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 mere¹ specious² assertions without any foundation, and desire to innovate³ without sufficient cause, three points present themselves for confirmation⁴, 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 incessantly⁵ transmitted by the action of the heart from the vena cava to the arteries⁷ 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 impelled⁸ in a continuous, equable, and incessant⁶ 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 veins¹⁰ 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, revolves¹¹, propelled and then returning, from the heart to the extremities¹², 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 distended¹³, to be, say, two ounces, three ounces, or one ounce and a half — in the dead body I have found it to hold upwards¹⁴ of two ounces. Let us assume further how much less the heart will hold in the contracted than in the dilated¹⁵ state; and how much blood it will project into the aorta¹⁶ upon each contraction¹⁷; 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 artery¹⁸ 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 vessel¹⁹, 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 scruple²⁰ of blood passes with each stroke of the heart, in one half-hour we should have one thousand scruples²¹, 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 ascertained²² 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 trifling²³ measure. For neither are the conduits small, nor the contractions²⁴ 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 dilating²⁵, 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 interval²⁶ 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 transfused²⁷ 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 accomplished²⁸ now more rapidly, now more slowly, according to the temperament²⁹, 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 pulsation³⁰, 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 dissection³¹ 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 vessels³² 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 killing³³ animals in the shambles³⁴, 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, collapsing³⁵, 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 spout³⁶ it forth³⁷ with force abundantly, impetuously, and as if it were propelled by a syringe. And then the experiment is easily tried of leaving the vein⁹ 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 replete³⁸ 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 transit³⁹ prevented in the embryo⁴⁰, by the want of movement in the lungs and the alternate opening, and shutting of their hidden and invisible porosities and apertures⁴¹. But the heart not ceasing to act at the same precise moment as the lungs, but surviving them and continuing to pulsate⁴² 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 exhausted⁴³, 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 jugular⁴⁴ 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 stunned⁴⁵, 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 investigation⁴⁶ of the subject.

1 mere   

adj.纯粹的；仅仅，只不过

参考例句：

• That is a mere repetition of what you said before.那不过是重复了你以前讲的话。
• It's a mere waste of time waiting any longer.再等下去纯粹是浪费时间。

2 specious   

adj.似是而非的；adv.似是而非地

参考例句：

• Such talk is actually specious and groundless.这些话实际上毫无根据，似是而非的。
• It is unlikely that the Duke was convinced by such specious arguments.公爵不太可能相信这种似是而非的论点。

3 innovate   

v.革新，变革，创始

参考例句：

• We must innovate in order to make progress.我们必须改革以便取得进步。
• It is necessary to innovate and develop military theories.创新和发展军事理论是必要的。

4 confirmation   

n.证实，确认，批准

参考例句：

• We are waiting for confirmation of the news.我们正在等待证实那个消息。
• We need confirmation in writing before we can send your order out.给你们发送订购的货物之前，我们需要书面确认。

5 incessantly   

ad.不停地

参考例句：

• The machines roar incessantly during the hours of daylight. 机器在白天隆隆地响个不停。
• It rained incessantly for the whole two weeks. 雨不间断地下了整整两个星期。

6 incessant   

adj.不停的，连续的

参考例句：

• We have had incessant snowfall since yesterday afternoon.从昨天下午开始就持续不断地下雪。
• She is tired of his incessant demands for affection.她厌倦了他对感情的不断索取。

7 arteries   

n.动脉( artery的名词复数 )；干线，要道

参考例句：

• Even grafting new blood vessels in place of the diseased coronary arteries has been tried. 甚至移植新血管代替不健康的冠状动脉的方法都已经试过。 来自《简明英汉词典》
• This is the place where the three main arteries of West London traffic met. 这就是伦敦西部三条主要交通干线的交汇处。 来自《简明英汉词典》

8 impelled   

v.推动、推进或敦促某人做某事( impel的过去式和过去分词 )

参考例句：

• He felt impelled to investigate further. 他觉得有必要作进一步调查。
• I feel impelled to express grave doubts about the project. 我觉得不得不对这项计划深表怀疑。 来自《简明英汉词典》

9 vein   

n.血管，静脉；叶脉，纹理；情绪；vt.使成脉络

参考例句：

• The girl is not in the vein for singing today.那女孩今天没有心情唱歌。
• The doctor injects glucose into the patient's vein.医生把葡萄糖注射入病人的静脉。

10 veins   

n.纹理；矿脉( vein的名词复数 )；静脉；叶脉；纹理

参考例句：

• The blood flows from the capillaries back into the veins. 血从毛细血管流回静脉。 来自《简明英汉词典》
• I felt a pleasant glow in all my veins from the wine. 喝过酒后我浑身的血都热烘烘的，感到很舒服。 来自《简明英汉词典》

11 revolves   

v.（使）旋转( revolve的第三人称单数 )；细想

参考例句：

• The earth revolves both round the sun and on its own axis. 地球既公转又自转。 来自《现代汉英综合大词典》
• Thus a wheel revolves on its axle. 于是，轮子在轴上旋转。 来自《简明英汉词典》

