Ill 



should be introduced for Ihe diminishing of the con- 

 centration of the blood by the addition af toxin. One 

 might expect that the decrease of concentration would 

 cause a diminishing of the haemolysis. Yet this does not 

 seem to be the case, because in blood dilution of about 

 the same concentration as the above mentioned, the action 

 is nearly independent of the amount of blood. Therefore 

 no correction in this regard has been introduced above. 

 This appears from the following experiment, in which 

 the same amount of ammonia (0,6 cc. 0,05 n NH 3 ) or 

 tetanolysin (0,6 cc. 0,2%, 8 days old) was added to 10 

 cc. blood dilution, of which the concentration varied 

 from 0,1 % to 10 %. 



Percentage Haemolysis Percentage Haemolysis 



of blood NH 3 Lysin of blood NH ;j Lysin 



0,1 5* 5* 2 5(5 16 



0,2 9* 8* 3 56 13 



0,3 14,5* 12,5* 4 43 11 



0,5 21* 18 6 67 



0,8 31* 19 8 5 5,5 



1,2 50* 18 10 4 5,5 



In the beginning, the amount of haemolysis is pro- 

 portionate to the added quantities of blood. This hap- 

 pens so long as the haemolysis is total. In this case 

 an excess of toxin is present, and is therefore able to 

 dissolve the whole quantity of blood and the strength 

 of colour is therefore in proportion to the added amount 

 of blood corpuscles. This occurs in the case of ammo- 

 nia up to 1,2% blood. So 0,1% of blood should corre- 

 spond to No. 4 in the scale of colours, 0,2 % to 8, 0,3 % 

 to 12, 0,5% to 20 and 0,8% to 33. This takes place 

 with ammonia, allowing for errors of experiment. In 

 the case of lysin, the proportionality extends only to the 

 blood concentration 0,3%, and is nearly right at 0,5%, 



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