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August 12, 1905


JAMA. 1905;XLV(7):466-467. doi:10.1001/jama.1905.02510070034006

The practical application by Widal of the principle that in bacterial diseases substances form in the blood which will agglutinate the bacteria causing the disease has led to important additions to the methods of bacterial diagnosis, and has rendered more certain, in some instances, the association of a given bacterium with a given disease. Notwithstanding the large number of diseases now held to be of bacterial origin, the number in which absolute proof of the relation of a given organism to a given disease has been brought forward is relatively small. If we accept Koch's postulates as a standard, and this is generally done by bacteriologists, there are many diseases now held to be bacterial in which absolute proof of this contention is lacking, and this is particularly the case in human diseases not transmissible to animals. It is just such diseases that the agglutination test is of the greatest