142 THE PRINCIPLES OF IMMUNOLOGY 



degree of susceptibility to hemolysis depends upon the amount of such 

 ether soluble activators as fatty acids (particularly oleic acid) and 

 their soluble soaps. He regards fatty acids, neutral fats and soluble 

 soaps as endocellular complement and assumes certain similarities with 

 serum complement. Certain soap serum mixtures were found to be 

 capable of completing an amboceptor cell mixture but numerous objec- 

 tions have been interposed against both the fact and the interpretation 

 so that at the present time there is no good ground for believing that 

 the activator of cobra lysin is a true complement or that Noguchi's soap 

 mixtures are comparable to serum complement. If the activator cannot 

 be regarded as complement, the venom lysin cannot be looked upon 

 as an amboceptor, for it shows no specificity and does not require 

 serum complement for activation. Kyes in a recent publication 

 gives what may be regarded as the modern view in regard to venom 

 lysis as follows : 



" i. There is present in all venoms a hemolysin existing as one of 

 a number of distinct toxins. 



" 2. This hemotoxin effects hemolysis only in conjunction with 

 a so-called complementing substance which, however, may be found 

 within the erythrocytes. 



"3. The reaction between the hemotoxin and lecithin is essentially 

 a chemical reaction resulting in the formation of a complete lysin. 



" 4. This complete lysin is a true toxin in that it stimulates the 

 production of a specific antibody." 



Although the experiments of Zunz and Gyorgy are not to be re- 

 garded as indicating that they have found other activating substances 

 for cobra venom hemolysis, nevertheless, they have determined that 

 hemolytic activity of cobra venom is increased by certain compounds of 

 protein destruction, including certain albumoses and amino-acids. 



The hemolytic property of cobra venom has served as a basis for 

 proposed clinical tests. Calmette noted that in tuberculosis the blood 

 contains more than the usual amount of lecithin and that small amounts 

 of serum of such patients served to activate cobra venom lysin. The 

 test is not positive in more than 78 per cent, of tuberculous patients and, 

 furthermore, is by no means specific. Similar increases of lipoid con- 

 tent of serum have been found in certain diseases of the central nervous 

 system, a fact leading to the Much and Holzmann psycho-reaction, 

 which also is not specific. Weil has maintained that in syphilis the 

 corpuscles are more resistant to venom hemolysis than is normal, 

 except in the earlier stages where the corpuscles are said to be hyper- 

 sensitive. As time has passed the suggested clinical tests have not 

 come into general use largely because of lack of specificity. Un- 

 doubtedly the blood exhibits alterations in lipoid content at different 

 times in various diseases, and in all probability there is a parallel altera- 

 tion in its power to activate venom lysin, but no one disease shows this 

 change exclusively or even constantly. 



Cytotoxins. Specificity. As erythrocytes may act as antigenic 

 substance, so may other body cells. The antibodies produced by injec- 



