34 THE EEPORT OF THE No. 36 



within seven daj^s or to treat the manure with such a substance as chloride of lime 

 or mineral oil as each lot is thrown on the heap to prevent the breeding of the flies 

 and such manure should be kept in a chamber to which flies cannot obtain access. 

 The first method is the best and most effectual and certain cities have now by- 

 laws enforcing such periodic removal of manure. All cities and towns should 

 enforce such removal or treatment, nor should they allow the accumulation of 

 rubbish and substances on which flies can breed as many local authorities are 

 accustomed to do. It is invariably found in such cases that the maximum number 

 of cases of zymotic diseases such as typhoid and epidemic diarrhoea are located 

 around such places. The change of attitude of people towards house-flies during 

 the last few years has been remarkable. Public opinion on such subjects is slow 

 in changing and although we had known for years from the work of Celli, Nuttall, 

 Hoffman and many others that flies were in the habit of carrying the bacilli which 

 cause certain of our infectious diseases such as typhoid fever, ophthalmia, tuber- 

 culosis, etc., it was not until medical men as a whole began to realize the important 

 role that house-flies play in the dissemination of these diseases that we really began 

 to move. But now there are fortunately few who do not realize the danger of the 

 house-fly. What could be more probable than the transference of dipease-earrying 

 bacilli by flies when they have access to the dejecta of incipient or carrier cases of 

 typhoid on the one hand and food materials on the other. Several observers during 

 recent campaigns and also in military camps in time of peace have observed flies 

 frequenting the food in the mess tents and carrying on their bristle-covered legs the 

 white disinfectant from the camp latrines. Such an observation is sufficient to 

 convince the most obstinate sceptic as the relation that flies may have in the trans- 

 ference of disease germs. Take, for instance, the flies in unsanitary localities ; they 

 are accustomed to frequent every kind of filth in the way of kitchen refuse and 

 excremental substances and to spend a portion of their time regaling their palates 

 with the food stuffs in the houses, especially such articles of food as sugar and 

 milk. It has been proved that milk to which flies have had access becomes seriously 

 contaminated with and infected by the bacilli which the flies have obtained from 

 filth of different kinds and milk is an excellent mediuni for the gTOwth of bacilli,, 

 especially during warm and hot weather. 



What are the methods, then, which we have of combating this most serious 

 menace, for, to my mind, the fly problem in our cities is far more important than 

 the mosquito problem towards the solution of which thousands of dollars are spent 

 annually — and compared with which the suppression of the fly danger is indeed 

 as simple. They are these. First, the abolition of their breeding places; the re- 

 moval within seven days in the summer, of collections of horse manure, decaying 

 and fermenting vegetable substances on wiiich the flies can breed. The substitu- 

 tion of the more sanitary system of sewage disposal by water instead of the older 

 and generally insanitary and dangerous methods of conservancy. The protection 

 of collections of manure or kitchen refuse; keep the lid on the refuse chamber. 

 Do not allow flies to have access to food, especially such foods as milk, sugar, etc., 

 but, where flies occur, keep all such food covered with a muslin covering. Farmers 

 and dairymen should not leave milk about exposed and accessible to flies. A 

 man would not be willing that flies should have access to a glass of milk intended 

 for his own consumption, and why should he leave milk exposed in pails in cow- 

 sheds and similar places where the flies have a maximum opportunity of covering 

 their legs and bodies with bacilli of all kinds, especially putrefactive bacilli. " Pre- 

 vention is better than cure " is almost a truism, but the welfare of the future will 

 depend almost entirely on that one word. Prevention. Nature is yielding up her 



