C14 'PLEURO -PNEUMONIA. 



vered from their effects. In structure and chemical constitu- 

 tion there is no difference, and often the most potent poisons 

 are simple fluids. The Belgian Commission appointed to 

 investigate the nature and influence of inoculation for pleuro- 

 pneumbnia very justly expressed an opinion that Dr Willems 

 had not proved that a specific product, distinguished by 

 anatomical characters, and appreciable by the microscope, 

 existed in this disease. 



The all-important question " Is inoculation of service?" 

 has, in my opinion, been solved. I cannot deal, in the 

 pages of this little work, with the large amount of conflicting 

 evidence on the subject. The Belgian and French commis- 

 sions, Reviglio's, Simonds', Hering's, my own observations, 

 and those of many more, prove that a certain degree of pre- 

 servative influence is derived by the process of inoculation. 

 It does not arrest the progress of the disease. It certainly 

 diminishes to some extent, though often very slightly so, the 

 number of cases, and particularly that of the severe ones. 

 This effect has been ascribed to a derivative action, inde- 

 pendently of any specific influence, and indeed similar to that 

 of introducing setons in the dewlap. I cannot speak very 

 favourably of the latter process, as indeed I cannot recommend 

 the inoculation of cattle. In London some dairymen have 

 considerable faith in this operation, though its effect is un- 

 certain, and its modus operandi a mystery. I should counsel 

 the keeper of dairy stock to select his own animals from 

 healthy herds, and strictly avoid public markets. In many 

 instances, to my knowledge, this has been sufficient to prevent 

 the invasion of this terrible disease. 



There is a vital question, the solution of which has rarely 

 been attempted, and which I desire particularly to refer to. 

 " Is it possible to rid her Most Gracious Majesty's dominions 

 of pleuro-pneumonia?" During last century the disease 



