

1905. | Chemistry of the Toxin-Antitoxin Reaction. 181 
On the presence of Free Lysin and Free Antilysin in mixtures which have 
attained equilibrium. Method: Filtration through Gelatine. 
The method employed was that of C. J. Martin (1896), and applied by 
Martin and Cherry (1898), in their investigation of the relations existing 
between diphtheria toxin and antitoxin. The fluids examined were forced by 
a constant air-pressure of 100 atmospheres through Pasteur-Chamberland 
filters filled with solid gelatine, and each filtrate was removed in successive 
fractions of about 4c.c. The hemolytic powers of these fractions of filtrates, 
of the residual fluid left in the filter case, and of the original fluid introduced, 
were then determined in the manner described above. 
Lysin.—On filtering a weak lysin solution through a filter prepared from 
15-per-cent. gelatine, the filtrate gave little or no hemolytic effect, but on 
diminishing the concentration of gelatine to 9 per cent., and using a stronger 
lysin, the filtrates obtained were strongly hemolytic. The first few fractions 
had practically no action on blood corpuscles, and the succeeding fractions 
increased at first rapidly in hemolytic power and then more slowly until a 
fairly constant value was reached, which approximated to that of the original 
lysin introduced. The gelatine, also, proved to be intensely hemolytic, 
whereas the original gelatine had no effect on red-blood corpuscles. Candles 
prepared from 15-per-cent., 11-per-cent., 9-per-cent., and 7°5-per-cent. gelatine 
were also used, and the residual fluids showed in all cases a greater hemolytic 
power than the original lysin, the difference being more marked with the 
higher percentages of gelatine. The gelatine filter is evidently more permeable 
to water than to the lysin. Similar concentration relations were found to 
hold for the filtration of crystalloids and inferior colloids, but the filter 
showed considerable differences in permeability to various crystalloidal 
substances.* 
Antilysin.—On filtering a 5-per-cent. solution of the antilysin in saline no 
trace of anti-hemolytic action could be detected in the filtrates. In this 
respect the antilysin behaves like a typical colloid, ¢.g., colloidal ferric hydrate 
was found even in concentrated solutions to be almost entirely retained by the 
gelatine on filtering under constant pressure. It is important to observe that 
if the pressure be suddenly diminished the concentrated contents of the 
gelatine, whether crystalloidal or colloidal, are swept into the filtrate. The 
filter showed considerable permeability to typical colloids, especially those 
which stained the gelatine, but on the whole retained this class of substances 
to. a greater extent than crystalloids. 
* Cf. also KE. W. Reid, 1901. 
