RED AND WHITE OXIDE OF PHOSPHORUS. 243 
ART. XLII.— UPON THE RED AND WHITE OXIDE OF PHOS- 
PHORUS.— By G. F. Muller, Lecturer in the School of Medicine of 
Rotterdann. 
Pelouze takes the white crusting upon old sticks of phos- 
phorus for a hydrate, and H. Rose does not consider it different 
from ordinary phosphorus, but in consequence of its state of 
aggregation. The red powder which sometimes invests 
phosphorus is prepared by exposing this substance in warm 
water to a current of oxygen gas, in which operation the 
phosphorus unites with this gas, emitting light and develop- 
ing heat. It is hence stated that the red powder is an oxide. 
Some years since I received several cylinders of phosphorus 
which had been kept thirty years in an open bottle exposed 
to the light. Their surface was entirely white and covered 
with a layer of white substance about a millimetre in thickness. 
I placed these cylinders in another bottle filled with pure 
distilled water, and it was not without surprise that, upon 
the following day I beheld them changed entirely to a red; 
and although it is now four years since they have been in 
contact with the light, they still retain the same beautiful red 
colour. 
This observation is opposed to the opinion of Pelouze and 
that of Rose. The only idea I can form of this sudden change 
of the white crust of phosphorus into red oxide by distilled 
water, is that the small quantity of oxygen in the distilled 
water must have changed the white coating into an oxide, and 
since this quantity of oxygen is very small, the white substance 
cannot be an oxide. I presume that the phosphuretted 
hydrogen always formed by phosphorus in water may be the 
cause of it. In order to determine this, I passed a current 
of phosphuretted hydrogen gas through water containing red 
oxide of phosphorus in a stateof extreme division. By this ope- 
ration the red oxide was by little and little reduced to the white 
substance, which, in its turn, was changed after some days to 
