APPENDIX. Ill 



If an old culture or its ' ' metabolic products ' ' are intro- 

 duced into the body of animals, within them there occurs 

 a union of the zymase with the body albumin — immun- 

 proteidin (Emmerich). These immunproteidins have the 

 same solvent action upon bacteria as the bacteriolytic 

 enzymes, but are more durable and, above all, more capa- 

 ble of persisting in the blood. At least in some infectious 

 diseases the immunproteidins can be produced synthetic- 

 ally in vitro instead of in the animal body, and thus, ac- 

 cording to Emmerich and Low, materials may be produced 

 rapidly and cheaply which possess very high immunizing 

 power. The immunproteidins operate also nuich more 

 strongly anaerobically than aerobically. The difference 

 between the Gruber-Durham reaction (agglutination with- 

 out death) and the R. Pfeiffer reaction (death in the ab- 

 dominal cavity) is essentially dependent upon the follow- 

 ing: In the peritoneal cavity a scarcity of oxygen prevails 

 and the peristalsis mechanically disturbs the agglutination; 

 also, Emmerich and Low find the bactericidal action of 

 normal blood to be dependent u])on enzymes. 



This mass of observations, which are most worthy of 

 notice, is not to be overlooked to-day, although there has 

 been no opportunity for substantiating them. If they 

 prove true, they render an essential revision of the whole 

 question of immunity necessary. 



Summarized presentations regarding immunity or of the greater part 

 of the subject are : Buchner, H., SehutzimpfuiiK, etc., in " Handbuch 

 der Therapie, ' ' Jena, 1897. Metschnikoff , ' ' Immunitat, ' ' Jena, 1897. 

 Trumpp, A. H. xxxiii, 70. Dieudonn6, ' ' Experimentelle und krit- 

 ische Beitrage zur Kenntnis deragglutinieren den Stoffe, etc. ' ' Habili- 

 tationsschrif t. Wiirzburg, 1898. Dieudonne, ' ' Schutzimpf ung und 

 Serumtherapie. " Leipzig, zweite Aufl., 1899. 



