228 TRANSFORMATION AND EQUIVALENCE OF FORCES. 



physical forces elsewhere stored up in fit forms and then 

 brought here. 



If we ask whence come these physical forces from which, 

 through the intermediation of the vital forces, the social 

 forces arise, the reply is of course as heretofore the solar 

 radiations. Based as the life of a society is on animal and 

 vegetal products; and dependent as these animal and vegetal 

 products are on the light and heat of the sun ; it follows that 

 the changes going on in societies are effects of forces having 

 a common origin with those which produce all the other 

 orders of changes that have been analyzed. Not only is the 

 force expended by the horse harnessed to the plough, and by 

 the labourer guiding it, derived from the same reservoir 

 as is the force of the falling cataract and the roaring hurri- 

 cane; but to this same reservoir are eventually traceable 

 those subtler and more complex manifestations of force 

 which humanity, as socially embodied, evolves. The asser- 

 tion is a startling one, and by many will be thought ludi- 

 crous ; but it is an unavoidable deduction which cannot here 

 be passed over. 



Of the physical forces that are directly transformed into 

 social ones, the like is to be said. Currents of air and water, 

 which before the use of steam were the only agencies 

 brought in aid of muscular effort for the performance of in- 

 dustrial processes, are, as we have seen, generated by the 

 heat of the sun. And the inanimate power that now, to so 

 vast an extent, supplements human labour, is similarly de- 

 rived. The late George Stephenson was one of the first to 

 recognize the fact that the force impelling his locomotive, 

 originally emanated from the sun. Step by step we go back 

 from the motion of the piston to the evaporation of the 

 water; thence to the heat evolved during the oxidation of 

 coal; thence to the assimilation of carbon by the plants of 

 whose imbedded remains coal consists; thence to the car- 

 bonic acid from which their carbon was obtained; and 

 thence to the rays of light that de-oxidized this carbonic 



