BA CILL US TYPHOS US. 419 



quantitative only, and not qualitative, so far as the 

 cholera spirillum and typhoid bacillus, at least, are 

 concerned. They conclude, nevertheless, that these 

 investigations will render valuable assistance in the 

 clinical diagnosis of cholera and typhoid fever. It 

 developed through further research that before the 

 development of the bactericidal substances agglutina- 

 tive substances usually appeared in the blood. 



WIDAI^XES^ The first practical application of the 

 use Trf^serum, however, for the early diagnosis of 

 typhoid fever on a more extensive scale was made by 

 Widal, and reported with great fulness and detail in a 

 communication published in June, 1896. Widal con- 

 firmed the reaction as above described, proved that the 

 agglutinative reaction was one of infection and usually 

 occurred early, elaborated the test, and proposed a 

 method by which it may be practically applied for 

 diagnostic purposes. Since then the serum test for 

 the diagnosis of typhoid fever has come into general 

 use in bacteriological laboratories in all parts of the 

 world, and though the extravagant expectations raised 

 at the time when Widal first announced his method of 

 applying this test have not been entirely fulfilled, it 

 has, nevertheless, proved to be of great assistance in 

 the diagnosis of obscure cases of the disease, and it is 

 now one of the recognized tests for the differentiation 

 of the typhoid bacillus. 



It should also be mentioned that to Wyatt Johnson, 

 of Montreal, belongs the credit of having brought this 

 test more conspicuously before the public by intro- 

 ducing its use into municipal laboratories, suggesting 

 that dried blood should be employed in place of blood- 

 serum (Widal having previously noticed that drying 



