THE MICROBE OF PLEURO-PNEUMONIA. 
385 
Cow No. j, received October 8th, i c.c. of a fifth culture 
in bag, representing a dilution to 1-40,000,000 of the serosity 
collected July 19. 
This animal presented nothing abnormal up to October 21 ; 
22d, there was at the point of inoculation, a hard, painful swell¬ 
ing, as big as a nut; 23d, the nodosity is surrounded by a quite 
large, soft oedema, the temperature is 39.2" ; 24th, the swelling 
is as wide as the palm of the hand, tense, warm and painful; 
26th, the swelling, always very tender, has increased, tempera¬ 
ture 39.6° ; this condition remains statiouaiy during the follow¬ 
ing days, then all diminishes, is resorbed, the temperature 
returns to normal; 31st, all is normal. 
* 
* * 
If the accidents observed in cows No. 2 and 3, after the 
inoculation of cultures in collodion bags, were truly of pleuro- 
pneumonic nature, these animals must have become immu¬ 
nized against the natural disease and against the inoculation 
of the virulent solution. The proof was necessary. The fol¬ 
lowing experiment confirms it: 