12 extremities   

n.端点( extremity的名词复数 )；尽头；手和足；极窘迫的境地

参考例句：

• She was most noticeable, I thought, in respect of her extremities. 我觉得她那副穷极可怜的样子实在太惹人注目。 来自辞典例句
• Winters may be quite cool at the northwestern extremities. 西北边区的冬天也可能会相当凉。 来自辞典例句

13 distended   

v.（使）膨胀，肿胀( distend的过去式和过去分词 )

参考例句：

• starving children with huge distended bellies 鼓着浮肿肚子的挨饿儿童
• The balloon was distended. 气球已膨胀。 来自《现代英汉综合大词典》

14 upwards   

adv.向上，在更高处...以上

参考例句：

• The trend of prices is still upwards.物价的趋向是仍在上涨。
• The smoke rose straight upwards.烟一直向上升。

15 dilated   

adj.加宽的，扩大的v.（使某物）扩大，膨胀，张大( dilate的过去式和过去分词 )

参考例句：

• Her eyes dilated with fear. 她吓得瞪大了眼睛。
• The cat dilated its eyes. 猫瞪大了双眼。 来自《简明英汉词典》

16 aorta   

n.主动脉

参考例句：

• The abdominal aorta is normally smaller than the thoracic aorta.腹主动脉一般比胸主动脉小。
• Put down that jelly doughnut and look carefully at this aorta.放下手头上的东西，认真观察这张大动脉图片。

17 contraction   

n.缩略词，缩写式，害病

参考例句：

• The contraction of this muscle raises the lower arm.肌肉的收缩使前臂抬起。
• The forces of expansion are balanced by forces of contraction.扩张力和收缩力相互平衡。

18 artery   

n.干线，要道；动脉

参考例句：

• We couldn't feel the changes in the blood pressure within the artery.我们无法感觉到动脉血管内血压的变化。
• The aorta is the largest artery in the body.主动脉是人体中的最大动脉。

19 vessel   

n.船舶；容器，器皿；管，导管，血管

参考例句：

• The vessel is fully loaded with cargo for Shanghai.这艘船满载货物驶往上海。
• You should put the water into a vessel.你应该把水装入容器中。

20 scruple   

n./v.顾忌，迟疑

参考例句：

• It'seemed to her now that she could marry him without the remnant of a scruple.她觉得现在她可以跟他成婚而不需要有任何顾忌。
• He makes no scruple to tell a lie.他说起谎来无所顾忌。

21 scruples   

n.良心上的不安( scruple的名词复数 )；顾虑，顾忌v.感到于心不安，有顾忌( scruple的第三人称单数 )

参考例句：

• I overcame my moral scruples. 我抛开了道德方面的顾虑。
• I'm not ashamed of my scruples about your family. They were natural. 我并未因为对你家人的顾虑而感到羞耻。这种感觉是自然而然的。 来自疯狂英语突破英语语调

22 ascertained   

v.弄清，确定，查明( ascertain的过去式和过去分词 )

参考例句：

• The previously unidentified objects have now been definitely ascertained as being satellites. 原来所说的不明飞行物现在已证实是卫星。 来自《简明英汉词典》
• I ascertained that she was dead. 我断定她已经死了。 来自《简明英汉词典》

23 trifling   

adj.微不足道的；没什么价值的

参考例句：

• They quarreled over a trifling matter.他们为这种微不足道的事情争吵。
• So far Europe has no doubt, gained a real conveniency,though surely a very trifling one.直到现在为止,欧洲无疑地已经获得了实在的便利，不过那确是一种微不足道的便利。

24 contractions   

n.收缩( contraction的名词复数 )；缩减；缩略词；（分娩时）子宫收缩

参考例句：

• Contractions are much more common in speech than in writing. 缩略词在口语里比在书写中常见得多。 来自《简明英汉词典》
• Muscle contractions are powered by the chemical adenosine triphosphate(ATP ). 肌肉收缩是由化学物质三磷酸腺苷(ATP)提供动力的。 来自辞典例句

25 dilating   

v.（使某物）扩大，膨胀，张大( dilate的现在分词 )

参考例句：

• Compliance is the dilating extent of elastic tissue below pressure. 顺应性是指外力作用下弹性组织的可扩张性。 来自互联网
• For dilating the bearing life, bearing should keep lubricative well. 为延长轴承寿命，轴承应保持良好的润滑状态。 来自互联网

26 interval   

n.间隔，间距；幕间休息，中场休息

参考例句：

• The interval between the two trees measures 40 feet.这两棵树的间隔是40英尺。
• There was a long interval before he anwsered the telephone.隔了好久他才回了电话。

27 transfused   

v.输（血或别的液体）( transfuse的过去式和过去分词 )；渗透；使…被灌输或传达

参考例句：

• He transfused his own courage into his men. 他用自己的勇气鼓舞了士兵。 来自《现代英汉综合大词典》
• The professor transfused his enthusiasm for research into his students. 教授把自己的研究热忱移注给学生。 来自辞典例句

