[ ^74 ] 
againft the pericardium, by the aorta, the pulmonary 
artery, and the right ventricle, all which appear to 
have been, at this time, greatly diftended beyond their 
natural bulk) mu ft have been thereby deprived of the 
fpace in the pericardium, neceffary to admit of its 
being diftended ; and the whole furcharge and d:- 
ftenfion muft, by the prefture of the pericardium on 
the auricle, neceftarily have been confined to the right 
ventricle, till it burft. 
Had thefe furcharges arifen in any other order, 
their effiedts muft have been greatly different: as for 
inftance, if the furcharge in the right ventricle had 
arifen from any other prefture, than from a diften- 
lion of the aorta, the extraordinary bulk of the 
aorta, and its prefture againft the pulmonary artery* 
would not have exifted, and the right auricle, not 
being then comprefted againft the pericardium, would 
have been at liberty to diftend, till the blood had 
made its way through its lides. 
In confirmation of this power, here attributed to 
the pericardium, of ftrengthening and fupporting its- 
contained parts, let it be obferved, that, in the cafe 
under conftderation, the place of the fifture in the 
aorta is precifely where the prefture of the pericardium 
is kept off from the aorta, to a conftderable degree, 
by the fttuation of the right auricle and the pulmonary 
artery. 
My Lord, in order to give a clear and diftindt idea 
of this very extraordinary cafe, I have here annexed 
two prints j [Vide Tab. XI. & XII.] the fir ft of 
which fhews the heart, as it appears when all its 
cavities and blood-veftels are filled with wax ; the 
ether is the fame print* having the orifice in the right 
ventricle* 
5 
