278 



COLLECTED STUDIES IN IMMUNITY. 



TABLE VI. 



GOINEA-PIG BLOOD (1 cc. 5%), EXTRACT OF Ox PANCREAS (10%). PORTION 

 LEFT FROIM THE ALCOHOLIC DISTILLATE SUSPENDED IN 0.85% SALT SOLU- 

 TION. 



We are therefore evidently dealing with a substance which in the 

 above treatment is dissolved in the alcoholic fluid but which is soluble 

 to only a very slight degree in salt solution. 



Naturally a certain degree of solubility is always one of the con- 

 ditions of the hgemolytic action observed, but this need only be a 

 minimal one. The blood-cells can anchor the amount of hsemolytie 

 substance in solution at any given time and so render the fluid capable 

 of taking up small amounts of the substance anew. This conception 

 of a relative insolubility of the substance is readily reconciled with 

 the hgemolytic action. The process which takes place reminds one 

 of that occurring with certain dyes, which, although not given off to 

 the water from the dyed fibre, are nevertheless able by means of the 

 watery medium to go from the dyed to undyed fibres. 



The coctostability of the hgemolytic substances of organ extracts, 

 their adherence to solid particles, their solubility in alcohol all these, 

 in our opinion, show that these substances cannot be classed as iden- 

 tical either with the "cytases" of Metchnikoff or with our complex 

 hsemolysins. Nevertheless we have still further examined these 

 substances f.or properties which characterize the haemolysins. 



In one case, therefore, we studied the action of our organ emulsion 

 on blood-cells at C. in order to determine the possiblity of separating 

 a possible amboceptor and complement. 



To each 1 cc. of a 5% suspension of guinea-pig blood which had 

 been thoroughly cooled on ice, varying amounts of cooled extract of 

 ox pancreas were added and the mixture kept at for two hours 

 and frequently shaken. In this case slight solution occurred only 

 with large quantities of the extract. Then the mixtures were cen- 

 trifuged, the sediment resuspended in salt solution (1.5 cc.),and the 



