778 BOARD OF AGKICULTURE. 



these afford the best conditions for introducing the germs into the lierd. 

 It is not uncommon to go along a pulilic ditch or a stream during an 

 epidemic and find the carcasses of liogs in every stage of decomposition, 

 thus acting as a bearer of infection to new herds. The conditions are 

 better now than ever before, but there are unscrupulous men who will 

 take that means of disposing of their dead, and some one else must 

 suffer. 



Some springs afford pure water but many have only a surface origin 

 and are no better than a tile drain. The worst feature connected with the 

 use of a spring as a water supply is the fact that no provision is made 

 for keeping the water clean and pure. The water usually collects in a 

 pool and receives the surface drainage from all the land around and 

 serves as a wallow. Under such circumstances it becomes little better 

 than a pond. 



In 1895 the experiment station made an Inquiry as to the source of 

 the water supply used by the breeders of pure-bred swine. It was found 

 that in nearly all Instances in which they escaped disease they used well 

 water. Hogs receiving well water do become affected, but when we 

 consider the numerous ways by which the infection can be can-led we 

 are not at all surprised. A good well, however, must always be con- 

 sidered as furnishing the maximum protection. 



A study was also made of the relation of rainfall to the disease. No 

 relationship could be traced to the total rainfall for the year or to the 

 total rainfall for any set of months. In general, a season with sutticieut 

 rainfall to keep a constant supply of fresh water in the streams or one 

 of sufficient drought so that the small streams, ponds, etc., become com- 

 pletely dry, are productive of least cholera. A year in which there is 

 much stagnant water Is productive of the greatest death rate. 



The argument is advanced that the greater loss occurs along the 

 rivers because more corn is raised, more hogs are fattened, and hence 

 they are more crowded. In order to detei-mine this point we divided the 

 counties in the State into groups according to the number of hogs raised 

 per square mile and determined the per cent, of loss^for these groups. 

 This is presented in the following tables: 



1883-1890. 



Number of Hogs Number of Per Cent. 



Per Square Mile. Counties. of Loss. 



1-24 1 8.1 



25-49 7 4.5 



50-74 20 5.9 



75-99 12 9.1 



100-124 16 8.?. 



125-149 11 7.9 



