4 THE DISEASES AND DISOROERS OF THE OX. 



mentioned that Klebs and Semmer have found the presence of 

 the disease-germs (micrococci) in the blood and lymphatic 

 glands."^ 



Moreover, in view of the fact that the insidious malady known 

 as *' contagious pleuro-pneumonia " is still rife in certain places, 

 it will be seen how important it is to know all that can be 

 learned as to its causation. Of this disease, too, we shall have 

 to speak fully in its proper place ; but we may here say that 

 slaughter of affected animals, and of animals supposed to be in- 

 fected, and disinfection of the contaminated sheds are, so far as 

 can be at present decided, the best means of dealing with this 

 severe cattle scourge. 



With regard to pleuro-pneumonia, then, as in the case of all 

 contagious diseases of lower animals, we must lay the greatest 

 emphasis of which we are capable on the method of stamping 

 out by slaughter of all animals affected, or supposed to be 

 affected. That is one point, and a point of immense im- 

 portance. 



Still, however, this disease breaks out again and again, in 

 spite of all that can be said, as a result of the fact that cattle- 

 owners do not grasp the conditions of the problem, and do not 

 carry out either one rational method or another. If for any 

 reason any of the members of an affected herd are not slaughtered, 

 then they should be skilfully inoculated for protective purposes* 

 As a matter of fact, they are in nine cases out of ten neither 

 slaughtered nor inoculated, and the only result which could pos- 

 sibly be expected is that the disease breaks out again and again, 

 and so spreads and spreads like the leaven in the meal. 



One of the questions which most nearly concerns the public 

 welfare and the public health is the determination when flesh is 

 good for use as human food. There is no doubt that this point 

 is at times one of some difficulty. It is possible to be too par- 

 ticular; but it is probable that the converse mistake is more 

 usual. 



Of the terrors of trichiniasis we need not here speak. They 

 are well known. How important it is that a knowledge of science 



* With micrococci of a first cultivation a calf was inoculated by Semmer and 

 Archangelski. After seven days it died of cattle plague. If, however, animals 

 (sheep) are inoculated with later cultivations, i.e. with an attenuated virus, they 

 thereby secure an immunity against attacks of virulent cattle plague. 



