660 SCIENCE PROGRESS 



uniformly distributed throughout its environment also becomes 

 dissipated. In organic systems in which potential energy passes 

 into the kinetic form, that is, in the animal, there is no such 

 necessary tendency, for the sensori-motor system is such that 

 the kinetic energy resulting from the processes of metabolism 

 can be directed. It may at once be truly dissipated, but it may 

 also be transformed into available energy. An animal may 

 uselessly dissipate its energy, with no other result than to cause 

 mechanical friction ; but it may also so use it as to create 

 differences of potential, whereby a part, at least, of the energy 

 transformed remains available for further change. In organic 

 systems in which potential energy accumulates, that is, in the 

 plant organism, the same tendency is carried much further, 

 inasmuch as stable chemical compounds of high energy-value 

 are formed as the result of the life-process. Thus in organic 

 systems generally the tendency of their energy-transformations 

 is opposed to that which characterises inorganic systems. In 

 the latter entropy is continually augmented ; in the former 

 entropy-augmentation is arrested. 



Further, the organism is that which affects compensatory energy- 

 transformations] and the more we think of it in this way the 

 more clearly do we appreciate the distinction between the 

 organic and the inorganic system. The green plant with its 

 environment, is the theatre of a twofold energy-transformation ; 

 on the one hand certain parts of the whole transform irreversibly 

 into the compounds water and carbon dioxide, while, on the 

 other hand, part, that is, the energy of radiation, transforms in 

 such a way as to reverse the tendency to dissipation which is 

 the result of the katabolism of the plant or its associated animal 

 life. The plant itself, that is, something which is neither the 

 metabolising proteid and carbohydrate, nor the carbon dioxide 

 and water, couples together the energy of radiation with the 

 transformed carbon dioxide and water so as to form carbo- 

 hydrate. This is essentially what occurs in the sjmthesis, with 

 absorption of available energy, of a chemical compound in the 

 conditions of the laboratory. Some substance which has never 

 been found apart from the tissues of a plant or animal is formed 

 from the inorganic materials by the chemist who sets up a 

 compensatory transformation. Clearly such syntheses do not 

 prove that there is no distinction between the organic and in- 

 organic, since they are effected by precisely the same means as 



