130 STATE BOARD OF HEALTH. [Jan. 



rats than could be supported if other kinds of food and other 

 methods of feeding were employed. 



While I am inclined to regard the infection of hogs as 

 more probably due to their eating uncooked swine-flesh con- 

 tained in the offal than to their killing and eating rats, still, 

 an investigation, to be at all satisfactory, should not ignore 

 this latter possibility ; and it is therefore desirable that some 

 means should be found of gaining access, for the purpose of 

 inspection, to the hog-pens of raisers in this vicinity, and, 

 if possible, of securing the co-operation of the raisers, in 

 ascertaining the prevalence of rats, and whether it is common 

 for hogs to eat them. 



However true it may be, that, owing to the rats, we 

 should never be able entirely to get rid of trichinae in hogs, 

 even if we could by a decree destroy every one now existing 

 in them, still, I doubt if rats are the only or even the 

 principal cause of the present alarming prevalence of this 

 parasite in the pork raised in the immediate vicinity of 

 Boston. I suspect that hog-flesh is, after all, a greater 

 source of the difficulty than rat-flesh. 



There are two principal ways in which it is possible for 

 pork to keep up the infection in hogs. It is a custom with 

 some private slaughterers, even with *the better class of 

 people and those otherwise well informed, to cast the viscera 

 of slaughtered animals, swine among others, to the pigs. 

 No surer way could be devised for perpetuating and increas- 

 ing the infection with trichinae.* At one of the State 

 institutions this practice was kept up until January, 1887, 

 when it was abandoned, as a result of some of the examina- 

 tions here reported, and the consequent discovery of the 

 enormous per cent, of trichinae (26 per cent.) found in the 

 pork raised and slaughtered at that institution. It is hoped 

 that the discontinuance of this practice will speedily show 

 some diminution in the number of hogs containing trichinae. 



But the acquisition of trichinae through the viscera of 

 slaughtered hogs is precluded in the case of those raisers 



* The danger which ensues to hogs, in consuming the viscera of slaughtered ani- 

 mals, is not so much due to the possibility of infection from intestinal trichinae or 

 young embryos, as from encapsuled muscle trichinae. Small in amount as the vol- 

 untary muscles are which are attached to the viscera (oesophagus, diaphragm, rec- 

 tum, etc.) they are sufficient to constitute the principal source of danger. 



