GEORGE FLEMING. 
32fi 
falls about the fifteenth to the twentieth day, leaving only a slight, 
but permanent cicatrix. 
The same changes occur in a dark skin, but they cannot all be 
so readily perceived, in consequence of the pigmentation. 
The size and prominence of the pustules may, of course, vary, 
and their base appear more inflamed in some cases than other, 
according to constitution, condition of the animal, and other cir¬ 
cumstances: the evolution being generally most notable in those 
which are in good health. The virus seems to be most active to¬ 
wards the sixth or seventh day after inoculation, and then rapidly 
loses its potency. Indeed, it has been found that though there is 
then not so much lymph as afterwards, between the third and 
seventh days is the period when it is most potent. 
As a rule, there is little or no general disturbance of health per¬ 
ceptible ; and though in the natural disease a more or less general¬ 
ized eruption has been observed in rare instances, yet it has not been 
noticed in the artificially induced malady; while it has not been 
at all unusual to discover a kind of secondary eruption, of exactly 
the same character, around the inoculation points—an eruption 
which might be due to accidental inoculation when the operation 
was performed. In the experiments of the Lyons Commission, a 
young bull, successfully inoculated in three places on the scrotum, 
on the sixth day had a newly-developed pustule behind one of the 
places. This had all the characters of the others, and though its 
presence was attributed to auto-inoculation, yet there was no cer¬ 
tainty that it was so produced. 
The natural cow-pox I have described in my work on “ Veter- 
inary Sanitary Science and Police ” (vol. ii., p. 91). The symp¬ 
toms and course of the disease may be briefly described as follows : 
After slight febrile disturbance, partial loss of appetite and suspen¬ 
sion of rumination, trifling constipation and diminution of the 
urinary secretion—symptoms which may, nevertheless, be absent 
or uuperceived—and lessened quantity, as well as altered quality 
of the milk (more aqueous and disposed to coagulate than usual), 
the udder is observed to be swollen, particularly near the teats, 
and is painful during milking. In two or three days there are seen 
on the udder, and chiefly on the teats, small hard tumors, varying 
