172 
the solution, we must conclude that either hyposulphite of 
nickel is not decomposed by sulphurous acid like the 
cadmium or zinc salt, but, under the influence and in contact 
with the metal and sulphurous acid, is converted into 
sulphuric acid, separating thereby sulphur, which combines 
with the nickel, thus :— 
2 (NiO,S,0,) + SO, =2 (Ni0,SO,) + 38 
or we have to admit a secondary reaction of the sulphurous 
acid upon the metallic nickel, thus :—= 
- 2Ni+2(SO,) = NiO,SO, + NiS 
I should decidedly favor the former view, which does not 
appear to be so very strange, if we remember that sulphurous 
and hyposulphurous acids are decomposed differently when 
combined with different oxides. I only recall the prepar- 
ation of trithionic acid either from bisulphite of potassa 
with flowers of sulphur, or from hyposulphite of potassa by 
sulphurous acid. We do not get trithionic acid if we take in 
these cases, soda instead of potassa salts. 
However we have in the fluid, after allowmg the reaction 
to proceed for a considerable length of time, NiO,SO, ; NiO, 
SO,; Ni0,8, O,; Ni8. | 
Aluminium and Magnesium with Sulphurous Acid.— 
These two metals dissolved readily, the fjrst in cold, the 
second in hot sulphurous acid. No sulphur is separated in 
the fluid, and no sulphuretted hydrogen gas is observed, 
as has been already mentioned. But upon analyzing the 
clear solution, we find in both cases SO,; SO,; 5,0,; 8, 
Oe. ) 
The presence of SO, and 8, O,, and the non-appearance 
of S, forces us to.admit two or three reactions taking place 
simultaneously and independently of each other. The first, 
the solution of the’ metal by decomposing water, liberating 
hydrogen, and dissolving as oxide in the sulphurous acid ; 
the second, the action of sulphurous acid upon the metal, by 
forming a sulphide and hyposulphite, and the third by form- 
ing a sulphate, hyposulphite, and trithionate. 
