178 On the Specific Gravity of the Gases, [March, 



On that account I think it will be useful to publish a new table 

 here. I shall at the same time give the authorities upon which 

 the specific gravities depend. 



Tahle of the Specific Gravities of the Gases. 



Names of the Gases, 



1 Air 



2 Phosgene gas 



3 Silicated fluoric acid . . 



4 Chlorine 



5 Nitrous acid 



6 Euchlorine 



7 Fluoboracic 



8 Vapour of ether 



9 Sulphurous acid ...... 



10 Vapour of alcohol .... 



1 1 Nitrous oxide ........ 



12 Carbonic acid 



13 Muriatic acid 



14 Sulphureted hydrogen . 



15 Oxygen 



16 Nitrous gas 



1 7 Olefiant gas 



18 Azote 



19 Carbonic oxide , . . . . 



20 Hydrophosphoric , . . . 



21 Steam 



22 Ammonia . 



23 Carbureted hydrogen . . . , 



24 Arsenical hydrogen . . . . . 



25 Phosphureted hydrogen ^ 



26 Hydrogen 



speciiic 

 erravitv. 



Weight of 

 100 Cubic 

 Inches. 



1 -0000 



30*50grs. 



3*669 



111*91 



2-990 



91*195 



2*483 



75*731 



2*427 



74*0234 



2*409 



73*474 



2-370 



72*31 



2*250 



68-625 



2*193 



66*89 



2*1 



64-227 



1*614 



49*227 



1-518 



46*313 



1*278 



38*979 



1-177 



35-89 



ri04 



33-672 



1*0388 



31*684 



0*974 



29-72 



0*969 



29-56 



0-956 



29-16 



0*870 



26*53 



0*6896 



21-033 



0*590 



18-000 



0*555 



16-99 



0-529 



16-134 



0-852 



25-986 



0*435 



13*265 



0-073 



2-230 



These specific gravities, as the reader will perceive, are all 

 referred to that of common air, which is reckoned unity. Sir 

 Humphry Davy has adopted hydrogen as the standard, because 

 it is the lightest ; but there are two objections to the adoption of 

 such a standard : 1 . Pure air can be obtained every where ; and 

 it is, in fact, by comparing the weight of the gas examined with 

 that of an equal bulk of common air that its specific gravity is 

 determined. To adopt hydrogen as a standard would be to add 

 another step to the process b^ which specific gravities are deter- 



