It is not the object of this paper to discuss the technic of obtaining the opsonic index, for full descriptions of this will be found in the literature. Neither will any attempt be made even to summarize the work of Metchnikoff, Mennes, Wright and Douglas, Neufeld, Rimpau and others whose researches have demonstrated the phagocytic activity of leucocytes and the factors influencing this activity.
Successful treatment of bacterial infections has been shown to be most marked when the process is localized. Wright treated a number of patients having localized tubercular infections with inoculations of Koch's new tuberculin with such good results that this substance has been used by many others as a therapeutic measure.
The tuberculo-opsonic index has been shown to be below normal in most cases of localized tuberculosis, though it may fluctuate if the tuberculous process is active and there is autoinoculation. In 150 cases of localized tuberculosis