[ 486 ] 
examining it in the room, was found to beat at the rate 
of 1 44 pulfations in a minute, which is more than dou- 
ble its ordinary quicknefs. To this circumflance the op- 
preffion on my breath muft be partly imputed, the blood 
being forced into my lungs quicker than it could pafs 
through them ; and hence it may very reafonably be con- 
jectured, that fliould an heat of this kind ever be pulhed 
fo far as to prove fatal, it will be found to have killed by 
an accumulation of blood in the lungs, or fome other 
immediate effeCt of an accelerated circulation (<>) ; for all 
the experiments drew, that heating the air does not make 
it unfit for refpiration, communicating to it no noxious 
quality except a power of irritating. In the courfe of 
this experiment, and others of the fame kind by feveral 
of the gentlemen prefent, fome circumftances occurred to 
us which had not been remarked before. The heat, as 
might have been expeCled, felt mofl intenfe when we 
were in motion ; and, on the fame principle, a blaft of 
the heated air from a pair of bellows was fcarcely to be 
born ; the fenfation in both thele cafes exaClly refembled 
that felt in our noftrils on infpiration. The reafon is ob^ 
vious; when the fame air remained for any time in contaCl 
with our bodies, part of its heat was deftroyed, and con- 
fequently, we came to be furrounded with a cooler me- 
dium than the common air of the room ; whereas when 
(b) Since this experiment, I have obferved the mucus froin my lungs to be 
more ferous than before, and to incline more to a faltifb tafte, though the . lungs 
themfelves feem perfectly found in all other refpefts; Which raifes a fufpicion 
thatfomeof the fmaller arteries fuifered a degree of dilatation from the increafed 
iropulfe of the bloods 
frefli 
