446 



THE DAIRYMAN S MANUAL. 



and, if care is not taken, are broken and may become raw 

 sores which are difficult to heal, which, in fact, sometimes 

 result very disastrously and even fatally. 



By and by the contained liquid becomes a thick yel- 

 lowish pus which dries into a scab, and this in time 

 becomes loose and falls off, being replaced by newly- 

 formed skin. "When one case is out of the way another 

 appears, and in a herd of twenty or more it may coutinue 

 the whole summer in its passage through the herd, 

 giving constant annoyance. During the progress of the 

 disease the udder is inflamed and tender, and the teats 

 are quite painful when pressed; so much so that milking 



N:>0^i^ ■ v;.X \:'////:yU^ 



Fig. 105.— APPEAEANCE OF COW POX. J..— MILKING TUBE. 



in the usual manner is impossible. Recourse is then had 

 to milking tubes. 



This disease is readily communicated to mankind and 

 to horses, and spreads from cow to cow, being usually 

 conveyed by the milker, w^hose hands and clothing soon 

 become infected with the rirus. The matter contained 

 in the vesicles is the true vaccine virus used for inoculat- 

 ing persons as an antidote to the more dreaded and viru- 

 lent small-pox, and in its effect upon mankind occasions 

 no worse disturbance than the slight fever and some- 

 times glandular swellings incident to the operation of 

 vaccination. The virus will often remain permanently 

 in a stable, and Avill cause every heifer which comes to 

 milk in it to contract the disease. When this is found 



