M. R. Bunsen on the Law of Absorption of Gases. 127 



4. Carbonic Oxide in Water. 



The gas was prepared by heating sulphuric acid with pure 

 formiate of magnesia ; treatment with a ball of potash showed it 

 to be perfectly pure. 



If the mean value from 1, 2, 3, from 2, 3, 4, 5, and from 

 4, 5, 6, be taken for the calculation of the constants, we get the 

 following formula : — 



c=0-032874-0-00081632* + 0-00001642 U 2 . . . (21) 



This gives for the temperature from 0° to 20°, — 



5. Protocarburetted Hydrogen in Water. 



I have used for this determination a gas, preserved in her- 

 metically-closed tubes, which is found in the mud-volcanoes of 

 Bulganack in the Crimea, where it occurs under similar circum- 

 stances as at Baku on the Caspian Sea. This gas was employed 

 because it appeared from my researches that it is the purest 

 which occurs in nature. By treatment with a potash ball, it was 

 freed from a trace of carbonic acid, and it contained, as the fol- 

 lowing analysis shows, neither nitrogen, oxygen nor olefiant gas: — 



