12 DISORDERS INCIDENT TO THE BODY THE OFFSPRING OF HEAT. 
quantity, the same intensity of heat, as the 
combustible body from which it escapes. Only 
by being carried upwards, and extending it- 
self, it has the property of communicating 
fire, and of carrying it further than the heat 
of the brazier does, which alone might not 
be sufficient to communicate it when even 
very near. This idea, though partially true, 
has been proved by expeiuraent to be subject 
to several contradictions. The flame of a 
spirit-lamp will render an iron wire white-hot, 
nor is it even in this state of so fierce a tem- 
perature as the source from whence its heat 
was obtained. 
The effects of heat in producing a noxious 
quality in the air, are well known. J'hose tor- 
rid regions under the line are always unwhole- 
some. At Senegal, the natives consider forty 
as a very advanced time of life, and generally 
die of old age at fifty. At Carthagena, m 
America, where the heat of the hottest day 
ever known in Europe is continual ; where, 
during their winter season, these dreadful 
heats are united with a continual succession 
of thunder, rain, and tempests, arising from 
their intenseness, the wan and livid com- 
plexions of the inhabitants might make 
strangers suspect that they were just reco- 
vered from some dreadful distemper : the ac- 
tions of the natives are conformable to their 
colour and in all their motions there is some- 
what relaxed and languid ; the heat of the 
climate even affects their speech, which is soft 
andslowr, and their words generally broken, 
t ravellers from Europe retain their strength 
and ruddy colour in that climate, possibly for 
three or four months, but afterwards suffer 
such decays in both, that they are no longer to 
be distinguished from the inhabitants by their 
complexiiin. However, this languid and 
spiritless existence is frequently drawled on 
sometimes even to eighty. Young persons 
are generally most a&cted by the heat of the 
climate, which spares the more aged ; but all, 
upon their arrival on the coasts, are subject 
to the same train of fatal disorders. Few 
nations have experienced the mortality of 
these coasts so much as our own : in our 
unsuccessful attack upon Carthagena, more 
than three parts of our army were destroyed 
by the climate alone ; and those that returned 
from that fatal expedition found their former 
vigour irretrievably gone. In our more for- 
tunate expedition, which gave us the Havan- 
nah, we had little reason to boast of our suc- 
cess ; instead of a third, not a fifth part of the 
army were left survivors of their victory, the 
climate being an enemy that even heroes can- 
not conquer. 
I’he distempers that thus proceed from the 
cruel malignity of those climates are many : 
that, for instance, called the Chapotonadas 
carries off a multitude of people, and ex- 
tremely thins the crews of European ships, 
whom gain tempts into those inhospitable 
regions. The nature of this distemper is but 
little known, being caused in some persons 
by cold, in others by indigestion. But its 
effects are far from being obscure ; it is ge- 
nerally fatal in three or four days : upon its 
seizing the patient it brings on what is there 
called the black vomit, which is the sad 
symptom after which none are ever found to 
recover. Some, when the vomit attacks 
them, are seized with a delirium that, were 
they not tied down they would tear themselves 
to pieces, and thus expire in the midst of this 
furious paroxysm. 1 his disorder, in milder 
climates, takes the name of the bilious fever, 
and is attended with gentler symptoms, but 
very dangerous in all. 
1 here are many other disorders incident to 
the human body thatseem the offspring ofheat: 
but to mention no other, that very lassitude, 
which prevails in all the tropical climates, 
may be considered as a disease The inhabi- 
tants of India, says a modern philosopher, 
sustain an unceasing languor from the heats 
of their climate, and are tor [dd in the midst 
of profusion. For this reason, the Great 
Disposer of nature has clothed their country 
with trees of an amazing height, whose shade 
might defend them from the beams of the sun , 
and whose continual freshness might, in some 
measure, temperate their fierceness. From 
these shades, therefore, the air receives re- 
freshing moisture, and animals a cooling pro- 
tection. The whole race of savage animals 
retire, in the midst of the day, to the very 
centre of the forest, not so much to avoid 
their enemy, man, as to find a defence against 
the raging heats of the season. This ad- 
vantage, which arises from shade in torrid 
climates. may probably afford a solution for 
that extraordinary circumstance related by 
Boyle, which he imputes to a different cause. 
In the island of 'J ernate, belonging to the 
Dutch, a place that had been long celebrated 
for its beauty and healthfulness, the clove 
trees grew in such plenty that they in some 
measure lessened their own value : for this 
reason the Dutch resolved to cut down the 
forests, and thus to raise the price of the 
commodity ; but they soon had reason to 
repent of their avarice ; for such a change 
ensued by cutting down the trees, that the 
whole island, from being healthy and delight- 
ful, having lost its charming shades, became 
extremely sickly, and has actually continued 
so to this day. Boerhaave considered heat so 
prejudicial to health, that he was never seen 
to go near a fire. 
An opposite set of calamities are the con- 
sequence in climates where the air is con- 
densed by cold. In such places all that train 
of distempers which are known to arise from 
obstructed perspiration, are very common — 
eruptions, boils, scurvy, and a loathsome 
leprosy, that covers the whole body with a 
scurf and white putrid ulcers. 'I hese disor- 
ders also are infectious ; and while they thus 
banish the patient from society, they gene- 
rally accompany him to the grave. '1 he men 
of those climates seldom attain to the age of 
fifty ; but the women, who do not lead such 
laborious lives, are found to live longer. 
One of the first things that our senses in- 
form us of is, that although the air is too fine 
for our sight it is very obvious to our touch. 
Although we cannot see the wind contained 
in a bladder, we can very readily feel its re- 
