INSECT TORMENTS 17 
act differently upon the atmosphere than soil and dust; but it will be prudent to 
make no definite assertions upon this subject. Chemistry has not yet solved any 
of the numerous mysteries of the unhealthiness of the air. It has taught us only 
that we are ignorant of many things which we thought we knew fifteen years 
ago, thanks to the ingenious dreams of the ancient eudiometry. 
“What is less uncertain, and confirmed, so to speak, by daily experiences, is 
that on the Orinoco, the Cassiquiare, the Rio Caura, and everywhere where the 
air is very unhealthy, the bite of the mosquitos increases the disposition of the 
organs to receive miasmatic impression. When during whole months one is ex- 
posed night and day to the torment of insects, the continual irritation of the 
skin causes febrile movements and depresses the functions of the stomach by 
the effect of the antagonism, so long known, between the dermal system and the 
gastric system. One begins to digest with difficulty; the inflammation of the 
skin brings about abundant perspiration ; one can not quench his thirst; and 
to his always increasing impatience follows, with persons of weak constitution, a 
condition of low spirits during which all the pathogenic causes act with force. 
Today it is not the dangers of navigation in little canoes, it is not the savage 
indians, or the serpents, the crocodiles, or the jaguars, which makes Spaniards 
fear the voyage up the Orinoco; it is, as they say naively, ‘the sweats and the 
flies’ Let us hope that man, in changing the surface of the earth, will little by 
little bring about a change in the constitution of the atmosphere. The insects 
will diminish when the old trees of the forest will have disappeared, and one 
will see in these desert countries the rivers bordered with villages, the plains 
covered with pastures and cultivated fields. 
“ Whoever has lived a long time in countries infested by mosquitos will 
have proven, as we have, that there is no radical remedy against the torment of 
insects. Indians covered with onoto, with bolary earth, or with turtle oil, 
are every instant slapping their shoulders, their sides, their legs, almost as 
though the body had not been painted. It is doubtful in general whether paint- 
ing is a relief—certainly no great relief. Europeans recently arrived on the 
Orinoco, on the Rio de la Magdalena, on the Guayaquil or the Chagres rivers (I 
mention the four rivers where the insects are the most numerous) at first cover 
the face and the hands. They soon find the heat too great, and they are tired of 
being completely inactive, and end by uncovering. Persons who do not wish to 
do any kind of work during the navigation of the rivers can bring from Europe 
an especial kind of clothing in the form of a sack under which they can rest 
hidden, opening it only every half hour. This sack should be held open by 
whalebone hoops, for a simple mask and gloves would be hardly bearable. Sleep- 
ing upon the earth, upon skins or in hammocks, we have not been able in the 
Orinoco region to use mosquito bars. A mosquito bar is useful only when it 
forms about the bed a tent so well closed that there is not the least opening by 
which a mosquito can enter. This condition is very difficult to bring about, and 
often one is forced (for example when going up the Rio de la Magdalena, where 
they travel with these mosquito bars), in order not to suffocate with heat, to get 
out from under his bar and to walk in the open air. A mild wind, smoke, and 
strong odors afford almost no relief in the places where these insects are very 
numerous and very voracious. It is wrongly stated that these little insects avoid 
the odor of the crocodile. We were horribly bitten at Bataillez on the road from 
Carthagéna des Indes to Honda, while we were dissecting a crocodile eleven 
feet long and which infected the whole atmosphere of the neighborhood. The 
indians recommend the exhalation of burnt cowdung. When the wind is very 
strong and accompanied by rain the mosquttos disappear for some time. They 
bite the most cruelly on the approach of a storm, and especially when the thunder 
is not followed by showers. 
