158 POPULAR SCIENCE MONTHLY. 



epinephrin? Where is there a more active agent in modifying the 

 nutritional processes of the body than the iodine-containing constituent 

 01 the thyroid, the iodothyrin. These may truly be counted as repre- 

 senting a type of substances manufactured or secreted primarily for the 

 physiological effect they are capable of exerting; but what about the 

 host of other substances present in the body, many of them simple 

 products of katabolism ? May they not have some marked physiological 

 property that if known would serve a sufficient excuse for their forma- 

 tion ? Or, may they not possess some hidden or obscure property which 

 if once understood would make clear a secondary or subsidiary function 

 of no small import for the maintenance of physiological equilibrium, 

 or for the welfare of the body? Many suggestions and some facts pre- 

 sent themselves, illustrating how direct and indirect influences may be 

 exerted, all pointing toward the harmonious action and interdepend- 

 ence in function of many of the substances formed in the body. Some, 

 however, undoubtedly have more or less of a toxic action, especially 

 when formed in excessive or undue amounts. Thus, the alloxuric bases 

 seemingly cause fever when injected into the circulation or taken per 

 os,* and according to the recent observations of Mandelf there is a very 

 striking relationship between the quantity of alloxuric bases eliminated 

 in the urine and the temperature of the body in cases of aseptic fevers, 

 indicating that these substances, with possibly other incomplete products 

 of tissue metabolism, are important factors in the production of febrile 

 temperature. We may confidently expect that a thorough study of 

 the physiological action of all the varied katabolic products formed in 

 the body will result in a decided expansion of our knowledge regarding 

 the part these substances may play in normal and abnormal metabolism, 

 and in nutrition in general. 



Just here, reference may be made to the many problems in the broad 

 field of nutrition that confront the physiological chemist of the present 

 day. The maintenance of life on a sound physiological basis is one 

 of the practical problems in physiological chemistry, and its solution 

 is not yet attained. We need fuller knowledge regarding the part 

 played by the different nitrogenous food-stuffs, the relative physiological 

 value of animal and vegetable proteid, the relative value of fats and 

 carbohydrates as nutrients aside from their different calorific power, 

 and by no means least a fuller and more accurate knowledge of the 

 true physiological needs of the body for proteid foods. Our present 

 dietetic standards are absolutely false and valueless. Our present con- 

 ception of the physiological needs of the body is altogether faulty and 

 distorted. Our ideas of the rate and extent of proteid metabolism 



* See Burian and Schur, Archiv fiir die gesammte Physiologic, Band 87, 

 p. 239. 



t ' The Alloxuric bases in aseptic fevers/ Am. Journal of Physiology, Vol. 

 10, p. 452. 



