362 Dr. J. O. W. Barratt. [ Deer 
extract was added. This group exhibited the effect of tumour extract in 
fixing a relatively small amount of complement. Sodium chloride was 
replaced in the third group by inactivated normal serum of the mouse, and 
in the fourth group by inactivated serum obtained from a mouse with a 
tumour. In both the latter groups a further and more considerable fixation 
of complement took place, and a comparison of the two enabled the effect of 
mouse carcinoma upon complement fixation to be determined. 
Experimental Results—When a complement deviation test, as above 
described, is applied to the serum of a mouse inoculated with mouse 
tumour, a positive reaction is obtained in some cases, in others a negative 
reaction is observed. 
The course of a positive reaction is exhibited in Tables I to IV, which will 
now be considered. : 
In Table I the action on sensibilised red blood cells of healthy human 
serum obtained a few hours before use is exhibited. An exceedingly slight 
degree of laking was produced by 0°001 c.c. of this serum, and it may be 
added that half this quantity produced no laking recognisable to the naked 
eye at the end of 90 minutes; 0:003 ec. and larger amounts of human 
serum produced complete hemolysis within this period of time. When 
active normal rabbit’s serum was employed instead of human serum in the 
experiments given in this and the following tables, the degree of the resulting 
hemolysis was slightly lowered. 
Table I—Heemolytic Power of Complement contained in Human Blood 
Serum. The contents of each tube were mixed with sensibilised red 
cells obtained from 0:02 c.c. of a 24-per-cent. suspension of the red cells 
of the rabbit, and kept, with occasional shaking, at 37° C. for 
90 minutes. | 
Degree of hemolysis at the end of— 
| 
N 0°85 per cent. | eee 
«| Active hum: luti 
of | Active human solution | 
Babes blood serum. of sodium | 18 hours 
aa chloride. | 30 mins. 60 mins. | 90 mins. (at room 
| | temperature). 
c.c. c.c. | 
1 0-001 0:06 Not recognisable Slight | Slight Partial 
2 0-003 0-06 Partial ' Complete | Complete Complete 
3 0 :009 0-06 Complete 4 s - 
4 | 0 "027 0 06 99 | 3) bP) 99 
5 | 0 ‘081 0 06 ” | 9 ” | ” 
It may here be pointed out that, although it is not difficult to recognise a 
pronounced degree of hemolysis, nevertheless, owing to the smallness of the 
