Mr Granam on Phosphuretted Hydrogen. 89 
alike, and yet possessing different properties, if established, would 
afford a firm basis for this doctrine. 
It was the importance of the theoretical results which might 
be looked for, that induced me to attempt to continue the inves- 
tigation beyond the point to which it had been carried by Rose. 
Holding the general doctrine of Isomerism as problematical, 
my inquiries were directed to the discovery, in one or other of 
the gases, of some adventitious matter, to the presence of which 
the peculiarities of the species might be attributed. 
It is to be understood that the spontaneously inflammable gas 
made use of in my experiments, was prepared by the well-known 
process of heating phosphorus, lime and water together. This 
gas is spoken of as “ the self-accendible gas,” or as “ the gas 
from phosphuret of lime.” The other gas, which is not sponta- 
neously inflammable, was prepared. by heating hydrated phospho- 
rous acid, or by allowing the preceding species, contained in low 
receivers, to stand over water for twenty-four hours. It is de- 
scribed as “ the non-accendible gas,” “the gas from phosphorous 
acid.” The ascendibility of the gas was judged of by allowing it 
to escape in bubbles into the air from the receiver containing it, 
either over water or mercury. The experiments were all made 
when the temperature of the atmosphere was between 60° and 
70° Fahrenheit. 
1, Inthe process by which the self-accendible gas is procured, 
free phosphorus distils over, of which a trace, in the state of va- 
pour, may well be supposed to remain in the gas for some time. 
Hence the idea has generally presented itself, that the free and 
highly accendible phosphorus present may be the cause of the 
spontaneous inflammability of the gas. Dr Daron, who all along 
maintained, the opinion, which has finally been established by 
Rose, that the two gases are of the same composition, was in the 
habit of referring the spontaneous inflammability of the one spe- 
cies to this cause. The speedy loss of the property in question, 
in the case of gas confined over water, seemed to favour this view. 
VOL, XIII. PART I. M 
