10 ©6©6l«CC ULLPE PER’s ENGLISH PHYSICIAN, 
The pericardium, or cytis of the heart, is. a membrane encompaffing the whole 
heart, whofe pyramidal figure it hath. It is fo far diftant from the heart as is fufi- 
cient to give way for the motion of the fame, and to contain the waterifh humour. 
It has two membranes, one exterior from the mediaftinum, tied before and behind to” 
the pleura, and is fibrous ; and one interior, from the external tunicles of the veffels 
of the heart; for within the pericardium, the veflels want their common tunicle, it 
having been fpent upon the pericardium. Theoriginal therefore of the pericardium, 
is at the bafis from the tunicles which compafs the veffels of the heart, which pro. . 
ceed from the pleura. It is conneéted circularly to the mediaftinum, and the neigh. 
bouring parts, with many fibres; but efpecially to the nervous circle of the dia. 
phragma, to which it cleaves fo exceeding faft, that it cannot be feparated from it 
without rending ; whereby the motion of the heart is directed. Within this pericar- 
dium (befides the heart) is contained a ferous or watery humour, tranfparently clear, 
and in fome like water wherein flefh has been wafhed: in tafte it is neither fharp, 
falt, nor acid. It proceeds out of the veffels of the heart, ~ being a watery part of 
the blood, as lympha, and other juices, which go to their proper receptacles. The 
ule. of this juice is to cool and moiften the heart, and to make it flippery, thereby to 
facilitate its motion: alfo, that the heart, by {wimming therein, may be lefs ponde- 
rous, and not {trike againft any part. Thofe who. have this humour confumed have 
their’hearts dry; if it be in too great a quantity, it caufes a palpitation of the heart, 
and fuffocation, and death follows therefrom; if it be quite confumed, a confump- 
tion of the body happens. ms 
The heart is a mufcular body, included in the pencantiace and fituated neatly i in 
the middle of the breaft, between the lobes of the lungs ; being the primary organ of 
the circulation of the blood, and confequently of life. Its figure is nearly conic, 
~ the larger end being called its bafe, and the {maller end its apex. Its lower part is 
plane, and the upper part convex. Its fituation is nearly tranfverfe, or horizontal 5 
fo thatits bafe is in the right, and its apex, with the greateft part of its bulk, is in 
the left, fide of the thorax ; and confequently it is there that the pulfation is felt. | 
| plane furface of the heart lies on the diaphragm ; the convex one is turned up- 
mis Th heart is connetted, 1{t; by the intervention of the pericardium: with the 
iaftindm, and witha large part of the middle of the diaphragm ; this is contrived 
by nature, to prevent i its being difplaced, inverted, or turned too “rudely about, 
a confequence of the various motions of the body. 2. Its bafe is connected to its 
common vefiels: but its apex is free, and is received ina kind of cavity in the left 
lobe of the lungs. The length of the human heart is about fix fingers breadth 5 
its breadth at the bafe is about. five Seems and its circumference about shire oe 
on 
