CONTAGIOUS DISEASES OF DOMESTICATED ANIMALS. 409 



tearing- the tissue of the hmgs, or separating them by means of the knife 

 from the walls of the chest. 



At Mr. Eadmacher's three post mortem examinations were made at his 

 solicitation, but the disease did not prove to be swine plague j no mor- 

 bid changes were found except an immense number of small acephalous 

 cysts or hydatids, situated on the serous membrane of the small intes- 

 tines. 



At most of the places named I obtained some valuable information as 

 to the means and vehicles by which swine plague is spread, corroborat- 

 ing in every respect what I found before. As of special interest the ex- 

 perience of Mr. John Haley deserves a brief mention. Mr. Haley is a 

 farmer of superior intelligence, a good observer, and well acquainted 

 with the symptoms of swine i^lague in all its various phases. His herd 

 of swine consisted (in October) of sixty animals. Last July one of his 

 pigs exhibited plain symptoms of the plague. In order to prevent, if 

 possible, further mischief, he killed the affected animal at once, and 

 buried it four feet deep. He acted in time, because no other animal 

 had yet become infected, and his herd was saved. If swine plague were 

 everywhere dealt with in like manner as soon as it makes its appear- 

 ance the losses would be very few. 



EXPERIMENTS WITH HEALTHY PIGS. 



The observations in regard to the spreading of swine plague from 

 place to place, from herd to herd, and from animal to animal, and the 

 results obtained in the treatment and the measures of prevention ap- 

 plied to the six herds experimented with, made it desirable to determine 

 with certainty three important points. First, although my observations 

 left no doubt in my mind as to the disease being frequently, and prob- 

 ably in a majority of cases, communicated by means of contaminated or 

 infected water for drinking, a,bsolute proof was yet wanting, which, it 

 seemed to me, was obtainable only by a direct experiment, in which 

 positively healthy pigs, while protected against any other possible 

 source of infection, are compelled to drink water contaminated or in- 

 fected either with parts of a carcass of a hog that has died of swine 

 plague, or with the excrements, excretions, or secretions of an animal 

 affected with that disease. Second, the results of my experiments in 

 regard to measures of prevention proved to be exceedingly favorable, 

 and notwithstanding the uncommon leniency of the disease in four or 

 five herds experimented with — in the sixth one, that of Mr. Graham, 

 the plague proved to be malignant enough — it cannot be denied that 

 the measures of j)revention employed were attended with very good 

 and satisfactory results, and effective ; but the question remained to be 

 answered whether the good results were due mostly, or exclusively, to 

 the strict separation, which undoubtedly was of the greatest importance, 

 as it prevented, to a certain extent at least, a further influx of the in- 

 fectious principle, or whether the same were chiefly the effects of the 

 disinfecting and antiseptic properties of the carbolic acid and the 

 hyposulphite of soda, administered in the water for drinking, notwith- 

 standing that three drops of carboUc acid added to three ounces of 

 water infected with one drop of pulmonal exudation (in an experiment 

 made June 9, 1879), did not seem to be able to destroy the Schizomycetes, 

 or to prevent altogether their development. This question, too, could 

 be answered only by subjecting an undoubtedly healthy pig to the in- 

 fluence of the infectious principle in such a way as would surely bring 

 on the disease, and by treating it at the same time with one of those 



