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F. S. BILLINGS. 
exactly corresponding to v. ovina verra. Goats react against inoc¬ 
ulation with ovine similar to the sheep ; which corresponds to their 
near zoological relationship. In seldom cases a variolic eruption 
has been observed by swine, for instance, when they have been 
introduced in an uncleaned and non-disinfected sheep-pen, in 
which variola-diseased sheep have been confined. Aside from the 
numerous resultless inoculations with ovine, by horses, dogs, rabbits, 
hares, and fowls, I will mention that inoculations of cattle gen¬ 
erated a local pustule—Sacco—and that positive results have also 
been received by rabbits—Gerlach—; re-inoculation of sheep 
gave positive results. 
With regard to the deportment of sheep towards the conta- 
gium of v. hum ana and that of other forms, the action of vacci 
nation is especially worthy of our attention. Vaccination of sheep 
gives as a rule a positive result, pustules develop as by ovination; 
however we frequently find pustules have developed on places 
«* 
where the animals were not inoculated, or in other words an ex¬ 
anthema develops similar to that of v. ovina vera. Sheep have 
a great inclination to generalize vaccine, and therefore the action 
of the same is entirely different with sheep as by man, by whom 
a general eruption is never observed. The assumption of some 
authors that this ovinisated vaccine is entirely identical with v 
ovina vera, appears as yet to want the necessary proof. Another 
metamorphosis which vaccine suffers in the ovine organismus is 
worthy of our attention ; it acquires the ability to disperse itself 
as a volatile contagium, while the original vaccine is of a fixed na¬ 
ture. 
Variola porcina is a seldom disease, and the reports of 
the same which are to be found in the literature are worse than 
scanty. According to its course, duration and termination, in se_ 
vere cases it bears the strongest resemblance to v. humana and v. 
ovina, in a light form to human varalois, in other, but very seldom 
cases, to the varicella of man. According to the descriptions 
which we have, the porcine variety complicates mostly young ani¬ 
mals; the exanthema being distributed over the entire body. 
They are in the beginning chiefly situated along the dorsal or ab¬ 
dominal surface, at another time along the mammae, and from 
