iJ! Questionsjbr Solution relating to Meteorology, 



^ It follows as a necessary consequence of these properties, that 

 the vast extent of sea which covers a large part of the globe, is 

 impregnated with a mixture of gases, the proportions of which, 

 near the surface, must be nearly the same as those just men- 

 tioned. I have ascertained that it is likewise so at the depth of 

 a thousand metres ; for sea-water, drawn from that depth, af- 

 forded me a mixture which contained 28 parts of oxygen in 100. 

 This experiment I formerly made in the Mediterranean. 



But here many important questions in terrestrial physics pre- 

 isent themselves, which the apparatus I then employed did not 

 enable me to solve. In proportion as we descend into the depths 

 of the sea, the pressure of the superior portion becomes greater ; 

 and as a column of sea-water, ten metres in height, is nearly of 

 the same weight as a column of air of the same base from th6 

 surface of the earth to the limit of the atmosphere, it follows 

 that, at the depth of a thousand metres, the water sustains a 

 pressure of a hundred atmospheres. How enormous, then, must 

 this pressure be on the lower beds, if the mean depth of the sea, 

 at a distance from the coasts, extends to several leagues, as the 

 laws of gravitation seem to indicate !* It is likewise proved, by 

 direct experiments, that water, when in contact at the surface 

 with compressed gases, and also sustaining their pressure, ab- 

 sorbs the same volume of these gases as if they were subjected 

 to the pressure of a single atmosphere merely ; so that the weight 

 absorbed becomes proportionably greater. If, then, the sin- 

 gle fact of a uniform absorption, propagated from one bed to 

 another throughout the whole mass of waters, be sufficient to 

 account for the presence of a considerable volume of air, how 

 greatly must the quantity be increased if it be in proportion to 

 the pressure according to the varying depth ! As this satura- 

 tion must have been in gradual operation since the seas were 

 formed, it must have modified by degrees the state of the atmo- 

 sphere, and perhaps continues to modify it still, if the affinity 

 which produces it is not satisfied. The influence of these phe- 

 nomena on the state of the atmosphere, and consequently on the 

 conditions of the existence of living beings on the surface of the 

 globe, well entitles them to be studied in order to have the ex- 

 tent of their operation ascertained. 



• IMecanique Celeste, torn, ii, p. 200. 



