382 Mr. J. Henderson- Smith. Increase in the [Mar. 26, 



rabbit serum necessary for total haemolysis was, of 1 hour sample, 0*6 c.c. 

 2J hours sample, 0'5 c.c. ; 5 hours sample, 0*3 c.c. ; 7J hours sample, 



3 25 ; 9 hours sample, 0*35 c.c. ; 12 hours sample, 0*4 c.c. Hence a rise to 

 double the amount in 5 hours. In the control tubes, 0*5 c.c. of the 



1 hour sample gave no lysis, but the same dose of the 5 hours sample gave a 

 trace. 



Example 3. — Dose of immune-body, 0*04 c.c. Ox corpuscles : 4 c.c. 1-per- 

 cent, suspension ; 2 hours at 37°. Quantity of normal guinea-pig serum 

 necessary for total haemolysis, of -J hour sample, 0*05 c.c. ; of 1 hour sample, 

 0*025 c.c. ; of 4 hours sample 0*03 c.c. 



2. Immune Serum. 



The immune sera examined were those of animals, mostly rabbits, injected 

 with blood-corpuscles, usually of the ox. In some cases the serum came 

 from rabbits, which had been injected with horse corpuscles, and in one case 

 from a goat injected with ox corpuscles. The results in all the cases were 

 concordant. Two factors in such sera require to be examined : the immune - 

 body and the complement. 



The immune-body is easily tested, since it does not appreciably, if at all, 

 deteriorate spontaneously. The immunised animal was bled as before, and 

 samples of serum withdrawn in the usual way. Each sample, after centrif uging, 

 was at once heated 30 minutes at 56° to destroy the complement, and, when 

 the last was ready, all were examined together. The method was similar to 

 that described in the last section. With a constant quantity of corpuscles 

 and a constant quantity of serum from a normal animal as complement, the 

 minimum dose of each sample necessary to produce total lysis was 

 determined. This was found to be the same for all the samples ; and in all 

 the experiments this proved to be the case. The immune-body, therefore, 

 does not vary, but is present in its full amount from the first. 



Example 4. — Dose of normal rabbit serum as complement, 0*15 c.c. ; 

 4 c.c. 1-per-cent. suspension ox corpuscles; 2 hours at 37° C. Immune 

 serum from rabbit injected with ox corpuscles. The dose required of this 

 serum after heating was for the 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, 

 and 12 hours samples the same, viz., 0*04 c.c. The dose of the 10 hours 

 sample was 0*045 c.c, which is probably an experimental error. 



The investigation of the complement in immune serum is more difficult. 

 We have no means of destroying immune-body, and leaving complement in 

 the serum, and Ehrlich's (3) method of absorption of the immune-body in 

 the cold is not suited to quantitative estimations of this kind, and has been 



