IV THE CELL AND THE ORGANISM 69 



alytic agents existing in colloidal form in the cells and 

 as having at their surfaces or in their ^' fields " the power 

 of transforming other substances in the presence of the 

 energy of sunlight or electricity. They do this according 

 to the well-known chemical and physical laws, without 

 themselves being thereby used up or transformed. The 

 cell has the power to build up or secrete these complex 

 enzyme compounds; with the help of these, again, it manu- 

 factures other complex substances necessary for the plant or 

 animal life. It carries on many other functions beyond 

 these manufacturing processes. Throughout it seems to fol- 

 low simple physical and chemical rules but on a new plan. 

 All this will serve to emphasise how vastly complicated 

 cell structures and activities must be. A large number of 

 the most complicated processes are carried on, scarcely one 

 of which the best-equipped laboratory in the world can 

 perform, and all are carried on by a little cell which is 

 microscopic or smaller in size! 



During recent years resolute attempts have been made to 

 repeat under artificial laboratory conditions what takes place 

 in the living plants, and certain very interesting results 

 have been obtained. Thus an attempt has been made by 

 Professor Baly and others to imitate photo-synthesis in the 

 laboratory. Light of a short wave-length from a mercury 

 vapour lamp was made to act on water and carbon dioxide, 

 and as a result formaldehyde was obtained and, as in the 

 green leaf, oxygen was set free: CO2 + H2O = CH2O + O2. 

 Light with a somewhat longer wave-length was made to 

 turn this formaldehyde into simple sugars.^ However inter- 

 esting and valuable these and similar results are, it is prob- 

 able if not certain that they have only a distant resemblance 

 to what takes place in the organic process, where the physical 

 factors of sunlight and electrical change acting in the field 

 of colloid chlorophyll are quite different, and the chemical 

 results are brought about by mainly different processes. 

 From a scientific point of view, however, the laboratory work 



* It is claimed that sunlight has quite recently been successfully substituted 

 for artificial light in these experiments. 



