600 THE OUTLOOK 



The biochemical relations between the soil and its bacterial flora 

 on the one hand and the crop on the other is already a flourishing 

 field of investigation, and the results of these inquiries have led to 

 very important improvements in agricultural practice. The further 

 development of this field, and especially the expansion of our knowledge 

 of the metabolism and symbiotic relations of bacteria, will point the 

 way to a multitude of new industrial and agricultural applications. 

 The subject of plant-pathology is also intimately related to biochemistry 

 and the investigation of the biochemical conditions underlying gall- 

 formation, for example, will undoubtedly shed a flood of light upon 

 the essential nature of the internal factors which govern the growth 

 of plants. 



It is in the practice of medicine, however, that the applications 

 of biochemistry will ultimately come to affect human welfare most 

 directly and profoundly. At the present moment the advances of 

 biochemical knowledge and technique are rapidly furnishing the 

 physician with diagnostic methods of precision, and indications for 

 treatment based upon exact knowledge, where but a few years ago 

 empiricism afforded the sole basis of treatment. The discoveries 

 which lie before us, however, will ultimately transform the scope, and 

 revolutionize the practice of medicine, and the substitution of knowl- 

 edge for empiricism, of science for craftsmanship, as yet barely begun, 

 will not cease until it is complete. The life of man may be regarded 

 from a material point of view as consisting on the one hand of a struggle 

 to obtain nutriment, clothes, and other essentials of existence, and on 

 the other hand a struggle to withstand the deleterious influences of 

 his environment and the imperfections of his own organization. Our 

 environment opposes us with climatic fluctuations and extremes, and 

 with pervading toxic agents, and an ever-present host of parasitic 

 organisms continually seeking, and barely failing in the conquest of 

 our tissues. On the other hand we display the imperfection of our 

 organization in disorders of function and in the culminating disorder 

 of senescent atrophy. 



Each of these disabilities we are seeking to conquer and in their 

 conquest and control biochemistry must necessarily play a leading 

 if not an absolutely decisive part. Our resistance to toxic agents of 

 environmental or endogenous origin is rendered possible by a peculiar 

 mechanism of adaptation, or " tolerance," which we as yet understand 

 very imperfectly. Its understanding and control will constitute one 

 of the most important among the forthcoming advances of our knowl- 

 edge, and must result, not only in a greatly improved knowledge of 

 the fundamental mechanisms of adaptation, but in throwing a flood of 

 light upon pharmacological science and therapeutic practice. The 

 advances of recent years have demonstrated to us that our resistance 

 to the invasion of parasites is determined by specific chemical agents 

 which our tissues manufacture the various antibodies. The chemical 

 nature of these substances is as yet hardly understood at all, yet this 



