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F E M A L E E D U C A TI O N.—No. I. ADDRESSED CHIEFLY TO THE YOUNG WOMEN OF THE OPERATIVE CLASSES.

By ELIZA METEYARD.

In the hope that I may do something towards the improvement of young women employed in factories, warehouses, shops, or at home in useful labours, I have undertaken to write this series of little papers. They will not refer so much to reading and writing, or grammar or accounts, as to such things as habits, manners, personal cleanliness, neatness and taste in dress, household management, and the care of children, which, though not classed under the name of education, are real proofs of it when practised, and of ignorance when neglected. On many of these points, particularly on those of taste and arrangement in dress, manners and deportment, nicety and elegance in homes, however humble, and to simple beauty brought from fields and woods for their adornment, too little has been written, and of that little nothing whatever has been addressed to the operative classes. It is, therefore, with some pride, and much pleasure, that I shall undertake this peculiar and novel portion of my task; and if thereby I shall be enabled to add one grace to humble life, I shall be fully rewarded: for it will expand itself, and lead to the cultivation of others, and thus fill up the blank of one of our great social needs—the power to recogmise, make use of, bring into alliance with common daily life things of grace and beauty, by those connected, however humbly, with the operative arts of the country. This has been long a need. We have too long forgotten that the things and circumstances which surround the individual, and constitute his daily life, form him and make him what he is. The intellectual classes are so well aware of this as to regard with watchful though unobtrusive care each act, each circumstance and moment, in the lives of their children; and this, as seen in its result, constitutes, more perhaps than any mere book knowledge, the vast difference which exists between the several classes of society. For I quite deny that refinement, politeness, good habits, taste in dress, or general superiority, need be, or is, the especial privilege of any class. I do not for a moment think that a man has less cause to be refined, though he work with his hands for his bread, or a young woman less tasteful in dress, or admirable in manners, though she pass two-thirds of each week beside the power-loom, or in the warehouse or shop. Butlet me be understood. I mean nothing affected, assuming, or vain, or in that sense which often makes the refinement and gentility of the upper classes ridiculous in the eyes of the thoughtful and sober; but in their true worth and real meaning— that of man or woman striving to perform all duties connected with a good life in the most cheerful, truest, best, and noblest manner. A king or a duke, a queen or a countess, can donomore; and, apart from the advantages which fortune, position, and education confer, the best of the graceful acts of life lie open for all to attain to and practice. It is from my belief that the operative classes of this country are making, and are destined to make, great advances in this direction, that I have been chiefly led to hold the young women of this class in view in writing these little papers; for, connected with labour which is not strictly servile, and of a kind often bearing a close relation to the most beautiful of the useful arts—trained by this very labour into a method which is not without its value, and possessing the immense advantage of some hours each day of independent leisure—I think the power is theirs, through self-improvement of not only adding to their own well-being, but immensely to that of those around them. For, if we but stay a moment, we see how much Divine Providence, through the agency of great improvements and discoveries, has given, and is giving, of beauty WOL. I.

