APPENDIX B. 



NOGUCHI'S BUTYRIC ACID TEST. 



FEELING that the lecithin, glycocholate of soda, 

 oleate of soda, and other compounds which had 

 been used in the various modifications of the 

 Wassermann test, might act as acids, and that this 

 acidification possibly gave rise to a precipitate of 

 globulins and related substances, Noguchi sought 

 to discover the nature of the Wassermann reaction 

 by studying the influence of various acids on the 

 serum of different individuals. He found that in 

 general a greater degree of precipitation was pro- 

 duced in syphilitic sera than in non-syphilitic ones. 

 It was natural to think that the deflection of com- 

 plement observed in the Wassermann test was due 

 to adsorption by the precipitate as such, but on 

 testing the precipitate itself this was found not to 

 be the case. 



The increased precipitation produced in syphilitic 

 sera by the addition of acid suggested an increase 

 and qualitative change on the part of the serum 

 globulin, and this possibility was also indicated by 

 the results obtained by Klausner. This author, it 

 may be stated, devised a test for syphilis, based 

 on the formation of a precipitate when the serum 



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