276 INFECTIVE DISEASES. 



of the disease was clearly showTi — the tendency to spread through a 

 whole herd. 



On examining the eruption carefully, the degree of severity was 

 found to difEer very much in different animals. In a few oases the 

 condition was most distressing, both to the cow and to the observer. In 

 such cases the teats were encrusted with huge, dark brown or black 

 crusts, which, when handled in milking, were broken and detached, 

 exposing a bleeding, suppurating, ulcerated base. Such ulcers varied 

 in size from a shilling to a florin, and in form were circular, ovoid, or 

 irregular. Weeks afterwards, when the animals had recovered, the 

 site of these ulcers was marked by irregular scars. 



All the milkers agreed as to the general characters of the malady, 

 laying particular stress on the teats being red, swollen, and painful when 

 handled. Vesicles would then appear on the teats — two, three, four, or 

 more on each teat. They were soon broken in milking, and irritated into 

 sores, which became covered with thick crusts. From four to six weeks 

 elapsed before they had entirely healed. Other more observant milkers 

 insisted that before the teats were red and swollen, spots or pimples first 

 appeared which came to a head. This head increased if it was not broken, 

 which might be the case if it was situated between the bases of the teats, 

 until it formed a greyish vesicle of the size of a threepenny-piece or 

 even larger. 



General Symptoms in the Cow. — As to the general condition of the cows 

 nothing abnormal was observed. They appeared in the best of health, 

 and in only one particular was any difference from their condition in 

 health stated to exist. This was, that in the majority of the cases there 

 could be no doubt that the milk had diminished. This might escape 

 notice by inexperienced milkers in any particular animal, but the total 

 amount of milk supplied by the herd was considerably below the average. 



History of the Eruption communicated to the Milkers. — The most striking 

 characteristic of this outbreak was the communicability of the disease 

 to the milkers. A milker, with vesicles which presented typically the 

 characters of casual cow-pox, was taken to London and kept under 

 observation. The various cases will be described in the order in which 

 they first presented themselves, their history being given as much as 

 possible in their own words. 



Case I. — J. K., milker, informed the author that he was the first to catch 

 the eruption from the cows. He stated that it came as a hard, painful spot, 

 which formed " matter " and then a " big scab." He had been inoculated 

 about seven weeks previously. He pointed to the scar which remained 

 on his right hand. This scar presented the characters of an irregular 

 cicatrix, indicating considerable loss of substance. He stated that he had 

 also two places on his back, where he supposes he had inoculated himself 

 by scratching. He had continued milking ever, since, but had had no 

 fresh places. 



Case II. — W. H., milker. He stated that he was inoculated from the 

 cows about the same time as J. R. They were the two milkers of 

 the herd in which the cow-pox first made its appearance. The eruption 



