PREVENTION OF PLEURO-PNEUMONIA. 167 



and swelling, general symptoms of fever, and gradual recovery. 

 The most common occurrence is sloughing of the tail." Dr 

 Willems, before referred to, arrived at the following conclusions 

 from his investigations : — 



" 1. Pleuro- pneumonia is not contagious by inoculation of the 

 blood, or other matters taken from diseased animals, and placed 

 on healthy ones. 



" 2. That the blood and the serous and frothy liquid squeezed 

 from the lungs of a diseased animal in the first stage of pleuro- 

 pneumonia, are the most suitable matter for inoculation. 



" 3. The inoculation of the virus takes from ten days to a 

 month before it manifests itself by symptoms. 



" 4. The matter employed for the inoculation has, in general, 

 no effect upon an animal previously inoculated, or having had 

 the disease. 



" 5. The inoculated animal braves the epizootic influences 

 with impunity, and fattens better and more rapidly than those 

 in the same atmosphere with it that have not been inoculated. 



" 6. That inoculation should be performed with prudence and 

 circumspection, upon lean animals in preference ; and towards 

 the tenth day after the operation a saline purge may be given, 

 and repeated if necessary. 



" 7. By inoculating pleuro-pneumonia a new disease is pro- 

 duced; the affection of the lungs, with all its peculiar characters, 

 is localized in some parts of the exterior, but whether it occasions 

 apparent morbid manifestations or not, the inoculated animal is 

 preserved from pleuro-pneumonia. 



" 8. The virus is of a specific nature ; it does not always act as 

 a virus. The bovine race alone is affected by its inoculation, since 

 other animals of different races, inoculated in the same manner 

 and with the same liquid, experience no ill effects." 



Professor Williams, in his excellent treatise recently pub- 

 lished,* says : — " In the most favourable instances, a slight 

 heat and swelling occurs round the inoculated spot in a period 

 varying from a week to two months; generally, however, the 

 eruption manifests itself from the 9th to the 16th day, accom- 

 panied l:)y slight rigors, loss of appetite, and slightly diminished 

 secretion of milk. When the operation has been properly per- 

 formed, and the virus carefully selected, the effects are generally 

 as above described, but when the virus is putrid or badly selected, 

 ■or, as sometimes happens, some peculiarity exists in the inocu- 

 lated animal, the primary swelling is excessive, the tip of the 

 tail becomes gangrenous, the animal suffers from a high state of 

 fever ; secondary deposits occur at the root of the tail, around the 

 anus, and in the abdominal glands, and death occurs in a few 

 days after the inoculation." 



* The Princi])les and Practice of Veterinary Medicinu, p. 153 



