420 CATTLE. 



siderably in size and form, and are filled with a purulent matter. In 

 the course of a few days a scab forms upon them, which peels off, 

 and the part underneath is sound. If the pustules are rubbed off in 

 the act of milking, or in any other way, small ulcers are left, which 

 are very sore, and sometimes difficult to heal. 



The best treatment is washing and fomenting ; a dose of physic, 

 and the application of the ointment for soie teats recommended in 

 page 408. The cause, like that of many other pustular eruptions, is 

 unknown ; except that it is contagious, and is readily communicated 

 from the cow to the milker, if the hand be not quite sound, and from 

 the milker to other cows. 



There is another kind of pustular eruption, of a more important 

 character, and with which the preceding one has been confounded. 

 It also consists of vesicles or bladders on the teats ; but they are 

 larger, round, with a little central depression ; they are tilled at first 

 •with a limpid fluid, which by degrees becomes opaque and purulent, 

 and each of them is surrounded by a broad circle of inflammation. 

 This is more decidedly a constitutional disease than the former. The 

 cow exhibits evident symptoms of fever ; she does not feed well ; 

 sometimes she ceases to ruminate, and the secretion of milk is usual- 

 ly diminished. 



These pustules go through a similar process with the former 

 ones — they dry up, and at length the scabs fall off, leaving the skin 

 beneath sound ; but if they are broken before this, the ulcers are 

 larger, deeper, of a more unhealthy character, and generally far more 

 difficult to heal. This is the genuine cow-pox. 



The treatment is nearly the same, except that, being accompanied 

 by more constitutional disturbance, an aperient is more necessary, 

 and it may occasionally be prudent to abstract blood. The frequent 

 application of Goulard's lotion, with an equal portion of spirit of 

 wine, will, at least in the early stage of the ulcer, be preferable to 

 the ointment ; but better than this, and until the ulcers are begin- 

 ning to heal, will be the dilute solution, of the chloride of lime. If 

 the teats are washed with this before the cow is milked, it will go 

 far toward preventing the communication of the disease. 



The most interesting circumstance connected with this pustular 

 eriiption is, that the persons on whom it appeared were, for a con- 

 siderable period, (it was once thought, during life,) protected from 

 the small-pox. This was known among farmers from time immemo- 

 rial. But to no one, whom experience had convinced of the active 

 protective power of the cow-pox, had it occurred to endeavor to as- 

 certain whether it might not be possible to propagate the affection 

 by innoculation from one human being to another, and thus communi- 

 cate security against small-pox at will. 



To the mind of Mr. Jenner, the probability of accomplishing this 

 first presented itself. He innoculated a boy with the matter take^ 



