1910. | Complement Deviation in Mouse Carcinoma. 365 
90 minutes in the third tube, while the rate and degree of hemolysis 
occurring in the fourth tube were also reduced, and in the fifth tube 
hemolysis, though not prevented, was retarded. It must also be observed 
that the actual increase of complement in passing from the third to the 
fourth tube is considerably greater than that between the second and third 
tubes, owing to the circumstance that the quantities employed have been 
selected so as to form a geometrical progression, the amount of complement. 
contained in each tube being three times that contained in the preceding 
tube. By adding equal increments of complement to the tubes, the difference 
between the last two series becomes more obvious, but as the number of 
tubes made up cannot be conveniently increased, it is necessary to reduce the 
range over which the investigation extends. In this, as in the previous 
series, no considerable change occurred on keeping the tubes at room tem- 
perature (14° C. to 17° C.) for a further period of 18 hours. In making the 
last two series of experiments, recorded in Tables III and IV, serum was 
obtained on the preceding day from a normal mouse and from a mouse with 
a tumour; both sera were sterilised at the same time, and were kept, as. 
already mentioned, for 24 hours before use. 
Hemolysis in these experiments proceeds slowly. The quantities dealt with 
being very small, it is not possible to attempt to discover the formula repre- 
senting the reaction velocity or to ascertain the end equilibrium. It is, 
however, clear that it is not at present permissible to treat the reaction as a. 
stoichiometric one, and to represent in terms of red blood cells the quantities 
of complement fixed. This is well exhibited in Table IV, Experiment 5, in 
which it is seen that the reaction rate is.retarded, though if the reaction were 
simply stoichiometric this should not occur, owing to the much greater 
amount of complement in tube 5 as compared with tube 4. A better means. 
of comparison would presumably be afforded by the determination of the 
reaction constants. 
In the observations recorded above, it was found, on comparing the third 
and fourth series (Tables III and IV), that the degree of hemolysis occurring 
when serum obtained from a mouse with a tumour was employed was less in 
degree, and proceeded more slowly, than when the serum of a healthy mouse 
was used. In other words, during the period of experiment, more com- 
plement was fixed with the former serum than with the latter. This result. 
was not, however, always observed. Sometimes the rate and degree of 
hemolysis were not appreciably different in the two series; the weight of the 
tumour of the mouse furnishing the former serum in these cases amounted to 
from about one-sixth to one-quarter or more of the total body weight. The 
number of experiments so far made does not furnish many data bearing upom 
