73^ DISEASES OF THE SKIN, 



rather firm in consistence, becomes easily reduced to powder. 

 The smell of the scab is peculiar, and is compared to the urine 

 of a cat, or to a cage where mice have been kept. Tliis is sup- 

 posed by Dr. Lowe to be due to a species of alcoholic fermenta- 

 tion (metJiT/lamine), in connection with the vegetable growth. 

 When a crust of recent formation is removed, a circular depres- 

 sion, wider and deeper than the favus, is seen, and at a more 

 advanced stage the ulceration penetrates below the dermoid 

 tissue. 



" On examining the hairs which pass through the favus 

 crusts, it will be often found that they present their healthy 

 structure. At other times they evidently contain long-jointed 

 branches, similar to those in the crust, running in the long 

 axis of the hair, which is exceedingly brittle. There can be 

 very little doubt that tlie tubes and sporules, after a time, 

 completely fill up the hair follicle, and thence enter the hair, 

 causing atrophy of its bull), and the baldness which follows the 

 disease." — (Bennett.) 



fe^^'s^c 



!FlG. 146 o, A light hair, containing branches of the achorion 



Schonleinii (magnified 300 diameters linear). The wood-cutter 

 has made the branches too beaded, b, A dark-coloured hair, con- 

 taining branches of the plant. — (Bennett.) 



Treatment. — The disease can only be eradicated by the 

 destruction of the parasitic growth, and as a rule this is not so 

 difficult to accomplish in the domestic animals as it seems to 

 be in man. I have, however, seen some very aggravated cases 

 in cats, but the severity of the disease was due more to neglect 

 than to any primary virulence. Corrosive sublimate made 

 into an ointment with lard is recommended by M. St. Cyr. 

 The iodine ointment seems to answer very well in this country, 

 but before it is applied, the scabs are to be removed by washing 

 them well with soft soap and warm water. 



