1904.] the Tubercle Bacillus In/ Human Blood Fluids, etc. 161 



phagoeytic effect obtained when bacteria are introduced into the blood 

 is dependent upon an action exerted by the blood fluids directly upon 

 the micro-organisms. 



We have investigated ' this question also in connection with the 

 'tubercle bacillus. In doing so a two-fold technical difficulty confronted 

 us :first, a difficulty associated with the circumstance that the tubercle 

 bacillus is available in ordinary cultures only in the form of agglo- 

 merated bacterial masses, and secondly, a difficulty associated with the 

 circumstance that unaltered tubercle bacilli when they have been 

 obtained in homogeneous suspension are agglutinated by the action of 

 both serum and physiological salt solution. 



The first difficulty can be surmounted by breaking up the bacterial 

 masses in a mortar in a 0'1-per-cent. NaCl solution, i.e., in a salt 

 solution diluted up to the point at which it will no longer bring 

 together by its agglutinating action tubercle bacilli which have been 

 mechanically separated. 



The second difficulty can be surmounted by heating the tubercle 

 culture to 100 C. 



We subjoin here a series of experiments (conducted before the 

 procedure last mentioned was thought out), with living tubercle bacilli 

 suspended in a 0'1-per-cent. NaCl solution. It will be seen that the 

 difference between the phagocytic effect obtained with the unheated 

 and the heated serum respectively is sufficiently pronounced to throw 

 altogether into the background the source of disturbance which is 

 associated with the presence of an agglutinating element in the serum. 



PRELIMINARY EXPERIMENTS. 



In this series of experiments a homogeneous suspension of living tubercle bacilli 

 was made bg rubbing up a small quantity of a tubercle growth (obtained from 

 a glycerine potato culture) in an agate mortar in l-m-1000 NaCl solution, 

 and tlien centrifugalising to get rid of the bacterial masses which had not been 

 into their elements, 



Experiment 1. 



A. 



A. E. W.'s unheated serum 2 vols. 



S. R. D.'s washed -corpuscles 2 ,, 



Suspension of living tubercle bacilli 1 vol. 



Phagocytic index (average of 67 P.W.B.C.), 5'4. 



B. 



A. E. W.'s serum heated to 60 C. for 20 mins. ... 2 vols. 



S. E. D.'s washed corpuscles 2 ,, 



Suspension of living tubercle bacilli 1 vol. 



Phagocytic index (average of 30 P.W.B.C.), 0'75. 



