292 • Fische/s Theory of Edema [Dec. 



sume a quantity of fresh or distilled water, and a frog living in a fresh 

 water pond ought to do Hkewise. But this does not occur. Clearly 

 the muscle swells only because removed from the body. The difference 

 between the muscle inside and outside of the body is this: Outside 

 of the body the muscle develops an acid reaction, and in this and 

 its effects upon the muscle colloids I would find the cause for the 

 increased absorption in distilled water. Added to this is the effect 

 of the diffusion of salts out of the muscle, for the higher the con- 

 centration of salts in an (hydrophilic) emulsion colloid the less does 

 that colloid swell in a dilute acid. Quite contrary to the generally 

 accepted belief, a loss of the osmotically active electrolytes of a tissue 

 may, therefore, distinctly favor the absorption of water. We will do 

 well to consider this whenever we try to define wherein lies the 

 " poisonous " effect of distilled water. That the extirpated muscle be- 

 comes acid in reaction must be borne in mind when we try to Inter- 

 pret the effects of acids, alkalies, and salts upon it. To put a muscle 

 into a dilute acid instead of into distilled water is simply to add the 

 effects of the external acid to that produced spontaneously by the 

 muscle. (Page 161.) 



On the osmotic conception of water absorption physically " isos- 

 motic " Solutions ought to be physiologically " isotonic." Yet experi- 

 mentally this is not found to be the case. On the colloidal basis of 

 water absorption this result, of course, does not surprise us, for physi- 

 cally isosmotic Solutions of different salts are not equally effective in 

 reducing the swelling of an (hydrophilic) emulsion colloid in a dilute 

 acid. (Page 162.) 



It is a simple matter, therefore, to account for all the available 

 experimental facts on the absorption of water by muscle on the col- 

 loidal basis. Not only are the facts which it has been difficult to 

 harmonize with the osmotic conception of water absorption explained 

 in this way, but all the phenomena which we have been most willing to 

 accept as osmotic may well represent only a fraction of that greater 

 series of phenomena which we have designated colloidal. The entire 

 question of the validity of the laws of osmotic pressure in the bio- 

 chemistry of water absorption is therefore raised in the special case of 

 muscle just as we have previously raised it in the case of spermatozoa, 

 isolated epithelial cells, and white blood corpuscles. That the laws of 

 osmotic pressure, even as rendered more generally applicable to bio- 

 logical material through Overton's special assumptions, are incapable 



