LAWS OF SOLUTION 



results obtained by the plasmolytic method have recently been called in 

 question, because no regard has been taken of the power of the colloids 

 of the cell to adsorb (imbibe) water (see page 62). 



The methods of hemolysis and plasmolysis have been used for the 

 investigation of many problems in medicine. In the case of certain 

 toxic fluids, such as snake venom, tetanus toxin, etc., determination of 

 the hemolytic power has proved of value in roughly assaying the dam- 

 aging influence on other cells than blood corpuscles. Studies in hemol- 

 ysis have also been especially valuable in working out the mechanism 

 by which cellular toxins in general develop their action, and the conditions 

 under Avhich this action may be counteracted, as by the development of 



Fig. 3. To show plasmolysis in cells from 

 plasmolysis in 0.22 M. cane 'sugar; C, pronounc 

 wall; p, the protoplasm. (After De Vries.) 



cells from Tradescantia discolor. A. norma 



discolor. A, normal cell; B, 



:cd plasmolysis in 1.0 M. KNO3; h, the cell 



antibodies. Furthermore, any solution that is to be injected into the 

 animal body, either intravenously or subcutaneously, should first of all 

 be tested by the above methods in order to find out whether it is isotonic 

 with the body fluids. If a hypertonic solution is injected, it will result 

 in the abstraction of water from the tissue cells, whereas a hypotonic 

 solution will cause the water content of these to increase. Advantage 

 has recently been taken of this water-abstracting effect of hypertonic 

 solutions in the treatment of wounds. By constantly bathing them with 

 strong saline solutions, an outflow of water is 'set up from the tissue 

 cells that border on the wound, and this tends to bring to the focus of 

 infection the defensive substances that are present in animal fluids. 



