APPENDIX 209 



intervention of an activating substance. To the 

 latter class belong the blood corpuscles of ox, 

 sheep, and goat. As already pointed out in dis- 

 cussing snake venoms, the activating substance is 

 present in blood serum; it is also present in com- 

 mercial lecithin. Haemolysis of either group of 

 blood corpuscles can be inhibited by means of 

 cholesterin, though just how this substance acts is 

 not clear. Much and Holzmann showed that the 

 blood serum of patients suffering from various 

 mental disorders, especially dementia praecox, and 

 manic-depressive insanity frequently inhibits hae- 

 molysis of human red blood corpuscles, and they 

 suggested that the reaction could be used for 

 diagnostic purposes. While it appears to be true 

 that the psychoses yield the largest proportion of 

 positive reactions, the value of the reaction for 

 diagnostic purposes is practically nil. At the same 

 time it is interesting to note that diseases of the 

 nervous system accompanied by demonstrable 

 lesions of the nerve tissue give the same reaction as 

 psychoses in which such lesions have not yet been 

 demonstrated. Much 1 therefore concludes that in 

 both cases the same substance circulates in the 

 blood, and that, moreover, in both this substance 

 is derived from a degeneration of the nerve tissue. 



1 Much, Die Immunitatswissenschaft. C. Kabitzsch, Wiirz- 

 burg, 1911. i 