and utility to the common people. The art of printing, travelling by steam, the discovery of plating metal by electricity, the wonderful improvements in pottery, the weaving and printing of cotton, the application of gutta percha to useful and ornamental purposes, are advances in the useful and beautiful arts which have brought refinement and all its innumerable consequences to the doors of the very humblest. And these things, like a chariot's ceaseless wheels, are rolling onward in their own grand way. A few years hence, and the working classes will, as a general rule, have better houses, and reap from their use all the advantages of such an accommodation. Still further improvements in the plating process I have spoken of, in pottery, in glass, and in many similar things, will give, and this cheaply, more comforts, elegancies, and luxuries to humble homes than two hundred years ago could be found in the halls of nobles or the palaces of kings. And it is that they may learn to use and to appreciate these advantages that I address myself to those on whom depends the future well-being of these homes, and the children that will be nursed and reared therein. For I have unbounded faith in what a woman, however humble, can do for the improvement of home. On her acts and care depend, in a great degree, whether it is peaceful or riotous, sordid or thrifty, dirty or clean; and when we consider for a moment the effect of these for good or evil upon husband and children, we see this tremendous moral responsibility of woman in its true light. But the beginning of many improvements that will, I foresee, in another generation, greatly alter the mental, moral, and social condition of the working classes of this country, will be made principally by young women before the time of marriage. That ceremony does not bestow sudden virtues, though it does a husband; and a girl that has been in her unmarried state dirty, thriftless goesiping, and evil-tongued, has little prospect of either making a Lappy home or rearing good and intelligent children. But if she is otherwise, a new world opens itself to her offspring; for the moral worth and virtues thus fostered raise them as it were into a new class and condition of society, and the labour of the country is advanced by a new intelligence brought to bear upon it in countless beneficial directions. This growth in refinement, manners, and education, on the part of the women of the operative classes is, I believe, one of the greatest needs of the time. The beginning, made at home, lies at the root of all social progress, as without it the general worth and intelligence of husbands and brothers lose half their value; but with it all the many advantages which men have beyond women in regard to association, and the sort of public education which naturally arises therefrom, goes home with them, and has there a value of its own. I think I need say little more on the immense importance of education and self-improvement to young women. Their intelligence in the humbler walks of life will go far to preserving the lives of two-thirds of the children that die under the age of five years—to rearing them in a way which shall insure straight limbs and sound bodies—to laying, through words of advice and good example, some of the nobler and brighter virtues of our being—to investing home with a cleanliness, order, and purity in act, of themselves lessons of priceless value, and in cases where womanly intelligence is of a higher kind, adding to these other lessons whereby great talents may be fostered, and through which a long generation shall be benefited and the country proud. Nay, more; let women make but homes as they should be, and half the inducements of the pot-house and the skittle-ground will cease to attract; let her aim at comeliness of person, and a self-respect in apparel and behaviour, and half the licentiousness complained of in the newspapers and in Parliament will pass away, and make the simple virtues of the people what they have always been, and always will be, the surest foundation of order and moral advance in the state. And where marriage is not the case, a self-improved intelligence will give woman the power to seek, through emigration, or through a change of work higher in its kind and better remunerated, means of a self-advance, which no laws or philanthropic associations can give, though they found Needlewomen's

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if the question were asked what is the difference between 12 apples and 5 pears? the answer would plainly be, we cannotte‘s; it is is irossible to answer this question as to tell the cock's name when the dimensions of the kitehem only are given. It is true that the difference between 12 and 7 is 5; but 5 is to answer to the question. Inlike manner, it is equally impossible to find the difference between units and teas, tens and hundreds, hundreds and thousands, &c., while we keep them in the same name: but if we reduce the tens into units, we ean then take units from them: if we reduce hundreds intoters, we can then take tens from them; and soon, whatever be the difference in the ranks of the numbers. On the above principle, therefore, we have the following rule for the subtraction of numbers consisting of several ranks and periods. Ruiz.-Arrange the number to be subtracted (which is called the subtrahemd), under the number from which it is to be taken (which is called the ody, in the same manner as numbers which are to be added together (see rule of simple addition, page 55, 2nd-col. No.IV.) Then draw a line under the subtrahend, and beginning at the units col subtract the units' figure in the subtrahend from the units figure in the minuend, and place the difference under the line in its proper column or place of units; and proceed to do the same with the figures in the column of tens. If the **:::::::::::::: minued be the same as that in or num or otrahend, their difference is 0, and, therefore, a ci is put in the place of units. But if the figure in the units column of the upper number or *d, be less than the figure in the same place in the lorer number or or. add ten units to the former, and then perform the

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Diore--e -o-o: More of OFäsariox. Here, beginning with the figures in the units' place, you say, 1 from *, ardo remains, and put the diference (6) under the lire in the place of units: then proceeding to the figuresin the tens' place, you say? from 8, and 5 remains, and put the difference (6) under the line in the place of tens; and in like manner proceed to hundreds, thousands, tens of thousands, &c., of down the differences in their respective places, until the whole difference be obtained. In the places of hundreds of thousands and millions in this example the differences are nothing, - ciphers are put in these places in order that the other may be in their own places, and that the want of figures in these may be properly indicated. The whole difference here between the two given numbers is two hundred ard twenty millions, twenty-four thousand, six hundred and sixty-six. ExAMPLE 2.-Find the difference between 101010101010 and 4268.010237.

Minuend 101010101010 Subtrabeni 4258010-37 Difference 95.742.099773

Mone of OPERATIox.

