THE PROTEIN POISON. 



By victor C. VAUGHAN, M.D. 



(Read April ig, 191 2.) 



For many years I have been studying the chemistry of the bac- 

 terial cell. In 1900 I devised the large tanks for growing massive 

 cultures. These have proved quite satisfactory, and I have bten 

 able to get bacterial cellular substances quite free from all impuri- 

 ties, in large amount. After many years of unsuccessful effort 

 Wheeler and I, in 1903, succeeded in partially isolating the poison- 

 ous group from the cellular substance of certain pathogenic bacteria. 

 This we did by heating the cellular substance with a two per cent, 

 solution of sodium hydroxid in absolute alcohol. When this is 

 done at the temperature of boiling alcohol the cell substance is 

 split up into a poisonous and a non-poisonous part. The former is 

 soluble in alcohol, while the latter is insoluble. This gives us not 

 only a method of preparation, but also one of partial separation. 

 I may say that the evidence that a distinct cleavage of the bacterial 

 cell is secured is shown by the fact that all the carbohydrate and all 

 the phosphorus in this cellular substance remains in the insoulble or 

 non-poisonous part. The poisonous portion contains no phosphorus 

 and no carbohydrate, but it does give the biuret and the Millon 

 reaction, and must therefore be classed as a protein. This protein 

 has never been obtained as yet in a state of chemical purity. The 

 best preparation that we have been able to secure up to this time 

 kills guinea pigs when injected intravenously, in doses of .5 of a mg. 

 There are certain reasons for believing that its effect upon man is 

 still more pronounced. 



Having found this poison in pathogenic bacteria we next looked 

 for it in non-pathogenic organisms, and we found it in these quite 

 as abundantly as in the pathogenic forms. It therefore follows 

 that the pathogenicity of the bacterial cell does not depend upon 



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