xvi Contents 



CHAPTER XV 



PAGTC 



PROTECTIVE VACCINATIONS 454 



Vaccinations against, I. Small-pox. II. Sheep-pox. III. Rabies.-IV. Rinder- 

 pest. V. Anthrax. VI. Symptomatic Anthrax. VII. Swine Erysipelas. 

 -VIII. Pleuropneumonia in the Bovidae. IX. Typhoid Fever. 

 X. Plague. XI. Tetanus. XII. Diphtheria. 



CHAPTER XVI 



HISTORICAL SKETCH OP OUR KNOWLEDGE OF IMMUNITY . . . . 505 



Methods used by savage races for vaccination against snake venom and against 

 bovine pleuropneumonia. Variolisation and vaccination against small- 

 pox. Discovery of the attenuation of viruses and of vaccinations with 

 attenuated micro-organisms. Theory of the exhaustion of the medium as 

 a cause of acquired immunity. Theory of substances which prevent the 

 multiplication of the micro-organisms in the refractory body. Local 

 theory of immunity. Theory of the adaptation of the cells of the im- 

 munised organism. 



Observations on the presence of micro-organisms in the white corpuscles. 

 History of phagocytosis and of the theory of phagocytes. Numerous 

 attacks upon this theory. Theory of the bactericidal property of the 

 body fluids. Theory of the antitoxic power of the body fluids. Extra- 

 cellular destruction of micro-organisms. Analogy between bacteriolysis 

 and haemolysis. Theory of side-chains. 



Progress of the theory of phagocytes. Attempts to reconcile it with the 

 humoral theory. Present phase of the question of immunity. 



CHAPTER XVII 

 SUMMARY 544 



Means of defence of the animal against infective agents. Absorption of micro- 

 organisms. Phagocytes, and their function in inflammation. The action 

 of phagocytes in the absorption of micro-organisms. The cytases, phago- 

 cytic ferments. The cytases are closely bound up with the phagocytes. 

 The fixatives and their function in acquired immunity. The fixatives are 

 excreted by the phagocytes and pass readily into the fluids of the body. 

 Essential mechanism of the action of the fixatives. Adaptation of 

 phagocytes to destroy micro-organisms in acquired immunity. Difference 

 between the fixatives and the agglutinins. Antitoxins and their analogy 

 with the fixatives. Hypotheses as to the origin of antitoxins. Cellular 

 immunity is a fact of general import. Susceptibility and its role in 

 immunity. Applications of the theory of immunity to medical practice. 



INDEX . .... 571 



