PREDISPOSING CAUSES 109 



only cholera but also tuberculosis finds its frequent origin in re- 

 fuse matter from these creamery establishments. 



There is another danger associated with the use of kitchen, res- 

 taurant, and hotel refuse, and that is the fact that this class of 

 refuse matter very frequently contains considerable amounts of 

 unused products from cured pork, such as bacon rinds, ham bones, 

 rib bones, etc. It has been conclusively demonstrated that these 

 scraps of animal tissue are often laden with the virus of hog-cholera 

 which has not been destroyed even by the long process of curing 

 through which pork is put in the modern meat-packing establish- 

 ments. These infected remains of hog-cholera animals are often 

 sufficient to introduce enough hog-cholera virus into a herd to form 

 the starting-point for an outbreak of cholera. 



During the summer of 1911, while stationed at Salt Ste Marie, 

 Mich., the author had occasion to investigate, with the officials 

 of the Canadian Department of Agriculture, an outbreak of hog- 

 cholera which was then widespread over the province of Ontario. 

 In this investigation particular attention was paid to the point 

 of whether or not the infected herds had been fed on kitchen, 

 hotel, and restaurant waste, and in a very large proportion of the 

 cases this was found to be the case. In the course of this investiga- 

 tion the source of the outbreak, which was one of the most severe 

 ever experienced in Ontario, was traced almost unquestionably to 

 this source. 



In Canada the government allows an indemnity for hogs slaugh- 

 tered by inspector's orders, but in no case will this compensation 

 be allowed where it is found that the owner has been feeding hotel 

 or other kitchen refuse. 



In many parts of the country hogs are fed upon the refuse or 

 offal around slaughter-houses, and some of this offal almost invari- 

 ably comes in part from animals which are affected with cholera. 

 This often proves the source of an epidemic of the disease in the 

 herds so fed, and, as slaughter-houses are very frequently located 

 along the course of a small stream, the discharges from the sick 

 animals are washed into the stream and carried along its course to 

 infect other healthy herds often miles away. 



(10) Unbalanced Rations. — This is also a frequent determining 

 factor in the outbreak of cholera in a herd. Every hog has a more 



