68 Measurement of the Bactericidal Poicer of Blood. [Aug. o r 



of the stem is passed through the flame of a peep-light in such a way 

 as to heat it without allowing it to fuse and to collapse under the 

 influence of the internal negative pressure. The sterilised extremity 

 is now snapped off by plunging it while still hot into the nutrient 

 broth. The inflow which takes place through the orifice thus pro- 

 vided is arrested by the pressure of the finger and thumb upon the 

 teat as soon as the cultivation chamber is about two-thirds full. 



The sealing up of the tube and the subsequent cultivations are 

 carried out in exactly the same manner as in the case of the ordinary 

 (aerobic) estimation described in Section I. 



Section III. — On the Bactericidal Effects produced by one and the same 

 Human Blood (a) Drawn off and Tested by the Aerobic Procedure 

 described in Section I ; and (b) Drawn off and Tested by the Anaerobic 

 Procedure described in Section II. 



In view of the fundamental theoretical importance which attaches to 

 the assumption that the bactericidal power of the blood is acquired 

 only after withdrawal from the organism, and, in particular, after the 

 disintegration of the leucocytes under the influence of air and contact 

 with the wall of unoiled or unparaflined receptacles, it seemed 

 important to reinvestigate the question ; I have therefore endeavoured 

 to ascertain whether there is any constant and important difference 

 between the bactericidal power of human blood (a) drawn off and 

 tested by the aerobic procedure described in Section I ; and (b) drawn 

 off and tested by the anaerobic procedure described in Section II. 



The results of this investigation are set forth below in tabular form, 

 and it will be observed that while they are, of course, inconclusive on 

 the wider question of the derivation of the bactericidal substances of 

 the serum, they would seem definitely to show that neither contact 

 with the external air, nor contact with ordinary glass surfaces, exerts 

 any important influence on the bactericidal power exerted by human 

 blood upon the typhoid bacillus and the cholera vibrio. 



