54 DISEASES OF SWINE AND OTHER ANIMALS. 



tJhat tlip lattor, bcyoud a doubt, coustitiite ilio principal dissf^minator of tlio infective 

 priuciplo. Wliother tlie colonies or vIkcouh clusters of bacillus-germs and i^artially 

 develo])e(l JHicilli are instrumental in bringing about the extensive eml)oli8m in the 

 liuigs aTid in other tissues, by merely closing the cai)illary vessels in a mechanical way, 

 or whet her t he presence, growth, development, and propagation of the hac'dli and their 

 germs produce peculiar chemical changes in the composition of the blood, which dis- 

 qualify the latter to pass with facility through the capillaries, or which cause a clot- 

 ting or retention of the same in the capillary system, is a question which I am not pre- 

 pared to decide. According to my own observations, it a])pea,rs that the colonies or 

 viscous clusters of bacillus-germs and partially developed haclUi get stuck in the capil- 

 laries so as to obstruct the jiassage, and constitute in that way tlie xirincipal, if not the 

 sole, cause of the embolism. Dr. Orth is of a different opinion. He says : "The prin- 

 cipal effect of the ' Schizomycetes ' {bacteria, hacilU, &g.) is an indirect one, viz., by 

 producing a poison (virus)." (Arcltiv.fuer wissenscliaftliche unci praJcfisclie Thierheilkunde, 

 1877, 2)a(je 1.) It is possible that the circulation of the blood in the capillary system 

 is interfered with by both mechanical obstruction and chemical changes. Still, it 

 seems to me that the observations of Dr. Orth and others apply more to the fully de- 

 veloped haclUi in the blood and in the lymj)h. The vitality of the bacillus-germs, 

 and especially of the haciUi, is not a very great one, except where the germs are con- 

 tained in a substance or a tluid not easily subject to decomposition; for instance, in 

 water which contains a slight admixture of organic substances. If such a fluid is kept 

 in a vial with a glass stoj), the germs remain for a long tim* (over six weeks) in nearly 

 the same condition, or develop very slowly, according to amount of oxygen and degree 

 of temperature. In an open vessel the development is a more rapid "one. If oxygen 

 is excluded, or the amount available exhausted, no further change seems to be taMug 

 place. In the water of streamlets, brooks, ditches, ponds, &c., the bacillus-germs are 

 not destroyed very soon. How long they retain their vitality I have not been able to 

 ascertain. In fluids and substances subject to putrefaction, the hacilli and their germs 

 lose their vitality and are destroyed in a comparatively short time ; at least they dis- 

 ai^pear as soon as those fluids (blood, for instance) and substances undergo decompo- 

 sition. In the blood they disappear as soon as the blood-corpuscles commence to 

 decompose. That such is the case has been ascertained not only by microscopical ob- 

 servation, but also by clinical experience. The hacilli and their germs are also destroyed 

 if brought in contact with, or if acted upon by, alcohol, carbolic acid, thymol, iodine, 



&G. 



2. CLINICAL OBSERVATIONS. 



The experimental pigs, Nos. 1 and A, put in pen No. 2, on November 13th (together 

 with experimental j)ig C), in which pen pig No. IX had died of swine-plague on the 

 28th of October, remained perfectly healthy, notwithstanding pen No. 2, which was 

 thoroughly infected, had received only an ordinary cleaning, but had not been disin- 

 fected. Consequently, it must be sui^posed that the infectious i^rinciple (the lacilli 

 and their germs) contained in i^articlcs of excrement and in the urine clinging to the 

 floor and lodged in the cracks between the boards must have been destroyed, because 

 I observed repeatedly that the pigs, probably in search of saline substances, licked 

 those parts of the floor which had become saturated with urine. 



Mr. Bassett, who had lost nearly his whole herd of swine — of one lot containing 

 originally forty-five animals only two survived — bought, about eighteen days after the 

 occurrence of the last death, two young, healthy pigs, and allowed them to run at 

 large in his orchard, a pasture, and one of his swine-yards, the same premises on whicli 

 the lot of forty-five animals just mentioned had been kei)t. The few surviving hogs 

 of his old herd, are kept in another yard farther north. Seeing that those two pigs 

 remained healthy, he thought he might risk it and buy some more, and about two 

 weeks later he bought sixty -nine (not ninety-live, as I believe I have stated in my re- 

 port) healthy Berkshire shoats, from five to six months old, at the auction of the Hon. 

 James Scott, president of the Illinois State Board of Agriculture, and turned them out 

 on the same premises (hog-lot, orchard, and pasture). After these sixty-nine shoats 

 had been there two days they discovered the burial places of the forty-three dead 

 shoats, hogs, and pigs, which, by the way, had been buried only from- two to 

 three feet deep. These they commenced to exhume immediately, and soon consumed 

 all the decom-iiosed carcasses. Mr. Bassett would have prevented this had ho discov- 

 ered them in time, l-^vexy shoat lias remained healthy up to date (November 29th), 

 and as the period of incubation (from five to fifteen days, or on an average seven 

 days) expired some time ago, it must bo supposed tliat the infectious principle, the 

 'bacilli and their germs, liad been thoroughly destroyed by putrefaction. It must be 

 mentioned that there are no straw-stacks, &lc., on the swine-range, and that the 

 ehoats have no access to any streamlet, ditch, or pool of water. 



Mr. Locke's herd of swine has been kept perfectly isolated in a pasture near the city 

 limits of Champaign, and has I'cmained exempt from swine-plague till lately. 

 The hog-pasture is close to the Illinois Central Eailroad track. Whether the tnfec- 



