ANTHRAX. 279 



principal heads, comprising respectively the influences of 

 temperature ; water spread over the surface of the earth, as in 

 morasses and stagnant ditches ; forage tainted with decomposing 

 animal and vegetable matters ; and contagion. 



Influence of temperature. — The hygrometric and therm ometric 

 conditions of the atmosphere, which always exercise a marked 

 action on the organism, disposing it under certain circumstances 

 to anthrax, are stated by several authors to be those charac- 

 terised by humid and persistent fogs, coldness, and humidity ; 

 a tempestuous atmosphere ; alternations of burning heats and 

 stormy rains. 



It rages as an enzootic on the borders of rivers, and in low 

 lands which have been inundated. In the months of July and 

 August, signalized by excessive heat, charbon has been frequent. 

 The years 1712, 1731, 1775, 1779, 1780, 1823, 1824, 1825, 

 1846, have furnished memorable examples. Under the influence 

 of excessive and prolonged heat, the rivers, ponds, brooks, &c. 

 were dried up, tlie soil opened in crevasses, and the disease was 

 d(jveloped to an enormous extent. In France it is stated that 

 a very warm summer is never seen without charbonous diseases 

 bein^' prevalent ; and it is concluded that a high temperature, 

 especially if preceded by a damp or moist atmosphere, is very 

 favourable to the development of charbon. 



Influence of ponds, morasses, and stagnant loaters. — The history 

 of the malady demonstrates that morasses are favourable to its 

 development, as it is observed that it is frequent in countries 

 where they occupy a large surface. It is also frequent in 

 countries exposed to inundations, and where water stagnates 

 on the suri'ace of the soil ; and where animals are made to 

 stand in mosses and stagnant waters, the malady commits great 

 ravages. This fact is remarkable, not only in Trance, but in 

 other countries. 



Observers who have closely watched these affections in this 

 country, where it seldom appears in the horse, almost unani- 

 mously conclude that in cattle and sheep they are due to dietetic 

 errors ; more particularly to sudden and violent changes in 

 diet, whether that change be from a poor to a highly nutritious, 

 more particularly a nitrogenous diet ; from dry and good food 

 to watery unripe provender ; to damaged food of any kind ; the 

 influence of undrained lands ; defective ventilation and drainage 

 of stables ; to food and water contaminated with the morbid 



