Louisa May Alcott - "Jo's Boys"

Dewitt H. Parker - "The Principles Of Aesthetics"

Constant - "Private Life of Napoleon Bonaparte, V3"

Ernest Scott - "Laperouse"

New Philadelphia Book Publisher Highlights Local Talent
Book and Publishing News from Publishers Newswire(tm)

Looking for Child to be on Cover of a New Book, 'The Model Child'
PHILADELPHIA, Pa. -- The Philadelphia literary world will celebrate the launch of two new players today, April 10th: Kay Square Press, a new publishing company focused on Philadelphia-area artists, their stories, and their art; and Kay Square's first release, 'With the Rich and Mighty: Emlen Etting of Philadelphia' (ISBN: 978-0-9815129-0-7), a critical biography by Kenneth C. Kaleta.

FlatSigned Press Alleges Don Imus Remarks Damage Legacy of President Gerald R. Ford
NEW YORK, N.Y. -- Nathan Yungerberg, an accomplished model scout and professional child photographer is launching a nation-wide casting call to find the cover model for his highly anticipated book release, 'The Model Child: A Parents Guide to the Child Modeling Industry' (ISBN: 978-0-9817018-0-6).

Books: The Harvard Classics Volume 38

V >> Various >> The Harvard Classics Volume 38




There are, as everyone knows, three sigmoid or semilunar valves
situated at the orifice of the pulmonary artery, which
effectually prevent the blood sent into the vessel from returning
into the cavity of the heart. Now Galen, explaining the use of
these valves, and the necessity for them, employs the following
language: [Footnote: De Usu partium, lib. vi, cap. 10] "There is
everywhere a mutual anastomosis and inosculation of the arteries
with the veins, and they severally transmit both blood and
spirit, by certain invisible and undoubtedly very narrow
passages. Now if the mouth of the pulmonary artery had stood in
like manner continually open, and nature had found no contrivance
for closing it when requisite, and opening it again, it would
have been impossible that the blood could ever have passed by the
invisible and delicate mouths, during the contractions of the
thorax, into the arteries; for all things are not alike readily
attracted or repelled; but that which is light is more readily
drawn in, the instrument being dilated, and forced out again when
it is contracted, than that which is heavy; and in like manner is
anything drawn more rapidly along an ample conduit, and again
driven forth, than it is through a narrow tube. But when the
thorax is contracted the pulmonary veins, which are in the lungs,
being driven inwardly, and powerfully compressed on every side,
immediately force out some of the spirit they contain, and at the
same time assume a certain portion of blood by those subtle
mouths, a thing that could never come to pass were the blood at
liberty to flow back into the heart through the great orifice of
the pulmonary artery. But its return through this great opening
being prevented, when it is compressed on every side, a certain
portion of it distils into the pulmonary veins by the minute
orifices mentioned." And shortly afterwards, in the next chapter,
he says: "The more the thorax contracts, the more it strives to
force out the blood, the more exactly do these membranes (viz.,
the semilunar valves) close up the mouth of the vessel, and
suffer nothing to regurgitate." The same fact he has also alluded
to in a preceding part of the tenth chapter: "Were there no
valves, a three-fold inconvenience would result, so that the
blood would then perform this lengthened course in vain; it would
flow inwards during the disastoles of the lungs and fill all
their arteries; but in the systoles, in the manner of the tide,
it would ever and anon, like the Euripus, flow backwards and
forwards by the same way, with a reciprocating motion, which
would nowise suit the blood. This, however, may seem a matter of
little moment: but if it meantime appear that the function of
respiration suffer, then I think it would be looked upon as no
trifle, etc." Shortly afterwards he says: "And then a third
inconvenience, by no means to be thought lightly of, would
follow, were the blood moved backwards during the expirations,
had not our Maker instituted those supplementary membranes. "In
the eleventh chapter he concludes: "That they (the valves) have
all a common use, and that it is to prevent regurgitation or
backward motion; each, however, having a proper function, the one
set drawing matters from the heart, and preventing their return,
the other drawing matters into the heart, and preventing their
escape from it. For nature never intended to distress the heart
with needless labour, neither to bring aught into the organ which
it had been better to have kept away, nor to take from it again
aught which it was requisite should be brought. Since, then,
there are four orifices in all, two in either ventricle, one of
these induces, the other educes." And again he says: "Farther,
since there is one vessel, which consists of a simple covering
implanted in the heart, and another which is double, extending
from it (Galen is here speaking of the right side of the heart,
but I extend his observations to the left side also), a kind of
reservoir had to be provided, to which both belonging, the blood
should be drawn in by one, and sent out by the other."

