CHEMICAL PATHOLOGY 



CHAPTER I 

 INTRODUCTION 

 THE CHEMISTRY AND PHYSICS OF THE CELL 



SIXCE Virchow founded modern pathology the unit of all 

 anatomical considerations of disease has been the cell, and in 

 physiology the same unit has been found equally useful. When 

 either physiological or pathological processes are studied from 

 a chemical standpoint, the cell is still found occupying nearly as 

 fundamental a position, for we can seldom go back to molecules 

 and atoms in investigating biological problems. Although we 

 know that within each cell are many different chemical sub- 

 stances, and that numerous different enzymes and other agencies 

 are exerting their influence upon them, yet we find that the 

 reactions are all profoundly affected by the environment in which 

 they occur, and it is the structure of the cell that determines 

 the environment of its chemical constituents. All chemical 

 reactions are modified by physical influences, and an enzyme 

 may have quite a different effect upon a substance when it acts 

 in a test-tube from what it will have when in a living cell, 

 whose structure permits the diffusion of one substance while 

 preventing that of another, and where countless other substances 

 and enzymes may participate in the changes. The cell is the 

 structural unit of the living organism, and as by its physical 

 properties it modifies chemical processes, so it becomes prac- 

 tically the unit in physiological and pathological chemistry. 

 All consideration of the chemistry of disease must thus refer back 

 to the chemistry and physics of the normal cell, and on this 

 account a brief resume" of these subjects may serve as a fitting 

 introduction to the strictly pathological matters to follow. 1 



1 Of necessity, only so much of the very extensive literature on cell structure 

 and cell chemistry can be considered as will have direct bearing upon the 

 subject matter to follow, referring the reader for more detailed information 

 to such works as Wilson's " The Cell in Development and Inheritance " ; 

 Mann's " Physiological Histology " ; Hammarsten's " Physiological Chemistry " ; 

 Abderhalden's " Lehrbuch der physiologischen Chemie " ; Gurwitsch's " Mor- 

 phologic und Biologic der Zelle"; Hober's " Physikalische Chemie der 

 Zelle und der Gewebe " ; Hamburger's " Osmotischer Druck und lonenlehre " ; 

 Loeb's " Dynamics of Living Matter ", for general discussion, and to the most 

 important monographs for treatment of special points. 



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