PROCEEDINGS 



OF 



THE ROYAL SOCIETY 



" Preliminary Note on the Use of Chloroform in the Preparation 

 of Vaccine." By ALAN B. GREEN, M.A., M.D. (Cantab). 

 Communicated by W. H. POWER, M.D., F.RS. Pveceived 

 April 16, Kead April 30, 1903. 



(From the Government Lymph Laboratories.) 



It is well known that glycerine exerts an action on vaccine 

 whereby the extraneous bacteria are eliminated in the course of a few 

 weeks, while the specific germ undergoes no undue deterioration from 

 the process. 



I have found that by the use of a solution of chloroform in dis- 

 tilled water, the extraneous bacteria of vaccine are eliminated in 

 from one to six hours, the specific germ remaining fully potent for 

 vaccination. 



The solution of chloroform that can most advantageously be 

 employed in the preparation of vaccine is a saturated solution in dis- 

 tilled water, having a strength of 1 in 200. This is the limit of such 

 solubility. 



The following method of using such solution has so far given the 

 best results : 



Vaccine emulsion is first prepared by triturating vaccine pulp with 

 distilled water. The presence of the water is essential, in order that 

 later chloroform may enter into solution with it. About three parts 

 by weight of water should be mixed with one part by weight of pulp. 

 Should a more viscid emulsion of vaccine be desired, glycerine may 

 be added without interfering with the action of the chloroform. I 

 have found that the usual admixture of one part by weight of vaccine 

 pulp and four parts by weight of a solution consisting of equal parts 

 by weight of glycerine and water forms a perfectly suitable emulsion 

 for this process. But glycerine is incapable of dissolving chloroform, 

 and the elimination of extraneous bacteria by this chloroform process 



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