HISTORY 247 



tines, and more or less discoloration of the skin, especially 

 over the ventral surface. 



§ 180. History. The earliest outbreak in this country, 

 of which there is knowledge of a disease supposed to be hog 

 cholera, occurred in the state of Ohio in 1833. It is presumed 

 that it was brought from Europe with some of the animals 

 imported from there for breeding purposes. After being intro- 

 duced, it spread at first slowly, but later with increasing 

 rapidity along the lines of commerce, until it invaded every 

 part of this country where swine raising had become an 

 industry. The disease was investigated and very carefully 

 described by Dr. C. Sutton, of Aurora, Ind., from 1850 to 

 1858. In 1861, Dr. Edwin M. Snow, of Providence, R. I., 

 contributed an important paper on this disease to the U. S. 

 Department of Agriculture. In 1875, Dr. James Law, of 

 Ithaca, N. Y., furnished to the same Department a valuable 

 paper setting forth the symptoms and morbid anatomy of this 

 disease. He believed it to be contagious although the specific 

 organism had not been found. The U. S. Commissioner of 

 Agriculture appointed in 1878 nine men for a period of two 

 months each to investigate the disease in various localities. 

 In their report the symptoms and morbid anatomy formerly 

 described were confirmed and two additional features set 

 forth. Law showed that it was transmissible by inoculation to 

 other animals, and Dr. Detmers described a microorganism 

 which he called Bacillus suis and Which he believed to be the 

 specific cause of the trouble. Later, Detmers described his 

 organism as a micrococcus. The work of investigation was 

 continued under the direction of the Commissioner of Agricul- 

 ture and finally, in 1885, the specific organism was discovered 

 by Salmon and Smith, who described its essential characters 

 and properties. It was called Bacterium of swine plague. 

 Since that time the disease has been under investigation and 

 the Bureau of Animal Industry has during the last few years 

 been actively engaged in the efforts to produce a specific, 

 therapeutic serum. 



In 1886, Dr. Theobald Smith discovered another bacterial 



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