120 PATHOLOGY 



ture, but rather as a most complicated machine, the working of which 

 for the most part is dependent on enzymes. Into the finer details 

 of the manner in which these mechanisms may be disturbed under 

 abnormal conditions we as yet have hardly been permitted to pene- 

 trate, but the extensive recent researches dealing with the nature 

 and mode of action of ferments in diverse physiological activities 

 have awakened a lively interest in fermentations in pathological 

 processes which augurs well for the future. 



Among the many intracellular ferments those causing self-digestion 

 or autolysis of cells are thought to play an active and essential 

 role in the removal of dead material, such as necrotic tissue in 

 infractions and inflammatory exudates. Some idea of the fermenta- 

 tive activities in autolysis may be obtained from its action in pneu- 

 monia. In a few days autolysis may so alter a mass of exudate 

 weighing several hundred grams that it is readily removed from the 

 lungs by absorption and expectoration. 



The biochemical mechanisms of normal and pathological pigment 

 formation have now been shown to depend on the action of oxida- 

 tive ferments. 



Cohnheim's demonstration that two enzymes, one coming from 

 the pancreas and the other from the muscles, are necessary for the 

 oxidation of sugar, appears to be a long step toward putting the 

 pathogenesis of diabetes in an entirely new light. While these and 

 other oxidizing ferments are the products of cellular activity, it at 

 once suggests itself that they need not be the products of the cells 

 of the same body which is later to use them. It has been suggested 

 that they may be introduced as needed much as antitoxins now are 

 introduced (Long). 



The results of the work of Croft Hill and of Kastle and Loewen- 

 hardt on the reversibility of ferment action have been eagerly 

 grasped by pathologists and made to throw new light on the prob- 

 lems of fat absorption and translocation. Indeed, the newer chemi- 

 cal methods of study are changing completely our older ideas about 

 fatty changes in the cells, ideas that were based almost wholly upon 

 morphological appearances. Great progress has been made also in 

 other respects in recent years from the application of the methods 

 of physiological chemistry to pathological problems, but I must 

 refrain from going into further details. As a result the field of pure 

 chemistry as an aid to medical diagnosis is enlarging, not merely as 

 regards various analytical procedures for the testing of fluids and 

 other substances, but the newer methods of physical chemistry 

 such as testing the solution content by electrical conductivity and 

 eryoscopy have been found useful in order to obtain information 

 of help in reaching a correct diagnosis or a better understanding of 

 the nature of the functional disturbance. 



