HORAAAR OT 
intercepting the influence of the heart, ftops the 
mite hye veffel bey ond the fituation of its application, 
That the phenomenon of the arterial pulfations is not owi 
to any contraction of the veffels is proved by the following 
.curious experiments of Bichat. * Take the arm of a dead 
fubjeét and place it in warm water ; then infert a fmall tube 
in the brachial artery, and fix its other extrenvity in the 
carotid of a large living dog. hing non the heart of the 
animal will propel the blood into the dea The artery 
pulfates lefs ftrongly indeed than in the tivinig ftate, but ora 
fufficiently to admit of the effect being felt even throu 
integuments. Mihi d the red blood is made to ‘circu ae in 
erable rapidit e latter 
fatfclont to prove we the het is the only agent by which 
the blood is made to move through the ‘arterial tubes. In 
fa& this fluid — anifog 
capillary fyftem fu 
ae of an se by fucceflive jets, 
the contractions of the heart. Now, if yor 
which you have introduced red Blood by means of a 
tibe connected with the artery of another animal, the ftream 
through the veins, becaufe the 
roniterseynedl, while it is 
hich arife from 
to a vein and an artery in fuch @ 
be introduced into 
= felotted. The It of all thefe experiments, which I 
have frequently rep site ought to have been Seale the 
converfe of their atta refult if the arteries tN Sp in 
ion 0 
tf a dog towards at eat, ad d its pote extre- 
in the crural or carotid of * nied d he direétion 
g from the heart : the heart of the firit wil ate oe 
See uce pulfation in the arteries of the fecond. If a tube, 
he bes ri a fome kind at its end, beinferted in =i 
What is felt in an evi: 
A farther binge shi the patie is piesa by the heart’s 
ation, is afforded by fome experiments of Bichat mentioned 
y fome ex 
on another occafion. ~ He expofed ‘the carotid artery and 
the heart by a fe€tion of one fide of the Chelt, in the fame 
animal ; the othet remained vof refpiration. The 
: a 
the Contractions of the heart ; but, i ina little time, the mo- 
fe anderen a co 
bestia hea art 
* tion, ae weak aay which j is the piecurfor of the total 
ceffition 
of all motion. 
nee fays the fame author, has felected, for ‘the i 
Shes ae artéries, a Some - which the vital pro- 
ion a8 thofe 
oF the BONE are remarkable teenie intenfity, are the ar- 
gle apa pofite’réafon. In this’ re 
. any inous, papers tibro- 
ems -to have 
ee 
Pink extrem 
organized the arteries in this manner,that their motions might 
not dilturb the unity of the impulfe prodaced by the heart. 
Suppofe their vital powers had refembled thofe of the in- 
teftines ; a convulfive ation of the aorta or the large trunks 
might have ftopped the circulation, and produced the moft 
alarming effects by countera¢ting the exertions of the heart. 
€ more attentively things are examined, the more peer 
fhall we be convinced of the neceflity that t Id be 
only a fingle impelling agent for the arterial pt sae and 
aa the latter, conftantly inert, fhould not have the power 
of arrefting the motions of the contained fluid.”? 
The aétion of the heart on the red blood ceafes, according 
to Bichat, in the 9d ae fyitem, where the place 
of its influence is fupplied by the tonic powers of’ ine ‘ling 
veffels. t > tebaka: the branches, and the 
divifions, ree to the aga iy ‘this 
blood is moved only by t e fm 
keeping vai d, laftly, in the gener 
pe ogee {tem as aa adtion of the veffels is the only power 
oyed 
“ The ulfe, Seetat 
extent in the firft o 
2 
3 
is only obferved in its greateft 
tubes ; 5 it is fenfibly weakened in 
n the ca aillars fy fte 
the heart 
In the fma 
- aétion is fenfibly diminifhed, cL the blood, Sivided into a 
flender 
itreams, requires, for the maintenance of i its motion, 
—_ a kind of ofcillation, or  indenhibie vibration of the 
cular. us -comparifon us the effential 
other moves them 
¢ portions, an prefides over the 
capil cect exhalation, and fecretion, Wherever 
there is a large cavity, as in the heart, ftomach, inteftines, 
&e. the former is efpecially obferved, while the fecond is 
confined to “oe cafe o' the 
ood contin it whale > an 
the firft of hete'p powers, which refides in the he 
its motion ; when it is in fmall ftreams, the in 
Pha of i veffels keeps up the movement. 
aduced by the Ualion of the Heart. 
full of blood, the im 
hoetrsye signe to the oppofite. 
nt St 2 are filled. 
cots of fae ounces, ; 
expelled by the ventricle, and fucceflivel 
eo ir ts of the arterial fyftem, ehh 
proceeds on aaa arteries being empty when 
ae heart es phan are ce es is ¢ 
a eg of 
bak the oh jf 
becaule 
