CONTAGIOUS disk\sp:s of domesticated animals. 11 



:fie(l, and three Jersey cows, in which I found no evidence of disease. 

 Only one animal bad been brought on the place within a year jireceding 

 the outbreak, and that was a Jersey cow named Mollie Lathrop 3rd, 

 No. 7627. She was obtained by exchange with Charles Decline, of New 

 Durham, N. J,, on April 10, 1883. This cow aborted the last of May, 

 but lias shown no other signs of sickness. At the time of examination 

 she was in tine condition, fat, glos««y, with no cough and no signs of 

 lung disease, revealed by either auscultation or percussion. 



I visited Charles Decline at New Durham, N. J., on August 30. He 

 stated to me that he exchanged cows with Williams about April 16. 

 His cow went to New London on the same boat that the other returned 

 by. According to the statement of Williams' farmer, the two cows were 

 together about a quarter of an hour at New London. The cow Decline 

 received from Williams sickened about the last of May. About a week 

 later, she and another Jersey cow which stood beside her, and which 

 was also sick, were killed and examined by his son, who is a veterinary 

 surgeon. Both were affected with lung disease which he pronounced 

 to be pleuropneumonia. The lungs were hepatized, marbled in color, 

 and attached to the walls of the chest. 



Decline purchased Mollie 3d of Mr. Whitenack, of Duuellen, N. J., 

 December 13, 1881. He says that he never had any disease among his 

 cattle until after the cow arrived from Connecticut, and attributes the 

 infection to her. 



It was evident that some of the facts connected with the history of 

 the disease in these two herds had been concealed, but it was very cer- 

 tain that the disease had existed in both herds, and it was very proba- 

 ble that one of the herds had been infected as the result of the exchange 

 referred to above. Considering that there had been no disease in Con- 

 necticut until nine weeks after the exchange, and that it was admitted 

 to have existed in Declines' herd four weeks earlier than it appeared 

 among Williams's cattle; and considering, further, that the vicinity of 

 New Durham has long been infected with i)leuro.-i)neumonia while none 

 had previously existed in the neighborhood of Salem, and the probabil- 

 ity is that the disease was carried from New Jersey to Connecticut. 

 There is one other possibility, however, viz., that both cows were in- 

 fected on the boat or between the boat landing and Decline's place. 



This theory is not probable, for the reason that a second cow was sick 

 at Decline's by the last of May, and this would retpiire the assuin]>tion 

 that two full periods of incubation had elapsed between April 10 and 

 May 30 ; that is, within six weeks. Now, it is very seldom that the pe- 

 riod of in(!ubation of pleuropneumonia is less than four weeks, and it 

 is generally longer than this; consecpiently, it is very unlikely that in 

 two successive cases on the same farm it would be reduced to throe 

 weeks. The admitted fact that both sickened at about the; same time 

 -is an indication that both were infected at the same time, and from a 



