AUTO-INOCULATION 



201 



poor results obtained during the first era of tuberculin treatment can, 

 according to Wright, be attributed to the failure of this observation. It 

 is the production of cumulative positive phases that is the aim of vaccine 

 treatment. (Chart 6.) 



Wright and his co-workers have noticed that an increase in the opsonic 

 index usually runs parallel with an improvement in the condition of the 

 patient. 



Inasmuch as an increase in the opsonic index is occasioned by introduc- 

 ing into the general system even a very small number of bacteria, it seems 

 probable that such spontaneous inoculation will take place during the 

 course of an infectious disease. In fact, a spontaneous rise in the opsonic 

 index is observed during convalescence or after the crisis of an infection. 

 A high index is, however, also noticed at other times; for example, tuber- 



Nov. Dec. 

 30 1 Z 3 4 



12 13 14 1516 17 18 192021 222324252627282930 



CHART 6. Opsonic curve during treatment with New Tuberculin. 



culous individuals show a higher index than normal persons. Wright 

 explains this by the so-called " auto-inoculation;" for example, after 

 moderate exercise, or work, tuberculin is liberated from the tuberculous 

 focus and in this way acts like a therapeutic injection of tuberculin, i.e., 

 the index will be raised. Therefore, an excessively high opsonic index is 

 of just as great diagnostic value as a low one. Wright furthermore 

 believes that constant irregularities or variations in the height of the opsonic 

 curve serve as plausible evidence for the existence of infection, because 

 under normal circumstances the curve should remain at a level. Not 

 infrequently, however, cases come under observation where in spite of a 



