HEART, 
brane ; rough on the outfide from its connection by cellular 
fubftance to the furrounding parts ; and perfectly polifhed 
internally, where it is moiftened by a ferous fecretion. Its 
ftrength is fo confiderable, that although it is very much 
thinner than the aorta, it will bear a heavier weight after 
death, without being torn. 
chat di 
Bi icardium Bee ge oot of two 
membranes, a » Abrus aa a ferous The for ae arifes 
circularly from the middle of the proieaiohie cen the 
ey with which it is perfectly identified, afcends 
round the heart, which it embraces as far as t 
the moft perfeét analogy 
rather thinner. It ogy 
ed. fibres, crofling in various ’ direttio 
ted, and fometimes collected into ae ‘atcouh 
are continued below with th c fibres 
rmed of whitifh irregularly dif- 
» fometimes ifc- 
A sg 
cellular fubftance to the ‘veffels, but more clofely to the 
art. The internal furface of this, every where in con- 
taé& with itfelf, fecretes the ferous fluid of the pericardium. 
nthe whole the itive oe, to Bichat's clafs of 
fibro-ferous membranes. ompares the two portions of 
which it sang in hats atte to the heart, to the dura 
mater <3 arachnoid coat in the head. Anatomie defcrip- 
tive, tome iv. 
The ixtirie of the ecient are {mall twigs derived 
from the internal mammary, phrenic, coronary, &c.; an 
the veins join the correfponding trunks. The abforbents 
enter the glands, which lie near the aorta and fuperior 
cava. It ree eceives no nerves. 
thould be diftended much more than ufual. 
Its extenfion in hydrops pe 
bility. Befides the organic fenfibility required for the 
pofes of its nutrition, it poffe ill hi 
rm ore the depofition of fluid from 
: fe ta pean which lubricates sit oppoted fur- 
faces of of the 
‘and in this cafe its properties are often 
“Th Nicholfon's erie Benth, ok 
y Dr. 
The latter adheres by a loofe: 
fide. 
the folution was not affeted by the oxymuriate of mercury. 
efe experiments fhew that it contained albumen. When 
it was faturated with oxymuriate of mercury, infufion of 
galls produced no effect, indicating the abfence of gelatine. 
Neutral acetate of lead produced a copious siescthtakes even 
after the fluid had been boiled to drynefs, and re-diffolved in 
water. Nitrate of filver indicated the prefence of muriatic 
acid, According to thefe exp igen igs parts contein, 
Of Water 
— Albumen - 
55 
— Muriate of foda 
5 cea it ‘from the ronnie wit, and Pacing its 
motions b 
during life. 
adhefion between the ba ‘éf the caeeesaias, and c's re- 
flected portion of the membrane, without ony remarkable 
influence on the heart’s a¢tion. 
Haller particularly infitts on the effects of the pericardium,, 
in bettowing fteadinefs and. precifion on the heart 
fupport of the peric Seillon. o long as ace: ect iv 
entire, the heart i is moved ef each contraétion is fimi- 
lar to the pre motions are all executed 
within the fame limits. divided and 
removed, every thing is ieopdistahy & difturbed ; the heart 1 
its motions wanders out of its accuftomed track, and doe 
not execute two pulfations alike.”’. Elem. Phyfiol. tom. i. 
291. 
“The heart, which is the central’organ of the OF whic 
fyitems, is a ho llow mufcle, the contractions cd whic 
el th 
othe t ertain portion of the 
eek of the large b sodovelfelé connected with it, in the 
pericardium. 
The heart lies behind the fternum, and the cartilages of 
the laft true ribs on the left fide ; in front of the ceefophagus,. 
of the defcending — and of the vertebral column, above 
the diaphragm ; w the aorta and pu § 
and between the two rite which enclofe i it Pgs i on every” 
It is fixed in its fituation Se dium, —s by- 
éted. 
rtion of the aia Piege 
of fupport, the heart follows the motions of t cle. 
defcends and paffes em go aig in steretica, afcends 
and comes a se t t 
a Oe 
pe apqneurotic 
comes Side the fternumm 
When we po on 5 ae ma “ide, the heart aes eiege a 
the pe oes ae To 
iy be be 
of the’ recy can inde “fel sisting 
hanging: the attietde: oF te 
, or ap : e 
thefe iiiel ons. Yet ye “mutt 
- eae according to. 
¥ 
