90 Mr Granam on Phosphuretted Hydrogen. 
I find, however, that if a small quantity of phosphuretted hydro- 
gen, when not self-accendible, be added to a confined portion of 
air, sticks of phosphorus introduced into that air do not smoke, 
that phosphorus has no disposition to combine with oxygen when 
phosphuretted hydrogen is present. In a transparent mixture of 
one volume phosphuretted hydrogen with one thousand volumes, 
or any smaller proportion of air, sticks of phosphorus remain un- 
affected, but the phosphuretted hydrogen itself always undergoes 
a slow oxidation. In a mixture of one volume phosphuretted 
hydrogen and two thousand volumes air, phosphorus smoked 
strongly for some time ; but at a certain period the action ceased, . 
long before the oxygen of the air was exhausted. A minute pro- 
portion of phosphuretted hydrogen is, therefore, sufficient to pro- 
tect phosphorus from oxidation, in which respect this gas resem- 
bles the hydrocarburets and essential oils, which have been shown 
to be equally efficacious in protecting phosphorus from oxidation. 
All these bodies appear to act in this respect in one way, name- 
ly, by taking the precedence of phosphorus in the process of oxy- 
genation. Phosphorus therefore being less oxidable than phos- 
phuretted hydrogen itself; cannot be supposed to take fire and 
to inflame the gas, or to be the cause of the ascendibility of the 
gas at low temperatures. 
On sending electric sparks through non-accendible phosphu- 
retted hydrogen itself; phosphorus is deposited, but the gas when 
still cloudy from the phosphorus suspended in it, proved to be 
non-inflammable on passing it into air. 
The loss of accendibility in the case of gas confined over water, 
is certainly wholly unconnected with the deposition of any free 
phosphorus from the gas, which may occur, but is due to the rise 
of oxygen from the water into the gas. It was observed that 
water which had been boiled to deprive it of all air, and which 
was then passed up to self-accendible gas confined over mercury, 
did not affect the gas in the course of forty-eight hours. In this 
case, moreover, the gas was agitated with the water. The gas 
