THE MICROBES OF HUMAN DISEASES. 205 
Ferran’s laboratory, that the instruments and methods 
in use there were primitive and insufficient. 
Until these facts have been confirmed by other 
observers, it seems prudent to regard P. Ferrani and 
B. komma as two absolutely distinct microbes. It 
does not follow that the culture liquids employed by 
Ferran did not contain the latter, but it is probable 
that it also contained, and in larger numbers, a second 
microbe (?), which is Peronospora Ferrani. 
It may: also be observed, the injection of Ferran’s 
culture liquid into the intestines of guinea-pigs pro- 
duced no effect, while subcutaneous injections soon 
killed these animals and distinctly affected men. This 
is precisely the opposite effect to that observed by 
Nicati and Rietsch at Marseilles, and by Bochefontaine 
in Paris. 
This is a crucial difference, since it shows that 
the two microbes are not identical, and all our know- 
ledge of cholera tends to show that its microbe has 
a special action on the intestines.* 
However this may be, Ferran carried on his 
culture experiments in the endeavour to obtain an 
attenuated microbe which might serve for preventive 
inoculations. He believes that he has succeeded, and 
* The experiments made by Gibier and Van Ermengen in August, 
1885, confirm this opinion. After inoculating a certain number of 
guinea-pigs, according to Ferran’s hypodermic method, with a virulent 
culture liquid, and giving them time to recover, the same liquid was 
injected into the stomach of these animals, and they all died with the 
symptoms and lesions of cholera 
