58 Huistence of Radicals in the Amphide Salts disproved. 
7. I fully concur with Gregory and Kane, in considering that 
water in hydrous sulphuric acid, in nitrie acid, chloric acid, and 
in organic acids, generally acts as a base; also, that in this basic 
water hydrogen performs a part perfectly analogous to that of a 
metallic radical; but, agreeably to this view, I cannot perceive 
any difficulty in accounting for the evolution of hydrogen, as 
suggested in the quotation above made, (6,) agreeably to which, 
when diluted sulphuric acid reacts with zine or iron, the libera- 
tion of hydrogen results from the superiority of the forces which 
tend to insert either of these metals in the place occupied by the 
hydrogen, over those which tend to retain it 77 statu quo. 
8. When oxide of copper is presented to chlorohydric acid, it 
is inferred that the hydrogen unites with oxygen, and the chlo- 
rine with the metal; and hence it seems to be presumed, that 
when oxide of copper is combined with sulphuric acid, a similar 
play of affinities should ensue: but would it be reasonable to 
make this a ground for assuming the existence of a compound 
radical, when the phenomena admit of another explanation quite 
as simple and consistent with the laws of chemical affinity ? 
9. Whether hydrogen be replaced by zinc, or oxide of hydro- 
gen by oxide of copper, cannot make any material difference. In 
the one case, a radical expels another radical, and takes its place ; 
in the other, a base expels another base, and takes its place. 
10. There can be no difficulty, then, in understanding where- 
fore, from the compound of sulphur and three atoms of oxygen, 
and an atom of basic water, hydrogen should be expelled and re- 
placed by zine, or that water should be expelled and replaced by 
oxide of copper; the only mystery is in the fact, that SO?, as an- 
hydrous sulphuric acid, will not combine with hydrogen, copper, 
or any other radical, unless oxidized. But this mystery equally 
exists on assuming that an additional atom of oxygen converts 
SO? into oxysulphion, endowed with an energetic affinity for 
metallic radicals, to which SO® is quite indifferent. 
1L. In either case, an inexplicable mystery exists; but it is, in 
the one case, associated with an hypothetical change, in the 
other, with one which is known to take place. 
12. But if hydrous sulphuric acid is to be assumed to be a hy- 
druret of a compound halogen body, (oxysulphion, ) because it 
evolves hydrogen on contact with zinc, wherefore is not water, 
which evolves hydrogen on contact with potassium, sodium, ba- 
