( 1^4 ) 
The Author, in order to fupport the Opinion of the 
Antients, brings feveral Arguments to confute the Sy- 
flem of Dr. Pitcairn: The inoft confiderable of which 
(and which indeed he makes his Argument um crucis) 
is, that the right Auricle and Ventricle being confider- 
ably larger than the left Auricle and Ventricle, and 
the pulmonary Artery having a larger Capacity than 
all the pulmonary Veins taken together, the Blood mull: 
evidently occupy a greater Space before than after its 
PalTage thro’ the Lungs ^ and becaufe the Difference 
in the Capacity of thefe Veffels cannot be ballanced 
by any Increafe of the Velocity, he concludes, that 
' the Blood is not attenuated and expanded, but rauft be 
condenfed in its PalTage through the Lungs. And this 
the Author conceives is done by the Air, which (as a 
Fluid relatively cold ) muft cool and condenfe the 
Blood, to which it is fo nearly applied in the Adlion 
of Infpiration. 
Had the Author of this Treatife been contented 
with fupporting the Opinion of the Antients, without 
endeavouring to fubvert the Syflem of Dr. Pitcairn , 
he would probably have found many Advocates for his 
Do6lrine, and few Oppofers. 
That the Blood is cooled by the Adion of Infpirati- 
on, is a Matter of which I believe few Phyficians 
doubt, when they conlider that in Inflammations of the 
Lungs, nothing is more earneflly defired than the 
breathing cool and frefh Air, nor does any thing more 
evidently conduce to the Cure of thefe and other Inflam- 
matory Difpofitions, than the Ufe of frefh Air. But 
that this is the foie Ufe of breathing, or that this cool- 
ing Power can over-balance the Expanfion from the 
Adion of Expiration , is what I can no ways conceive. 
- If 
