138 THE AMERICAN FARMER. 



It is most destructive to the young cattle of America and the continent, and is 

 characterized by an alteration and malcondition of the organic elements of the blood. In 

 whatever part of the body the disease locates, that part turns black in color, and the blood of 

 the animal becomes thick and black, hence the term &quot;black leg,&quot; and &quot;quarter evil.&quot; 

 Diseases of this class are often so virulent and are propagated so extensively by contagion, 

 that no state or condition of the animal system will be a protection against its deadly effects 

 by contact. The causes of this disease may be traceable to the influence of temperature, 

 e vaporization from morasses, stagnant swamps, ditches, etc. ; also food or water that has been 

 tainted with decomposing animal and vegetable substances and contagion. One of our 

 leading veterinary surgeons says relative to this disease: 



&quot; Rapid alternations of heat and cold, accompanied by excessive dryness or persistent fogs, 

 torrid temperature, followed by storms, produce such wide contrasts in the air in which the 

 animals under consideration live, and which they breathe, that it is not surprising to find 

 their constitutions impaired when they are exposed to such violent changes, especially when 

 we consider the fact that the health of the blood, so to speak, depends upon its exposure in a 

 natural and temperate way to atmospheric influence. Each inspiration brings into contact 

 with the blood the atmosphere surrounding the animal, and if at one moment it is hot, and 

 at another cold and dense with moisture, it must certainly have a deleterious influence. 



This cause alone breeds many diseases, and doubtless favors charbon. The disease is 

 common in districts where large territories are covered with stagnant water, and 

 where during very dry seasons such moisture is taken up, and the decomposing vegetable 

 matters are exposed. Again, lowlands subject to semi-yearly inundations, when the water 

 lingers for a long time on the pastures, render the animals living thereon particularly liable 

 to charbon. In portions of the continent where this condition exists to a considerable extent, 

 the disease is enzootic. In Siberia, where marshes are numerous, it is stated that in 1784 

 nearly 100,000 animals perished. (Annals of Veterinary Medicine.) 



Thus the bitter experience of the past has taught the stock-owners in certain districts 

 where the action of the miasmatic gases and effluvia are so destructive, to move their animals 

 to the hills during the heat of the day. In these low, marshy districts during hot weather, 

 not only do gases emanate, but animalculge are propagated to a certain extent; thus the food 

 of cattle in such places furnishes the myriads of infusoria. The gases gain access with the 

 air breathed. Soil also has its influence in the production of charbon. Clay and calcareous 

 lands prevent the escape of water; hence stagnation, putrefaction, and effluvia. Other causes 

 might be noted did time permit. 



Black-leg is a disease of young cattle. It usually attacks those that are growing the 

 fastest and doing best. Of a sudden the animal becomes listless, drops its ears, looks dull, 

 a swelling is noticed along the back, neck, loins, or on a limb. If the latter, lameness is 

 present. The creature now either lies or stands quietly and refuses to move; rumination and 

 appetite are gone, bowels constipated, and urine high-colored. It must not be supposed that 

 the disease localizes itself in a leg only, from its name, for it is a systematic disease and 

 develops in any part, according to circumstances. The swellings, when rubbed by the hand, 

 feel as though there is air under the skin; it crackles sometimes. These swellings are 

 enormous, and at first are hot, after a time becoming deathly cold. 



This disease does not have a long duration, and the animal usually sinks in a few hours, 

 or, I might say, from a few minutes to thirty-six hours. The pulse runs high from 80 to 

 110 beats per minute; eyes are dreamy in expression, cars pendant; the animal has no incli 

 nation to move; its movements stiff, is tender about the loins, lies down and objects to, rising. 

 The swellings are very characteristic of the disease, when once understood. The animal gets 

 more depressed as time advances, and in a few hours is unable to rise. It may have 

 convulsions, or die from exhaustion of the heart s action. The swellings noticed are blood 



