DISEASES OF THE SKIN 135 



glands, (3) Diseases of the sebiparous glands, (4) Diseases of the hair and 

 hair follicles. 



Hebra in 1845 adopted a pathological system, dividing skin diseases 

 into twelve classes: (1) Hyperfemias, (2) Anaemias, (3) Anomalies of secretion 

 of glands, (4) Exudations, (5) Haemorrhages, (6) Hypertrophies, (7) 

 Atrophies, (8) Neoplasms, (9) Pseudoplasms, (10) Ulcerations, (11) Neu- 

 roses, (12) Diseases caused by parasites. 



Dr. Tilbury Fox, whose work on skin diseases is constantly referred to 

 by dermatologists, proposes a system of classification which he considers 

 will be found the best for all practical purposes, in the following ten 

 groups: — (1) Eruptions of the acute specific diseases, such as small-pox, &c. 



(2) Local inflammations, including erythema, roseola, urticaria (nettle-rash) 

 and certain medicinal rashes; catarrhal inflammations, as in eczema; papu- 

 lar inflammations, for example, lichen and prurigo; bullous inflammations, 

 including herpes, &c.; suppurative inflammations, including pustular erup- 

 tions; squamous inflammations, including pityriasis, rubra, and psoriasis. 



(3) Diathetic disorders, including strumous and leprous diseases of the skin. 



(4) Hypertrophic and Atrophic diseases, as warts, corns; and ichthyosis, 

 afl'ecting the epithelium; also keloid, fibroma, scleroderma, affecting the con- 

 nective tissue of the skin ; and among atrophies, senile decay and atrophy. 



(5) New formations — cancer, lupus, and rodent ulcer. (6) Hsemorrhages, 

 for example, purpura. (7) Neuroses, as hyperaesthesia, anaesthesia, and 

 pruritis. (8) Pigmentary alterations. (9) Parasitic diseases, including animal 

 or dermatozoic itch, and phthiriasis or lousiness, effects of fleas, bugs, gnats, 

 &c., and vegetable or dermatophysis, as in diff'erent forms of ringworm. 

 (10) Diseases of the glands and appendages, sweat glands and sebiparous 

 glands, diseases of the hairs and their follicles, and diseases of nails. 



This method of classification appears to be most applicable to the skin 

 diseases of the horse. 



GENERAL OBSERVATIONS ON THE SUBJECT OF DIAGNOSIS 

 AND TREATMENT 



It may be stated at the outset that the horse is comparatively exempt 

 from many of the diseases referred to in the systems of classification which 

 have been quoted; but in making this admission it is important to note 

 that the skin diseases of the horse did not attract any particular attention 

 from the older veterinary writers, and even in regard to the authorities 

 of the present time, although they have adopted a system of classification 

 taken with certain modifications from the system accepted by the most 

 distinguished dermatologists, nothing like a special course of study of the 



