(150) 



STRUCTURE, DEVELOPMENT, AND BIONOMICS OF HOUSE-PLY. 391 



infantry, and he shows how this affects the incidence of enteric 

 fever. In the British Army in India, 190205, the ratios per 

 1000 per annum of cases admitted were : cavalry 41*1, and 

 infantry 15*5 ; and in the U.S. Army were : cavalry 5'74, 

 and infantry 4'75. He states that : "A study of the incidence 

 of enteric fever shows that stations where there are no filth 

 trenches, or where they are a considerable distance from the 

 barracks, all have an admission-rate below the average, and 

 all but one less than half the average." 



All these facts are equally applicable to the conditions in our 

 own towns and cities. Where the old conservancy methods are 

 used, such as pails and privy middens, the incidence of typhoid 

 fever is greater than in those places where the system of water 

 disposal has been adopted. I have examined the annual 

 reports of the medical officers of health of several large towns 

 where such conversions are being made, and they show a 

 falling-off of the typhoid fever-rate coincident with this 

 change. In Nottingham, for example, 1 in the ten years 1887 

 1896, there was one case of typhoid fever for every 120 houses 

 that had pail-closets, one case for every 37 houses with privy 

 middens, and one case for every 558 houses with water-closets. 

 The last were scattered, and not confined to the prosperous 

 districts of the town. 



One of the most important investigations on the relation 

 of flies to intestinal disease was that of Jackson (1907). 

 He investigated the sanitary condition of New York 

 harbour and found that in many places sewer outfalls had not 

 been carried below low-water mark, consequently solid matter 

 from the sewers was exposed on the shores, and that during 

 the summer months on and near the majority of the docks 

 in the city a large amount of human excreta was deposited. 

 This was found to be covered with flies. The report, consi- 

 dered as a mere catalogue, is a most severe indictment against 

 the insanitary condition of this great water front. By means 

 of spot-maps he shows that the cases of typhoid are thickest 



i " Typhoid Fever and the Pail System at Nottingham," ' Lancet,' 

 November 29th, 1902, p. 1489. 



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