288 CONTAGIOUS DISEASES OF DOMESTICATED ANIMALS. 



of the actual condition of afiairs in the hog-growing sections of the 

 country. Practically all of the hogs which go to the packing-houses 

 are raised upon farms miles, and generally hundreds of miles, from any 

 large city where offal could be obtained, and they are never fed upon 

 anything but vegetable food. The blood and offal at the large pack- 

 ing-houses is dried at a high temperature and sold for fertilizers, and is 

 never fed to the hogs even in the stock-yards. The foreign microsco- 

 pists have the proof of this in their own hands, if they would only give 

 the matter a little consideration before accepting the absurd statements 

 of ignorant and prejudiced jjarties. 



During the killing season as many as 60,000 hogs are received at the 

 Chicago stock-yards in a single day, and it is evident that it would be 

 impossible to furnish accommodations for holding this enormous num- 

 ber for any considerable time before killing. IsTow, the trichinie which 

 are found in American pork are in the vast majority of cases encysted, 

 and for this condition to be reached time is required, and much more 

 time than it is possible to hold hogs in the cities where alone offal for 

 feeding them can be obtained. It is four weeks after infection before 

 cysts are formed, and it is six weeks to two months before they reach 

 the condition in which they are generally found by the microscoi)ic ex- 

 amination of our meats. While we know from our own observation in 

 all the cities where hogs are packed that the animals are not, fed upon 

 offal previous to killing, we have here in the condition of the trichinae 

 themselves the best and the most incontrovertible evidence that the 

 animals were not infected by offal fed while they were held at the pack- 

 ing-houses before slaughter. 



It is evident from what has just been said that we are unable at pres- 

 ent to give a satisfactory explanation of the manner in which Western 

 hogs become infected with trichinae, for the conditions of life, at least 

 so far as we are able to see, appear in the vast majority of cases to be 

 all that can be desired. The infected hogs must be traced to the coun- 

 ties from which they come, and even to the farms on which they are 

 raised, and the conditions studied as they exist on known infected 

 I)remises, before it will be possible to give a solution to this difficult 

 question. And until this is done no effectual rules for prevention can 

 be formulated further than in a general way to recommend that the 

 hogs have no access to an3^ animal matter except what has been thor- 

 oughly^ cooked. 



SALT USED IN PACKING. 



The salts most generally used in packing in the United States are the 

 Syracuse solar salt, of which 2,500,000 bushels were manufactured last 

 year ; Michigan solar salt, of which 50,000 bushels were manufactured 

 last year, and Turk's Island salt. For rubbing hams either the ground 

 solar salt or the Syracuse factory filled dairy salt is employed. 



