344 Dr. A. B. Green. On some Additional Points in [Apr. 19, 



The Species of Micro-organisms Killed by the Chloroform Process. 



In addition to the extraneous micro-organisms mentioned* as 

 commonly occurring in crude calf vaccine and as being eliminated 

 therefrom by means of chloroform, experiments have been made with 

 further species of bacteria. These, with the exception of B. proteus 

 vulgaris and B. coli communis, have never been found in vaccine lymph 

 at these laboratories, but they have been subjected to the action of 

 chloroform in order that knowledge of the germicidal value of that 

 process might be extended. The bacteria thus experimented with 

 are : — B. proteus vulgaris, B. prodigiosus, B. pyocyaneus, B. fluwescens 

 liquefaciens, B. coli communis, B. typhosus, B. diphtherial, B. mallei, 

 B. pestis, B. tuberculosis, and Spirillum cholera Asiatica. 



Broth emulsions of these bacteria were first experimented with. As 

 soon as an emulsion was established a suitable culture medium was 

 inoculated with a small portion of it and duly incubated, in order to 

 ascertain whether the species of micro-organism in question could be 

 easily recovered from the emulsion. The passage of chloroform 

 vapour and air through the emulsion was then begun, and during the 

 process at regular intervals further cultivations were made from it. 

 In every instance the bacteria of experiment were found to have been 

 killed, at intervals ranging from 1 — 8 hours from the commence- 

 ment of the process. 



In a second set of experiments vaccine emulsions were prepared by 

 mixing one part by weight of pulp with two parts by weight of water. 

 To these emulsions the bacteria to be experimented with were added, 

 and cultivations at once made therefrom in each instance, to ascertain 

 whether recovery of the bacteria was possible. Passage of chloroform 

 vapour and air through the emulsions was then carried out and further 

 cultivations made from them from time to time. As in the case of the 

 broth emulsions, after the passage of the chloroform vapour and air 

 for a few hours, the bacteria in the vaccine emulsions were killed. 



In the case of each experiment of the two foregoing series, a 

 "control" preparation was established in which the bacteria were 

 found to be still alive after the bacteria of the corresponding experi- 

 mental preparation had been killed. 



The vaccine used in these experiments was collected for experimental 

 purposes only. 



The Keeping Properties of Chloroformed Vaccines. 



The keeping properties of chloroformed vaccines have been tested in 

 the following ways : 



First, vaccine lymph freshly collected from the calf was divided into 



* ' Roy. Soc. Proc.,' 1903. 



