GREASE. 507 



motion to influence the air around, which an artful person 

 might manage with ease. When this kind of eye is ex- 

 amined closely, the pupil will be found of one invariahle 

 size and unvarying hue ; it will not enlarge and diminish as 

 in a healthy horse, when removed farther from, or nearer 

 to, the light ; for the retina, ceasing to be influenced by the 

 luminous ray, no longer controls the movements of the 

 iris. It is, therefore, from the peculiarities in the manner 

 of the horse, the invariable size of the pupil, and a greenish 

 glassy cast in such eyes, that these cases may be distin- 

 guished. As it has hitherto proved incurable, we shall 

 waste no time on its treatment. 



EXCRESCENCES, &C. ON THE EYES. 



It remains to observe, that small polypous excrescences 

 sometimes form on the globe of the eye, or on the eyelids. 

 Fungoid projections on the transparent cornea likewise 

 sometimes follow accidental abrasions, or may be they are 

 spontaneous productions. When they are of the nature of 

 polypi, cut them off. When of the fungoid kind, the chlo- 

 ride of zinc in solution, or a minute quantity of the ung : 

 precip : rub : softened with oil and painted over it every 

 day, or second day, will effect a removal. 



CHAPTER XIX. 



DISEASES OF THE SKIN. 

 GREASE. 



This disease appears to be dependent on a morbid altera- 

 tion in the quantity and quality of the sebaceous matter 

 secreted by the glands of the extremities. The inflamma- 

 tion which first brings about this effect exhibits some singu- 

 larities not observable in the inflammations of other parts ; 

 and had the assertion of Jenner been true, that matter from 

 it was capable of raising a disease again communicable, 

 its character as a specific disease would stand on equal 

 grounds with syphihs or small-pox. But that capability is 

 now questionable, although not decidedly proved to be erro- 

 neous ; and as on this it rests its main support to the 



