

1905. | Chemstry of the Toxin-Antitoxin Reaction. 191 
The Validity of the Application of Chemical Mass Action Equations to the 
Lysin-Antilysin Action. 
Nernst (1904) has insisted that the views of Arrhenius and Madsen on 
the mass action of toxin and antitoxin can have no true theoretical founda- 
tion. If the reaction consist in a chemical change, it seems to me that 
the chemical law of mass action would be applicable in the manner given 
below. If, on the other hand, the observed mass action differs widely from 
the deduced, we can conclude that the toxin-antitoxin reaction is not a 
purely chemical one. ; 
The anti-body, e.g., antilysin, is a typical colloid, and its active chemical 
mass will, like that of a solid suspension, be constant. Similarly, the 
chemically active mass of the compound between antilysin and lysin is 
constant, as this also occurs in the form of a fine suspension. The active 
mass of the lysin will vary with its concentration, as this substance is not. 
present in the form of a typical colloid. It has properties such as diffusi- 
bility, and the power of passing a gelatine filter similar in magnitude to 
those found for crystalloids and inferior colloids. 
These conditions are not unlike those studied by Walker and Appleyard 
(1896) in the case of a solid suspension of diphenylamine in picric acid 
solutions. If this analogy is a true one, the chemical equation expressing 
the combination of lysin with antilysin should be similar to that given by 
these authors for the combination of picric acid with diphenylamine, viz., 
lysin, water +antilysin = compound + water. | 
The lysin is removed by the solid suspension of antilysin, and a solid 
suspension of compound (lysin, antilysin) is produced with the liberation 
of the water which held the lysin in solution. The velocity of combination 
will be K,CK’ where K, is the velocity constant, C the concentration of the 
lysin, and K’ the constant active mass of the antilysin. When the reaction 
is reversible, «¢., possibly at high concentrations of antilysin, the velocity 
of dissociation will be K,K’’K’”’ where K, is the velocity constant, K’’ the 
constant active mass of the compound, and K’” the constant active mass 
of the water. For equilibrium K,CK’ = K,K”K’”, or 
Oe eK = constant. 
From which it follows that at any definite temperature the concentration 
of the lysin must be a constant. The compound (lysin, antilysin) and free 
antilysin can only exist side by side in the aqueous medium when the latter 
has a certain fixed absolute concentration. The relative concentrations of 
