MEDIATE CONTAGION IN PLEURO-PNEUMONIA. 
71 
came from Dexter avenue, between Wood and Lincoln streets, 
and belonged to Patrick Kane. This cow had been kept alone 
in a stable, between the south branch of Chicago river and the 
canal. There is only a narrow strip of land at this place and but 
very few cows are on it. Thorough and repeated inspections of 
all the cows on this strip of land failed to discover any further 
evidences of the disease. No other affected cattle were there. 
/ 
A search through the books showed that a cow previously kept in 
that stable had died of acute lung plague on March 18, 1887, 
and owing to the lack of co-operation at that time, and the con¬ 
version of the State Commission to Dr. Gadsden’s theory, the 
stable was not disinfected. A new cow was taken in from the 
stock-yards and it was this one which contracted pleuro-pneumonia 
and died. 
I saw an equally satisfactory case of mediate contagion at 
Peoria in 1884. The plague was taken to that city by some 
cows purchased by Mr. Tripp at a sale at Virginia, Ill., on Feb¬ 
ruary 21. These cows mixed with diseased animals at Virginia, 
and one of them sickened about April 1. She was in a herd of 
thoroughbred Jerseys, and the only other herd which became 
affected in that locality was also a herd of Jerseys, located seven 
or eight miles from the first one, and belonged to Mr. Bailey. 
Now the animals in these two herds had certainly not been 
within half a mile of each other, and only one of them could have 
been that near. That one had been for a few weeks at the 
owner’s stable in the city, where she had been kept to supply the 
family with milk. This was at the time the first cases appeared 
in the other herd. The nature of the plague was not recognized 
and the local veterinarians incautiously went from the pleuro¬ 
pneumonia cases at Tripp’s stable to treat Bailey’s cow for a 
slight attack of indigestion. A month later Bailey’s cow was 
taken to his farm, seven miles away, but it was not until a second 
month had elapsed that she showed signs of lung disease. From 
her the disease extended, and was not eradicated until every ani¬ 
mal in the herd was destroyed, although every effort was made to 
check its progress by promptly isolating the sick and by disin¬ 
fection. 
