191 1] William J. Gies 43 



in kind and varied in character, but often are also unique; and 

 many are wholly inexplicable on the basis of our present knowl- 

 edge. 



Normal organisms are specially constituted to achieve two fun- 

 damental biological results, vis., their self-preservation and re- 

 production. In effecting its own nutrition, an organism directly 

 adds to its mass and enlarges its structure, as in growth; or it 

 mainly " repairs " its parts, directly or indirectly f rom nutrient 

 material, as in maturity. Nutrient materials (as a group) also 

 supply energy, in one form or another, which is available for trans- 

 formations to the advantage of the organism. Normal reproduc- 

 tion is, in effect, the nutrition of immature organisms derived 

 directly from mature ones. 



These two major functions of normal organisms (self-preser- 

 vation and reproduction) are, in effect, the development, repair 

 and reproduction of structure, as well as the maintenance of con- 

 tinuity in coördinated chemical processes. The mechanico-chemi- 

 cal functions of an organism (external respiration, heart-beat, ex- 

 cretion, etc.) are contributory to the highest efficiency of the major 

 functions just mentioned, and, therefore, are essentially nutritional 

 in ultimate significance. The chemical nature (composition), of 

 an organism, as well as the peculiarities and functions of its tis- 

 sues, are best understood when studied with due regard for the 

 relations of all the parts and constituents to the nutritional 

 processes. 



Normal nutrition, whether in growth, in maturity, or in old 

 age, is primarily chemical in method and constitutes the chief sub- 

 ject-matter of physiological chemistry. Pathological chemistry 

 compromises the facts pertaining to nutrition in disease. The 

 hygiene of nutrition is obviously a matter of fundamental personal 

 and domestic importance. 



With these ideas on the general nature and practical Import of 

 biological chemistry before us, I think I can best perform the 

 function allotted to me by presenting a general outline of the prin- 

 cipal course in general physiological chemistry, that is, in the 

 Clements of normal nutrition, which we have been giving for about 

 six years at the Columbia Medical School, which we have lately 



