74 SMALL- I'OX IN SHF.EP. 



their faces, and that, under such circumstances, the 

 malady proves liii^ddy destructive. The papulae vary in 

 size and number : they imi)art a firm unyielding sen- 

 sation to the finger, and ^vhen cut into, present an 

 appearance not very dissimilar to a section of a wart : 

 their vascularity is not great, excepting on the surface, 

 or rather on that part which is continuous with the 

 vascular layer of the dermis. 



The changes which produce these nodules e\'ident]y 

 affect the corium, and probably are to be referred to 

 two especial causes— a rapid development of the com- 

 ponent parts of the skin, from the increased quantity 

 of blood sent to it, and the inflammatory action which 

 results, producing a deposition of lymph into the in- 

 terstices of the corium. On forcibly detaching a little 

 of the wool, the exposed nodules undergo a singular 

 change ; for a few seconds they have a whitish appear- 

 ance, which is followed by a return of their usual red- 

 iiess; — a phenomenon which shews that their colour 

 chiefly depends on the blood circulating through the 

 capillaries of the papillated surface of the dermis, and 

 not on an equal distribution of this fluid throughout 

 their entire substance. 



This stage of the disease is thus described by Sacco, 

 an Itahan author : " The eruption of the sheep-pox," 

 says he, '' shews itself in the form of small red points, 

 which gradually enlarge, and attain the figure and size 

 of a lentil. In general the eruption of these pustules 

 [papulae ?] is copious : they often unite one with the 

 other, so as to produce in the skin prominences similar 

 to a bunch of grapes. The greater part of these 

 pustules [papulae?], on being pressed upon by the finger, 

 prove to be hard bodies, like small glands, and if they 



