346 GENERAL PHYSIOLOGY 



minutest details, and it were possible artificially to establish them 

 exactly, life could be produced synthetically, just as fire is pro- 

 duced, and the ideal that existed in the imagination of the mediae- 

 val alchemists in their attempted production of the homunculus 

 would be achieved. 



But, notwithstanding the fact that this theoretical possibility 

 cannot be denied, every attempt at the present time to produce 

 life artificially and to imitate in the laboratory the obscure act of 

 spontaneous generation must appear preposterous. So long as our 

 knowledge of internal vital conditions, i.e., of the composition of 

 living substance, is so imperfect as it is now, the attempt artificially 

 to compound living substance will be like the undertaking of an 

 engineer to put together a machine the most important parts of 

 which are wanting. For the present the task of physiology can 

 consist only in the investigation of life. When physiology shall 

 actually have accomplished this, it may think of testing the 

 completeness and correctness of its achievement by the artificial 

 inauguration of life. 



