4 re of Chloroform in 1lt? Preparation of Vaccim. [Apr. 1 6 7 



a few weeks of collection, that is within the time required for glycerine 

 to exert fully its influence in eliminating extraneous organisms. Some 

 of these vaccines may, at the time of their collection, have possessed 

 a high vaccination value. Vaccine, characterised by this high but 

 somewhat transient potency, can, by means of the chloroform process, 

 be used at once, before its activity has deteriorated, thus allowing 

 greater economy of vaccine material than would otherwise be possible. 

 (c) For a similar reason the chloroform process might be of con- 

 siderable use in hot climates where the preservation of the potency of 

 vaccine is frequently a matter of considerable difficulty. 



Experiments are at present being made to test the duration of the 

 potency of chloroformed vaccines. A further account of this process 

 will be given in the Report for 19021903 of the Medical Officer of 

 the Local Government Board. 



In conclusion I wish to express my indebtedness and thanks to Dr, 

 F. R. Blaxall for the generous help and advice he has given me. My 

 thanks are likewise due to Mr. H. 8. Fremlin, with whom I am also- 

 associated in the work of these laboratories, and to Mr. 8. IX 

 Rowland, of the .lenncr Institute of Preventive Medicine, for the help 

 he has aftbrded me. 





