PREVENTION OF PLEURO-PNEUMONIA. 173 



it concludes : — " From the nature of the subject a considerable 

 time must elapse before any positive conclusion can be acquired 

 on this point." 



In 1852 Dr Ulrich was commissioned by his government to 

 go to Cologne, and into Belgium, in order to make observations 

 on the subject of inoculation for pleuro-pneumonia. He was in 

 communication with Dr Desaive, inoculator for the district of 

 Cologne, and M. Sticker, who was employed at the same time 

 and places by the Prussian government, and for the identical 

 purposes ; he had likewise the advantage of communications with 

 l)r Willems of Hasselt, and M. Verhezeu, Director of the Eoyal 

 Veterinary School at Brussels. His conclusions are as follow : — 



" 1. It is an established fact that, in many stables wherein 

 pleuro-pneumonia had raged for several years, as well as in 

 others which had only been infected by it of late, the disease 

 disapjDeared shortly after inoculation. That, on the other hand, 

 cases have occurred in which the disease has continued to rage 

 after, and in spite of, inoculation. 



" 2. In many cases of beasts dying afterwards of the disease, 

 inoculation has not proved successful. At the same time there 

 exist examples of the contrary ; animals in whom inoculation 

 has quite succeeded, and yet for all that, they have become 

 afterwards the subjects of the disease. 



"3. Cases have occurred wherein inoculation has proved 

 without effect on beasts already in a state of convalescence from 

 the disease. And others have occurred wherein inoculation has 

 proved equally successful, notwithstanding the subjects were 

 convalescent. Others again have presented themselves wherein 

 inoculation has failed to take any effect on beasts, either before 

 or after this operation. The assertion of Dr Willems, that 

 inoculation takes no effect on calves, is not borne out by experi- 

 ence, since several calves have died after inoculation. 



" 4. In many cases wherein inoculation had been practised on 

 cattle recently purchased, and put into stables formerly infected 

 but since purified, no fresh case of the disease has presented 

 itself for three months after occupation. 



" 5. No instance has come to our knowledge wherein in- 

 oculated animals placed in purified stables have become infected. 

 Nevertheless, a member of the Agricultural Association of 

 Dusseldorf has assured the members at a recent sitting, that 

 inoculations made at Eheinberg had been attended with the 

 results of propagating pleuro-pneumonia, which before was in 

 that situation unknown. 



" 6. In some isolated instances, animals not inoculated stand- 

 ing by the side of others in the same stable, which were infected, 

 caught the disease ; while others which had been inoculated were 

 preserved from taking it. 



