1904.] the Tubercle Bacillus ly Human Blood Fluids, etc. 165 



B'. 



Patient's washed corpuscles 2 vols. 



A. E. W.'s serum 2 



Suspension of living tubercle bacilli ..... 1 vol. 



Phagocytic index (average of 31 P.W.B.C.), 2'1. 



B". 



A. E. W.'s washed corpuscles 2 yols. 



Patient's serum 2 



Suspension of living tubercle bacilli 1 vol. 



Phagocytic index (average of 30 P.W.B.C.), 1-3. 



It will be seen that the phagocytic effect obtained with the patient's 

 white corpuscles (in A') was (in B') increased more than three-fold in 

 consequence of the replacement of their native serum by that of the 

 control blood. The phagocytic effect obtained with the white corpuscles 

 of the control blood (in A") was (in B") diminished in an almost corre- 

 sponding degree (approximately two and a half times), by the replace- 

 ment of their native serum by that of the patient. 



These results are, it may be pointed out, in conformity with those 

 recorded in our previous paper* in connection with the phagocytosis 

 of the staphylococcus pyogenes. 



II. Action exerted upon the Tubercle Bacillus by the Blood-fluids of those 

 who are the subject of Tubercular Infection. 



The blood fluids of the subjects of a particular bacterial infection 

 may be expected to differ with respect to their content in bacterio- 

 tropic substances from the blood fluids of normal persons. An 

 increased content in these elements may be expected in the case 

 where there has been active response on the part of the machinery of 

 immunisation to the stimulus of infection ; diminished content 

 (a) where that machinery is becoming exhausted, and (b) where 

 infection is dependent upon a native, or at any rate, antecedent 

 deficiency in protective substances. 



Agglutinating effect. We have in no instance found the agglutinating 

 power of the blood of tubercular patients higher than that of certain 

 normal bloods. Sometimes we have found it notably decreased. 

 In three cases we have found it altogether absent. On the average 

 we find that it does not differ sensibly from that of the normal blood. 



It would seem to follow and this conclusion is in conformity with 

 that arrived at by others that no indication as to the presence or 

 absence of tubercular infection can be drawn from the measurement 

 of the agglutinating power, unless perhaps in the case where that 

 reaction is found to be quite absent. 



* ' Boy. Soc. Proc.,' vol. 73, pp. 129 and 130. 



N 2 



