284 NATURE AND LIFE. 
are always more or fewer sick ones to be found, necessa- 
rily transport the seeds of the plague. The Crimean War 
afforded many proofs of this; on that occasion it was our © 
troops that imported the cholera into the East. The fol- 
lowing fact is peculiarly instructive: the Bosquet division, 
affected with cholera, pitched camp at Baltchick the 9th of 
August, where a great part of our squadron, till then ex- 
empt, was anchored. At the end of ten days it was at- 
tacked, and in less than a week it counted more than eight 
hundred dead in an effective force of thirteen thousand sail- 
ors. If further instances were needed, we might mention 
also the introduction of the cholera in 1865 at Guadeloupe. 
The labors of Marshal de Calvi and of a skillful surgeon in 
our navy, Pellarin, prove that the cholera was brought into 
Pointe-d-Pitre by the ship Sainte-Marie, equipped at Bor- 
deaux the 14th of September, 1865, cleared the same day for 
Matamoras, in Mexico, and touching at Pointe-a-Pitre the 
20th of the following October. 
On the whole, it is certain that the cholera travels from 
one country to another by the change of place of masses 
of human beings, which are true moving centres. It regu- 
‘ larly follows the great channels of communication, frequent- — 
ed roads, navigable rivers, etc. Whether the question is 
as to pilgrims in India, caravans in upper Asia and Eastern 
Russia, armies crossing the Caucasus, or in our Crimean 
expedition, immigrants in America, or Moslem pilgrims to 
Mecca, the conditions of transmissibility of the epidemic 
are still the same, its propagation is always more rapid 
in proportion as the means of communication are more 
speedy. 
How does a human being transport the cholera? The 
question is not completely settled. Some believe that the 
epidemic germs are planted in the organism itself, and 
there preserve their vitality. Others, as Pettenkofer, who 
has published remarkable essays on this subject, suppose 