Here, beginning with the figures in the units' place, as before, you find that the units' figure in the upper number is 0, and that in the lower number is 7; therefore, borrowing 10 (which is equivalent to 1 in the tens' place), you say 7 from 10, and 3 remains, and put the difference (3) under the line in the units place. Then, arrying 1 to 3, the tens' figure in the lower number, and adding it, which makes 4 tens, you Sorrow 10, and add it to 1, the tens' figure in the upper number, which makes ll tens, and say 4 from ll, and 7 remains; and you put the difference (7) under the line in the place of tens. Again, remembering that the 10 which was last Borrowed was ten tons, or a hundred, you carry one to 2, the hundreds' in the lower number, and add it, which makes 3; you then borrow 10, subtract 3 from it (as there is a cipher, or nothing, in this place, in the upper number), and put the difference (7) under the line in the place of hundreds. Now, remembering that the 10 which was jost borrowed was ten hundreds, or a thousand, you carry 1 to 0, the thousands' in the lower number, which makes but 1, and subtract this 1 from 1, the thousands' figure in the upper number; the difference being nothing, you put a ci , or 0, in the place of thousands below the line. As you did not borrow 10 in the last step of the operation, of course you do not carry 1 this time, to the next place of figures in the lower number, but continue the subtraction as at first.

Here, a practical suggestion may be given as to the easiest mode of carrying on this - all cases where the figure, in any rank or place of the minuend, is less than the corresponding figure in the subtrahend, without formally, or even mentally, adding 10 (that is, technically, borrowing 10), just read the figure as if 1 stood on the left of it, and subtract the corresponding figure in the subtrahend at once. Then, without formally or even mentally adding 1 (that is, §: cally, carrying 1), to the next figure on the left in the subtrahend, just read it as if it were the next higher figure in order, and subtract as before. Thus, continuing the operation in the preceding example, from the place where it was stopt above, say 1 from 10, and 9 remains; 1 from 1, and 0; 8 from 10,

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1 from 10, and 9; putting down these remainders in their

roper places as fast as they are uttered. In all this operation, o never forget the principle, that in consequence of the tenfold manner of increase in the value of the digits or figures, according to the decimal scale of notation, to borrow 10 in any #. of the minuend, and to carry 1 to the nect higher figure of the subtrahend, is just the same thing as to increase both numbers by 10 in the rank or place denoted by that figure of the minuend; and that this operation does not alter the value of the difference, while it renders the process of subtraction as easy as it could be made on o other principle.

#, the general rule, it may be of use to add this direction: that when there are fewer figures in the subtrahend than in the minuend, the process of subtraction must be continued to the highest figure in the minuend, just as if ciphers, were placed under each of its figures, where there are none in the subtrahend.

PRoof of SUBTRAction.

The best and the easiest proof of subtraction is to add the difference to the subtrahend, and if the operation is correct, the sum of these two numbers must be equal to the minuend. The principle of this method of proof is self-evident; for, if the àifference between two numbers be added to the less number, the sum is equal to the greater humber. An ingenious method of provin subtraction by casting out the nines, as it is called, was supplie by a correspondent, and inserted in No. IV.,. page 64. The principles on which the four common rules of arithmetic are proved by casting out the nines, will be explained in a future number. In connexion with the rules of Addition and Subtraction, there are two very useful theorems, which we subjoin for the advantage and practice of our readers. Take any two numbers, say 12 and 8, and find their sum and difference, namely, 20 and 4. Now observe, that if we add 20 and 4, we have 24, or twice the greater number, 12; and if subtract 4 from 20, we have 16, or twice the smaller number. Now these results would take place with any two numbers; and in order to satisfy yourself, try as many pairs as you please; but choose even numbers to avoid the trouble of fractions at present. The general theorems deducible from these invariable results, are– 1. –If the sum of any two numbers be added to their difference, the result is double the greater number. 2.—If the difference of any two numbers be subtracted from their sum, the result is double the smaller number. ExAMPLE:—The sum of two numbers is 1050, and their difference is 428, what are the numbers ? Here, 1050-1-428–1478, which is the double of 739; therefore 739 is the greater number. Again, 1050–428–622, which is the double of 311; therefore 311 is the less number. Paoor. 739-1-311=1050, the sum; and 739–311=428, the difference. ExERCISE.-At an election, the whole number of voters was 9068, and the successful candidate had a majority of 2734: how many persons voted for each candidate : We now proceed to give a few questions for exercise,

Questions Fort Exercise on THE PREcept.NG Lesson.

