BACTERIAL INOCULATION 247 



the dose cast into the circulation, and in view of the 

 fact that the inoculation consists of living bacteria, 

 not as in ordinary bacterin therapy of measured dead 

 microorganisms, the method is attended by a certain 

 amount of danger and should be utilized only by ex- 

 perienced hands. 



Duration of Active Immunity, — In general it is 

 admitted, and may be stated, that the greatest and 

 most lasting immunity is produced by inoculations with 

 living bacteria, then with dead bacteria and finally with 

 the products of bacterial growth. This has been quite 

 satisfactorily demonstrated by animal experimenta- 

 tion, and a common procedure is to begin the process 

 of immunization with inoculations of dead bacteria, 

 followed by the living microorganisms. Thus far, 

 the profession has not seen fit, nor would patients sub- 

 mit to injections of living bacteria, although by re- 

 sort to the technic of Williams and Webb — inocula- 

 tions at first with a single living bacterium, then by 

 cautious count progressively increasing the dosage — ■ 

 or supplementing inoculations of dead by living or at- 

 tenuated bacteria, no danger should be incurred, and 

 the day may not be far remote when such a practice 

 in expert hands will be an unobjectionable and com- 

 mon procedure. 



Immunity is never absolute, but the protection af- 

 forded by bacterial inoculations lasts indefinitely, fre- 



