126 PHARMACEUTICAL BACTERIOLOGY. 



posite, which give evidence of being a decided improvement over the simple 

 sera. They are called composite because they have the peculiar qualities 

 of two distinct forms of immunity for example, diphtheria-immune horses 

 may be used in the subsequent bacterial inoculation, which gives the result- 

 ing immune-serum a double content of a corresponding antibacterial body 

 and of diphtheric antitoxin. This subject is as yet entirely in the experi- 

 mental stage. It is also known that one kind or type of immunity has some 

 influence not only upon other immunities, but also upon other diseases. 

 The antitoxin of diphtheria, for example, appears to act as a cure or pro- 

 phylactic against pathological conditions other than diphtheria. 



We now come to a third class of substances used in the treatment of 

 disease, namely, the bacterial vaccines, also designated bacterins and opsono- 

 gens (Ohlmacher). The term vaccine (from Vacca, a cow) is appropriately 

 applicable to the small-pox remedy, but is entirely inapplicable to these 

 newer agents. Either bacterin or opsonogen is a suitable name. 



Bacterins are simply suspensions of dead pathogenic germs which are 

 used in the treatment of disease. They produce their beneficent effects by 

 acting upon the bacteria so that they may be taken up and digested by the 

 white blood-corpuscles (phagocytes), as has already been explained. A 

 homologous or autogenous bacterin is prepared from germs taken direct 

 from the patient and is used in treating the same patient. A heterologous 

 bacterin is one which is derived from a source other than the patient under 

 treatment. A mixed bacterin is one in which the germs (of the same species) 

 used are derived from several sources. The manufactured bacterins (heter- 

 ologous) ready for use by the physician are called stock vaccines or stock 

 bacterins. 



The following is a tabulation of antitoxins, toxins, antibacterial sera and 

 bacterins found upon the market and used by physicians and veterinarians. 



i. For Human Use. 



A. Antitoxic Sera or Antitoxins. 

 Antidiphtheric serum. 



Liquid or usual form. 



Concentrated form. 



Dry form (official in some pharmacopoeias). 

 Antitetanic serum. 



Liquid or usual form. 



Dry form. 



B. Antibacterial Sera or Bactericidal Sera. 

 Antistreptoccocic serurrL 

 Antipneumococcic serum. 

 Antimeningitic serum. 



