14 BIOLOGICAL ASPECTS OF HUMAN PROBLEMS 



gains in knowledge. Of the simpler proteins more 

 is known, and the chemical components of some of 

 the simplest are established. What concerns us 

 here is the fact that some bodies related to simplest 

 proteins have been made by chemical synthesis. In 

 1829 the noble-minded German chemist Wohler 

 convinced skeptical scientists that he could make 

 urea from ammonium cyanate. This was an epoch- 

 making discovery, for it showed that the chemist 

 can synthesize an organic substance formed in nature 

 by the animal body only. Now we have been shown 

 by Fischer that certain natural proteins can be made 

 in the laboratory. Yet this admirable achievement 

 leaves a wide gap to the synthesis of living proto- 

 plasm. It is certain that no one has yet transformed 

 dead into living matter. The satisfactory synthesis 

 of higher proteins would be a step, but only a step, 

 in the right direction. It is true that Verworn has 

 defined life as the metabolism of proteins, but the 

 conception is patently inadequate. In order to 

 feel sure that success has been reached in converting 

 dead into living 'matter, it would be necessary to 

 show that the artificial substance is capable of growth 

 and reproduction. For me it seems inconceivable 

 that any artificial product should be capable of 

 reproducing and growing, since these functions 

 imply an organization based on hereditary experi- 

 ences, memories, and processes which there is little 

 hope of blindly imitating. Brooks eloquently, if 

 not convincingly, touched the heart of the difficulty 



