470 Observations on Inoculation with the Virus of 



buried. There were also working oxen and a number of stores 

 on the farm, but they were at a considerable distance from the 

 cows, and had not been exposed to infection. 



The cows were carefully examined ; and two of them, in which 

 the internal temperature was above 104°, were removed and 

 isolated. Both these animals were afterwards attacked with 

 pleuro-pneumonia in a severe form. On a subsequent visit two 

 more animals were removed, and, after the lapse of a fortnight, 

 two others were selected and separated from the herd. In all of 

 the isolated animals evidence of the existence of pleuro-pneu- 

 monia was observed in a few days after their removal, and nearly 

 all of them died or were killed. Another examination of the 

 herd was made a few weeks after the last two animals were 

 removed, and in every case the temperature ranged from 100° 

 to 102°. From this time no signs of pleuro-pneumonia were 

 apparent, and the disease ceased with the loss of six animals out 

 of twenty-two. But the chief feature of the narrative is yet to be 

 introduced. 



Early in the outbreak of the disease, when only two or three 

 of the cows had been attacked, the owner was advised to have 

 the whole of his stock inoculated. The operation was performed 

 on the calves, which have been alluded to as infected with the 

 disease, by the veterinary surgeon in attendance, and in this case 

 the progress of the disease, instead of being cut short, was 

 accelerated — a result which has been noticed in similar instances 

 by Continental observers. Mr. Priestman inoculated the re- 

 mainder of the stock, which had not at the time been in any way 

 exposed to infection. The cows, however, among which the dis- 

 ease really existed were left untouched, as it was feared that the 

 milk would be rendered unwholesome by the introduction of the 

 virus of lung disease into the system. 



If inoculation had been performed on these cows, the only 

 cattle on the farm on which its protective effects would have 

 been fairly tested, the cessation of the disease would, un- 

 doubtedly, have been ascribed to its influence. 



In the next instance the outbreak occurred among thirty-five 

 inoculated cows in a London cow-shed. All the animals had, at 

 different periods, been inoculated by Mr. Priestman, and I had the 

 opportunity of watching many of the animals for some months, 

 both before and after the operation. During October, 1873, 

 three fresh cows were purchased, and, after being inoculated, 

 were kept in a shed by themselves until they had recovered 

 from the operation. In the following month a second lot of six 

 animals was purchased, and similarly treated before being placed 

 with the herd. Mr. Priestman suspected that some of these 

 animals had been taken from an infected herd, and events 



