182 Mr. J. A. Craw. On the Physical [ Mar. 22, 
» Miaxtwres—The mixtures of lysin and antilysin were brought to a state of 
equilibrium by heating at 37° C. before filtering. They embraced weakly 
hemolytic fluids (Nos. 1, 2, and 3, Table I), neutral fluids, a¢., mixtures 
which did not hemolyse in the standard time (No. 4), and fluids containing 
a large excess of antilysin (Nos. 5 and 6). 
Nos. 1, 2, and 3 were exactly of the same constitution, viz., equal volumes 
of a lysin of constant value and a 5-per-cent. solution of antilysin in saline. 
No. 1 was heated 1 hour at 37° C., and kept at 10° C. for 1 hour. Nos. 2 
and 3 were heated for 3 hours at 37° C., and allowed to stand 18 hours 
at 10° C.* 
No. 4 consisted of equal volumes of a 1-per-cent. solution of a lysin which 
had been precipitated by ammonium sulphate, and of a 5-per-cent. solution 
of antilysin in saline. No. 5 contained one volume of the 1-per-cent. lysin 
to two volumes of 5-per-cent. antilysin, and No. 6, one volume of 1-per-cent. 
lysin to four volumes of 5-per-cent. antilysin. Nos. 4, 5, and 6 were heated 
for 3 hours at 37° C., cooled 1 hour at 10° C. and filtered. 
Examination of the Filtrates for the Presence of Lysin.—The last fractions 
of the filtrate from No. 1 indicated a trace of hemolysis, the corresponding 
fractions from Nos. 2 and 3 were unquestionably hemolytic. 
The filtrates from Nos. 4, 5, and 6, as well as the original fluids introduced, 
did not produce hemolysis. 
Examination of the Gelutine for the Presence of Lysin.—After filtration the 
gelatine of the filters 1 to 6 was melted out at 37° C.,and in all cases was found 
to be intensely hemolytic, whereas the original gelatine had no hemolytic effect 
in the standard time. 
Examination of the Residual Fluids for the Presence of Lysin.—The 
residual fluids were in all cases decidedly hemolytic, as can be seen in Table I. 
This increment in hemolytic power was to be expected for Nos. 1, 2, and 3 from 
the results given above for the filtration of lysin alone, and is simply a concen- 
tration effect that might be brought about by removing the water in other 
ways, ¢g., by evaporation under diminished pressure. The result, however, 
appears to be most remarkable when it is considered that No. 4 is a neutral 
mixture, and Nos. 5 and 6 highly over-neutralised. 
Control filtrations of saline showed no hemolytic power in either filtrate, 
residue, original fluid, or gelatine, so that the hemolysis obtained above’ was 
certainly not due to impurities introduced by the apparatus. 
* The experiment with No. 3 was performed 30 days after the experiments with Nos. 1 
and 2 and the agreement in the hemolytic values obtained testifies to the constancy of 
the lysin. 
