CONTRIBUTIONS TO THE THEORY OF LYSIN ACTION. 5 



order to throw some light on these problems that Ehrlich devised 

 his side-chain theory. 



At first Ehrlich 's theory was applied to the origin of the anti- 

 toxins and to the chemical relation existing between the toxins and 

 certain atomic groups of the protoplasmic molecule. Pfeiffer him- 

 self applied the theory to the substances specifically bacteriolytic 

 for cholera bacilli, and was able to demonstrate experimentally that 

 the source of these bodies was in the spleen, the bone-marrow, and the 

 lymph bodies (Pfeiffer and Marx, Zeitschr. f. Hyg., Vol. 37, 1898). 

 Wassermann, who in his well-known tetanus experiments had fur- 

 nished the first demonstration of the soundness of the side-chain 

 theory, succeeded in showing the source of the specific typhoid 

 bactei/olysin. The study of these bacteriolytic processes brought up 

 a number of important questions directly concerning the side-chain 

 theory, and we felt compelled to examine these experimentally. 



According to Ehrlich's theory, if any substance, be it toxin, 

 toxoid, ferment, or constituent of a bacterial cell or of a blood- 

 corpuscle, possess the property of combining with side-chains of the 

 protoplasm, the possibility is given for the formation of a corre- 

 sponding antibody. The antibody, according to the theory, must 

 possess such a group as will fit the haptophore (the specific com- 

 bining) group of the invading substance. The soluble body, therefore, 

 produced in response to the invading substance (toxin, toxoid, etc), 

 must combine chemically with the latter. If the invading substance 

 is in soluble form, as, for example, the toxins, the neutralization 

 proceeds in the solution. If, however, it is not directly soluble, 

 being originally an insoluble part of, say, a bacterial or blood cell, 

 then the dissolved antibody in the blood will be abstracted from 

 its solvent fluid and anchored by the cell particle. In the well-known 

 experiment of Wassermann on tetanus poison, the same thing is seen. 

 In this the invading substance (tetanus toxin) is abstracted from 

 its solution and anchored by the crushed brain cells. In order to 

 maintain the analogy we should expect that in our experiment the 

 immune body dissolved in the goat serum would be anchored by the 

 erythrocytcs of sheep blood. 



The manner of procedure in this experiment is very simple and 

 consists in the addition to sheep blood, or a dilution of the same,, 

 of immune serum which has been heated to 56 C. in order to destroy 

 its solvent properties. The mixture is then centrifuged to separate 

 the cells and the fluid. In case the immune body has been anchored 



