Ill 



so it is probably right also at 0,4%. The lysin em- 

 ployed is thus only able to dissolve a third part ol" the 

 blood, which the ammonia solution dissolves. When 

 the blood concentration is increased beyond the limit 

 tor complete haemolysis, the degree of colour increases 

 slightly, but almost imperceptibly; it reaches a maxi- 

 mum when the blood concentration is about twice as 

 much as the greatest amount in complete haemolysis. 

 Still, the increase in the strength of colour from where 

 haemolysis begins to where it reaches its maximum, is 

 very insignificant, in fact only 15 %. After this maximum 

 is reached, the colour begin to slowly decrease in strength, 

 more slowly in the case of lysin than in the case of am- 

 monia. The determination of colour becomes more diffi- 

 cult in the case of higher blood concentrations and is 

 therefore rather incertain, for red blood corpuscles cling 

 to the sides of the test tubes and prevent an exact 

 examination. 



In the case of a blood dilution of 10%, f. inst., no 

 perceptible haemolysis takes place in the ammonia so- 

 lution, the blood having the property of fixing 0,6 cc. 

 of 0,05 n NH 3 . This combination is yet, to a small 

 extent, counteracted through hydrolysis. The corpuscles 

 clinging to the sides of the test tube give a false appea- 

 rance of depth to the colour. The same applies to lysin, 

 though not to the same extent, haemolysis always oc- 

 curring, however strong the blood dilution may be; 

 therefore the colour does not sink so rapidly in this 

 case with increasing concentration of blood. But also 

 in this case blood corpuscles cling to the test tubes and 

 make the colour appear darker than it really is. It is 

 therefore desirable in these experiments not to use too 

 concentrated blood dilutions. About 1 to 2% are likely 

 to furnish the best results. With too little concentration 



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