264 CONTAGIOUS DISEASES OF DOMESTICATED ANIMALS. 



the disease to the herd by person or foiiiites, or introduced it by inocu- 

 lation. If thi' latter, it woukl seem to support the hypothesis of some^ 

 who, while admitting that the introduction of the virus ino a muscle, 

 instead of by the breath or into the lun<>', generally causes a milder dis- 

 ease, which is protective, yet that occasionally, under conditions not yet 

 known, it will resume its malignant activity and light ui)on the organ 

 which seems to afford Hs chosen nidus. It seems somewhat analogous 

 to the old facts as to the inoculation for sm 11-pox, in which undoubtedly 

 the introduction of the virus into the skin or Hesh instead of into the lung 

 did modify and mitigate the diseas*'. But in this it was a known fact 

 that now and then a strange exception wouM occur, resulting in second- 

 ary fever and death. While single cases prove but little, and the mind 

 must suspend its judgment until other cases occur, or until the occur- 

 rence is explained, it must be confessed that these cases were a re- 

 straint upon what had b fore seemed to us to be legitimate conclusions. 

 The great asserted facts upon which the more recent hopes as to in- 

 oculation of cattle have been predicated are (a) that the virus thus intro- 

 duced never causes any affection of the lung, and {b) that the animal 

 that has been inoculated does not impart the disease to others. 



In view of the immense interests involved, this Government should 

 institute a series of experiments to settle this matter, and either arrive 

 at the conclusion that systematic and rational extinction of the disease 

 is to be secured by slaughter, or define how it can be aided or secured, 

 if at all, by systems of regulated inoculation. Since the important ex- 

 periments and deductions of Pasteur, Chauveau, Touissant, Koch, and 

 many others, it seems almost imperative that, this Government should, 

 by systematized methods of histology, pathology, and laboratory inves- 

 tigations, aud by the experience of skilled observers, determine the 

 means of checking those marauding epizootics that imperil the health 

 and life of so many millions of animals of various species, and with it 

 imperil the industrial interests of all classes and the very life and 

 health of a race so dependent on good meat and good milk for food. 



FOOT AND-MOUTH DISEASE. 



We are fortunately dependent on foreign authorities for the most 

 accurate descriptions of this disease. Unlike pleuro-pueumonia, it is 

 readily communicable "to sheep, goats, swine, and i^oultry; it is easily 

 transmitted to the human subject. It has been described as existing 

 in the horse, dog, wild fowl, deer, wild boar, cat, «Sic." The milk of 

 animals in many cases seems to have conveyed the disease to man, al- 

 though some regard this as having occurred only when there were vesi- 

 cles upon the udder or teats, the secretions from which had mingled 

 with the milk. (Walley, Edinburgh, 1870.) The same author also 

 speaks of it as "one of the most infectious and contagious maladies 

 which affect domestic animals, and the easiest of transmission," and as 

 remarkable "in the effect which the milk of animals affected with it 



