VITALITY. 47 



assumed would have assented, in a general way, to its 

 correctness. Their assent, however, was more poetic 

 than bcientific, and they were by no means prepared to 

 see a rigid mechanical signification attached to their 

 words. This, however, is the peculiarity of modern 

 conclusions : that there is no creative energy what- 

 ever in the vegetable or animal organism, but that all 

 the power which we obtain from the muscles of man 

 and animals, as much as that which we develop by the 

 combustion of wood or coal, has been produced at the 

 sun's expense. The sun is so much the colder that we 

 may have our fires ; he is also so much the colder that 

 we may have our horse-racing and Alpine climbing. It 

 is, for example, certain that the sun has been chilled 

 to an extent capable of being accurately expressed in 

 numbers, in order to furnish the power which lifted this 

 year a certain number of tourists from the vale of 

 Chamouni to the summit of Mont Blanc. 



To most minds, however, the energy of light and 

 heat presents itself as a thing totally distinct from 

 ordinary mechanical energy. Either of them can never- 

 theless be derived from the other. Wood can be raised 

 by friction to the temperature of ignition ; while by 

 properly striking a piece of iron a skilful blacksmith 

 can cause it to glow. Thus, by the rude agency of his 

 hammer, he generates light and heat. This action, if 

 carried far enough, would produce the light and heat of 

 the sun. In fact, .the sun's light and heat have actually 

 been referred to the fall of meteoric matter upon his 

 surface ; and whether the sun is thus supported or not, 

 it is perfectly certain that he might be thus supported. 

 Whether, moreover, the whilom molten condition of our 

 planet was, as supposed by eminent men, due to the 

 collision of cosmic masses or not, it is perfectly certain 

 that the molten condition might be thus brought about. 



