16 On Volcanos and Earthquakes. 



periments made on it, appears to be a compound of 24 oxy- 

 gen, 75 azote, and 1 carbonic acid gas; total 100. Where- 

 as, the air absorbed by water, aUhough a compound of the 

 three same gases, contains them in different proportions. 

 The analysis of the air contained in spring water has been 

 made at different times, in different places, and by different 

 persons, and, consequently, the results are all different and 

 uncertain. The analysis of the air contained in rain water, 

 river water, and particularly sea water, should be the object 

 of our immediate researches, as going more directly to our 

 purpose ; but 1 could not find any publication on this sub- 

 ject. To arrive at any positive result would require no small 

 trouble, and meet with many difficulties, as the analysis 

 should be performed at sea, in different latitudes, and upon 

 water taken at various depths. It is probable, however, from 

 what information we can collect, that the relative propor- 

 tion of the three gases is altered ; that the absorbed air con- 

 tains more carbonic acid, less azote, and the same relative 

 quantity of oxygen, which alteration must increase its densi- 

 ty. These considerations have induced us, in the foregoing 

 table, to represent the density of the air and water by the 

 numbers 800 and 1, instead of 833 and 1. This is the expla- 

 nation we have promised to give. 



The depih of the sea water is not a variable, it is an abso- 

 lute quantity ; a measure which will be determined to a foot 

 by calculation as soon as we have exactly the relation of the 

 three gases it contains. By our computation, which is, how- 

 ever, not far from the truth, we found it twenty-five thou- 

 sand six hundred feet, or four miles and seven-eighths ; but 

 whatever be the depth, at the point of contact, the air must 

 be exactly of the same density with the water. It cannot be 

 more or less ; for, if it were less, it would rise to the surface ; 

 if it were more, a new quantity of it would shower again 

 through the water. 



Air compressed under such an immense weight must have 

 a tremendous force of elasticity. It is superior to any thing 

 we have as yet produced in our most powerful engines, not 

 excepting Perkins' high pressure steam artillery ; so that, if 

 we conceive a tube of sufficient length and resistance to 

 open a communication through the sea between that im- 

 mense reservoir of compressed air and our atmosphere, the 

 projectiles placed in this tube would acquire a velocity seve- 

 ral times greater than that of a cannon ball -, this air then 



