Principle of the Conservation of Energy. 61 



perpetuity of the forces of nature had made such progress in 

 all branches of Natural Philosophy, that there was scarcely any 

 doubt left that this principle would be found to comprise a true 

 law for the whole of nature, and perhaps one of the grandest 

 and most successful laws known to us. 



The first conclusion I drew from the said principle was this : 

 As no power is lost in nature, so no power is able to grow up in 

 nature except at the expense of some other power. But if we 

 accept the hypothesis of the celebrated Kant and Laplace, which 

 supposes the world originally given by the Creator as an ex- 

 tremely subtile elastic fluid, rotating round an axis, and kept 

 together by the mutual gravitation of the particles of the fluid, 

 which they supposed to contain all the chemical elements, the 

 new principle allows us to go back one step more than Kant 

 and Laplace did, and to commence with the supposition that 

 the original material substance had none of the qualities which 

 characterize the chemical elements, except in so far as it was 

 subject to the force of gravitation. Then, according to the said 

 principle, it is evident that, without generating a quantity of 

 energy {vis viva) equal to the work done by the force of gravity, 

 no condensation of the fluid could take place ; and as no loss of 

 energy could occur, it may be admitted that the quantity of 

 energy generated made its appearance in the form of electricity 

 or chemical affinity, different in quality and quantity according 

 to the situation of the matter in the universal globe, which, 

 during the conversion of the quantity of energy thus generated 

 into chemical affinity, may be supposed to have divided itself 

 into a great number of smaller globes in a more or less fluid 

 condition. 



As soon as the different chemical substances came into con- 

 tact with each other, chemical action of course began, and the 

 heat was raised very considerably ; but as the pressure and heat 

 were very different in different parts — of the earth, for instance, 

 — it is possible to understand how the variety of minerals could 

 arise which compose the crust of the earth, and of which it must 

 necessarily be composed in order that organized beings may be 

 able to live upon it. During these great preparations, by which 

 the earth was acquiring its adaption to the future life upon it, the 

 chemical forces were in a great measure converted into heat, a part 

 of which is preserved in the earth so as to keep the temperature 

 of the surface very nearly constant. 



At the same time that the material substances were losing 

 their violent characters, the surface of the earth was passing over 

 from the fluid into the solid state to give a field for a vigorous 

 vegetation, which directly appeared as soon as the ground was 

 so far prepared that the plants could meet with the forces pro- 



