Tin: LUNG rLAtiTK OF CATTLK. 57 



tierd inoculation with the small pox inMtcr itself, with a virw of inducing 

 a less dangerous type of that disease tlian it' it wen 1 eont rartrd in the 

 ordinary way. What was produced was a mild case of small-pox, which 

 was, however, dangerously infecting to any unprotected person who 

 came within the sphere of its influence. The exact counterpart of this 

 is to le found iii the inoculation of lung plague virus on the surface. 

 In both cases alike there is produced a disease of the superficial st nur- 

 tures, in which the virulent genus are multiplied by myriads, and from 

 which these germs can l>e given on" through the nir or by direct contact 

 to infect other susceptible subjects. 



It can be freely conceded that this disease in the tail is far less likely 

 to infect other animals than the same affection in the lungs. The density 

 of tin* textures prevents that abundant proliferation and swelling which 

 take place in the lungs or other organ of soft texture. There is, there 

 fore, materially less poison to be diffused. But, more important still, 

 the tidal air passing in and out of the lungs continuously acts like a 

 bellows in keeping up a constant efilux of the virulent germs from 

 within. To this there is no equivalent in the case of the inoculated 

 tail. Finally, the air in the substance of lungs is not the pure air which 

 surrounds the tail, and which tends to disinfect and destroy virulent 

 germs, but it has been robbed of 4 per cent, of its oxygen, and charged 

 A\ith 4 per cent, of carbonic acid, beside water, vapor, and organic mat- 

 ter, conditions which greatly favor the preservation of disease germs 

 and the intensifying of their virulence. Much, therefore, which favors 

 the propagation of the disease from the lungs is absent from the affection 

 in the tail. But the difference is only one of degree, not of kind. And 

 numerous instances can be adduced in which inoculated animals have 

 proved the centers for new diffusions of lung plague. 



Reynal mentions the case 1 of an inoculated Brittany cowaf the Alfort 

 Veterinary School, which infected two others standing on the two sides 

 of her. (Police Sanitaire des Animaux Domestiques. j 



Mr. Watson, after a most extended experience in Australia and Few 

 Zealand, where they inoculate cattle by the ten thousand, records it as a 

 common observation that the disease is transmitted by inoculated cattle. 



Inoculated cattle convey the contayion to those which are not inoculated. This has been 

 proved by the disease breaking out among cuttle, where it had not previously shown 

 itself, after their coming in contact with some inoculated animals w hi eh were free from 

 the disease when inoculated. Cases of this sort, and even of cattle being inoculated 

 before the disease had broken out among them, are so few that decisive evidence in 

 this way is far from plentiful, but it is sufficient to establish the general fact. Fur- 

 ther, it has frequently been the case, when all the others were inoculated, that a few 

 head have been missed, and the j.Tcentage of deaths among those which were not 

 operated on was always excess! v : thereby showing that the inoculation of the disease 

 on every side of them not only rendered their escape from the contagion impossible, 

 but seemed to increase the virulency of the disease. (The Breeder.,' Live Slock Jour- 

 nal, April, 1*80.) 



Iii his letter quoted above, Mr. Everard 12. Corbet furnishes the same 

 testimony as to inoculation in South Africa, saying that the disease is 

 " introduced to a greater or less extent each time of inoculation." 



We might add other instances of this kind that have come under our 

 own notice, but the above are more pertinent as coming from parties 

 who are strong advocates of the practice of inoculation. 



LUNG PLAGUE MUST BE SPREAD BY A GENERAL INOCULATION. 



Having established the fact that inoculated animals are infecting, it 

 is easy to show that a general adoption of this measure must be a most 



