H. The child's saucepan is silvered over on the inside. What is that for?

T. To prevent the food from getting any taint from the metal of the saucepan; for silver is not capable of being corroded or dissolved by any of the acids or other liquids used in food, as iron and copper are.

H. And that is the reason, I suppose, that fruitknives are made of silver?

T. It is; but the softness of the metal makes them bear a very poor edge.

G. Does silver melt easily?

T. Silver and gold both melt more difficultly than lead; nor till they are above a common red heat. As to the weight of silver, it is nearly one-half less than that of gold, being only eleven times as heavy as water. H. Is quicksilver a kind of silver?

T. It takes its name from silver, being very like it in colour; but in reality it is a very different thing, and one of the most singular of the metal kind.

G. It is not malleable, I am sure.

T. No; not when it is quick or fluid, as it always is in our climate. But a very great degree of cold makes it solid, and then it is malleable, like other metals.

G. I have heard of killing quicksilver; pray what does that mean?

T. It means destroying its property of running about, by mixing it with something else. Thus, if quicksilver be well rubbed with fat, or oil, or gum, it unites with them, losing all its metallic appearance, or fluidity. It also unites readily with gold and silver, and several other metals, into the form of a sort of shining paste, which is called an amalgam. This is one of the ways of gilding or silvering a thing. Your buttons are gilt by means of an amalgam.

G. How is that done?

T. The shells of the buttons, which are made of copper, are shaken in a hat with a lump of amalgam of gold and quicksilver, till they are all covered over with it. They are then put into a sort of frying-pan,

and held over the fire. The quicksilver, being very volatile in its nature, flies off in the form of smoke, or vapour, when it is heated, leaving the gold behind it spread over the surface of the buttons. Thus, many dozen are gilt at once, with the greatest ease.

H. What a clever way! I should like vastly to see it done.

T. You may see it any day at Birmingham, if you happen to be there; as well as a great many other curious operations on metals.

G. What a weight quicksilver is; I remember taking up a bottle full of it, and I had like to have dropped it again, it was so much heavier than I expected.

T. Yes; it is one of the heaviest of the metalsabout fifteen times as heavy as water.

G. Is not mercury a name for quicksilver? I have heard them talk of the mercury rising and falling in the thermometer and barometer, or weather-glasses.

T. It is. You, perhaps, may have heard too of mercurial medicines, which are those made of quicksilver prepared in one manner or another.

G. What are they good for?

T. For a great variety of complaints. Your brother took some lately, for the worms; and they are often given for breakings out on the skin, for sores and swellings, and for affections of the liver. But they have one remarkable effect, when taken in a considerable quantity, which is, to loosen the teeth, and cause great expectoration. This state is called salivation.

H. I used to think quicksilver was poison.

T. When in its common state of running quicksilver, it generally does neither good nor harm; but it may be prepared, so as to be a most violent medicine, or even a poison.

G. Is it useful for anything else?

T. Yes-for a variety of purposes in the arts, which I cannot now very well explain to you. But you will perhaps be surprised to hear that one of the finest red paints is made from quicksilver.

G. A red paint!-which is that?

T. Vermilion, or cinnabar, which is a particular mixture of sulphur with quicksilver.

H. Is quicksilver found in this country?

T. N. The greatest quantity comes from Spain, Istria, and South America. It is a considerable object of commerce, and bears a high value, though much inferior to silver. Well-so much for metals at present. We will talk of the rest on some future opportunity.

FLYING AND SWIMMING.

"How I wish I could fly!" cried Robert, as he was gazing after his pigeons, that were exercising themselves in a morning's flight. "How fine it must be to soar to such a height, and to dash through the air with so swift a motion!"

"I doubt not," said his father, "that the pigeons have great pleasure in it; but we have our pleasures, too; and it is idle to indulge longings for things quite beyond our power."

R. But do you think it impossible for men to learn to fly ?

F. I do for I see they are not furnished by nature with organs requisite for the purpose.

R. Might not artificial wings be contrived, such as Dædalus is said to have used?

F. Possibly they might; but the difficulty would be, to put them in motion.

R. Why could not a man move them, if they were fastened to his shoulders, as well as a bird?

F. Because he has got arms to move, which the bird has not. The same organs which in quadrupeds are employed to move the fore legs, and in man the arms, are used by birds in the motion of the wings. Nay, the muscles, or bundles of flesh, that move the wings, are proportionally much larger and stronger than those bestowed upon our arms; so that it is im

possible, formed as we are, that we should use wings, were they made and fastened on with ever so much

art.

R. But angels, and cupids, and such things, are painted with wings; and I think they look very natural.

F. To you they may appear so; but an anatomist sees them at once to be monsters, which could not really exist.

R. God might have created winged men, however, if he had pleased.

F. No doubt; but they could not have had the same shape that men have now. They would have been different creatures, such as it was not in his plan to create. But you, that long to fly-consider if you have made use of all the faculties already given you! You want to subdue the element of air-what can you do with that of water? Can you swim ?

R. No, not yet.

F. Your companion, Johnson, I think, can swim very well.

R. Yes.

F. Reflect, then, on the difference between him and you. A boat oversets with you both, in a deep stream. You plump at once to the bottom, and almost inevitably lose your life. He rises like a cork, darts away with the greatest ease, and reaches the shore in perfect safety. Both of you, pursued by a bull, come to the side of a river. He jumps in, and crosses it. You are drowned if you attempt it, and tossed by the bull if you do not. What an advantage he has over you! Yet you are furnished with exactly the same bodily powers that he is. How is this?

R. Because he has been taught, and I have not.

F. True-but it is an easy thing to learn, and requires no other instruction than boys can give one another, when they bathe together; so that I wonder anybody should neglect to acquire an art at once so agreeable and useful. The Romans used to say, by 23*

8 2

way of proverb, of a blockhead, "He can neither read nor swim.' You may remember how Cæsar was saved at Alexandria, by throwing himself into the sea, and swimming with one hand, while he held up his Commentaries with the other.

R. I should like very well to swim, and I have often tried, but I always pop under water, and that daunts

me.

F. And it is that fear which prevents you from succeeding.

R. But is it as natural for man to swim as for other creatures? I have heard that the young of all other animals swim the first time they are thrown into the water.

F. They do-they are without fear. In our climate, the water is generally cold, and is early made an object of terror. But in hot countries, where bathing is one of the greatest of pleasures, young children swim so early and well, that I should suppose they take to it almost naturally.

R. I am resolved to learn, and I will ask Johnson to take me with him to the river.

F. Do; but let him find you a safe place to begin at. I don't want you, however, to proceed so cautiously as Sir Nicholas Gimcrack did.

R. How was that?

F. He spread himself out on a large table, and, placing before him a basin of water with a frog in it, he struck with his arms and legs, as he observed the animal do.

R. And did that teach him?

F. Yes to swim on dry land; but he never ventured himself in the water.

R. Shall I get corks or bladders ?

F. No; learn to depend on your own powers. It is a good lesson in other things, as well as in swimming. But corks or bladders, if accidentally allowed to get out of their proper position, are very dangerous, and have occasioned the loss of many lives.