Galen adduces this argument for the transit of the blood by the
right ventricle from the vena cava into the lungs; but we can use
it with still greater propriety, merely changing the terms, for
the passage of the blood from the veins through the heart into
the arteries. From Galen, however, that great man, that father of
physicians, it clearly appears that the blood passes through the
lungs from the pulmonary artery into the minute branches of the
pulmonary veins, urged to this both by the pulses of the heart
and by the motions of the lungs and thorax; that the heart,
moreover, is incessantly receiving and expelling the blood by and
from its ventricles, as from a magazine or cistern, and for this
end it is furnished with four sets of valves, two serving for the
induction and two for the eduction of the blood, lest, like the
Euripus, it should be incommodiously sent hither and thither, or
flow back into the cavity which it should have quitted, or quit
the part where its presence was required, and so the heart might
be oppressed with labour in vain, and the office of the lungs be
interfered with. [Footnote: See the Commentary of the learned
Hofmann upon the Sixth Book of Galen, "De Usu partium," a work
which I first saw after I had written what precedes.] Finally,
our position that the blood is continually permeating from the
right to the left ventricle, from the vena cava into the aorta,
through the porosities of the lungs, plainly appears from this,
that since the blood is incessantly sent from the right ventricle
into the lungs by the pulmonary artery, and in like manner is
incessantly drawn from the lungs into the left ventricle, as
appears from what precedes and the position of the valves, it
cannot do otherwise than pass through continuously. And then, as
the blood is incessantly flowing into the right ventricle of the
heart, and is continually passed out from the left, as appears in
like manner, and as is obvious, both to sense and reason, it is
impossible that the blood can do otherwise than pass continually
from the vena cava into the aorta.

Dissection consequently shows distinctly what takes place in the
majority of animals, and indeed in all, up to the period of their
maturity; and that the same thing occurs in adults is equally
certain, both from Galen's words, and what has already been said,
only that in the former the transit is effected by open and
obvious passages, in the latter by the hidden porosities of the
lungs and the minute inosculations of vessels. It therefore
appears that, although one ventricle of the heart, the left to
wit, would suffice for the distribution of the blood over the
body, and its eduction from the vena cava, as indeed is done in
those creatures that have no lungs, nature, nevertheless, when
she ordained that the same blood should also percolate the lungs,
saw herself obliged to add the right ventricle, the pulse of
which should force the blood from the vena cava through the lungs
into the cavity of the left ventricle. In this way, it may be
said, that the right ventricle is made for the sake of the lungs,
and for the transmission of the blood through them, not for their
nutrition; for it were unreasonable to suppose that the lungs
should require so much more copious a supply of nutriment, and
that of so much purer and more spirituous a nature as coming
immediately from the ventricle of the heart, that either the
brain, with its peculiarly pure substance, or the eyes, with
their lustrous and truly admirable structure, or the flesh of the
heart itself, which is more suitably nourished by the coronary
artery.




CHAPTER VIII

OF THE QUANTITY OF BLOOD PASSING THROUGH THE HEART FROM THE VEINS
TO THE ARTERIES; AND OF THE CIRCULAR MOTION OF THE BLOOD


