphur, selenium, and 
tellurium, with two radicals, with one of which an acid is 
