MEDIATE CONTAGION IN PLEURO-PNEUMONIA. 
69 
what there is to show the spread of this plague by mediate con¬ 
tagion. Dr. F. M. Roll says in his Thierseuchen: 
“ The contagion can be spread by different and especially by 
porous objects, as by clothing worn by persons attending to dis¬ 
eased animals, by blankets used about such animals, by stable 
utensils of different kinds, by animals that have been sheltered in 
infected stables,, by straw, hay, etc., which has been stored in 
such stables. The tenacity of the plague is very great and it can 
be preserved even for months under favorable circumstances, as 
experiments have shown. Lydtin (thierarz rnitth, xi) cites a case 
of the introduction of infection by the cooled meat and lung parts 
of a diseased cow, which had been killed three or four days 
before. Twenty-five days after taking these parts into the stable 
a cow became sick, and at the autopsy it was demonstrated to be 
lung plague. A few days later a second cow, and shortly after a 
third one became affected with the disease.” 
Beeker remarks that the emanation from a burial pit in which 
the carcasses of some pleuro-pneumonia heifers were buried three 
months before, had caused the development of the disease in 
other cattle. 
It has been repeatedly proved that cattle which were kept in 
stables in which some months before animals had died of pleuro¬ 
pneumonia and which stables had not been disinfected, have con¬ 
tracted the disease. Cases are frequently reported in which the 
disease has been awakened after months by hay, straw and 
manure, which were contaminated by the secretions of affected 
cattle. 
Dictionnaire de Medecine de Chir. et d’Hygiene Yeterin- 
aires, par Hurtrel D’Arboval—rewritten by A. Zundel. Yol. III^ 
p. 93 : 
“This volatile virus is found above all in the breath of the 
animals, and this is why the disease is easily carried by people 
who have been in contact with sick beasts and whose clothes are 
impregnated with the emanations of the animals, by cow dealers, 
butchers and quacks. It has been carried by healthy animals 
which had cohabited with the sick ones and which appeared 
themselves refractory to the disease; it has been observed to be 
