PHYSICO-CHEMK^AL PROPERTIES 8l 



received 0.5 c.c. of tlie iincliluted filtrate intra\en()iisly while the 

 other two recei\'ed 0.5 c.c. of a 1:10 dilution of the purified 

 fiaction. 



Tlie ptirified fraction of Andervont and Shear appeared to be 

 more potent than the filtrate. The intra\enoiis injection of a 

 1:10 dilution of the stock solution of the pmified fraction pro- 

 duced reactions at practically all sites of intradermal injection 

 both of the filtrate and of the purified fraction, while the intra- 

 \'enotis injection of the iindikited filtrate elicited reactions only 

 in those sites which had received the highest concentration of the 

 filtrate or of the purified fraction. A positive reaction was obtained 

 with 0.0005 iiigins. of the purified fraction. 



CHEMICAL STUDIES ON ACTIVE PRINCIPLES OF VIBRIO CHOLERAE 



Linton, Singh and Seal (1935) tested the phenomenon-pro- 

 ducing potency of the following fractions: 



1. \V'hole killed heavy suspension of Vibrio cliolerae derived 

 from various groups. 



2. A-fraction. This fraction dissolves out of vibrios at 50° c. 

 in alcohol made 0.025 N with HCl. Accordino to Linton, Sinoh 

 and Seal, the A-fraction has a specific rotation of about — 12.0° 



(in N/2 alkaline at 37° c.) and nitrogen distribution which is 

 characterized by the possession of about twice the amotuit of 

 amide nitrogen and one-half the amount of humin nitrogen 

 occurring in the whole protein. "A" occurs in Ijoth the pseudo- 

 and euglobulin fractions of the protein, increases ^vhen the ^vhole 

 protein is kept in distilled water at 10° c. and destroyed by 0.125 

 N HCl extraction. It yields about 1 to 2 per cent of vibrio dried 

 weight. 



3. The B-fraction was obtained by Linton, Singh and Seal after 

 removal of the A-fraction Ijy means of boiling the vibrios for 

 fifteen minutes in 75° alcohol. The material was diluted with 

 saline and made 0.05 N Avith HCl. B-fraction has a rotary powder 

 of 46.0° and nitrogen distribution indistinguishaljle from that 

 of the whole vibrio protein. It was found in both the globulin 

 fraction and A-fraction. The yield is not affected by high concen- 

 tration of HCl, nor does it increase in A'ibrio protein Avhen kept 

 in the refrigerator in distilled water. B-fraction is about 6 per 

 cent of dry weight of the protein. 



4. Residue fraction is closely allied to B-fraction and consists 



