‘ 
heart, we fee them croffing irregularly i 
HEART. 
becomes weaker, aad ceafes altogether at the time of deat 
fo that it is the offspring and attendant of. the vital powers, 
* yitz filia viriumque.animalium,”’ in the lan wage o of Hal- 
The contraétion of the heart Sabet in which the 
fides are approximated fo as to efface 
ie 
af 
enerally aa asa sin {late ; gee Haller ‘uischies it 
completely with the condition of the organ after death, ob- 
ferving that the only difference is, that the cavities are full 
inthe one cafe and empty in the other. « Hoc alteram 
cordis ftadium in vivo ani: aa Sra requies, in cadavere 
mortis et inertie ftatus e uments adduced in the 
oe paragraph render it oath ul how far this is true, 
and lea 
con sower 3 at all 
events, we fhall not be likely to admit that the flate of the 
living heart between two contraétions is the fame. with that 
of the a — death. The contraction then muft be 
regarded as the mott active part of the nomena ; the di- 
latation baring, for its object only the production of new 
contractions. 
In whatever part we obferve the mufcular fibres of the 
in all direétions, 
decuffation, apparent at firft fighti in the right auricle, 
where the ‘mufeular fafcicul i 
areal they &, is rendered onic by the aid ae 
Sifihion in the a pa ance of the parietes both of the ven- 
3 and of the left auricle. Hence we infer that the 
cavities are contracted, and equally diminifhed in fize in all 
ions at once. Bu ommon feptum feparatés the 
auricles and a common feptum separates the ventricles. 
Thefe - wipleeaaame to each other, are e 
throu 
th ry veins at the 
left ; uently, the two ventricles are filled at the fame 
iaftant. Hence the two auricles contraét together, and t 
two ventricles contract Sh ie in the next period of time. 
In both cavities the blood is preffed from all Nides, and with 
an equal force fre ges the common feptum; which cannot 
be carried towards one fide or the other, but remains motion- 
lefs, and e ] tion of its breadth. Thus, 
the firtt firtt remarkable fad exhibited to us in the motions of 
the heart taken altogether, is, that the proper parts of the 
rat ae a ued pu. to their common part, which is the cen- 
2p hs 
ontractions of po —— 8 are oO) 
eck. ahd external fibre: 
traction. here the powe 
not been exbauRed. the whole of each ventricle is contracted 
at once 3 and the circumference approaches to the feptum. 
a 
At the fame time ai apex is attracted towards the bafis, 
orter and more obtufe, and is flightly turned 
liter a sate avary Be the whole heart i is posagab 
ait 
compared to cathe oGerrer tee 
. ek with which septs are ae beak 3 oS dies refpedctive 
Atuations, a opening the it will. be feen that the 
feptum is rendered fhorter ; and that the columns attached 
the valves are fhortened, and bro rought nearer ~ ~ 
auricular epenings, fo that the tendinous’ threads 
laxed. 
o 
5 
_ The heart does not undergo merely a change of Sasi 
in its fyftole, but is alfo tnd in its fituation ; 3—ex perienc 
a general locomotion. Th € apex, in a ek to the bafis, 
ILATION. 
In the contra&tion of the right auricle all its dimenfions 
are reduced. The r portion is sa € e 
preffed_ towards the’ heart ; and the 
the ah This is the reverfe of what happen in the ven 
ticles, where the motion is from below upwards. e 
of the cavity is drawn towards the left, and ca 
thinfete diameter rece reg diminifhed. The fam 
pheno 
the diameters of the cardiac cavities are reduced 
in the taco ve of the organ 
behind, and eaatecsole Sac, vag fourd i in ve eee 
after death, aller reed 
animal me whole contents are driven 
excite a conftant exertion of i ‘eats which 
vent the accuftomed i et from taking “ally = For a8 ‘ 
{malleft mein of froth produces an foceleak contraction 
a fi 
of the heart in a frog; and when e spear cngheligia J 
animal we » as complete poffible, by prei- 
fure, the {mall quantity left behind prevented the heart 
refting. In cold blooded animals t 
/ e 
in its fyftole, which could not happen, unlefs the red bed 
were completely expelled. The auricles too of 
ed animals, which are of a violet colour, on account of their- 
thinnefs, when di diftended with blood, are pale and colourlefs - 
when cont ily, fays Haller, in numerous ex-- 
periments on the incubated chick, where the blood is in- 
tenfely rey I seer found that it was fo completely. 
expelled from e and pellucid heart, that the organ . 
rem: i 
In Schering ts the facie of the heart, we may be c contidaalds 
a pans ge ign ark in the latter an oppofite: 
“The wrinkles of the: 
— are a gt -and p. sage viele; sitens. becomes Sarthe, level, . 
and foft: it is extended into a greater length, ‘the bafis” 
retreating from the apex, and the apex from the bafis, and 
at the fame time turning backwards, and to the le. c= 
