REPORT ON MINERAL AND THERMAL WATERS. 73 



globe, and probably pervades every portion of its solid contents, 

 is a factj of which a little reflection will convince us. 



Independently of, the cracks and fissures, by which the earth's 

 crust is everywhere intersected, the large cavities it so frequently 

 envelopes, and its general porosity and permeability to water 

 containing air in solution, the solid strata themselves have the 

 property, as has been shown by Saussure*, in various degrees, 

 of absorbing oxygen and nitrogen gases ; though it is to be re- 

 marked, that by a curious provision of nature, apparently de- 

 signed to forward the process of internal oxidation, the two 

 gases are absorbed, not in the proportion of five to one, but in 

 nearly equal ratios. 



Professor Meinecke of Hallef is the only person, so far as I 

 know, who has availed himself of this, as a principle on which 

 to explain other phsenomena ; and his remarks, owing to certain 

 loose and fanciful speculations interwoven with them, have not 

 yet obtained much attention. 



Nevertheless, if it be true, that air pervades even the solid 

 portions of our globe, down at least to a considerable depth, it 

 seems not absurd to imagine, that it may suddenly be augmented 

 by an increase of atmospheric pressure above, or diminished by 

 processes taking place in the interior of the earth. ^ 



Such, in the main, are the views of Professor Meinecke, who 

 imagines the amoiint of air retained in the interior of the earth, 

 to be in a state of constant oscillation, and thus, reacting upon 

 the atmosphere above, to be one of the causes of the variation 

 of the barometer. He even attributes, to an extraordinary ab- 

 sorption of air within the earth, a remarkable sinking of the 

 barometer, which took place without any other assignable cause 

 at Christmas 1821. 



The sulphuretted hydrogen, which so many springs contain, Origin of 

 has been attributed to the action of organic matter upon alka- the sui- 

 line and earthy sulphates; and M. Henry of Paris t has cited hydro"en. 

 an example, where a spring, which at its source contained sul- 

 phates of soda, magnesia, and lime, but no sulphuretted hydro- 

 gen, was found to have acquired a trace of that gas, at the ex- 

 pense of its sulphuric acid, after mixing with the water of a 

 washing place. 



It seems probable, that the hepatic smells, which occur in the 

 waste and stagnant waters of towns, sometimes arise from this 



* Bihliotheque Britannu/ue, vol. xlix. p. 319. 

 t Schweigger's Journal, vol. viii. 1823. 

 X Jowual do Pharmanic for 1827, p. 493. 



