Prof. Graham on Phosphurettea I Hydrogen, 430 



of one volume phosphuretted hydrogen, and one thousand 

 volumes, or any smaller proportion whatever, of air, sticks of 

 phosphorus remain unaffected, but the phosphuretted hydro- 

 gen itself always undergoes a slow oxidation. In a mixture 

 of one volume phosphuretted hydrogen and two thousand air, 

 phosphorus smoked strongly for some time, but at a certain 

 period the action ceased, and long before the oxygen of the air 

 was exhausted. A minute proportion of phosphuretted hydro- 

 gen is, therefore, sufficient to protect phosphorus from oxida- 

 tion, in which respect this gas resembles 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, namely, by taking 

 the precedence of phosphorus in the process of oxygenation. 

 Phosphorus being, therefore, less oxidable than phosphuretted 

 hydrogen itself, cannot be supposed to take fire, and to in- 

 flame the gas, or be the cause of its accendibility at low tem- 

 peratures. 



On sending electric sparks through non-inflammable phos- 

 phuretted hydrogen itself, phosphorus is deposited; but the 

 gas, while 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 con- 

 fined over mercury, did not affect the gas in the course of 

 forty-eight hours. In this case, moreover, the gas was agi- 

 tated with the water. The gas continues in general sponta- 

 neously inflammable over mercury for forty-eight hours, and 

 sometimes for three or four days, but ceases to be so in a very 

 short time after the admission of a small proportion of air, 

 particularly if the air be added in a gradual manner. Thus, 

 if to the gas be passed up one twentieth part of its bulk of 

 cork or dry stucco, containing air in its pores, a white smoke 

 appears in the gas, and it ceases to be spontaneously inflam- 

 mable in the course of a few minutes. The same mass of 

 stucco, warmed before being passed up into the gas, did not 

 produce the same effect. The self-accendible gas always de- 

 posits on standing a solid matter of a lively yellow colour, con- 

 taining phosphorus, but in quantity too minute for analysis. 

 This matter is not acted on by any of the ordinary solvents, 

 such as alcohol, aether, alkalies, muriatic acid; but is destroyed 

 by chlorine-water and by nitric acid. The precipitation of 

 this matter is most rapid in the case of gas over water, and is 

 indicative of deterioration of the gas. 



3 F2 



