138 THE PRINCIPLES OF IMMUNOLOGY 



that any so-called anti-complements operate differently from these anti- 

 amboceptors. Numerous substances and physical conditions are anti- 

 complementary in that they destroy or inhibit the action of complement. 

 These have been pointed out in discussing the nature of complement 

 and must be considered in all experiments which utilize complement. 

 It has been suggested that in the interaction between amboceptor and anti- 

 amboceptor a precipitate is formed which fixes complement and that 

 if such were the case the complement should not be recoverable. Muir 

 has shown that it is possible to recover complement, as we have pointed 

 out above. Nevertheless, even such a form of fixation may permit of 

 dissociation, and, as we shall show in discussing complement fixation, 

 there is much evidence in favor of the view that the action of these 

 antilysins is dependent upon the fixing properties of precipitates. 



Physical Hemolysis. Hemolysis is produced not only by the 

 serum components discussed in the preceding paragraphs but also by 

 chemical and physical agents, by bacterial products, by certain vegetable 

 poisons and by venoms. Studies of these forms of hemolysis are of 

 interest not only because of their intrinsic value but also because they 

 serve to throw some light on serum hemolysis. 



The necessity for using an isotonic salt solution for the preservation 

 of erythrocytes is well known and equally well known is the fact that 

 reduction of salt content of the menstruum beyond a certain point leads 

 to solution of hemoglobin, which in distilled water is seen as complete 

 hemolysis. This is not merely a question of solubility of hemoglobin 

 for this substance is soluble in physiological salt solution to the same 

 degree as in distilled water. For the same reason it is not a matter 

 of simple osmosis of the hemoglobin. Although distilled water pro- 

 duces swelling of the cells before the solution of hemoglobin the 

 rupture of the cell is of no especial importance for cells may be cut 

 into pieces in physiological salt solution without hemolysis appearing. 

 From experiments of Fischer it would appear that the hemoglobin is 

 held in combination with the stroma by adsorption and that the action 

 of the water causes a physical separation. By combining fibrin, a 

 hydrophyllic solid colloid, with carmine, a hydrophobic colloid dye, 

 Fischer was able to produce phenomena closely resembling hemolysis. 



Fragility of Erythrocytes. The corpuscles of different animals 

 differ in the point to which reduction in salt concentration of the sur- 

 rounding menstruum leads to hemolysis. This is spoken of as a differ- 

 ence in resistance to hypotonic salt solution or a difference in fragility. 

 There may be a very slight difference in fragility of the corpuscles of 

 different individuals of the same species and diseased conditions may 

 lead to well-marked alterations. In man a simple secondary anemia may 

 lead to a normal or reduced fragility, whereas pernicious anemia leads to 

 increased fragility. Obstructive jaundice is accompanied by decreased 

 fragility, whereas familial hemolytic jaundice shows increased fragility. 

 In the anemia of animals following removal of the spleen there is a 

 decrease of fragility or, in other words, an increase of resistance to 

 hypotonic salt solutions and also to other hemolytic agents. 