Thus far I have spoken of the passage of the blood from the veins
into the arteries, and of the manner in which it is transmitted
and distributed by the action of the heart; points to which some,
moved either by the authority of Galen or Columbus, or the
reasonings of others, will give in their adhesion. But what
remains to be said upon the quantity and source of the blood
which thus passes is of a character so novel and unheard-of that
I not only fear injury to myself from the envy of a few, but I
tremble lest I have mankind at large for my enemies, so much doth
wont and custom become a second nature. Doctrine once sown
strikes deep its root, and respect for antiquity influences all
men. Still the die is cast, and my trust is in my love of truth
and the candour of cultivated minds. And sooth to say, when I
surveyed my mass of evidence, whether derived from vivisections,
and my various reflections on them, or from the study of the
ventricles of the heart and the vessels that enter into and issue
from them, the symmetry and size of these conduits,--for nature
doing nothing in vain, would never have given them so large a
relative size without a purpose,--or from observing the
arrangement and intimate structure of the valves in particular,
and of the other parts of the heart in general, with many things
besides, I frequently and seriously bethought me, and long
revolved in my mind, what might be the quantity of blood which
was transmitted, in how short a time its passage might be
effected, and the like. But not finding it possible that this
could be supplied by the juices of the ingested aliment without
the veins on the one hand becoming drained, and the arteries on
the other getting ruptured through the excessive charge of blood,
unless the blood should somehow find its way from the arteries
into the veins, and so return to the right side of the heart, I
began to think whether there might not be a MOTION, AS IT WERE,
IN A CIRCLE. Now, this I afterwards found to be true; and I
finally saw that the blood, forced by the action of the left
ventricle into the arteries, was distributed to the body at
large, and its several parts, in the same manner as it is sent
through the lungs, impelled by the right ventricle into the
pulmonary artery, and that it: then passed through the veins and
along the vena cava, and so round to the left ventricle in the
manner already indicated. This motion we may be allowed to call
circular, in the same way as Aristotle says that the air and the
rain emulate the circular motion of the superior bodies; for the
moist earth, warmed by the sun, evaporates; the vapours drawn
upwards are condensed, and descending in the form of rain,
moisten the earth again. By this arrangement are generations of
living things produced; and in like manner are tempests and
meteors engendered by the circular motion, and by the approach
and recession of the sun.

And similarly does it come to pass in the body, through the
motion of the blood, that the various parts are nourished,
cherished, quickened by the warmer, more perfect, vaporous,
spirituous, and, as I may say, alimentive blood; which, on the
other hand, owing to its contact with these parts, becomes
cooled, coagulated, and so to speak effete. It then returns to
its sovereign, the heart, as if to its source, or to the inmost
home of the body, there to recover its state of excellence or
perfection. Here it renews its fluidity, natural heat, and
becomes powerful, fervid, a kind of treasury of life, and
impregnated with spirits, it might be said with balsam. Thence it
is again dispersed. All this depends on the motion and action of
the heart.

The heart, consequently, is the beginning of life; the sun of the
microcosm, even as the sun in his turn might well be designated
the heart of the world; for it is the heart by whose virtue and
pulse the blood is moved, perfected, and made nutrient, and is
preserved from corruption and coagulation; it is the household
divinity which, discharging its function, nourishes, cherishes,
quickens the whole body, and is indeed the foundation of life,
the source of all action. But of these things we shall speak more
opportunely when we come to speculate upon the final cause of
this motion of the heart.

As the blood-vessels, therefore, are the canals and agents that
transport the blood, they are of two kinds, the cava and the
aorta; and this not by reason of there being two sides of the
body, as Aristotle has it, but because of the difference of
office, not, as is commonly said, in consequence of any diversity
of structure, for in many animals, as I have said, the vein does
not differ from the artery in the thickness of its walls, but
solely in virtue of their distinct functions and uses. A vein and
an artery, both styled veins by the ancients, and that not
without reason, as Galen has remarked, for the artery is the
vessel which carries the blood from the heart to the body at
large, the vein of the present day bringing it back from the
general system to the heart; the former is the conduit from, the
latter the channel to, the heart; the latter contains the cruder,
effete blood, rendered unfit for nutrition; the former transmits
the digested, perfect, peculiarly nutritive fluid.




CHAPTER IX

THAT THERE IS A CIRCULATION OF THE BLOOD IS CONFIRMED FROM THE
FIRST PROPOSITION


But lest anyone should say that we give them words only, and make
mere specious assertions without any foundation, and desire to
innovate without sufficient cause, three points present
themselves for confirmation, which, being stated, I conceive that
the truth I contend for will follow necessarily, and appear as a
thing obvious to all. First, the blood is incessantly transmitted
by the action of the heart from the vena cava to the arteries in
such quantity that it cannot be supplied from the ingesta, and in
such a manner that the whole must very quickly pass through the
organ; second, the blood under the influence of the arterial
pulse enters and is impelled in a continuous, equable, and
incessant stream through every part and member of the body, in
much larger quantity than were sufficient for nutrition, or than
the whole mass of fluids could supply; third, the veins in like
manner return this blood incessantly to the heart from parts and
members of the body. These points proved, I conceive it will be
manifest that the blood circulates, revolves, propelled and then
returning, from the heart to the extremities, from the
extremities to the heart, and thus that it performs a kind of
circular motion.

