^56 APPLIED IMMUNOLOGY 



titioner desiring to give the inoculations. Otherwise, 

 in the event of an unhappy result, the former will 

 accuse the latter of incompetence and the latter the 

 former of faulty technic. This seems like stringent 

 doctrine, but we believe in the long run will redound 

 not only to the credit of physicians and bacterin 

 therapy, but also and especially to the better health 

 of patients. Even in the experience of expert bac- 

 teriologists it becomes at times no easy task to isolate 

 from a mixed infection the fundamental etiological 

 bacterium. Obviously, a bacterin prepared from a 

 superimposed or secondary infection, even though that 

 bacterium be preponderant, would produce little or no 

 effect, curatively, upon the primary or underlying 

 morbid process. Stock bacterins, if employed — a pro- 

 cedure at times advisable — should be polyvalent, that 

 is, constituted by as many strains as may be obtain- 

 able of the particular species of bacterium in question. 

 Caution should always be exercised to determine by 

 bacteriological methods the exact identity of the in- 

 fecting bacterium in a given case before proceeding 

 with the '' supposedly correct " stock bacterin. On 

 more than one occasion we have found patients falsely 

 immunized with a stock preparation devoid of the 

 bacterium actually causing the disease. Such failures 

 discredit physicians vastly more than the mode of 

 therapy. The advantage of the autogenous prepara- 



