[ 2 7 T ] 
having been at the neceffary-ffool • as the office then 
required cannot be executed, but by fuch a preffure 
on all the contents of the lower belly, and, confe- 
qutntly, on the great defending artery, as mull, of 
neceffity, fubjeft the trunk of the aorta, and all its 
upper branches, to a furcharge with blood continually 
increaling, in proportion as the preffure may happen 
to be continued longer, or exerted with greater vio- 
lence, in confequence of a coffive habit, or any other , 
refinance. 
As to the fecond queffion ; viz. how it could 
happen, that the blood ffiould force its way rather 
through the fide of the ventricle than of the auricle ? 
fince it is well known, that when the ventricle is fully 
diff ended with fluids, they will eafily pafs back into 
the auricle ; fo that under fuch a diftenfion, as the' 
ventricle muff have buffered, before it burft, it fhould 
feem to have made one continued cavity with the 
auricle ; of which cavity, the auricle, being by much 
the weakeff part, muff have been the rnoff liable to 
a rupture. This certainly is the circumftance, in 
which the very great Angularity of the cafe before us 
confiffs ; and many difficulties offer againff any ob- 
vious explanation. 
Two circumftances, however, feem to throw fome 
light on this obfcure and difficult queffion. The firff 
confiffs in the texture, connexions, and capacity, of 
the pericardium ; the fecond, in the order, in which 
the feveral furcharges muff have arifen. 
The pericardium is a ffrong tendinous membrane, 
inelaffic in every direction, containing the two auricles, 
the two ventricles, and the two great arteries, as in a 
purfe : it is fixed to its contents at the back of the 
two 
