BODIES GENERALLY EXISTING AS GASES. 173 



These numbers may all be taken as the results of experiments. Where the tem- 

 peratures are not those actually observed, they are in almost all cases within a degree 

 of it, and proportionate to the effects really observed. The departure of the real ob- 

 servations from the numbers given is very small. This table I consider as far more 

 worthy of confidence than the former, and yet it is manifest that the curve is not 

 consistent with the idea of a pure single substance, for the pressures at the lowest 

 temperature are too high. I believe that there are still two bodies present, and that 

 the more volatile, as before said, is condensable in the liquid of the less volatile ; but 

 I think there is a far smaller proportion of the more volatile (nitrogen, or whatever 

 it may be) than in the former case. 



Olefiant gas. — The olefiant gas condensed in the former experiment was prepared 

 in the ordinary way, using excellent alcohol and sulphuric acid ; then washed by 

 agitation with about half its bulk of water, and finally left for three days over a thick 

 mixture of lime and water with occasional agitation. In this way all the sulphurous 

 and carbonic acids were removed, and I believe all the ether, except such minute 

 portions as could not interfere with my results. In respect of the ether, I have since 

 found that the process is satisfactory ; for when I purposely added ether vapour to 

 air, so as to increase its bulk by one-third, treatment like that above removed it, so as 

 to leave the air of its original volume. There was yet a slight odour of ether left, but 

 not so much as that conferred by adding one volume of the vapour of ether to 1200 

 or 1500 volumes of air. I find that when air is expanded Jth or Jrd more by the 

 addition of the vapour of ether, washing first of all with about -roih of its volume of 

 water, then again with about as much water, and lastly with its volume of water, 

 removes the ether to such a degree, that though a little smell may remain, the air is 

 of its original volume. 



As already stated, it is the presence of other and more volatile hydrocarbons than 

 olefiant gas, which the tensions obtained seemed to indicate, both in the gas and the 

 liquid resulting from its condensation. In a further search after these I discovered 

 a property of olefiant gas which I am not aware is known (since I do not find it re- 

 ferred to in books), namely its ready solubility in strong alcohol, ether, oil of turpen- 

 tine, and such like bodies*. Alcohol will take up two volumes of this gas ; ether can 

 absorb two volumes; oil of turpentine two volumes and a half; and olive oil one 

 volume by agitation at common temperatures and pressure ; consequently, when a 

 vessel of olefiant gas is transferred to a bath of any of these liquids and agitated, 

 absorption quickly takes place. 



Examined in this way, I have found no specimen of olefiant gas that is entirely ab- 

 sorbed ; a residue always remains, which, though I have not yet had time to examine 

 it accurately, appears to be light carburetted hydrogen ; and I have no doubt that 

 this is the substance which has mainly interfered in my former results. This sub- 



* Water, as Bekzelius and others have pointed out, dissolves about ^th its volume of olefiant gas, but I 

 'find that it also leaves an insoluble residue, which bums like light carburetted hydrogen. 



