374 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



tumor, and undoubtedly originated in tlio mucous meiubrano of the nasal cavity. Its 

 interior concave surfafo, communicating ^vitli the latter, -was coated vitli a thick layer 

 of a dirty-white or gray -yellowish detritus, the earn© as coats the siulaco of the ulcer- 

 ous tumors which occur in the large intestines. Its external Buri'aco was convex or 

 Bemi-glohular, dark-colored, and almost smooth. 



Internal morbid chanfjes. — TAVo-thirda of both lobca of the lungs hepatized ; some 

 almost clear or slightly straw-colored serum in the pericardium and in the chest ; froth 

 in the bronchial tubes; all lymphatic glands enlarged, but no other morbid changes, 

 except a small quantity of serum in the abdominal- cavity. The tumor, according to 

 Mr. McKay, made its appearance two months ago, at the lioginning of the disease. 



12. Post mortem examination of a small jiig four months old, belonging to M. Philippi, 

 ten miles north of Chami)aign, Champaign County, Illinois. This animal was very 

 emaciated, and may not have weighed over ten pounds. Its temperarure was 106'-^ F. 

 It had been sick four weeks, and was killed by bleeding. Date, June 24. 



Morbid changes. — Small quantities of serum in the pericardium and in the thoracic 

 and abdominal cavities ; lymphatic glands enlarged ; capillary ves.sels of the auricles 

 of the heart gorged with dark-colored blood, and hepatization in the lungs, Gomprising 

 thiee-foui'ths of the left and one-half of the right lobe. 



5. Experiments. 



The experiments made previous to December 1, and recorded in my 

 first report, have proved : 1. Tliat swine plague is infectious, and can 

 be communicated or transmitted from diseased Logs or pigs to healthy 

 animals in two different ways : by direct inocubition, and by an intro- 

 duction of the infectious principle, either with the food or with the water 

 for drinking, into the digestive canal. 2. That an exceedingly small 

 quantity of the infectious principle is sufficient to produce the disease. 

 3. That the period of incubation, or, more correctly, the stage of coloni- 

 zation, does not exceed fifteen days, and lasts on an average from six to 

 seven days. 4. That small ScMzomyceteSj the hacilli stiis and their germs, 

 which are found in all the morbid products, in the blood and other fluids, 

 and in all excretions of the diseased animals, constitute, almost beyond 

 a doubt, the infectious principle and the real cause of the disease. 



I concluded, when I went to work again on the 15th of December last, 

 to make another series of experiments for the purpose of ascertaining 

 with certainty, if possible : 1, whether the infectious principle consists 

 solely in the hacilli and their germs ; 2, whether an animal that has had 

 the disease, and has recovered, has lost all further susceptibility, or is 

 yet subject to future attacks ; and, 3, whether swine plague can be com- 

 municated to other animals besides swine. To enable the reader to draw 

 his own conclusions, I will first briefly relate the experiments made, and 

 then state the conclusions I have arrived at. 



On January 9 I bought two healthy pigs (which I shall designate as 

 pigs Nos. 1 and 2) of Mr. H. Lamken, at Prairieville, and put each pig 

 by itself in a clean and comfortable pen, which had not been occupied 

 by any hogs or pigs for a long time. On January 17 I bought anothei 

 pig, seven or eight months old, of Mr. E. Taddicken, at Prairieville. 

 This pig had recovered from swine plague about two months before, and 

 had become somewhat stunted in consequence of its sickness, but had a 

 very good appetite, and did not exhibit any symptoms of existing fever 

 or of active disease. It was designated as pig Ko. 3, and was put by 

 itself in the pen occupied by pig is^o. 2, which latter was i)ut in with jng 

 No. 1. 



January 21. — Charged one ounce of fresh milk, just drawn from the cow, with a mere 

 speck of tiie proliferous growth of the stomach of John Lord's pig, which had been 

 killed by bleeding. The milk thua charged, and contained in a perfectly clean two- 

 ounce vial, clased by a tight-fitting glass stopper, was kept at a constant temperature 

 of 90 to luboF. 



Januanj 22. — None of the experimental piga, so far, have shown any symptoioa of 



