METABOLISM AND THE DISTRIBUTION OF MATERIAL 231 



microscopic changes. He designated this condition swelling of the brain 

 in contrast with edema of the brain; it is possible to demonstrate the fluid 

 transudate from the blood. In swelling of the brain, it is dry, solid and 

 gelatinous. REICHARDT' s observation was made about the time FISCHER 

 published his theory so that it seems apropos to mention it. J. BAUER 

 and BAUER and AMES tested slices of brain and cord and found that 

 swelling was observed occasionally with a one thousandth normal acid- 

 ity, but with greater concentration (even of carbonic acid), a shrinking 

 always occurred. On this account they reject FISCHER'S acid theory. 



Contradicting J. BAUER, FISCHER in experiments (with HOOKER) 

 found that nervous tissue behaved toward salts and acids like fibrin 

 and other tissue. He explains the disagreement by the fact that 

 BAUER chose tissue which had been dead 6 to 24 hours. The optimal 

 concentration for swelling had already been exceeded by the post 

 mortem development of acid. 



The fourth objection was raised by pathologists who maintained 

 that what FISCHER described was not edema at all. The main loca- 

 tion of edema, connective tissue, exhibits apparently, like fibrin, the 

 swelling and shrinking phenomena with acids and salts but is essen- 

 tially dissimilar from edematous tissue and more like hyaline or amy- 

 loid degeneration. (MARCHAND, KLEMENSIEWICZ, H. SCHADE.) The 

 fibers show the chief swelling in acids but in edema the main swelling 

 is extrafibrillar. FISCHER fails to distinguish between swelling of the 

 protoplasmic substance and turgor of the entire tissue. Against this 

 view that in edema the aqueous fluids accumulate in the tissue 

 spaces and not merely in the protoplasma and that increased inhibi- 

 tion of water by the cell is not the criterion of edema, M. H. FISCHER 

 argues that the tissue spaces are not filled with air but by colloid ma- 

 terial which may very well contribute to the edema by acid swelling. 



LUBARSCH noted marked swelling of the tissue in his histologi- 

 cal studies but determined a difference in kidney edemas due to 

 clamping the renal artery or renal vein. The changes are similar; 

 those produced by clamping the vein are reversible but those due to 

 clamping the artery are irreversible if the artery is clamped off for 

 three hours. The sensitive cells are killed. This contradicts 

 FISCHER'S theory which requires the damage to be the same in either 

 case. KURT ZIEGLER made the important observation that chlorid 

 metabolism as well as water metabolism play an important part in 

 edema. Chlorid and water retention alternate as primary factors 

 in edema, but in all cases, there are nutritive disturbances which 

 affect chiefly muscles and connective tissue. P. TACHAU offered 

 experimental verification by feeding mice excessive amounts of sodium 

 salts. There occurred edema about the head, neck and attachment 



