10 THE THEORY OF IONS 



definite forms of crystalline architecture are produced. 

 Thus molecular force becomes structural. It re- 

 quired no great boldness of thought to extend its 

 play into organic nature, and to recognise in mole- 

 cular force the agency by which both plants and 

 animals are built up." 



It may be considered proved that all the energy 

 of this earth is derived from the sun. Growth and 

 reproduction have, however, been supposed to be 

 the production of a special kind of energy called 

 vital force, under the influence of which plants and 

 animals exhibit the special manifestations of a 

 living organism. But within the last generation 

 our ideas of the vital processes have become con- 

 siderably changed, and few observers at the present 

 day would argue that all the phenomena observed 

 in an organism are the result of a single kind of 

 energy or force. Indeed, from our knowledge of the 

 transformation of energy, the phenomena of vitality 

 may be considered to be due to a combination of 

 forces acting in harmony ; and, as we travel back- 

 ward in our analysis, we arrive at the conclusion 

 that the sun is the physical source of that exhibition 

 of force which we call life. The matter in living 

 organisms is the same as the matter of inorganic 

 substances. No substance in an animal or vegetable 

 differs from the same substance in the earth, air or 

 water. Every portion of an organic being can be 

 reduced to purely inorganic matter. Is the force 

 which is required to form organic substance in an 

 animal body different from the force or forces 

 required to form the same substances outside the 

 organism ? True it is that certain protein sub- 