1. Subtract 12345678 from 123456789. 2. Subtract 1123344567 from 2468759768. 3. Find the difference between every two successive numbers in the square contained in question 6, on the Rule of Simple Addition, page 58, No. III., taking care always to place the larger number uppermost—that is, for the minuend. 4.—Find the difference between a million and a thousand and one * 5.—From 4850902 subtract 98.998; from the remainder subtract the same number; and from every successive remainder, subtract the same number, until a remainder at last be obtained from which it cannot be subtracted ; and then, tell how many times the subtraction has been performed. 6. What is the difference between a hundred thousand and ten millions one thousand, and a hundred millions ten thousand and one? 7. 1000000000–123456789; and, 142857142857–42857142858?

LESSONS IN PHYSIOLOGY..—No. III. M. A. N.

Do you think that you are now so familiar with the bones and
e muscles as to be ready for a third lesson If so, then we
are now going to take up a very interesting subject. It is the
circulation of the blood. The building up of every part of
the body is dependent on the material derived from the blood;
and to find out how this precious fluid is conveyed to every
*; is the object of the present lesson.
or this circulation the most beautiful provision has
been made in the heart, the arteries, the veins, and the
lungs. Some idea of the arrangement and connexion of
those various parts may be obtained from the engraving.

REPRESENTATION of THE HUMAN HEART, vessels, AND LUNgs.

A Wena cava ascendens. G. Left auricle.
B. Vena cava descendens. H. Left ventricle,
C Right auricle. I Aorta ascendens
D Right ventricle. and branches.
E Pulmonary artery. K Coronary arteries.
F Pulmonary veins.

The heart is divided into the right and the left sides; and each of these two sides is composed of two cavities, with muscular walls. These cavities are placed one above the other, and communicate the one with the other by means of a large opening. The superior cavity, which is called the auricle from its resemblance to the ear in shape, and whose walls are thinner and of a globular form, is in communication with a number of veins; while the inferior cavity, which is called the ventricle, from its sac or pouch-like appearance, and whose walls are thicker, and of the form of a cone or pyramid, is in communication with a large artery, which bears the name of the Aorta, and which, subdividing in its course, terminates in myriads of very minute ramifications closely interwoven with the texture of every living part.

The two sides of the heart are placed the one against the other—auricle in contact with auricle, and ventricle with ventricle, and united by elements common to the structure, and yet without any communication of their cavities with each other. That is to say, auricle does not communicate with auricle, or ventricle with ventricle, but the right auricle with the right ventricle, and the left auricle with the left ventricle.

If we look upon the heart as representing a root, and the aorta as the principal trunk rising from the left ventricle, we shall discover, how like two beautifully ramified trees, the vessels in which the blood flows gradually divide themselves into branches, and twigs, and minute ramifications finer than the hairs of our head, and terminate at the circumference of the body, the limbs, and the internal organs. The other trunk is named the PULMoNARY ARTERY which arises from the right ventricle, and is extended through the lungs. We have thus two systems of arteries. We have the pulmonary artery which has its trunk in the right ventricle, and its extremities in the lungs or organs of respiration. We have also the aorta, which has its trunk in the left ventricle, and its extremities in every part of the body.

LM Carotid arteries.
No Wertebral arteries.
PQ Subclavian arteries.
R Aorta descendens.
SS Outline of lungs.

These arteries or tubes, by which the blood is distributed to *** * of *ebody, are composed of three membranes or * * *ve other minute arteries in such a manner as * * * * * **fally compli*** *** **work. is *** * *man vessels may * *****d as the minutest **ons of the veins and *** *tween which it **, and through which * Mood has to travel from o to one to the other. For so * only 40 the arteries com- o monieate with each, and this -o *munication become more distribution of capillaries or small o as the arteries are blood-vessels at the surface of the Mistant from the heart, but skin of the finger. the arteries deliver the blood into the capillary network, and from thence the veins receive it, because in that delicate network the veins seem to originate. As it is the office of the arteries to convey the blood from the heart, so it is the office of the veins to convey it back to the same great centre. From the extremities of the arteries in which they have their origin, we can trace them back till they terminate in the auricles of the heart, through the vena cava in thoriaht, and through the pulmonary veins in the left.