28 accomplished   

adj.有才艺的；有造诣的；达到了的

参考例句：

• Thanks to your help,we accomplished the task ahead of schedule.亏得你们帮忙,我们才提前完成了任务。
• Removal of excess heat is accomplished by means of a radiator.通过散热器完成多余热量的排出。

29 temperament   

n.气质，性格，性情

参考例句：

• The analysis of what kind of temperament you possess is vital.分析一下你有什么样的气质是十分重要的。
• Success often depends on temperament.成功常常取决于一个人的性格。

30 pulsation   

n.脉搏，悸动，脉动；搏动性

参考例句：

• At low frequencies, such as 10 per sec., pulsation is sensed rather than vibration. 在低频率（譬如每秒十次）时，所感觉到的是脉冲而非振动。 来自辞典例句
• If the roller pulsation, the pressure on paper as cause misregister. 如果滚子径向跳不静，则差纸的不张辛有不小有小，致使套印禁绝。 来自互联网

31 dissection   

n.分析；解剖

参考例句：

• A dissection of your argument shows several inconsistencies.对你论点作仔细分析后发现一些前后矛盾之处。
• Researchers need a growing supply of corpses for dissection.研究人员需要更多的供解剖用的尸体。

32 vessels   

n.血管( vessel的名词复数 )；船；容器；（具有特殊品质或接受特殊品质的）人

参考例句：

• The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
• All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》

33 killing   

n.巨额利润；突然赚大钱，发大财

参考例句：

• Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
• Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。

34 shambles   

n.混乱之处；废墟

参考例句：

• My room is a shambles.我房间里乱七八糟。
• The fighting reduced the city to a shambles.这场战斗使这座城市成了一片废墟。

35 collapsing   

压扁[平]，毁坏，断裂

参考例句：

• Rescuers used props to stop the roof of the tunnel collapsing. 救援人员用支柱防止隧道顶塌陷。
• The rocks were folded by collapsing into the center of the trough. 岩石由于坍陷进入凹槽的中心而发生褶皱。

36 spout   

v.喷出，涌出；滔滔不绝地讲；n.喷管；水柱

参考例句：

• Implication in folk wealth creativity and undertaking vigor spout.蕴藏于民间的财富创造力和创业活力喷涌而出。
• This acts as a spout to drain off water during a rainstorm.在暴风雨季，这东西被用作喷管来排水。

37 forth   

adv.向前；向外，往外

参考例句：

• The wind moved the trees gently back and forth.风吹得树轻轻地来回摇晃。
• He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。

38 replete   

adj.饱满的，塞满的；n.贮蜜蚁

参考例句：

• He was replete with food and drink.他吃喝得饱饱的。
• This immense space may be replete with happiness and glory.这巨大的空间可能充满了幸福和光荣。

39 transit   

n.经过，运输；vt.穿越，旋转；vi.越过

参考例句：

• His luggage was lost in transit.他的行李在运送中丢失。
• The canal can transit a total of 50 ships daily.这条运河每天能通过50条船。

40 embryo   

n.胚胎，萌芽的事物

参考例句：

• They are engaging in an embryo research.他们正在进行一项胚胎研究。
• The project was barely in embryo.该计划只是个雏形。

41 apertures   

n.孔( aperture的名词复数 )；隙缝；（照相机的）光圈；孔径

参考例句：

• These apertures restrict the amount of light that can reach the detector. 这些光阑将会限制到达探测器的光线的总量。 来自互联网
• The virtual anode formation time and propagation velocity at different pressure with different apertures are investigated. 比较了在不同气压和空心阴极孔径下虚阳极的形成时间和扩展速度。 来自互联网

42 pulsate   

v.有规律的跳动

参考例句：

• Hues of purplish,rose and amber begin to pulsate in the sky.淡紫色的、玫瑰色的和琥珀色的色调开始在天空中微微颤动起来。
• Building facades pulsate with millions of lights and glowing neon display.在千万灯光和霓虹灯的照耀下，建筑物的外墙规律地闪动着。

43 exhausted   

adj.极其疲惫的，精疲力尽的

参考例句：

• It was a long haul home and we arrived exhausted.搬运回家的这段路程特别长，到家时我们已筋疲力尽。
• Jenny was exhausted by the hustle of city life.珍妮被城市生活的忙乱弄得筋疲力尽。

44 jugular   

n.颈静脉

参考例句：

• He always goes for the jugular.他总是直奔要害而去。
• Bilateral internal jugular vein stenting is also a rare procedure.两侧内颈静脉支架置放术也是少见的技术。

45 stunned   

adj. 震惊的，惊讶的 动词stun的过去式和过去分词

参考例句：

• The fall stunned me for a moment. 那一下摔得我昏迷了片刻。
• The leaders of the Kopper Company were then stunned speechless. 科伯公司的领导们当时被惊得目瞪口呆。

46 investigation   

n.调查，调查研究

参考例句：

• In an investigation,a new fact became known, which told against him.在调查中新发现了一件对他不利的事实。
• He drew the conclusion by building on his own investigation.他根据自己的调查研究作出结论。