HOG-CHOLERA. 41 



ture of 140° Fain*., which must extend through a piece of pork, is 

 necessary to the positive death of the parasites. 



The direct application of dry heat, by means of a hot table, to 

 specimens under the microscope, demonstrates that a temperature 

 of 50° C. — 122° Fahr. — is necessary to kill trichinae. 



The ordinary processes of cooking, salting, and smoking are not 

 always a sure means of killing these parasites. 



All hogs should be subjected to microscopic examination by ex- 

 perts, and no hog allowed to be cut up for sale as food until such 

 an examination had been made. Those found invaded should be 

 branded trichinous, and their sale as food forbidden by law under 

 penalty of a heavy fine. 



HOG-CHOLERA. 



Pneumo-enteeitis Suis Contagiosa. 



This peculiar infectio- contagious disease of the porcine family 

 has been known to agriculturists and veterinarians for centuries. 

 For years it has been looked upon as a form of anthrax, typhus, 

 erysipelas, etc. ; but it has remained for our country to institute the 

 first extensive researches as to its nature, though Klein, in England, 

 anticipated them by doing some good work in this direction. On 

 the Continent of Europe the disease has not as yet been scientifi- 

 cally studied. 



I have nothing but praise for the admirable reports of Messrs. 

 Detmers and Law upon the porcine pest, issued by the Agricultural 

 Department at Washington in 1878, and most earnestly recommend 

 it to public consideration. 



In 1877 our national commissioner reported a loss to the coun- 

 try of $16,653,428 from contagious animal disease. 



Etiology. 



As with all forms of infectio-contagious diseases, we find also in 

 hog-cholera, that it was a long time before we gained any accurate 

 knowledge with reference to the nature of the elements causing it. 

 Some have asserted that pigs will not contract the disease when fed 

 on succulent vegetable food ; but Law has proved the fallacy of 

 this opinion by direct experiment. Naturally, unfavorable nutri- 

 tive and hygienic conditions will favor the development of this as 

 well as other diseases, but they are not the direct cause. 



