• 71 



olefiant gas. nitric oxide gas, carbonic acid, nitrogen, ammonia or 

 muriatic acid gas, which, in a proportion varying from a twentieth ot 

 a vohnne to five volumes, will at once take away the property m ques- 

 tion .^secondly, certain porous bodies, more especially charcoal ;— 

 thirdly, various acids, such as sulphuric, arsenious, phosphorous, and 

 phosphoric acids;-/oMrf%, solution of caustic potass and potassium ; 

 -fifthly, alcohol, ether, naphtha, and the various essential oils. 

 These substances produce their effect sometimes in most minute pro- 

 portions, commonly in a very short space of time, and without neces- 

 sarily occasioning any change in the volume of the gas, or any other 

 alteration whatever, except simply the loss of the property of kindling 

 spontaneously on its coming in contact with the air. 



The only agent which the author has found to possess the power 

 of restoring spontaneous inflammability to gas which has b.en de- 

 prived of that property, by keeping or otherwise, is nitrous acid va- 

 pour. A large proportion of this vapour has no such effect, but a 

 small proportion, varying between a thousandth and a ten-thousandth 

 of the gas, will immediately communicate the property of kindling 

 spontaneously in the air, even to the phosphuretted hydrogen pre- 

 pared by heating hydrated phosphorous aci 1, which variety of gas is 

 well known to be always naturally destitute of this remarkable cha- 

 racter. 



Gas which has been rendered spontaneously inflammable in this 

 way is similaily actqd on by keeping, by other gases, by acids, by 

 potassium, and by the hydrocarburets, as the common phosphuretted 

 hydrogen, prepared from lime and phosphorus. 



The author concluded his observations by stating, that the analo- 

 gous action of nitrous acid, and the circumstance that the agents 

 which take away the property of inflaming spontaneously are chiefly 

 deoxidating substances, would lead to the conjecture that this pro- 

 perty is owing to the accidental presence of a minute trace of a com- 

 pound of oxygen and phosphorus not hitherto known, but analogous 

 in composition to nitrous acid among the compounds of oxygen and 

 nitrogen. On account of the extremely minute proportion in which 

 it exists in the spontaneously inflammable phosphuretted hydrogen 

 gas. he WHS unable to insulate it. But an important additional rea- 

 son for believing in its existence appears to the author to be the fact, 

 that while the compounds of phosphorus and of nitrogen severally 

 with oxyf^en coincide in composition in other respects, an oxide of 

 phosphorus has not yet been discovered which coincides in composi- 

 tion with nitrous acid among the oxides of nitrogen. 



