(545) 
X/^/^j"/ with the point or edge of your knife. This done, put in 
your finger, and with your nail feparate the Nerve , which paffeth 
along the fide of the Pericardium toward the "fia^hragme. Then 
put inaPr^^^^ a little inverted at the end like a hook, and ap- 
prehend x}L\t Nerve y and pull it to the Orifice of the Breaft, and 
cut it off, and fow the hole up very clofe. Do the fame on the 
other fide, and prefently let the Dog loofe^ and you will plainly 
fee him draw his breath exadily like a Wind-broken Horfe : Which 
yet you will fee plainer^ if you run him a little in a firing after he 
is cut. But that any one may perform this Experiment the eafi- 
er, let him firft take notice^how the Nerves oi the Diaphragms 
pafs along on each fide of the Fericardmm in zdead Animalj be- 
fore the trial be attempted in a Living one. 
The moft obvious objervations from this Experiment, are 
1, That the whole of iJ^//>/>4^/i?;^ is quite altered. For, 
as in a/^^/^^Animal^ in Infpiration the Belly fwells by the lifting 
up the Bowels by the Contra5iion of the Diaphragme ^ and in 
Bxfpiration the Belly falls by the Relaxing of the fame : In a 
wind-broken Dog or Horfe 'tis quite contrary. For in them it is to 
be feen plainly^ that when they draw their breath, their Belly is 
drawn in very lank and fmall, and when they breath up^ their Bel- 
ly is relaxt and fwells again. 
2, It being certain, that the Lungs do not move of themfelves 
at all, but wholly depend upon the Exp an [ton of the Thorax by 
the Jntercofial Mufcles^ and the Diaphragme 'j by this Experiment 
it doth appear, how much the fmgle motion of either of them doth 
particularly contribute to Refpiration. For, zW Infpiration being 
made by the D/to^^/V;^ of the Thorax, and that Dilatation being 
caxi(edpartly by the Intercojlal Mufcles drawing up the Ribs, and 
f artly at the fame time the Diaphragme by its ContraBion draw- 
ing downward the lower fmallRibs^ to which 'tis joyned, and alfo 
lifting up the Fifcera of the lower Belly, by which they dojojntly 
make all the fpace, they can, for the Air to come in and diftend 
the Lungs: It muft hence neceflarily follow , that the Intercoflal 
Mufcles and the Diaphragme being conftituted for two diftant Em- 
ployments (though both to the fame end) and neither being able 
to perform the Office 3 where one ceafeth from it s work, 
the other for the exigence of Nature mufttake more pains to 
K k k 3 fupply 
