DISEASES OF SWIXE AND OTHER ANIMALS. 37 



gation, or in some invisible cheuiical agency or mysterious fluid, per- 

 meating', as lias been supposed, tlie whole animal organism, and con- 

 tained in, or clinging to, all those substances which possess infectious 

 properties, or constitute the bearers or vehicles of the contagion. As 

 all microscopical examinations of the blood, morbid tissues, and morbid 

 jjroducts of forty-two animals, which had been affected with swine- 

 plague and had died of that disease or been hilled by bleeding, and 

 repeated microscopical examinations of the excretions (urine and excre- 

 ments) of diseased animals, have revealed in every case the presence of 

 mimerous bacillus-germs (micrococci of Hallier) and developed haciUi 

 suiSj I deemed it necessary to ascertain first, if i)ossible, the relation 

 which these extremely small microscopic bodies may have to the mor- 

 bid process and to the infectious principle. For that purpose I com- 

 menced another series of experiments, and bought again, on September 

 24:th, three very nice, perfectly healthy pigs, each a little over three 

 months old, of Mr. Burton, residing four miles southeast of Champaign. 

 I designated one of them, a nearly tuU-bred Berkshire barrow, as pig A ; 

 another one, a Poland-China sow, as pig B ; and the third one, also a 

 Poland-China sow, as pig C. 



Account of x^igs yl, I?, and C. — The same arrived at 10 o'clock, a. m. 

 Pig A was put in i)en No. 1 with pig ISTo. 1 ; pig B in pen Xo. 3 with pig 

 Ko. C ; and pig C by itself in the thoroughly cleaned and disinfected -pen 

 Xo. 2, formerly occupied by pigs ISTos. 2 and 3. Pen Xo. 3 had been 

 clean and empty since September Gth, and was again disinfected with 

 carbolic acid before pig C was put in. 



September 25. — All three pigs, A, B, and C, perfectly healthy. 



SejJtemher 2G. — All three pigs perfectly healthy ; have good appetite. 



Bepteml)cr 27. — The same ; inoculated pig C with cultivated baciUi 

 and bacillus-germs. On September 23d, Professor Bnrrill charged two 

 drachms of fresh cow-milk with a mere speck, smaller than a pin's head, 

 of a decaying morbid growth, or ulcerous tumor of the ccecum of pig 

 No. 5, and kept the vial well closed, at a temperature of 92^ P. On 

 the evening of September 2Gth the milk was examined under the micro- 

 scope, and was found to contain numerous hacilU suis and bacillus- 

 germs (see drawing III, figs. 3 and 4), the same as found in the blood- 

 serum, or exudation of diseased lungs, and in the decaying substance 

 of the intestinal morbid growths. The inoculation with this milk was 

 executed in the same way as the inoculations of pigs Nos. 2 and 3 ; two 

 punctures were made on the external surface of the left ear. 



September 28, — All three pigs perfectly healthy. The inoculation- 

 l)unctures on the ear of C slightly swelled. 



September 29. — Pigs A, B, and C, all right. 



September 30. — All three i^igs perfectly healthy; no symptoms of 

 disease. 



October 1. — The same. 



October 2. — Pig A perfectly healthy ; pig B shows sym]>toms of sick- 

 ness, sneezes, has erui^iou on the ears, diminished appetite, and is not 

 as lively as formerly. As a full accomit of pig B has already been given 

 in the chapter on symjitoms and morbid changes, it will not be necessary 

 to repeat what has been said then?, and pig B nmy be dropped. Pig C 

 apparently all right in the morning. At noon, pig C, too, commences to 

 sneeze ; sneezes a good deal, and shivers like a man suffering from ague, 

 but has good appetite. 



October 3. — Pig A perfectly healthy. Pig C shows slightly diminished 

 appetite and other ])lain sym]>toms of indisposition ; is less lively, and 

 has a tendenc}" to lie down; the sneezing continues. 



