102 MICRO-ORGANISMS IN RELATION TO MAN, 
A further experiment was made to ascertain if it was 
possible to restore to health a fowl so inoculated by again 
increasing the temperature. A hen was inoculated, and sub- 
jected, like the first, to the cold water treatment ; and when it 
became evident that the fever was at its height it was taken 
out of the water, carefully wrapped in cotton wool, and placed 
in a chamber at a temperature of 95° F. Little by little its 
strength returned; it shook itself, settled itself again, and 
in a few hours was fully restored to health. The organism 
was conquered, and fowls killed after having been thus 
treated, showed not the slightest trace of splenic organisms. 
This experiment has been given at some length because it 
illustrates a point which I wish to emphasise in connection 
with the relationship between micro-organisms and disease. 
This is, the absolute necessity that before any organism is 
credited with the production of any particular disease, not only 
must the organism in question be isolated from the tissues or 
fluids of the animal affected, but it must also be possible to 
produce in healthy animals of the same species, the same 
disease by means of pure cultures of the organism, grown 
outside the body. 
During the past summer, we constantly read in the daily 
papers statements to the effect that suspicious cases of cholera 
had occurred in various parts of England, and that the dejecta 
had been submitted to experts to pronounce upon the correct- 
ness or otherwise of the diagnosis. On this account and by 
reason of its general interest I have considered that no more 
appropriate example could be taken of the relations between a 
special bacillus and a special disease, and the manner in 
which this relationship is established, than that afforded by 
Koch’s discovery of the comma bacillus in cases of Asiatic 
cholera, and its relationship to that disease. Since cholera 
appeared in this country in the great epidemic of 1832, great 
attention has been paid to the phenomena connected with it. 
One of the results of this has been to establish the fact that 