Let us assume, either arbitrarily or from experiment, the
quantity of blood which the left ventricle of the heart will
contain when distended, to be, say, two ounces, three ounces, or
one ounce and a half--in the dead body I have found it to hold
upwards of two ounces. Let us assume further how much less the
heart will hold in the contracted than in the dilated state; and
how much blood it will project into the aorta upon each
contraction; and all the world allows that with the systole
something is always projected, a necessary consequence
demonstrated in the third chapter, and obvious from the structure
of the valves; and let us suppose as approaching the truth that
the fourth, or fifth, or sixth, or even but the eighth part of
its charge is thrown into the artery at each contraction; this
would give either half an ounce, or three drachms, or one drachm
of blood as propelled by the heart at each pulse into the aorta;
which quantity, by reason of the valves at the root of the
vessel, can by no means return into the ventricle. Now, in the
course of half an hour, the heart will have made more than one
thousand beats, in some as many as two, three, and even four
thousand. Multiplying the number of drachms propelled by the
number of pulses, we shall have either one thousand half ounces,
or one thousand times three drachms, or a like proportional
quantity of blood, according to the amount which we assume as
propelled with each stroke of the heart, sent from this organ
into the artery--a larger quantity in every case than is
contained in the whole body! In the same way, in the sheep or
dog, say but a single scruple of blood passes with each stroke of
the heart, in one half-hour we should have one thousand scruples,
or about three pounds and a half, of blood injected into the
aorta; but the body of neither animal contains above four pounds
of blood, a fact which I have myself ascertained in the case of
the sheep.

Upon this supposition, therefore, assumed merely as a ground for
reasoning, we see the whole mass of blood passing through the
heart, from the veins to the arteries, and in like manner through
the lungs.

But let it be said that this does not take place in half an hour,
but in an hour, or even in a day; any way, it is still manifest
that more blood passes through the heart in consequence of its
action, than can either be supplied by the whole of the ingesta,
or than can be contained in the veins at the same moment.

Nor can it be allowed that the heart in contracting sometimes
propels and sometimes does not propel, or at most propels but
very little, a mere nothing, or an imaginary something: all this,
indeed, has already been refuted, and is, besides, contrary both
to sense and reason. For if it be a necessary effect of the
dilatation of the heart that its ventricles become filled with
blood, it is equally so that, contracting, these cavities should
expel their contents; and this not in any trifling measure. For
neither are the conduits small, nor the contractions few in
number, but frequent, and always in some certain proportion,
whether it be a third or a sixth, or an eighth, to the total
capacity of the ventricles, so that a like proportion of blood
must be expelled, and a like proportion received with each stroke
of the heart, the capacity of the ventricle contracted always
bearing a certain relation to the capacity of the ventricle when
dilated. And since, in dilating, the ventricles cannot be
supposed to get filled with nothing, or with an imaginary
something, so in contracting they never expel nothing or aught
imaginary, but always a certain something, viz., blood, in
proportion to the amount of the contraction. Whence it is to be
concluded that if at one stroke the heart of man, the ox, or the
sheep, ejects but a single drachm of blood and there are one
thousand strokes in half an hour, in this interval there will
have been ten pounds five ounces expelled; if with each stroke
two drachms are expelled, the quantity would, of course, amount
to twenty pounds and ten ounces; if half an ounce, the quantity
would come to forty-one pounds and eight ounces; and were there
one ounce, it would be as much as eighty-three pounds and four
ounces; the whole of which, in the course of one-half hour, would
have been transfused from the veins to the arteries. The actual
quantity of blood expelled at each stroke of the heart, and the
circumstances under which it is either greater or less than
ordinary, I leave for particular determination afterwards, from
numerous observations which I have made on the subject.

Meantime this much I know, and would here proclaim to all, that
the blood is transfused at one time in larger, at another in
smaller, quantity; and that the circuit of the blood is
accomplished now more rapidly, now more slowly, according to the
temperament, age, etc., of the individual, to external and
internal circumstances, to naturals and non-naturals--sleep,
rest, food, exercise, affections of the mind, and the like. But,
supposing even the smallest quantity of blood to be passed
through the heart and the lungs with each pulsation, a vastly
greater amount would still be thrown into the arteries and whole
body than could by any possibility be supplied by the food
consumed. It could be furnished in no other way than by making a
circuit and returning.

