202 Report on Stejjpe Murrain or Rinderpest, 



progress of pleuro-pneumonla here, attends it everywhere ; and 

 throughout the continent it is looked upon as an incurable dis- 

 ease, and dealt with accordingly. Its great fatality arises from 

 the circumstance that the nature of the changes which take place 

 in the lungs is such as immediately to arrest their function as 

 perfect aerifying organs, and soon to destroy to a greater or less 

 extent the integrity of their structure. The true pathology of 

 pleuro-pneumonia is one of the qucestiones vexatce of science. In 

 this Report we have not immediately to do with this question, 

 still we may observe that the most eminent professors of veteri- 

 nary medicine throughout Europe hesitate to declare, as sonje 

 medical men have done, that the changes wrought in the lungs are 

 altogether due to inflammatory action. 



In Belgium, in France, and in many parts of Italy, the disease 

 is designated exudative pleuro-pneumonia — a name which, while it 

 marks a peculiarity in the disease, implies, at the same time, that 

 it differs somewhat in its results from ordinary inflammation of the 

 lungs and their investing membrane, and which is correctly called 

 pleuro-pneumonia. We have no hesitation in giving it as our 

 opinion that the changes which are originally effected in the lung 

 tissue can take place otherwise than by inflammatory action. We 

 observe, as the analogue of these changes, that in the advance- 

 ment of the disease, the interstitial areolar tissue, contiguous to 

 the more affected parts of the organs, is primarily choked with 

 serous effusion, which, by its pressure upon the air-cells and 

 their rete of capillary vessels, obstructs both the admission of air 

 to the cells and the circulation of the blood through the vessels, and 

 thus leads to an imperfect decarbonisation of the blood, as well 

 as to far more important changes in the fluid itself. Not only, 

 in many diseases, are serous exudations often and entirely inde- 

 pendent of inflammation, but fibrinous are equally so in the 

 opinion of some of the ablest pathologists of the present day. 

 These deposits may result from the vital force of the vessels 

 being impaired by some depressive influence acting on the 

 nervous system, either generally or locally, as well as by some 

 unexplained or ill-understood alteration taking place in the com- 

 position of the blood, by the existence within it of morbific 

 animal or vegetable pioducts. The fibrinous depositions in 



either infectious or incurable. For several seasons prior to 1857 I had a few cases 

 annually amongst my cattle, of which some died and others recovered. The dis- 

 eased animals were not separated from their companions unless likely to die, and 

 then not until the last stages of the complaint, yet the disease never spread, nor 

 was any large proportion of the herd attacked, and I could generally trace the 

 outbreak to the prevalence of cold fogs or to rapid alternations of temperature, 

 especially if occurring in spring or autumn. With reference to the possibility 

 and mode of cure, see Mr. Horsfall's paper in the present volume, p. 189. — 

 H. S. Thompson. 



