OF GASEOUS BODIES. 1 13 



counteracted and diminished by its affinity for pon- 

 derable matter y by which the (Ethereal atmospheres 

 are drawn into a smaller compass. The reduction 

 of volume and elastic force are referable wholly 

 to this one cause. 



Perhaps the principle cannot be better illus- 

 trated than by a consideration of the statical and 

 dynamical changes that are produced on hydro- 

 gen and chlorine, by their mutual action upon 

 each other. 



We have seen, that the specific gravity and 

 atomic weight of chlorine are 36, compared with 

 hydrogen as 1 ; and that the elastic force of hy- 

 drogen is immense. It has been also shown by 

 Faraday; that the elastic force of chlorine is low 

 that it may be liquefied by a pressure equal to 

 4 atmospheres at the temperature of 60 F.* 



But when 1 volume of chlorine is made to unite 

 with 1 of hydrogen, they form 2 volumes of hydro- 

 chloric acid gas, the specific gravity of which is 

 18-5 ; or a mean between that of its constituents. 

 During this combination, the hydrogen loses the 

 greater part of its elastic force, while that of the 

 chlorine is greatly augmented. That is, a defi- 

 nite proportion of caloric is attracted by the heavier 

 atoms of chlorine from the lighter atoms of hydro- 

 gen, by which its particles are removed farther 



* When combined with aqueous vapour it may be liquefied, and 

 even solidified, at the temperature of 32 F. 



I 