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The blood is returned from every part of the body, except the lungs, into the right auricle from the three following sources:The vana cava auroiuon, which brings it from the head, neck, chest, and superior extremities, The vana cava inroluon, which brings it from the abdomen or belly, and the inferior extremities, The coaonany vaun, which receives it from the coronary

arteries of the heart. You will now very naturally ask—and how is the blood from the lungs returned? After coming into contact with the atmospheric air in these of respiration, it is conveyed back by the pulmonary veins to the left auricle of the heart, As we have two systems of arteries, so we have two systems of veins, The one has its minute divisions or roots in every part of the body, and terminates by the two principal trunks of the vena cava in the right auricle. The other has its roots or extremities in the organs of respiration, and terminates by means of the four trunks of the rvivoxany veux in the left auricle of the heart. What, then, is the difference between an artery and a veinn During life, an artery is distinguished by its pulsation. The ulse may be compared to a wave which commences in the eart, and travels onwards through the whole arterial system, When your doctor wants to feel your pulse he puts his finger upon your wrist as being more convenient; but the pulse is not

confined to the wrist. There is another method of distinguishing an artery. It is this. If it be wounded, or if you cut it, the blood escapes by jets. But a vein does not pulsate, and its blood is of a much darker colour. The walls of veins are thin, and soft, and but slightly elastic, while those of the arteries are thick, and firm, and elastic in a high degree. The direction of the blood in their arterial and venous vessels is constant; but relatively to the heart, which is their common centre, this direction is both centripetal and centrifugal. In the venous system it is centripetal—the blood being conveyed from all parts of the body to the right auricle through the vena cava, and from the lungs to the left auricle by the pulmonary veins. In the arterial system it is centrifugal— the blood being carried from the right ventricle to the surface of the lungs or respiratory organs through the medium of the pulmonary artery, and from the left ventricle to every part ot the body through the medium of the aorta. Such is the wondrous mechanism which determines and directs the circulation of the blood. In the course of its circulation the blood is found to be in two entirely different conditions—it is partly arterial, and partly venous. It is the blood, as it exists in the arteries, which only is capable of affording nourishment, and of supporting life. What, then, becomes of the blood in the veins On arriving at the right auricle of the heart, the auricle contracts,

