164 



HEALTH AND DISEASE 



Symptoms. — In consequence of the common occurrence of a form of 

 eczema, in which the eruption is distinctly circular, the term ringworm 

 is frequently applied to that disease, which is not associated with the 

 presence of a fungus and is not contagious iu its character. In eczema 

 tlie round patch which characterizes the eruption is developed at once, ])ut 



in ringworm it commences as a 

 small pimple and spreads day by 

 day in widening circles until a 

 rounded patch is produced. True 

 ringworm is in all cases due to 

 the growth of the fungus {Tricho- 

 pJiyton) in the hair follicles, and 

 fi'equently in the interior of the 

 hair, and the diagnosis of the 

 disease implies the detection of the 

 fungus under the microscope. For 

 this purpose a few hairs and a 

 certain small proportion of scab 

 should be removed from one of 

 the spots of the skin, placed in 

 a little solution of potash, with 

 a few drops of glycerine added, 

 in order to render the opaque 

 scal:)s transparent. If the disease 

 is ringworm the appearance pre- 

 sented will be that which is indicated 

 in Plate XXXVI, figs. 9 and 10. 



Another method of diagnosis 

 has been suggested, which, taken 

 in connection with the clinical 

 symptoms, i.e. itching and the 

 appearance of gray scabs along 

 the back, the sides of the withers, 

 and, in bad cases, on the neck and head, may lead to a correct conclusion; 

 but absolute proof of the nature of the disease can only be obtained by 

 microscopic inspection. The method proposed is as follows: — A few drops 

 of chloroform are allowed to drop on one of the suspected spots; if, after 

 the evaporation of the fluid, some of the hairs present a white or pale- 

 yellow colour, it is concluded that the disease is ringworm. 



Two varieties of ringworm have been distinguished by writers — the 

 common kind, in which the scab is gray and the hairs are inclined to break 



Yig. 272. — Ringworm 



