i6^ Amlyfts of the Air. 
weight of a Cylinder of Mercury, whofe bafe 
is commenfurate to the area of the ' 25 /^- 
yhragm,zr\A its height 2 inches, whereby the 
diaphragm muft at that time fuftain a 
weight equal to many pounds. Neither are 
its counter- afting mufcles, thofe of the 
rneUy able to exert a greater force. 
For notwithftanding a man, by ftrongly 
compreffing a quantity of air included in his 
mouth, may raife a column of Mercury in 
an inverted fyphon, to 5 or 7 inches height, 
yet he cannot with his utmoft (trainings 
raife it above 1 inches, by the contracting 
force of the mufcles of the Abdomen h 
whence we fee that our loudeft vociferations 
arc made with a force of air no greater than 
this. So that any fmall impediment in 
breathing will haften the fuffocation, which 
confifts chiefly in the falling flat of the 
lungs, occafioned by the groflhefs of the 
particles of a thick noxious air, they being 
in that floating ftate mofl: eafily attracted by 
each other : As we find in the foregoing 
experiments that fulphur and the elaftick 
repelling particles of air do: And confe- 
quently unelaftick, fulphureous, faline and 
other floating particles will moll eafily 
coalefce, 
