64 IMMUNE SERA. 



tion. They used a haemolytic serum derived from 

 goats which had been treated with human blood. 

 One volume of this was able to dissolve an equal 

 volume of human blood within a few minutes. This 

 specific serum was injected into patients suffering 

 from lepra, in doses of one-half to seven c.c., sub- 

 cutaneously. As a result there was, of course, first 

 a reduction of red cells, due to haemolysis. This was 

 followed after about six days by an increase of the 

 same, and also by an increase in their haemoglobin 

 content. Certain other symptoms which showed 

 themselves on the leprous nodules Metchnikoff 

 ascribes to the leucotoxin which the serum contains. 

 These experiments have, however, had no further 

 practical results. 



