51 
In some instances I obtained the same bronze or gold- 
like substance by treating copper vanadiate suspended in 
water with sulphurous acid gas, and in many others the 
effect of the gas was formation of vanadic oxide in solution. 
I intend to elucidate this point by further experiments. 
The copper vanadiate was prepared by precipitation of 
ammonium vanadiate with copper sulphate. The mother 
liquor contained both copper and vanadic acid. After 
evaporation the latter is found in the residue as meta- 
vanadic acid, with the same metallic appearance as that 
just described, and can be obtained by washing with water. 
The crystals obstinately retain copper, sometimes as much 
as 12 per cent, which is best removed by repeated treatment 
with aqueous sulphurous acid. A sample of the substance 
so prepared was analysed by Professor Roscoe with the 
following results : 
Weight of substance taken 0.4505 gram. 
Loss on ignition 0 f 0411 „ 
Hence the per centage composition is found to be 
Water 9.12 
Venadium pentoxide 90.88 
100.00 
The samples of vanadium bronze obtained by these three 
different methods had the same composition, the same 
appearance, and the same chemical properties. It is essen- 
tially distinguished from the amorphous brick-red hydrated 
vanadic acid by its indifference to reagents. Sulphurous 
acid scarcely acts on it, neither does ammonia, and even a 
solution of sodium carbonate dissolves it only after very 
long continued boiling. In the air it is perfectly perma- 
nent. It is very probable that this meta-vanadic acid will 
become a favorite bronze, valued even higher than gold. 
