386 TUBERCULOSIS 



no reason whatever for thinking that the opsonic index affords 

 any clue to the amounts of these substances formed. And, of 

 course, as is held by many, if the beneficial effects are due to 

 repeated slight local reactions, acting in a way as yet not under- 

 stood, the opsonic index is of little value. It should not be 

 forgotten that a polynuclear leucocyte will engulf an enormous 

 number of tubercle bacilli in a short time even when the opsonic 

 index is low, and it seems improbable that it ever falls so low 

 (even when the negative phase is most marked) as to prevent 

 these leucocytes from doing their work, presuming the bacilli are 

 accessible. A high opsonic index may have some action in 

 preventing generalization of the bacilli e.g., at a surgical opera- 

 tion but even this is not certain. 



It must be noted that the beneficial effects of vaccine treatment 

 by the opsonic control are not denied, but that the opinion is 

 expressed that the same benefits may be obtained by simpler 

 methods. 



Space forbids more than a reference to the use of auto- inocula- 

 tion by graduated exercise, massage, etc. This is supposed to 

 expel some bacilli or products thereof into the lymph spaces, etc., 

 where they act as a vaccine. The benefits of these measures is 

 undeniable, but it may be doubted whether it is due entirely or 

 in part to auto-inoculation, and it would appear preferable to 

 employ vaccines in known doses. 



3. The use of small doses without opsonic or other control. This 

 combines the advantages of practicability and safety, and often 

 gives good results. How they compare with those obtained 

 by the other methods cannot be accurately known. Probably 

 no harm has ever resulted from - f -^ milligramme of TR, and if 

 this amount is given once in every ten days, or even once a week, 

 many cases improve in a most striking manner. My experience 

 has been mainly confined to its use in surgical cases, and though 

 I have met with numerous disappointments (which I believe are 

 not unknown with the most strict opsonic control), I have seen 

 others in which rapid cure e.g., of a chronic sinus or tuberculous 

 ulcer has been obtained. I should not recommend it or any 

 other method of vaccine treatment in place of surgical or 

 sanatorium treatment, where applicable ; in conjunction with 

 other methods, it has its place. 



Preventive Treatment. This is at present of but little importance 

 in human pathology. A person who is in danger of becoming 



