INFECTIOUS DISEASES OF CATTLE. 379 



litter is advisable, together with the scraping of the floor, mangers, 

 and walls of the stable with hoes and the removal of all dust and 

 filth. This should be followed by the burning of all such accumula- 

 tions, inasmuch as this material likewise contains the infectious prin- 

 ciple and is best destroyed by heat. Heat may be applied to the 

 surface of the affected pen, byre, or barnyard by means of a cyclone 

 burner, which consists of a tank, pump, hose, and cyclone nozzle for 

 spraying with paraffin (gas oil). The latter is ejected in the fonn of 

 spray, which when ignited gives a very hot and effective flame to be 

 applied to the infected ground. Where such burning is impracticable 

 the surface soil of the yard and surroundings should be removed to a 

 depth of 5 or 6 inches and then placed in a heap and thoroughly 

 mixed with air-slaked lime. The fresh surface of the soil thus ex- 

 posed may then be sprinkled with any of the above-mentioned disin- 

 fectants. 



In addition to these artificial substances there are several natural 

 sanitary agents of great importance as destroyers of virus. These 

 are cleanliness, ventilation, drying, and sunshine. All virus, ex- 

 cepting such as may live in the soil, is killed sooner or later by drying 

 and sunshine, and the importance of these factors in the daily life of 

 animals need not be insisted on here. Finally, all sanitary measures 

 which contribute to the healthfulness of animal surroundings are 

 directly or indirectly inimical to disease germs, and all carelessness 

 in the keeping of animals may be regarded as an ally of these de- 

 structive organisms. 



CONTAGIOUS PLEUROPNEUMONIA. 



Definition and history. — This disease has been eradicated from the 

 Ignited States, and it is not probable that it will ever be seen in this 

 country again. As, however, much interest was manifested in regard 

 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 necessan\ 



The contagious pleuropneumonia of c<attle is a specific epizootic 

 disease 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 with its German name 

 of Lungen^euche. In French it is spoken of as the perlpneumonie 

 contagieuse. 