This truth, indeed, presents itself obviously before us when we
consider what happens in the dissection of living animals; the
great artery need not be divided, but a very small branch only
(as Galen even proves in regard to man), to have the whole of the
blood in the body, as well that of the veins as of the arteries,
drained away in the course of no long time--some half-hour or
less. Butchers are well aware of the fact and can bear witness to
it; for, cutting the throat of an ox and so dividing the vessels
of the neck, in less than a quarter of an hour they have all the
vessels bloodless--the whole mass of blood has escaped. The same
thing also occasionally occurs with great rapidity in performing
amputations and removing tumors in the human subject.

Nor would this argument lose of its force, did any one say that
in killing animals in the shambles, and performing amputations,
the blood escaped in equal, if not perchance in larger quantity
by the veins than by the arteries. The contrary of this
statement, indeed, is certainly the truth; the veins, in fact,
collapsing, and being without any propelling power, and further,
because of the impediment of the valves, as I shall show
immediately, pour out but very little blood; whilst the arteries
spout it forth with force abundantly, impetuously, and as if it
were propelled by a syringe. And then the experiment is easily
tried of leaving the vein untouched and only dividing the artery
in the neck of a sheep or dog, when it will be seen with what
force, in what abundance, and how quickly, the whole blood in the
body, of the veins as well as of the arteries, is emptied. But
the arteries receive blood from the veins in no other way than by
transmission through the heart, as we have already seen; so that
if the aorta be tied at the base of the heart, and the carotid or
any other artery be opened, no one will now be surprised to find
it empty, and the veins only replete with blood.

And now the cause is manifest, why in our dissections we usually
find so large a quantity of blood in the veins, so little in the
arteries; why there is much in the right ventricle, little in the
left, which probably led the ancients to believe that the
arteries (as their name implies) contained nothing but spirits
during the life of an animal. The true cause of the difference is
perhaps this, that as there is no passage to the arteries, save
through the lungs and heart, when an animal has ceased to breathe
and the lungs to move, the blood in the pulmonary artery is
prevented from passing into the pulmonary veins, and from thence
into the left ventricle of the heart; just as we have already
seen the same transit prevented in the embryo, by the want of
movement in the lungs and the alternate opening, and shutting of
their hidden and invisible porosities and apertures. But the
heart not ceasing to act at the same precise moment as the lungs,
but surviving them and continuing to pulsate for a time, the left
ventricle and arteries go on distributing their blood to the body
at large and sending it into the veins; receiving none from the
lungs, however, they are soon exhausted, and left, as it were,
empty. But even this fact confirms our views, in no trifling
manner, seeing that it can be ascribed to no other than the cause
we have just assumed.

Moreover, it appears from this that the more frequently or
forcibly the arteries pulsate, the more speedily will the body be
exhausted of its blood during hemorrhage. Hence, also, it
happens, that in fainting fits and in states of alarm, when the
heart beats more languidly and less forcibly, hemorrhages are
diminished and arrested.

Still further, it is from this, that after death, when the heart
has ceased to beat, it is impossible, by dividing either the
jugular or femoral veins and arteries, by any effort, to force
out more than one-half of the whole mass of the blood. Neither
could the butchers ever bleed the carcass effectually did he
neglect to cut the throat of the ox which he has knocked on the
head and stunned, before the heart had ceased beating.

Finally, we are now in a condition to suspect wherefore it is
that no one has yet said anything to the purpose upon the
anastomosis of the veins and arteries, either as to where or how
it is effected, or for what purpose. I now enter upon the
investigation of the subject.




CHAPTER X

THE FIRST POSITION: OF THE QUANTITY OF BLOOD PASSING FROM THE
VEINS TO THE ARTERIES. AND THAT THERE IS A CIRCUIT OF THE BLOOD,
FREED FROM OBJECTIONS, AND FARTHER CONFIRMED BY EXPERIMENT


So far our first position is confirmed, whether the thing be
referred to calculation or to experiment and dissection, viz.,
that the blood is incessantly poured into the arteries in larger
quantities than it can be supplied by the food; so that the whole
passing over in a short space of time, it is matter of necessity
that the blood perform a circuit, that it return to whence it set
out.

But if anyone shall here object that a large quantity may pass
through and yet no necessity be found for a circulation, that all
may come from the meat and drink consumed, and quote as an
illustration the abundant supply of milk in the mammae--for a cow
will give three, four, and even seven gallons and more in a day,
and a woman two or three pints whilst nursing a child or twins,
which must manifestly be derived from the food consumed; it may
be answered that the heart by computation does as much and more
in the course of an hour or two.