830 



MANGE. 



the skin, particularly of the neck, withers and loins. This dis- 

 ease is easily cured if properly managed. 



The natural history of these insects is not well known. 

 They live only upon, or beneath, the skin of animals. There 

 appears to be a distinct variety, peculiar to each species of 

 animals. They live for a considerable time after being re- 

 moved from the skin, but for how long a period is not pre- 

 cisely known. According 

 to experiments made it 

 appears that they can live 

 in pure water for three 

 i hours ; in strong vinegar, 

 alcohol, and in a solution 

 of kali carbonicum, twenty 

 minutes ; in a solution of 

 sulphuric acid, twelve 

 minutes; in turpentine, 

 nine minutes ; and in a so- 

 lution of arsenic, four min- 

 utes. When they are not exposed to such violent and de- 

 structive immersions, it has been said that they will retain life 

 for six or eight days. From a comparison of the acari of 

 mangy animals, it is supposed that the variety peculiar to 

 the horse can live for a much longer period. Mangy horses 

 have been removed from their stalls, washed with various pre- 

 parations, put into another stable, and completely freed from the 

 effects of the disease ; but upon returning to their former stalls, 

 or using unwashed their accustomed harness, the disease soon 

 showed symptoms of its return. This fact accounts for the 

 trouble experienced in curing this disease. The insect is 



THREE FRIENDS. 



