CONTAGIOUS DISEASES OF DOMESTICATED ANIMALS. 383 



lesions whatever, is doubtful, aud a question I have not been able to 

 decide. Aocordiug to what I have been able to see and to observe it is 

 not probable, still it may be possible. 



The bacilli aud their germs can be conveyed from oue place to an- 

 other not only iu aud with the morbid products of the disease, and the 

 tissues, fluids, and excretions of the diseased and dead animals by them- 

 selves, or by adhering- to aud contaminating other inanimate things, 

 fluid or solid, but also independent of any other vehicle tlirouglf the air 

 at a distance of a mile, if circumstances are favorable, aud in the water 

 of running streams. They are even able to proi)agate in water, esi)e- 

 cially if it is not free from organic admixtures. An incident happened 

 while I was, last winter, at Gap Grove, which is worth relating. On 

 January- 27, iu the afternoon, I filtered some pulmonal exudation of a 

 pig that had died of swine plague through several papers for the pur- 

 pose of freeing it from the bacillus germs which it contained. The filter- 

 ing was done on a small table in a corner of the room, aud the apparatus 

 was left standing on that table with the wet papers (4) iu the funnel after 

 the filtrate had been removed. In the evening the latter was examined 

 under the microscope on another table in the opposite part of the room, 

 and as my two highest objectives are immersion lenses, I had to use wa- 

 ter, and had a tumblerful of clean well-water on my table, just drawn 

 from a deep well. When through with my work, instead of pouring the 

 water out, I placed the tumbler on another table about four feet distant 

 from the filtering apparatus. Next morning I went to Chicago to return 

 on the 30th. In Chicago I procured a new objective, also an immersion 

 lens, a;nd about the first thing I did after my return was to try that ob- 

 jective. Finding everything undisturbed in my room, and the tumbler 

 with water exactly where I i)laced it, and not intending to examine but 

 a test object, I did not go for fresh water, but used a drop of the water 

 in the tumbler for the immersion. While adjusting the focus, I discov- 

 ered that the water, which I knew had been absolutely fi'ee from organic 

 bodies, was swarming with hacilli and bacillus germs of the same kind 

 as those iu the pulmonal exudation. I made then a thorough examina- 

 tion of the water not only with the new, but also with the old objectives, 

 and found that every drop taken from above (the surface) contained 

 myriads of hacilli, some of them moving very lively, while in a drop 

 taken from near the bottom but comparatively few could be found. 

 The filtering paper left in the funnel wet and full of bacillus germs and 

 bacilli was perfectly dry. All the moisture ha,d evaporated ; the aqueous 

 vapors had carried the bacillus germs with them into the air, and many 

 of them undoubtedly had been deposited in the tumbler and in the water 

 it contained, and had there developed and i^ropagated. Another solu- 

 tion is not well possible. The next day the water was examined once 

 more, and it was found that the number of the hacilli had become still 

 greater. Soon after I dropped a few grains of thymol into the water, 

 and two hours later every bacillus had been destroyed — at least none 

 could be found. 



The peculiarities and the "freaks" in the spreading of swine plague 

 are best illustrated by a brief history of the disease and its progress on 

 Henry Miller's farm, one mile north of Prairieville. Late in the fall of 

 1877, wben no swine plague was existing within fifteen or twenty miles 

 of his place, Mr. Miller bought twenty-six shoats in. a part of ^^itesido 

 County in which swine plague at that time wns prevailing and had been 

 prevailing very extensively. Those shoats themselves aiypeared to be 

 healthy, but had been exposed, as was learned afterwards, to the influ- 

 ence of the infectious principle, and it is possible and even probable that 



