INCUBATION PERIOD OF CHOLERA 163 



kind of food for any length of time and remain free from disease. 

 If cholera does not make its way into the herd some other 

 disease will. 



When to the ordinary leavings of the table and kitchen, such 

 as bread crusts, sour milk, potato peelings, rotten apples, etc., we 

 have added scraps of pork, such as bacon rinds, ham trimmings 

 and bones, and rib bones or other scraps of pork, we are certainly 

 adding something which is most dangerous, and is very likely to 

 result in an outbreak of cholera in the hogs which are so fed. As 

 we shall find out a little later on, when we closely sttidy cholera, 

 the germs or virus of the disease are to be found in the blood. By 

 the blood the virus is carried to all parts of the body and deposited 

 in every tissue. The very small blood-vessels in the skin are filled 

 with this virus-carrying blood, and the same is true of the small 

 vessels located in the little hollow spaces of bone. 



From the results which have followed the feeding of pork trim- 

 mings to healthy animals it cannot be doubted that when from 

 fresh pork, such as is commonly sold in the retail markets of our 

 cities, these trimmings may contain a sufficient amount of the virus 

 to produce disease. It has also been found that the germs of cholera 

 are so hard to kill that they are not always destroyed by the ordi- 

 nary curing processes which are used in preparing pork for the 

 market. As a result, when these trimmings are fed to healthy 

 animals they are made sick, and by this means cholera may be 

 spread over large sections of the country. 



Another very costly lesson which this man learned from this 

 outbreak, and which we should take advantage of, is the fact 

 that we cannot feed carcasses of dead hogs to our healthy ani- 

 mals and expect them to keep well. This is, of course, the more 

 true if the hog which has died was suffering from cholera, as is only 

 too often the case. This feeding of dead cholera hogs was the 

 direct cause of the outbreak on this farm. It cost this man nearly 

 one thousand dollars to learn the lesson. You now have the op- 

 portunity of profiting from this man's experience at practically no 

 cost whatever. The object of telling about so many of these 

 everyday cases throughout this work is in order that the reader 

 may the more plainly see what have been the experiences of 

 others. Experience is the best of all teachers, and everyone 