and sends the blood into the right ventricle; this again is stimulated to contraction, and the blood is propelled into the wilmonary artery, out of which, by a similar contraction, it s forced into the smaller branches of the artery, and these bring it into contact with the inspired air in the lungs. On reac o the lungs, the blood is of a dark red hue approaching to purple, but leaves them of a brightfloridcolour approaching to scarlet. This change is due to the elimination or discharge of carbonic acid gas, and the imbibing of oxygen from the air. Having thus lostits superfluouscarbon, and having its capacity much increased for receiving and entering into combination with the caloric or heat generated in the lungs, the blood is conveyed back by the pulmonary veins to the left auricle of the heart, which being stimulated to contraction propels the blood into the left ventricle, which in its turn also contracts, and forces the fluid into the aorta, which, as we have seen, divides and subdivides in its course, and ultimately terminates in a multitude of thread-like branches, which become interwoven with the very texture of every living part. In these minute vessels the veins have their origin. ese veins Rradually coalesce and form larger trunks, till at last they terminate un two, and by these two the whole current of the venous blood is brought back in a direction contrary to that of the arterial blood, again passes into the lungs to undergo the same purifying process as before, and is again conveyed to the last side of the heart to be put in circulation. The time occuF. in this circulation may be eighty, a hundred, or a undred and twenty seconds of time. Each of the cavities of the heart presents alternately two opposite states—one of dilatation, and the other of contraction. During the relaxation, the walls permit the cavity to be filled and distended by the introduction of the blood; but during the contraction, the walls diminishin their length, energetically approach each other till they come close together, force out all the blood, and leave no cavity whatever. Let us try to understand this. Let us suppose that the left auricle is filled and distended by the flowing in of arterialized blood from the four E. veins; it suddenly and energetically contracts, and y expelling the blood ceases to present a cavity: it so happens that at the very same instant the left ventricle is in a state of relaxation, and its walls offering no resistance to the introduction of the blood, the blood by means of a free opening which enables the cavity of the ventricle to communicate with the cell of the auricle, briskly flows into the ventricle and fills it. But how is the blood which has thus passed into the ventricle prevented from flowing back into the auricle if there be a free passage between those two cavities? To provide against this there exists in the heart itself a beautiful little apparatus which hermetically seals this opening at the very same moment that the ventricle contracts. If you will carefully examine the two engravings (see page 68) you will the better be able to discover how this little apparatus works. In the engraving to the left you have the ventricle laid open, and you trace a ring composed of strong tendon, very tough and without extension, whose superior border (a) surrounds the free passage between the ventricle and the auricle, and whose inferior border plunges into the cavity of the ventricle itself. This inferior border gives attachment to two series of firm, yet strong cords, the one (b) anterior, and the other (e) posterior, and which are seen to fix themselves in the summit of two muscular columns (df) detatched from the anterior and posterior walls of the cavity. Each of these two columns exhibits two juttings or projections, separated by a little gutter. Look now at the engraving on the right, and you will see that at the moment of contraction those two columns (df) approach each other till they come into contact, and embrace each other in such a manner, that the right projection of the anterior column fills up the gutter of the posterior column, and the left projection of the posterior column fills up the gutter of the anterior column. The two columns are now seen to make but one. The cords, bent by the abridgment or shortening of the columns, have been drawn out, and with them the inferior edge of the tendonous ring, in such a manner that the cords have become vertical, the ring drawn together, folded and knit, and closed like the mouth of a purse. But this is not all. To this tendonous ring, which encircles the orifice or opening between the auricle and ventricle, there is fixed the base of a valve, which in the left division of the heart is called the mitral valve, from its likeness to a bishop's mitre. This valve is brought into action at the moment in which the ventricle begins to contract. As the contracting walls of the ventricle press on the blood, the valve is pressed up by it towards the opening between the two cavities of the auricle and the ventricle, and completely closes it. Or, if possible, to put it in yet simpler words, the flaps of the valve, which are completely thrown back during the rush of blood from the auricle to the ventricle, are now drawn into a position to allow the blood to get behind them and bring them together, so as completely to close the assage. p The walls of the left ventricle are considerably thicker than those of the right, and their power of contraction is greater. This difference, which is as three to one, is required by the force necessary to drive the blood into the aorta, and through this large artery into every part of the body. It requires but little force to send the blood into the pulmonary vessels. We have seen that the heart has four distinct cavities. Now each of these cavities is nearly equal in capacity—each of them in the full-sized heart holding about two ounces of fluid. This, therefore, is the quantity of blood which is sent forth at each successive contraction of the ventricles. The whole quantity of blood seems to be about one-fifth of the entire weight cf the body. Suppose a man to weigh one hundred and

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sixty pounds, he would have in his body two-and-thirty pounds of blood ; and if we allow seventy-five pulsations to a minute, then if we o these seventy-five pulsations by the two ounces of blood propelled at each contraction of the ventricles, we shall find that at least one hundred and fifty ounces of blood must pass through each ventricle of the heart in that short space of time. At this rate it would require more than three minutes and a half to perform the entire circulation. It may, however, be effected in onethird of that time. We have something more to say of the blood—of its composition and its use—but we must reserve it for our next lesson.

QUESTIons Fort ExAMINATION.

o provision do we find in the body for the circulation of the blood P How is the heart divided, and of how many cavities does 34 consist P How are these cavities situated in relation to each other, and what are their names 2 Why is the superior cavity called an auricle, and the inferior cavity a ventricle Do these cavities communicate with each other, and in what way? What great artery arises from the left ventricle, and whither does it reach in its ramifications? What artery arises from the right ventricle, and to what does it extend ? Give the two systems of arteries in their origin and progress. In what do the arteries terminate and the veins begin? What is the office of the arteries and the veins From what three sources is the blood returned from every part of the body to the heart? How is the blood returned from the lungs 2 Give the two systems of veins in their origin and progress. What is the difference between an artery and a vein When is the direction of the blood centripetal, and when centrifugal? What are the two conditions in which the blood is found to exist in the human body? What becomes of the venous blood? Describe the circulation. Has each cavity of the heart the power to dilate and contract? What takes place during these two opposite states? How is the blood prevented from flowing back after it has emptied itself from one cavity into another ? Why are the walls of the left ventricle thicker than the right? What is the capacity of each cavity of the heart 2 What is the quantity of blood in the body ? How long does it require for the blood to perform an entire circulation ?

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