Absobption of Liquids by Animal Tissues 



membrane is impermeable, includes NaCl, KCl, and CaCl2. The second fact 

 brought out by this table is, that the phenomena of swelling and shrinkage of the 

 corpuscles, when placed in salt solutions of various dilutions, are mder the influence 

 of osmotic pressure differences and not under the influence of specific ionic effects. 



These experiments confirm in a simple way the results of Gryns and Oker-Blom, 

 by showing the permeability of the corpuscle to various substances and the imper- 

 meability to others. 



III. EXPERIMENTS ON MUSCULAR TISSUE 



The work on the influence of osmotic pressure upon phenomena of swelling in 

 muscle has been largely carried out by Professor Loeb and his pupils. He found, in 

 his work on the effects of ions, that the addition of a small amount of a dilute acid or 

 alkali to a physiological salt solution caused a muscle, immersed in such a solution, to 

 take up water, or, in other words, to gain in weight to a considerable extent. Further 

 investigation showed that this effect was due to the number or concentration of free 

 H ions in the former and of free OH ions in the latter case. Miss Cooke, working 

 under the direction of Professor Loeb, found that a muscle immersed in |^ m NaCl for 

 some time (eighteen hours) neither gained nor lost in weight. She therefore 

 assumed that such a solution was isosmotic with the muscle-plasma. This conclusion 

 is open to some of the objections raised against the work on red corpuscles, with the 

 addition that here we are dealing with a membrane, the sarcolemma, which allows the 

 passage of ions in both directions, and hence does not as fully obey the laws of 

 osmotic pressure as do the corpuscles. As will be shown later, the sarcolemma is 

 permeable to Na and K ions, and hence we should expect the same result with 

 isosmotic solutions of Na and K salts. This, however, is not the case, as Loeb himself 

 points out in his further work along this line. He shows that a muscle immersed in 

 ^m NaCl for eighteen hours gains only slightly (5 per cent.) in weight; one immersed 

 in |m KCl gains 50 per cent,, while in y^^m CaCl2 it loses 20 per cent. He advances 

 as explanation the hypothesis that we have to do with a chemical combination of the 

 ions of the salt with the proteid molecule, giving us what he terms "ion-proteids," 

 which he assumes show similar reactions, especially as regards their fluid absorbing 

 power to those of soaps. 



From the study of the work of Hofmeister, Lewith, van Bemmelen, Pauli, and 

 Hardy on effects of salts upon colloids, we obtain a much clearer insight into the 

 properties, both physical and chemical, of the body-colloids. Hofmeister attempts 

 to show that the albumin and globulin precipitating power of salts is due to their 

 dehydrating power, giving as his reasons for this view (1), the precipitating power 

 remains practically the same for action of different salts on various colloids (the degree 

 of dissociation of the salts being a great factor) ; (2), this power goes parallel to other 

 physical and chemical properties of salts which are dependent on dehydrating power. 

 In his work on the phenomena of swelling he calls attention to the fact that we must 

 take cognizance of three forces, viz. : capillary imbibition, endosmotic imbibition, and 



110 



