HEAT. 
of the year, and that it ies entirely difappeared, +: leaft as an 
epidemic, as the winter has come on. A high degree of heat 
is equally inimical to it ; for it has never been bien within 
the tropics, and it difappears or mee in Egypt, as foon 
as the tropical heats come on at Midfummer. ere are cer- 
tain epidemics, therefore, which at their fpecific and re- 
{pective ranges of heat, on either fide of which they cannot 
See Edinburgh Med. and have Journal, vol. iii, 
p- pes et feq. where this letter is prin 
1X reap injrous to to the hu- 
fudden 
= 
uces fome di 
coup de foleil, as the French term it, and acute ardent fevers ; 
of the latter, are various diforders of the liver and alimentary 
|, connected with a fuperabundant fecretion of the bile ; 
and Pops difeafes of the fkin, fuch as the * prickly heat,’’ or 
ine. 
The coup de foleil, or infolation, does not appear to arife 
from the ee of the wmalphess alone, pi occurs only when 
are expofed to the direét ation of the rays of the 
n, efpecially during any ate or atties exertion. 
inte he heat of the fun’s rays, acting efpecially on the head, 
reafes the action of the bl pod-vellel, and occafions fuch a 
{tion in the brain, a 
P. f05:) : The figns which lead to this cataftrophe are a 
and his futhed ntenarice ; an univerfal languer with 
a Raesine ; fome 7 exceedingly fi fick, and have pont 
The fo is fo confufed and giddy, that the 
well as cooks, did their butinefs within doors,’ Several 
living need (See 
Kap of be none water. 
in his kitchen, digte fees Sin the floor and fifteen’ from the 
fire, the windows and doors being all open on both fides. of 
the houfe, the thermometer flood at 11 * Yet labourers 
and tradefmen worked abroad as usual ; end blackfmiths, as 
le 
indeed died fuddenly both in town and country ; ae 
the aing the at eho was healthy. 
in confequence of an obfervation, that a dog, ac- 
idewtally fhut up in a fugar-baker’s ftove, in.which the 
mercury rofe to 146°, fuddenly died, and pues rapidly 
to an extreme degree, cs fa was led to uce fome 
erroneous inferences in refpect to the effects of 
ee his Elements of Chemiflry, tom, i, 
p. 265. caufe of death, in this cafe, was doubtlefs 
the waren air a the ftove, and not the extreme heat; for 
fubfequent experiments have proved that even the human 
body 1s capable of exifting with impunity, for a confiderable 
me, ina dry atmofphere, heated feveral degrees above the 
The experiments to which .we 
Dr. George Fordyce, fir Charles 
Blawien ‘ed hom gentlemen, in the year 1774, and were 
repeated by thefe and other perfons both in London and 
in Liverpool, in the following year, ¢ an account.of 
them in the Philofophical 'T’ po vol, Ixv. pps 1145 
463, and 484. See alfo the particular detail of them ,under 
the article Animal Hear.) In the firft experiments, the heat 
of the rooms, in which they remained many minutes, was varied 
from 119’ up to 2114 that is, within one degree of the 
heat of boiling water. Dr. Dobfon and his friends at Li- 
verpool, who repeated the capcinentts ventured on the 
temperature of 224°. But in the fecond feries of trials in 
pevon flaggers ee he rape ts to walk ; and fo vehement London, the air of the apartments was heated to the enor- 
the circulation in the veflels within ‘and without the mous temperat of 260 '; and the experi no 
fronton: that he compares the Pp of the arteries to doubt that they could have fuftained a higher degree of 
the noife hammers knocking on his fkull. If, in heat without ma ience. The pulfations of the 
this cafe, the a perfon efcapes convulfions or aa _ arteries were increafed to about 1401in a minute ; the heat 
7 tal fuch a tightnefs will quickly be ived about of the body did not rife more than from three to five a ea 
as ifthat part was art ine with cords. A profound above api ufual ftate,.or 97° of Fahrenheit. Thefe high 
fleep foon enfues, during which infpiration is performed ina degrees of pent weer. much lefs difagreeable when t 
sucker fe son pues am Sse Foes one snuelopei ufual clo than when it was ex- 
re hurried, is attended naked to the pte air. ante sites oe pe 
i as. t was produc ut tion of t in 
the i Teanes cafe kept out the —— heat in a cone 
degree, yee the fame angel t peach er es t pe 0} 
2 a 
But although the human body is capable of 
thefe extremely high partes ol Sapo ay peg time 
pws, experience hewn that acontinued at- 
sg wap poms tao Sania isa dieak seeoer 
to diforder 
rete le 
canal, which 
our own 
tly occur, dependent upon the 
bid eeetiny the bile, A ee a A el el al 
soe ita egy 
of the al - 
eee 1789» 1790» “ji = "many Ina 
ops 
