1904.] the Tubercle Bacillus ly Human Blood Fluids, etc. 175 



of the blood may fail to furnish indications of an abnormally low 

 resisting power on the part of the untreated patient ; and while it may 

 yield only tardy information of the alterations effected in the blood 

 fluids by inoculation ; and while it may sometimes altogether fail to 

 distinguish between the patient's condition before and after successful 

 immunisation ; the measurement of the opsonic power satisfies it would 

 seem all these desiderata. 



We have already seen in Table I that it distinguishes* between the 

 tubercular subject and the person with normal resistance. And we 

 shall see in the table below that it furnishes prompt and clear 

 indication of the negative phase which supervenes upon inoculation, 

 and again of the positive phase which succeeds the negative phase 

 wherever the organism possesses the necessary power of response. 

 Furthermore the measurement of the opsonic power of the blood dis- 

 tinguishes clearly between the untreated tubercular patient and the 

 patient who has made progress in the direction of immunisation. This 

 will appear clearly on comparing, in Table III below, the opsonic 

 indices achieved after inoculation with those set forth in Table I. 



In conclusion we may note, that while we are jointly responsible for 

 the observations set forth in Sections 1, 3, and 4 of this paper, the work 

 which is embodied in Sections 2 and 5 has been separately undertaken 

 by one of us. 



* It will not, however, invariably do so. 



