CONTAGIOUS PLETJEOPNEUMONIA. 367 



to it for a number of years, and as our cattle are still prohibited from 

 some foreign markets on account of its previous existence here, the 

 subject is treated at greater length than would otherwise be necessary. 



The contagious pleuropneumonia of cattle is a specific, epizootic 

 diseasQ which affects bovine animals, and from which other species 

 are exempt. It is characterized, when the disease results from ex- 

 posure in the usual manner, by an inflammation of the lungs and 

 pleurae, which is generally extensive, and which has a tendency to 

 invade portions of these organs not primarily affected and to cause 

 death of the diseased portion of the lung. This disease is frequently 

 called the lung plague, which corresponds to its German name 

 of Lungenseuche. In French it is spoken of as the peripneumonie 

 contagieuse. 



The history of the contagious pleuropneumonia of cattle can not be 

 traced with any certainty to a period earlier than the beginning of 

 the eighteenth century. No doubt it existed and ravaged the herds of 

 Europe for many years and perhaps centuries before that time, but 

 veterinary knowledge was so limited that the descriptions of the 

 symptoms and post-mortem appearance are too vague and too limited 

 to admit of the identification of the maladies to which they refer. It 

 has been supposed by some w^riters that certain passages in the writ- 

 ings of Aristotle, Livy, and Virgil show the existence of pleuro- 

 pneumonia at the time that their works were composed, but their 

 references are too indefinite to be seriously accepted as indicating 

 this rather than some other disease. 



It seems quite plain that as early as 1Y13 and 1714 pleuropneu- 

 monia existed in Swabia and several Cantons of Switzerland. There 

 are even clearer accounts of its prevalence in Switzerland in 1732, 

 1743, and 1765. In 1769 a disease called murie was investigated in 

 Franche-Comte by Bourgelat which undoubtedly was identical with 

 the pleuropneumonia of to-day. From that period we have frequent 

 and wxll-authenticated accounts of its existence in various parts of 

 Europe. During the period from 1790 to 1812 it was spread through- 

 out a large portion of the Continent of Europe by the cattle driven 

 for the subsistence of the armies, which marched and countermarched 

 in all directions. It was generally prevalent in Itnlj in 1800. It 

 appears to have been unknown, however, in the Department of the 

 Nord, France, until 1826, but during the years from 1820 to 1840 it 

 penetrated into most parts of that country. During the same period 

 it was introduced into and allowed to spread over Belgium and 

 Holland. 



This contagion is said to have been carried to Ireland from Hol- 

 land in 1839, and is reported as existing in England in 1842. The 

 disease was brought to the United States at several different times. 

 Probablv its first introduction was with a diseased cow sold in Brook- 



