C 2 45 ] 
ture dill continuing, and probably increafing, more 
and more air becomes extravafate, until, as in the 
prefent cafe, the quantity becomes fo great, as not only 
to impede the coutTe of the blood through the lungs, 
but the internal preflure of the extravafate air pre- 
vents the ingrefs of a quantity of frefh air, fufficient 
to cool and attenuate the blood. In fadt, a fmall part 
only of the lungs is employed ; as the extravafate air, 
though dill in an elaftic date, anfwers by no means 
the purpofesof frefh air in refpiration j as the former, 
by its confinement in the lungs, is very foon deveded 
of its vivifying fpirit, that principle which is foon 
dedroyed in animal bodies, and which fume chemi- 
cal phyfiologids have fuppofed to be an acid nitrous 
Gas, and is mod eflential to human life. Hence, in 
a very diort time, the effedls are too obvious to be 
mentioned 3 and death mud loon follow, as hap- 
pened to the perfon, who is the fubjedt of this com- 
munication. 
I am, with all poffible regard, 
Gentlemen, 
July 6, 17^4. Your mod obedient 
Humble fervant, 
W. Watfon. 
XLIV. An 
1 
