152 CLASSICS OF MODERN SCIENCE 



resist the contagion, in whatever state their nipples may chance to be, 



if they are milked with an infected hand. 



Whether the matter, either from the cow or the horse, will affect 

 the sound skin of the human body, I cannot positively determine; 

 probably it will not, unless on those parts where the cuticle is ex- 

 tremely thin, as on the lips for example. I have known an instance 

 of a poor girl who produced an ulceration on her lip by frequently 

 holding her finger to her mouth to cool the raging of a Cow-pox 

 sore by blowing upon it. The hands of the farmers' servants here, 

 from the nature of their employments, are constantly exposed to 

 those injuries which occasion abrasions of the cuticle, to punctures 

 from thorns and such like accidents ; so that they are always in a 

 state to feel the consequences of exposure to infectious matter. 



[It is singular to observe that the Cow-pox virus, although it renders 

 the constitution unsusceptible of the variolous, should, nevertheless, leave 

 it unchanged with respect to its own action. I have already produced 

 an instance to point out this, and shall now corroborate it with another. 



Elizabeth Wynne, who had the Cow-pox in the year 1759, was in- 

 oculated with variolous matter, withott effect, in the year 1797, and 

 again caught the Cow-pox in the year 1798. When I saw her, which 

 was on the 8th day after she received the infection, I found her infected 

 with general lassitude, shiverings, alternating with heat, coldness of 

 the extremities, and a quick and irregular pulse. These symptoms were 

 preceded by a pain in the axilla. 



It is curious also to observe that the virus, which with respect to 

 its effects is undetermined and uncertain previously to its passing 

 from the horse through the medium of the cow, should then not only 

 become more active, but should invariably and completely possess 

 those specific properties which induce in the human constitution symp- 

 toms similar to those of the variolous fever, and effect in it that 

 peculiar change which forever renders it unsusceptible of the vario- 

 lous contagion. 



May it not then be reasonably conjectured that the source of the 

 Small-pox is morbid matter of a peculiar kind, generated by a dis- 

 ease in the horse, and that accidental circumstances may have again 

 and again arisen, still working new changes upon it, until it has ac- 

 quired the contagious and malignant form under which we now com- 

 monly see it making its devastations amongst us? And, from a 



