good fairy, the special friend of learned men, came pass ing by that way. She raised her enchanted wand with the tip of her finger, and all at once a little girl dressed in rags appeared in the midst of our astonished professors. Without giving them time to recover themselves, the child put her hand into the little patched waist of her dress, and drew forth a rounded object, about the size of her closed fist from which hung a quantity of tubes spreading in all directions.

"See !" cried she; "here is the machine your banker demands of you."

Picture to yourself a small closed bag, narrowing to a point at the end, and separated within into two very distinct compartments by a fleshy partition which went across the inside from the top to the bottom. Such was the object held up by the little girl. From each of these compartments issued a thick tube, ramifying into endless smaller ones; and they were moreover each surmounted by a sort of pouch, into which ran another tube, of the same description as the first. Each of these four portions (the two compartments and their pouches) was in constant but independent motion, distending and contracting alternately; and by carefully examining the noiseless play of this singular machine, (the walls of which were, by the magic power of the fairy, rendered transparent to the bystanders,) the learned assembly were very soon enabled to convince themselves, that it fulfilled all the monstrous conditions exacted of them by the fantastic millionaire.

All was in movement together, I told you; but let us begin at one end. The right-hand compartment and its pouch represented the first pump; the pump employed to draw, by the same stroke, the water from the stagnant channel, and that from the taps. It was perfectly easy to distinguish the two systems of pipes, and how

they united together at the small pouch on their arrival. When this was distended, a vacuum was created inside, which was instantly filled by the liquid from the tube which ran into it, (do not ask me why or how; I will explain that presently). When it contracted again, the liquid which had just entered was not able to get back, being prevented from so doing by a very ingenious and simple contrivance, which requires a brief explanation.

Take off the lock from your chamber-door, which opens inside; then, standing outside, push against it with your shoulder, and you will get in without any difficulty. But when you are in, try to push the door open again with your shoulder in order to get outside into the passage, and you will find that you will not be able to pass through, and this simply because it does not open on that side.

Which was exactly what happened to the liquid in the pouch!

The door between the tube and the pouch only opened inwardly, and the liquid finding itself pressed on all sides in proportion as the pouch contracted more and more, and unable to return, was obliged at last to make its way through another similar door which led to the large compartment below. Here the same game recommenced. The compartment which had distended itself to receive it, contracted in its turn, and the liquid finding the road again barred behind it, had no choice but to force its way through the tube which led to the airreservoir.

Here commenced the work of the second pump,-the pump of the left compartment. The little pouch, when distended, was filled by the liquid from the reservoir, and then forced it forward into the large compartment below, always by means of the same process. This compartment again drove it, by a powerful contraction, into

the large conducting tube charged with the office of its general distribution throughout the body. At the end of all which, it returned once more into the right-hand pump as before, to pursue the same course again, &c., &c.

Thus, as you see, the whole mechanism turned upon two little points of detail, of the simplest description possible; namely, first, on the entrance-doors only opening on one side; and secondly, on the elastic covers of the pouches and compartments distending and contracting spontaneously. It was the prettiest thing in the world to see this unpretending-looking little bag working thus, quite naturally, without a suspicion that it was solving a problem which so many men, proud of their science, had given up as hopeless. Certainly here was a machine which made no noise! Once installed in its dark closet, it would have been necessary to place your hand upon it to find out that it moved at all. My lord could certainly sleep beside it without disturbance.

"How much do you want for it?" said they to the poor little beggar girl. "Name your price; have no fear; we will pay you anything you wish."

"I cannot give it to you," replied the child; "I need it too much myself: IT IS MY HEART. Now that you have seen it, make another like it, if you can." And she disappeared.

It is said that the engineer, who longed to see his idea carried out, tried hard to construct a similar machine with gutta-percha and iron wires, and to set it in motion by electricity. But history does not tell us that he succeeded, and we have yet to ask ourselves whether the richest man in the world, aided by the wisest men in the world, could ever provide himself with a miracle of wonder, such as the ragged child had received as a free gift from the hands of a gracious Creator.

LETTER XIV.

THE ARTERIES.

IF

If you have thorougly understood the story I last told you, my child, it will have revealed to you the whole mystery of the circulation of the blood, and you are at the present moment wiser than all the learned men of antiquity and the middle ages, for they had none of them the faintest surmise of the truth.

It may, perhaps, seem odd to you that men should have existed for upwards of five thousand years without making inquiry into a matter which so closely concerned them, and which was so easy to find out. Is it not almost incredible that so many hearts should have beaten for so long a period without any of their owners having felt a wish to know exactly why? Yet so it is. The ac tion of the heart and the flow of the blood have not been understood for much more than two hundred years, and the man whose name is attached to this great discovery richly deserves that we should say a few words about him.

He was called Harvey. He was an Englishman; physician to King Charles I., who was beheaded in 1648; and when he first ventured publicly to teach that the blood was constantly circulating from one end of the human body to the other, perpetually returning and re tracing its steps, a great scandal was created in the world. He was called a fool,-an impertinent innova

tor, a madman. His words shattered old doctrines, and he only received for his reward all the petty annoyances which men are apt to lavish so freely upon any one who tells them something new; because-do you see?—it is so disagreeable to be disturbed in one's habits and preconceived ideas.

Harvey is not the only one in the history of mankind who has committed the sin of being right in defiance of the opinions of his age. It is true posterity takes account afterwards of the labors of genius, and inscribes a fresh name upon her list. But one must pay for this glory One cannot have everything at

in one's lifetime.

once.

This is an old story, my child, but always new nevertheless; and for my own part it is, I own, one of my pleasures to amuse myself by reflecting how much cause for laughter three-fourths of the great men of the present day are providing for the little girls who shall be alive two centuries hence. Time is a great avenger, and puts many things and men in their proper places.

Let us pause here a moment while we are speaking of Harvey. I should be curious to know what any one of the courtiers of Charles I., bedecked in feathers, ribbons and laces, would have said to the valet who would have placed the excellent Harvey, with his insane invention, above his most gracious majesty, the lord and king of all Great Britain! And yet what is his most gracious majesty to you to-day? What do you owe to him? in what does he interest you? While you can never hear the name of Harvey pronounced without remembering that you are under many obligations to him! A thousand years hence, when society shall have made the great progress which may reasonably be expected, the name of Harvey will be familiar to every one who owns a