102 



Mr. E. Ponder. The Hcemolytic 



addition of glycocholate, then, a change of physical state of the latter occurs, 

 with a sudden change of surface tension, as before, but more evenly distri- 

 buted throughout the fluid, instead of being more marked at the cell interfaces. 

 Haemolysis will therefore be slower ; the possibility that the glycocholate and 

 the histamine may form some species of adsorption compound which has 

 scarcely any hemolytic action might further enter into the explanation. 



Such a consideration is further supported by the fact that the occurrences 

 are so influenced by small changes in reaction ; the process of adsorption and 

 similar colloid phenomena being very sensitive in this respect. It may be 

 also noted that the curious results obtained by varying the quantities of the 

 interacting substances point to changes more complex than simple chemical 

 interaction. It appears at times that the phenomena do not occur until 

 certain quantities of the interacting substances are present, e.g., in Tables XIII 

 and XIV, columns 1 and 2. Here possibly the amount of histamine added 

 was insufficient to disturb the glycocholate sufficiently to cause the change of 

 surface tension necessary to produce haemolysis. 



Not the least interesting of these occurrences is the change which seems to 

 occur in the blood cells themselves, both on standing and under the action of 

 histamine. The latter occurrence seems to have no explanation which is even 

 probable at present. The fact that blood cells, prepared in such a way that 

 coagulation is permitted, are insensitive, may be due to some protective action 

 exerted by some product of coagulation. 



The whole subject, which may at first sight seem of little practical conse- 

 quence, is of great importance. The facts show that haemolysis by simple 

 chemical substances depends on complex factors, and any information which 

 can be gained regarding the true manner of action in these relatively simple 

 cases is of interest in the consideration of the vastly more complex phenomena 

 of haemolysis by haemolysins of animal origin. 



Summary. 



T. Sodium taurocholate and sodium glycocholate are to be considered as 

 colloids. They protect colloid gold against precipitation of electrolytes. 



2. Sodium glycocholate is a feebly haemolytic agent. If histamine or 

 histidine be added to it in suitable proportions, a highly haemolytic mixture 

 results, although histamine and histidine are of themselves non-haemolytic. 

 The reaction of the hfemolysing fluid influences the speed of haemolysis. 



3. Histamine, if brought in contact with blood cells, renders them 

 immune to haemolysis by the histamine glycocholate mixture. Histidine 

 acts similarly. This appears to be due to some change in the cells 

 themselves, and not merely to the presence of the histamine in the fluid. 



