VOL. LII.] PHILOSOPHICAL TftANSACTIONS. 587 



of the blood-vessels bears a general proportion to the size and capacity of the 

 heart itself. Very few anatomists, in describing this organ, have estimated its 

 size by its weight. Dr. Haller, where he treats so amply and professedly on 

 the heart, does not, from his own knowledge, mention its weight. From 

 Tabor, he says, it is estimated at 10 oz; but this is supposed to be when freed 

 from the auricles, as well as the extremities of the larger vessels. Its mean 

 weight by some other anatomists is reckoned at 13 oz. ^ 



Aneurisms of the heart, both with and without polypose concretions, are not 

 unfrequent; many instances occur in the writers of observations. Dr. Douglas 

 saw a young man, who died of a palpitation of the heart, the left ventricle of 

 which was found 3 times larger than the right. This case bears considerable 

 analogy to the instance before us; and is quoted, among several others, by the 

 Baron Van Swieten, in treating on aneurisms of the heart. The baron also re- 

 lates a case from Lancisi, in which the left ventricle was twice as large as the 

 right, and the whole heart weighed 24- lb. Hoffman, in his Systema, when 

 treating on the palpitation of the heart, gives us a case, where the heart was 

 greatly distended ; but he does not ascertain to what degree by any method what- 

 ever; he only says, cor mirae fuit magnitudinis. 



De Haen, in his Ratio Medendi, tells us he was present at the opening of a 

 man, whose heart was 3 times larger at least than in its natural state. The di- 

 latation was in its left ventricle, which was so thin as to resemble a whitish mem- 

 brane only; and the heart was broader at its apex than at its base. 



De Haen likewise, in his Ratio Medendi, informs us that the heart of a 

 woman, who died of a fever, with extreme debility, weighed 24 oz., even after 

 it was washed, and wiped very dry. This increased weight and magnitude arose 

 more particularly from the left ventricle. The extension of the ventricles was so 

 great, that they both together contained more than a quart. Though tliis 

 woman was no more than 37 years of age, the aorta at its base was degenerated 

 mto bone, and was 4 inches in circumference. Besides the whole portion of the 

 aorta at its base being ossified, there were interspersed in several parts of its 

 length, what our author calls insulae osseae. In one who lived so long as the 

 excellent Wepfer, such appearances are not extraordinary; but in one so little 

 advanced as the woman in question, these ossifications are very unusual. 



It would be endless to quote instances of the preternatural dilatation of this 

 organ : to name no more, we have a very recent and striking one of this kind, 

 in the body of our late most gracious sovereign, whose sudden death was owing 

 to the rupture of the right ventricle of the heart ; a circumstance which cannot 

 be conceived to have taken place without a previous gradual dilatation of the 

 same, and that probably to a very considerable degree. 



In cases of this kind, commonly one of the ventricles is found distended to a 



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