242 LECTURES ON IMMUNITY 



cholesterin, may be due to a secondary action, whereby 

 the velocity of the process is retarded, concurring with 

 the chief action of the poison. 



Detre and Sellei had observed that the haemolytic action 

 of mercuric chloride is diminished by the presence of 

 lecithin. Against this Sachs stated that lecithin ac- 

 celerates the action of mercuric chloride. Sachs rightly 

 holds the opinion that no poisonous combination of mer- 

 curic chloride and of lecithin exists, but that we here 

 observe an action of the lecithin on the erythrocytes, 

 whereby these are rendered more accessible to the mer- 

 curic chloride. Here we find that Sachs takes up the 

 opinion of Bordet regarding the sensibilisating action of 

 certain substances on erythrocytes. Evidently the lecithin 

 enters into the cell-membranes and increases their per- 

 meability to the haemoglobin or to the mercuric chloride. 



According to this observation it seems obvious to sup- 

 pose that the action of lecithin on erythrocytes treated 

 with cobra-poison is due to a similar circumstance. The 

 slowness of the hsemolytic action in this case speaks in 

 favour of this opinion. If the chief part of the lecithin 

 remains in the fluid, the absorbed part in the membranes 

 of the erythrocytes is proportional to the f power of the 

 quantity of lecithin, diminished by the chemically bound 

 part of it. The results given above regarding the action 

 of cobra-poison in presence of lecithin will then be under- 

 stood if we make the very plausible hypothesis that the 

 haemolytic action is proportional to the concentration of 

 the cobra-poison, and further that the permeability of the 

 cell-membranes is proportional to the absorbed quantity 

 of lecithin. 



