“Fig. 1 shows umbilicated pustules with an intense edema of the foot, considerably increasing

“Fig. 1 shows umbilicated pustules with an intense edema of the foot, considerably increasing in its size and causing much pain. Fig. 2 shows the epidermis raised in a large, irregular patch by the confluence of pustules.” 

A Practical Treatise on Smallpox by George Henry Fox, 1903