others from enquiring fo much into the life, as the impor- 
tance ot it require. Bur tho I can't agree to that Per fpira,- 
iion^ Refiigeration^ and Refplration, which they make it the- 
Inftrument oi, yet perhaps the Air, that was inclos'd in that 
Cavity, may thro the augmentation of the Body of the Pnl- 
hs, md its own RarefuBion (which is at laft fo great as to 
occupy half the Shell) break the Membrme^ which feparated 
it from the PhUhs, and thereby give fo much Eefpiration as 
to form the chirping Voice^ which is often heard before the 
breaking of the Shell, and with it give an Addition of 
Strength to enable it to break the Shell. But how it fhou'd 
refpire fooner is to me inconceivable. 
There are many Problems of great feeming difBculty, the 
folutions of which flow naturally from what has been laid 
down here: But intending to profecute this Subjed farther, 
and to treat of the Impediments of Refpiration, and the 
Gonfequences of Refpirationobftruded or intermitted, Iffiali 
referve 'em for that opportunity, and content my felf here 
to attempt the Harveyan Problem only, which has given 
abundance of Authors fo much perplexity. 
That incomparable Philofopher enquires, Why, a Foetus, . 
taken out of the Uterus with the Membranes entire^ fldall live 
in Water fome hours without commHnication with the external 
Air whereas if it he taken out and fufercl once to breathy it 
cant afterwards furvive a moment without the benefit of K^fyi- 
ration. 
Granting the Fad to be a& he has deliver 'd it, which yet - 
is not fo in all cafes, the main difFiculty is grounded on ^ 
Miftake, which from the ftating of the Queftion I find this 
Great Man to have flipt into. For he thinks, that a Fietus 
is fooner fuffocated after having once breathe!, than if it had 
not breatlid at all, and that by breathing it had contrafted 
fomething which render'd it more perifliable. Idem tamen ^^^^ q^^^ 
fecundis exutus^ (fays he) fi femel zQXQm intra Pulmones at- -^nm. Ctp. 
traxerit, pojiea ne momentum quidem temporis abfq-^ eo durare ^^^^^^*^- 
fo^t^ fed confefiim moriatur § And prefently after, Siqnidem > 
