DISEASES OF SWINE AND OTHER ANIMALS. 43 



bo very desirable, and, indeed, necessaiy, in order to obtain absolute 

 certainty as to tlie trne nature of tlie cause or causes. 



One tiling I aan sure of, and that is that an exclusive corn diet, as has 

 been asserted by several agricultural writers, wallowing in dirt and 

 nastiness, starvation, in and in breeding, «&c., although by no means 

 calculated to promote health or to invigorate the animal organism, can- 

 not constitnte tlie cause and cannot jtroduee a solitary case of swine- 

 ]dague, unless the infectious principles (the bacUll and tlieir germs) are 

 present. If they are, then, of course, dirt and nastiness, consumption 

 of nnclean food and of dirty water, facilitate an infection, and warmth 

 and moisture, pregnant witii organic substances, or organic substances 

 in a state of decay, are undoubtedly vrell calculated to preserve the 

 Ijacillus-germs and to develop the hacilli. 



Whether the disease can be communicated to other animals besides 

 swine or not, is a question I am trying at present to decide. Some time 

 ago I had an occasion to throw away some morbid tissues (parts of dis- 

 eased lungs) of a diseased hog, which I had used for microscopical ex- 

 amination. I threw them — very carelessly, I admit^ — into an empty lot 

 full of rank weeds, across the road. About a week after several chickens 

 (four or five) died in the neighborhood, of so-called "chicken-cholera." 

 Although there was no proof whatever that these chickens had con- 

 sumed the morbid tissues, there was a possibility that they had. I 

 bought two healthy chickens, kept them separate, each in a coop, and 

 fed them with the morbidly changed colon of a diseased pig. They 

 consumed the same in my presence, but up to date (November 12th) no 

 results have made their appearance. Further, as no case of an infection 

 of any other animals besides swine has come to my knowledge, it would 

 seem that swine-plague is a disease peculiar to swine like pleuro-pneu- 

 monia to cattle. 



G. THE MOEBID PROCESS. 



Concerning the nature of the morbid process, or the manner in which 

 the morbid changes are brought about, the microscope has made some 

 important revelations. 



In all those post-mortem examinations (fifty-three in number) which I 

 have made since August 3rd, and in all those I had an opportunity of 

 making before that time, I found the lungs more or less atiected. The 

 same were partially hepatized, and partially filled yet with fluid exuda- 

 tion or blood-serum. Besides that, where the morbid changes in the 

 lungs were of recent origin, innumerable small red specks, ca^lsed by 

 capillary hypersemia, or, rather, a stagnation of the blood or embolism 

 in the capillaries, could be observed. In several other cases — four or five 

 in number — where the morbid changes in the lungs were not of a recent 

 origiu, or older than, say, two weeks, innumerable small, round, and 

 larger confluent tuberculous-looking centers of beginning supi)uration or 

 decay (incipient abscesses) presented themselves, especially in the lower 

 and anterior portions of the lungs, and usually more i)ronounced in the 

 right lobe than in the left one. My friend. Dr. Prentice, who is not 

 only a veterinary surgeon, but also a practiciug physician, pronounced 

 the" lungs of Mr. Bassett's boar (tw6 years old, and three weeks sick), 

 thus changed, similar or identical in aiipearance to the consumptive or 

 tuberculous lungs of a human being. Close investigatioji, liowever, 

 soon revealed the fact that all the morbid changes found in the lungs of 

 dilierent animals — innumerable small red specks, accuuudation of blood- 

 serum or exudation, hepatization, red, browu, and gray, and incijnent ab- 

 scesses — are the products or the consequences of extensive capillary em- 



