Professor De la Rive on Electricity. 275 



rible, both from their size, and the great density of the liquids 

 It is difficult to conceive how the earthy crust could resist this 

 power, if, as must be granted in this hypothesis, a void space 

 exists between the solid covering and the liquid mass. 



That we may thoroughly analyse, and be able to prove the 

 theory of a solid nucleus, we must go back to the first formation of 

 the earth. This is what M. Ampere has done. He begins by ad- 

 mitting, as Herschel had proposed, supporting his views on the 

 appearance of celestial bodies generally , and more especially of the 

 Nebulae, that the substance of which these luminaries are com- 

 posed was at first in a gaseous state ; which constituted a chaos. 

 All the bodies, whether simple or compound, which have con- 

 curred in the formation of our planetary system, and of the 

 earth in particular, must, at this epoch, have had a tempera- 

 ture higher than that at which the least volatile of all their sub- 

 stances would remain in a liquid state. That liquid or solid 

 bodies should be formed from this immense gaseous mass, it 

 was necessary that it should have cooled down ; and the first 

 deposition would take place, when the temperature descended to 

 that point when the least volatile amongst them would cease to 

 subsist in the state of an elastic fluid. When all this first sort 

 of matter, furnished by a determinate portion of the vast ex- 

 pansive mass, had united in a single liquid body, (a mass which, 

 in virtue of the mutual attraction of all its parts, must have 

 taken the form of a flattened spheroid, if it revolved upon itself), 

 there would be no new deposition, until, by the continuation of 

 the refrigeration, the mass had descended to a temperature at 

 which a second gaseous substance, on being condensed, would 

 become liquid. On this happening, this second substance would 

 be deposited upon the first, around which it would form a 

 concentric layer. By the continuation of the cooling process, 

 the other gaseous substances would successively come to be de- 

 posited. 



Each of these depositions would probably be formed of one 

 single substance, whether it was simple or compound ; for it is 

 difficult to admit, and we find no examples of it, that two dif- 

 ferent substances become liquid at precisely the same degree of 

 temperature. These substances thus deposited in regular and 

 concentric layers, must have probably acted chemically the one 

 upon the other. Hence would result the formation of combi- 



