4G BOARD OF AGRICULTURE. [Pub. Doc. 



MII.K SUPPI.Y AND THE PUBI.IC HEAT.TH. 



BY AVILLIAM T. SEDGWICK, PROFESSOR IN THE MASSACHUSETTS INSTI- 

 TUTE OF TECHNOLOGY. 



It is of recent years only that milk supply has come to be 

 regarded as of importance to the public health. Previous to 

 1881 it was not very generally known that milk is a ready 

 vehicle of infectious disease. It is said that the first epidemic 

 of typhoid fever traced to milk was one in 1857, studied by 

 Dr. Michael Taylor. In 1867 the same epidemiologist showed 

 that scarlet-fever might be distributed in the same way, and 

 simultaneously Prof. Oswald Bell arrived at the same con- 

 clusion through his investigation of an outbreak of that disease. 

 In 1877 an epidemic of diphtheria was traced to a milk sup- 

 ply. These and other cases which had been reported were 

 brought together in 1881 by Mr. Ernest Hart, and laid before 

 the International Medical Congress of that year in a striking 

 paper which at once drew universal attention to milk supply 

 as a vehicle of infectious disease. Mr. Hart in his paper 

 gave the history of fifty epidemics of typhoid fever, which up 

 to that time had been charged to infected milk, besides fifteen 

 epidemics of scarlet-fever, and four of diphtheria. "The 

 record," says the eminent medical writer from whom these 

 statements are taken, " since 1881 has not been less striking ; 

 indeed, since the method of investigating these occurrences 

 has been more generally understood, milk has been constantly 

 and justly incriminated as a cause of zymotic disease in man." 



The year 1881 was important to the milk-supply industry 

 in another and very different direction. In that year a method 

 was invented by which it became easy to investigate with 

 some accuracy the ordinary fermentations of milk, by ob- 

 serving the numerical increase of its bacterial ferments and 

 studying their progressive effects. The same method led 



