MISCELLANY. 
On the action of weak alkaline solutions upon some of the ■metals 1 by M. 
Vogel de Munich.— (Extract.) I may add some observations upon the 
manner in which the alkalies appear to affect the oxidation of copper. 
Daily experience teaches us that diluted sulphuric acid has the property 
of hastening the oxidation of copper by means of the air. But here the 
acid plays an active part, for it combines with the oxide of copper, which 
is formed by means of the oxygen of the air. 
We cannot arrange, in the same class, the simultaneous action of the 
alkalies and air upon copper, because the diluted solution of the alkalies 
employed, does not suffer any change, or combine with the oxide of cop- 
per formed. 
The alkalies appear, then, to act in a passive manner; nevertheless, 
they tend to set in action, and promote the affinity which exists between 
the copper and the oxygen of the air. 
For this reason, we may consider the phenomena as a catalytic effect, 
similar to that of spongy platinum upon hydrogen and oxygen, or to the 
action which gold has upon the deutoxide of hydrogen. 
We have already, in chemistry, many examples of this kind, in which 
we may perceive an influence purely catalytic, or even a mixed catalytic 
influence ; that is, catalysis accompanied by more or less of affinity. 
CONCLUSIONS. 
It results from the experiment related — 
1. That iron and steel may be protected from rust, by weak alkaline 
solutions. 
2. That bars of steel preserve their metallic lustre even when in contact 
with one another. 
3. That the absence of air is not the cause why steel is preserved from 
oxidation. 
4. That antimony and nikel do not lose their lustre in weak alkaline 
solutions. 
5. That bismuth becomes of a brass-yellow, and afterwards of a purple 
color. 
6. That zinc and cadmium becomes covered with yellowish-gray films. 
VOL. V, — NO, I. II 
