608 ANNUAL KEPOE.T SMITHSONIAN INSTITUTION, 1911. 



from infection during collection and transportation. Under some 

 conditions the protection of the consumer against milk-borne infec- 

 tion may be best brought about by compulsory pasteurization of that 

 portion of the milk supply winch can not otherwise be raised to proper 

 standard. Whatever method of control be adopted, it is certain 

 that any genuine improvement hi the character of a milk supply 

 will be followed in the long run by a lessening in the amount of 

 typhoid fever, diphtheria, scarlet fever, and to some extent tuber- 

 culosis. The early detection of a single case of typhoid fever or 

 scarlet fever on a dairy farm may be the means not only of preventing 

 an extensive epidemic, but of avoiding the formation of scores of new 

 foci winch can in turn serve to light up subsequent cases for many 

 years. Proper pasteurization of milk has been followed in many 

 cities, as in Glasgow, Liverpool, and London, by an immediate and 

 material reduction in the amount of typhoid fever. In other words, 

 the connection between an expenditure of public money and a direct 

 return in prevention of disease can be more clearly demonstrated 

 in the case of milk-supply control than in some other of the usual 

 municipal health department activities. 



The question whether the quality of a city milk supply can be more 

 favorably influenced by inspection and supervision at the source, or 

 by generally enforced and controlled pasteurization is one upon 

 which there is still some difference of opinion among experts. There 

 is little doubt, however, that simply as a matter of economy of 

 administration much k to be said at present in favor of centralized 

 pasteurization of a large portion of the supply. Viewed as a method 

 for preventing a large number of cases of infectious disease at rela- 

 tively small expenditure the pasteurization of milk certainly ranks 

 high among effective health measures. 



One of the important bacteriological advances of the last few years 

 has been the discovery that a considerable number of healthy persons, 

 convalescents, or others, harbor disease germs and that these persons 

 are important agents in spreading disease. The detection and 

 proper treatment of disease-germ carriers, particularly in the more 

 serious diseases and before or in the early stages of an epidemic, is 

 now recognized as an important although difficult task. The whole 

 question of the control of germ carriers is one that needs more careful 

 study with a view to determining the actual results of the methods 

 adopted. From this point of view, inspection of school children, 

 especially at the beginning of the school year, is probably to be 

 classed as a highly profitable activity, although it is to be wished 

 that fuller and better-studied statistics were available. 



Inspection of school children is highly valuable, also, in detecting 

 various common congenital or acquired defects. If the defects are 

 remediable, their early discovery may avoid development into per- 



