106 Mr Graham on Phosphuretted Hydrogen. 



That the vapour of some acid of nitrogen, which, in the pre- 

 sent state of our knowledge of that class of compounds, seems to 

 be the nitrous acid, is capable of rendering phosphuretted hydro- 

 gen spontaneously inflammable, when present to the extent of 

 one ten-thousandth part of the volume of the gas : 



That the last gas has a general resemblance to phosphuretted 

 hydrogen, as obtained in the spontaneously inflammable state by 

 ordinary processes, which, it is probable, owes its ready accendi- 

 bility to the presence of an equally minute trace of a volatile 

 compound of phosphorus and oxygen, analogous to nitrous acid. 



