454 Water Absorption by Protoplasm [Mar. 



products of metabolism, without appreciably changing the actual alka- 

 line reaction, constantly take up alkali from blood and protoplasm. 

 In this manner there is a tendency to disturb the normal protective 

 eqiiilibrium between bases and acids. This tendency is held in check 

 by the kidney, which in the process of urine formation reverses the 

 reaction of neutralization of acid and restores to the blood that alkali 

 which has served as a carrier of acid."^^ (Page 309.) 



We agree again, but I repeat that this neutralization mechanism 

 either mechanically or chemically has been impaired in every con- 

 dition that is characterized by "edema." 



Fischer bases his whole conception on the action of acid as acid. 

 That acid, as acid, is the responsible and aggressive agent in the pro- 

 duction of any natural edema is something that I cannot see. 



A criticism of my ability to express myself clearly. To avoid 

 dispute, I have never said more than that the acid content of the 

 cells is raised in edema. Very evidently the acid need not remain 

 there "as acid." It may neutralize basic salts, combine with pro- 

 tein, and in other ways distribute itself between the difTerent phases 

 of the cell. 



On the other band, that acid by reducing basicity or effecting a 

 reaction-discoördination or inducing some other molecular disequili- 

 bration, may be an inciting cause, or a stimulating influence, or an 

 indirect though none the less influential factor, is quite comprehensible. 

 As a link in a chain of factors, the influence of acid in eflfecting 

 abnormal hydrophilia is conceivably important. (Page 309.) 



As far as I understand this I agree entirely. 



Fischer's book has the great merit of sharply stimulating questions. 

 Do any non-acid products of intermediary metabolism retard or accel- 

 erate the presumed action of lactic acid in edema? Fischer does not 

 discuss this matter. Has it been definitely established, directly or by 

 methods of exclusion, that nothing occurs in an edematous part but the 

 production of organic acid to account for an increased affinity of the 

 colloids for water? (Page 309.) 



Not at all. This is a field for research, 



Has Fischer duly considered, in this connection, the eflPect of patho- 

 **Henderson: Journal of Biological Chemistry, 191 1, ix, p. 423. 



