CONTAGIOUS DISEASES OF DOMESTICATED ANIMALS. 375 



disease. All seem to be in good health. Nos. 1 and 2 are thrifty and growing. Inoc- 

 ulated No. '.i, the one that recovered Iroui a previous attack, in ihe ear, by means oi' a 

 small inoculation-needle, -with a little jnico (less than half a drop) pressed out of tho 

 )irolileroua growth of the stomach of John Lord's pig, killed by bleeding for the pur- 

 ))03o of obtaining fresh material for inoculation, so as to exclude any possibility of 

 I»roducuig pyicmia. 



Jamtary 2o. — Inoculated pigs Nos. 1 and 2 also in the ear, by means of a fcmall inoc- 

 nlation-iieedlo, with the milk charged with iacilli and bacillus germs on Januarir 21. 

 Examineil under the microscope, aini ruilk, besides its nonnal constituents, contained 

 numerous iflciZZi and bacillus germs. 



Jajuiarn 24. — All three j)igs apparently in good health. None of them show any 

 symptoms of a reaction. 



January 25. — All experimental pigs apparently healthy. 



January 26. — Experimental pigs apparently healthy : all have good appetite. 



Janvary 27, 28, and 29. — All three experimental pigs have good appetite. No symp- 

 toms of disease. 



January 30. — Pigs Nos. 1 and 3 indisposed, but have some appetite. Pig No. 2 ap- 

 parently healthy. 



January 31. — Pigs Nos. 1 and 3 show plain symptoms of disease, are sneezing fre- 

 quently, and show a tendency to hide in their bedding. Pig No. 2 apparently all 

 right. 



February 1.— Experimental pigs Nos, 1 and 3 evidently sick, both sneeze and cough 

 a great deal, and do not seem to have much appetite. Pig No. 2 apparently not 

 atiected. 



February 2. — Experimental pigs about the same as yesterday. 



FeJrniary 3. — Pig No. 1 hides in its bedding, is emaciated, and has no appetite. Pig 

 No. 3 is sick, but eats some. No. 2 is doubtful. 



February 4. — All three pigs about the same as yesterday. 



February 5. — Pig No. 1 has no appetite whatever, and is very poor. Nos. 2 and 3 

 about the same as the day before. 



February 6. — Pig No. 1 about tho same as yesterday. No. 3 appears to be slightly 

 improving. No. 28neezes and shows other symptoms of a mild attack. 



February 7. — Pig No. 1 eats a little. In Nos. 2 and 3 no visible changes. 



As I was called away to CMcago, I lia<l to leave the pigs to tbeir fate; 

 but in order to learn AYliat would become of them, I left tiiein with Mr. 

 H. Lamlien, with the underistanding that he. was to pay for pigs Kos. 2 

 and 3, should they be ali^^e three we«ks after date. Pig Ko. I'was con- 

 sidered as not being worth anytliing. In due timo Mr. Lamkea sent me 

 the money and a note, in which he stated that pigs Nos. 2 and 3 were 

 alive and improving, and pig. No. 1 of no account, but still alive. 



I intended to subject the causal connection of the haeilli and their 

 germs with swine plague to one more (negative) test by inoculating 

 healthy animals with, morbid fluids (exudations) of diseased animals 

 after they had been freed from baciilus-germs, and filtered for that pur- 

 pose some pulmonal exudation and blood serum through sixteen papers, 

 but did not succeed. The last filtrate examined under the microscope 

 still contained a large number of bacillus-germs or globular bacteria. 



The ex}W3rim8nts related above prove two things: First, that an in- 

 oculation with haeilli and bacillus-germs, cidtivated in an innocent fluid, 

 such as iresh milk, pan and will produce the disease with just as much 

 certainty as an inoculation with i>ulmonal exudation, or with any othei 

 bearer of the infectious princii>le taken directly from a dead or diseased' 

 hog. Second, that an animal that has been afflicted with swine plague, 

 and has recovered, has not lost its susceptibility, but may coiitractthe 

 same disease again, though probably in a milder form. The latter fact 

 has received further confirmation by a statement of Mr. Eeichard, an 

 intelligent farmer and reliable observer, residing near Prairievilie, who 

 inlbrmed me that one of his hogs haul been sick with swine plague three 

 times, but had (partially) recovered after each attack, and was still living, 

 but of not much value. Such cases would probably occur of rener, if it 

 was not for the malignancy of the disease; the first attack has generally 

 a fatal termination, and the usually ^ery short life of the hog. 



