382 
PATHOLOGICAL PACTS 
by cold, conveyed from place to place in garments, and 
attached to the walls of houses. How can we explain why, 
for the space of eighteen years prior to 1794, there was not 
a single instance of the vomito at Vera Cruz, though the 
concoiu'se of unacclimated Europeans and of Mexicans from 
the interior, was very considerable ; though sailors indulged 
in the same excesses with which they are still reproached; 
and though the town was not so clean as it has been since 
the year 1800 ? 
The following is the series of pathological facts, considered 
m their simplest point of view. When a great number of 
persons, born in a cold climate, arrive at the same period in 
a port of the torrid zone, not particularly dreaded by naviga- 
tors, the typhus of America begins to appear. Those per- 
sons have not had typhus during their passage ; it appears 
among them only after they have landed. Is the atmospheric 
constitution changed ? or is it that a new form of disease 
developcs itself among individuals whose susceptibility is 
highly increased ? 
The typhus soon begins to extend its ravages among other 
Europeans, born in more southern countries. If propagated 
by contagion, it seems surprising that in the towns of the 
equinoctial continent it does not attach itself to certain 
streets ; and that immediate contact* does not augment the 
danger, any more than seclusion diminishes it. The sick, 
when removed to the inland country, and especially to cooler 
and more elevated spots, to Xalapa, for instance, do not com- 
municate typhus to the inhabitants of those places, either 
because the disease is not contagious in its nature, or 
because the predisposing causes are not the same as in the 
regions of the shore. When there is a considerable lowering 
of the temperature, the epidemic usually ceases, even on the 
spot where it first appeared. It again breaks out at the ap- 
proach of the hot season, and sometimes long before ; though 
* In the oriental plague (another form of typhus characterised by 
great disorder of the lymphatic system) immediate contact is less to be 
feared than is generally thought. Larrey maintains that the tumified 
glands may be touched or cauterized without danger; but he thinks we 
ought not to risk putting on the clothes of persons attacked with the 
plague. — Alemoire sur les Maladies de l’Armce Franeoise en Egypte, 
p. 35. 
