176 ON INOCULATION AS A MEANS FOR THE 



exhibiting various deformities, from loss of tissue or whole 

 parts, &c. 



" 8. The practice of inoculation appears to reduce the suscep- 

 tibility of animals to the contagion of pleuro-pneumonia ; but for 

 how long has not been positively determined. The longest known 

 period is six months. In order to understand more clearly the 

 absolute value of inocidation as a means of preserving bovine 

 animals from attacks of pleuro-pneumonia, it will be useful to 

 compare the results with those obtained by careful observations 

 on the transmission of disease by cohabitation. Of 100 animals 

 exposed to contagious influences, 32 '61 were unaffected, and 

 2173 became mildly affected. In other 45"65 animals the 

 disease was more or less intense, 35"95 recovered, and 8'69 suc- 

 cumbed to the consequences of the disease. In 100 inoculated 

 animals, 61*11 showed the mildest effects, and 38-88 suffered in 

 an aggravated degree. Of the 38'88 sufferers, 27 "77 recovered, 

 after exhibiting intense local and constitutional signs, gangrene, 

 &c., and 11 "11 died from those effects. 



" The first important truth wliich is gained by these investiga- 

 tions is, that inoculation causes greater mortality than that 

 which results from the disease for which it is brougjht forward 

 as a prophylactic. In addition, the animals recovered from the 

 gangrenous forms have lost much of their commercial value by 

 reason of the unsightly deformities which they have contracted ; 

 Avhile, on the contrary, those which contracted the disease in the 

 usual way recovered their value, as well as aptitude for milking 

 or fattening. Notwithstanding, it is only right to say that the 

 greater number of animals which recovered from pleuro-j^neu- 

 monia, contracted after inoculation, did not recover from the 

 disease resulting from it. In the majority of cases investigated 

 by the Commission, the ^^ost mortem appearances disclosed por- 

 tions of the lungs to be undergoing degeneration {veritable 

 m^ortification). A circumscribed mass of tissue is involved in 

 gangrenous disease, surrounded by healthy substance, and the 

 former interferes with the function of respiration and purifica- 

 tion of the blood to such an extent as to preclude the animal 

 from use as a milker or feeder." 



The Commission closes its remarks by adding, that although 

 the results of the experiments that have been instituted point 

 strongly to the excess of mortality from inoculation, the freedom 

 of the animals employed may be traced to their being brought 

 from the country, and so less liable to the deteriorating influences 

 of close sheds, &c., which are well known to produce greater 

 susceptibility to diseases of all kinds. They likewise state that, 

 while it does not appear from their experiments that inoculation 

 is an advantageous proceeding, it is nevertheless shown to possess 

 a preservative power, and they are of the opinion that tlie prac- 



