191 1] William J. Gies 289 



the eye, for not only is the eye built up of a series of different colloids 

 (sclera, Cornea, lens, vitreous humor), but the same conditions which 

 govern the absorption of water by fibrin also govern the absorption of 

 water by the eye. On the ground of these experiments we can, there- 

 fore, no longer insist that an eye becomes glancomatous because water 

 is forced into it. It does this because chemical changes occur within 

 the eye which increase the affinity of the ocular colloids for water so 

 that these are enabled to absorb water f rom any available source. In 

 cur experiments with enucleated eyes this source is the Solution into 

 which the eye has been dropped; in the body it is the liquids flowing 

 about or through the eye. (Page 128.) 



In harmony with the observations on fibrin, gelatin, and muscle, 

 electrolytes sharply antagonize the swelling of enucleated eyes in 

 the acid Solutions employed by Fischer, whereas non-electrolytes 

 are without special restraining effects. 



Discussing the passive congestion edemas of the kidney and 

 liver, pp. 141-9, Fischer says: 



In the light of our colloidal conceptions of water absorption, how 

 must we interpret the phenomena that characterize the passive conges- 

 tion edemas of the kidneys and the liver? The cause of the edema is 

 again to be sought in the tissues. The circulatory disturbances leading 

 to an edema of these organs all have this in common : they lead to a State 

 of lack of oxygen in the tissues, in consequence of which acids are pro- 

 duced in them. These acids increase the affinity of the tissue colloids 

 for water, whereby they are enabled to absorb an increased amount of 

 water from any available source. This idea is supported by the follow- 

 ing: 



It is a well-known fact that when the efferent (renal) vein of the 

 kidney is tied in animals, the organ becomes filled with blood, and that 

 the kidney tissues proper swell and become progressively firmer in con- 

 sistence. This is the typical picture of a passive congestion sufficiently 

 severe to permit of the development of an edema in the congested area. 

 We need not repeat that what happens in this experiment is usually 

 interpreted as an edema due to an increased blood pressure, alterations 

 in vascular permeability, etc. All these explanations fall as soon as it is 

 stated that ligature of the renal artery leads to the same series of 

 changes in the kidney as ligature of the renal vein (with the exception 

 of the overfilling of the blood vessels). (Page 142.) 



After our remarks on the essential role played by lack of oxygen, 



