782 ANIMAL PARASITIC SKIN DISEASES. 



as they appear. For this purpose infusion of stavesacre, or 

 tobacco, are very efficacious and easy of application. Either 

 •of these may be employed in this form, in the proportion of 

 one ounce of the vegetable to twenty or forty of water. When 

 prepared it is desirable that the water be kept near the boiling- 

 point for some hours, and then allowed to stand for some time 

 longer before being strained for use. 



Another very potent parasiticide in these invasions, I have 

 found, is a mixture of creosote, one part ; glycerine or spirit, 

 two parts ; Avater, forty parts ; while, where great objection is 

 taken to the use of any active or poisonous material, a good 

 dressing of oil, vegetable or animal, and an after- washing with 

 soft soap, will usually destroy the greater number of perfect 

 insects. 



Scabies — Mange — Scab. 



Definition. — A true devmatozoic shin disease characterized 

 hy TThore or less itching, and occasioned eruption of papides, 

 vesicles, or pustules, hut diagnosticated by the presence of some 

 variety of acari in or upon the slcin. 



Patholog-y. a. History, etc. — From very early periods it 

 seems probable that something was known of this skin disease 

 in animals as well as men. In the writings of Aristotle there 

 are recognitions of phenomena connected with skin affections 

 which can only be rationally interpreted by believing that the 

 observers were aware of the existence of mites burrowing in the 

 skin ; and scattered through the writings of those who took 

 cognizance of matters agricultural during the Roman period 

 and the time of the Saracenic ascendency down to modem 

 times, we may gather information enough to satisfy us that 

 parasitic diseases of the skin, probably scabies in animals as 

 well as men, were not unrecognised. 



h. Nature. — Aftecting the horse we are aware of scabies 

 evidencing itself in at least three separate forms, from the 

 existence in or upon the skin of certain acari, or mites, of the 

 family Acarida, class Arachnida. Any distinct and particular 

 features these several forms may exhibit are apparently owing 

 to individual peculiarities of the separate and distinct acari. In 

 two of these forms the habitats of the mites, and the lesions 

 Avhich they produce, are distributed over different parts and 



