RESEARCH IN MEDICINE 129 



Before and for some time after these events a great volume of work 

 in physiological chemistry was done in laboratories of organic chemistry 

 and of physiology; but the events at Tubingen and Strassburg served 

 to concentrate attention on physiological chemistry and eventually to 

 hasten the establishment of independent laboratories. For the first few 

 years progress was slow; in 1882, to quote Dr. Marshall again, only two 

 such independent laboratories, those of Tiibingen and Strassburg, 

 existed in Germany. In the intervening thirty years the situation has 

 changed. Now, such laboratories exist wherever adequate teaching or 

 intelligent research in medicine is attempted. 



The early physiological chemistry was quite different from that 

 with which we are familiar to-day. It was largely the analysis of the 

 chemical composition of various body tissues and fluids. This early 

 conception, however, soon gave way to a dynamic conception, the idea 

 of function, and present-day investigators in physiological chemistry 

 are concerned chiefly with the ways and means of cell action. The 

 chemical constitution of the cell, its enzymes, the methods by which it 

 builds up complex bodies from simple substances, or disintegrates a 

 compound to its simplest constituents; in brief, the problems of diges- 

 tion, metabolism and secretion in health and disease. These are the 

 problems which concern this science and which, as its methods have 

 been extended to include the study of the vegetable kingdom, as well as 

 the lower forms of animal life, is now more frequently known by the 

 broader term, biological chemistry. The dynamic point of view which 

 to-day characterizes physiological chemistry is largely due to two influ- 

 ences which have come from the outside: (1) The study of intramolec- 

 ular structure as carried out on the sugars, purins and proteins by the 

 Fischer school, and (2) the study of the nature of chemical reactions, 

 as taught by the modern school of physical chemistry, led by van't Hoff. 



Its fundamental problems which during recent years have engaged 

 the attention of its best workers and which still hold their attention are 

 (1) the chemical composition of the protein molecule, (2) the part 

 played by ferments or enzymes in the metabolic changes which occur 

 within the cell and which are responsible for the functions of the various 

 organs and tissues, (3) the general problems of nutrition and the rela- 

 tive values of different food-stuffs, (4) the question of the interrelation 

 of function, that is, of the influence of the secretion of the cells of one 

 organ or tissue on the cells of a remote organ or tissue, (5) the mechan- 

 ism, from a chemical point of view, of natural and acquired resistance 

 to disease and of phenomena associated with such resistance. 



All of these investigations, it is seen, have for their object a better 

 knowledge of the mechanism of cell activity. 



Experimental Pharmacology or pharmaco-dynamics, as it is some- 

 times called, applies the methods of physiology and chemistry to the 



