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Angular and extraordinary in itfeif j- and as the heart 
mud; have been merely paftive, and, confequently, 
there muft have been home other concurrent circum- 
ftances neceflary to produce fuch an effect ; I judged, 
at the time, when the report was drawn, that a more 
minute and exact detail would not only be expeded 
by the world, but would be highly proper, as our in- 
quiry furmfhed diffident matter. 
Two queftions naturally arile upon the face of our 
report; viz. by what means the right fide of the 
heait became lo charged with blood, as to be under 
a neceffity of burfting ? and how it could happen, 
that, as the ventricle (when under great diften lions) 
generally makes one continued cavity with the auricle, 
and is much thicker and ftronger than the auricle, 
the blood fhould, neverthelefs, force its way, by 
burfting the ventricle, rather than the auricle, feem- 
inglyin contradiction to the known property of fluids, 
to force their way, where the refiftance is leaft ? 
Upon examining the parts, we found the two great 
arteiies, (the aorta and pulmonary artery, as far as 
they are contained within the pericardium) and the 
right ventricle 01 the heart ftretched beyond their na- 
tuial ftate; and, in the trunk of the aorta, we found 
a tranfveife fillure on its inner fide, about an inch and 
half long, through which fome blood had recently 
palled, under its external coat, and formed an elevated 
echymofts. This appearance fhewed the true ftate of 
an incipient aneurifm of the aorta ; and confirmed 
the dodrine, which I had the honour to illuftrate, 
by an experiment, to the fatisfadion of the Society, 
in the Tear 1728; [See the Philosophical Tranf- 
adions, N 402.] viz. that the external coat of the 
artery 
