264 Inoculation for Pleuro- Pneumonia in Cattle. 



is well known that if these are employed, care being taken to 

 prevent their wealiening effect on the constitution by the exhibition 

 of tonic medicine^ or the use even of a nutritious diet, not only 

 Pleuro-pneumonia but many other diseases will be sometimes 

 prevented. 



Further, with regard to protection, we must call attention to 

 the present amount of loss in Mr. Paget's herd. The inocula- 

 tions were begun at the end of November, and with irregular 

 intervals carried on so as to be completed by the beginning of 

 February. Now, dating from the end of November to the end of 

 May, when we have the last report of the health of the animals, 

 it will be seen, by reference to the particulars contained in this 

 report, that during these six months no less than jive in- 

 oculated animals have died of Pleuro-pneumonia after inocula- 

 tion. This on the year, at the same ratio, would give 10 per 

 cent. — a number equal to the annual average loss of M. Willems 

 sen., and to guard against which he adopted inoculation.* 

 It must likewise not be forgotten that in many instances on the 

 Continent, the disease, instead of decreasing, has progressed much 

 more rapidly after inoculation than before, affecting indiscriminately 

 the inoculated and the ?zo72-inoculated animals. A fact of this 

 kind was to be expected with a contagious disease like Pleuro- 

 pneumonia, Vi^hen inoculation was roughly done on animals already 

 of iceak constitution and perhaps badly kept, as thereby their 

 susceptibility would be further increased to the influence of the 

 contagion. 



To proceed to other matters. It is stated in the fifth conclusion 

 of the Dutch Commission, and admitted by all observers, that 

 the lungs are not specially diseased from an inoculation, although 

 death may result therefrom. To the arguments advanced in our 

 former report on this head, we may add that the ?2o?z-production 

 of Pleuro-pneumonia by inoculating an animal with the serous 

 exudation from a diseased lung, must be admitted as one good 

 proof among many others that such exudation is not a special 

 " virus." If the exuded serous fluid produced a special and well- 

 marked inflammatory action locally, prior to generating a peculiar 

 condition of the constitution, although the evidences of the latter 

 might be so slight as to be hardly recognized, as is the case with 

 the vaccine lymph ; or if it caused sooner or later the disease 

 Pleuro-pneumonia itself, altogether independent of such local in- 

 flammation, of which we have an example in Rabies, then there 

 would be no difficulty in admitting that the inoculation of cattle 

 was founded on scientific principles. Neither of these properties 

 has, however, as yet been satisfactorily proved to belong to the 



* See First Eeport, Journal, vol. xiii. p. 37G. 



