SANITATION ON FARMS FREEMAN. 653 



after vacation can be traced directly to the bad sanitation of country 

 resorts. If, therefore, the health of the cities is to be improved the 

 health of the country must also be bettered. And if the nation is 

 ever to stamp out disease it must be by a general attack in both the 

 city and the country. 



In addition to the crying need for such work rural conditions offer 

 to the scientific sanitarian the attraction of almost unparalleled oppor- 

 tunities for research work in the transmission of disease. In typhoid 

 fever, particularly, the key to the eradication of summer typhoid is 

 to be found in the country. To trace the means of dissemination of 

 typhoid bacilli in a city, with its manifold sources of food supply, 

 the complication of the milk supply, with daily contact between 

 thousands of persons, any one of whom may be in the incubative stage 

 of the disease or may be a typhoid carrier, and with the constant 

 temptation to attribute the infection to the water supply, is beset 

 with so many difficulties as to make it almost hopeless. The best 

 that can be done is to draw general conclusions from the study of 

 large groups of cases, and even here it is difficult to exclude the 

 general factors of flies, milk, and water. 



In the country conditions are very different. Given a country 

 district free from typhoid for several years, the first- case is easily 

 discovered, and the transmission of the disease may often be worked 

 out with mathematical accuracy. Water and milk are of course 

 easily excluded; flies may be considered with some accurate idea as 

 to their importance as a factor in transmission ; and the actual amount 

 of contact resulting in infection may often be determined exactly. 

 If this work be extended over a largre area and be combined with 

 careful statistical studies it will throw more light on the city problem 

 than can be obtained in the city itself by any means known at present. 



Nor is typhoid the only disease which can be advantageously studied 

 in the country. We have found the study of the transmission of 

 smallpox in rural districts to be of great interest by reason of the fact 

 that the time, place, and manner of contact can be worked out with 

 ease and certainty. Diphtheria and scarlet fever, studied case by case 

 in rural districts, should throw great and much-needed light on the 

 transmission of these diseases. 



It may not be amiss at this point to call attention to the value of 

 the case method of study of infectious diseases in rural work. A per- 

 sonal visit to each patient, the collection of the data needed at the 

 place where the disease occurred, and the interpretation of the epi- 

 demiologic evidence in the light of the other information secured by 

 a visit to the premises, offers by far the most promising method for 

 the solution of the problems now pressing for solution. 



The rural districts, however, offer even greater possibilities in 

 practical prevention than as a field for studies in the transmission of 



