14 



Prof. II. Muir and Mr. C. H. Browning. [May 17, 



mixture as of pure C has to be added before a free dose of C is 

 ob rained. Of course, if the C molecules had a much greater affinity 

 than the Cd molecules, the actual amount of C added would be approxi- 

 mately the same in the two instances. This, however, is very far 

 from being the case. In other experiments we have found, when 

 lysis is produced first, then a small quantity of Cd added and allowed 

 to combine, and then increasing amounts of C, that the surplus C 

 appears to come off less sharply than when C alone has been added. 

 This would appear to indicate that a certain amount of Cd is displaced 

 by C ; it must, however, be a small amount. 



We may therefore conclude that the C and Cd have approximately 

 the same combining affinity for the E + IB molecules after lysis. If 

 there is a difference in favour of the energy of combination of the 

 former, it is a slight one. 



On the Relative Firmness of Union of C and Cd with Anti-C. 



Here the mode of procedure is of the same nature. A given amount 

 of anti-C is added to salt solution in two series of tubes. To the A 

 tubes increasing amounts of pure C are added ; to the B tubes the 

 same amounts of a mixture of C and Cd in equal parts. One and 

 a-half hours at 37 C. are allowed for combination, and then red 

 corpuscles treated with IB are added to each tube to find how much 

 C is obtainable. 



Examples : 



1. 0*1 c.c. anti-C in each tube. 

 A. 



* This tube was accidentally broken. 



