water; they are called gills. The mammal exposes its blood to the air in organs called lungs; and in the same way, as you have heard before, the leaves expose the sap to the air. You heard of the ascent of the sap from the root to the stem. Let us talk of its progress from the stem to the leaves. Imagine the sap making its way up to the stem! The poor sap is thin and tasteless, for it is little more than water, with a very small portion of the earth's juices; but, as I said before, it is coming up to the leaves to have its qualities changed-to be made rich and nutritious. So it comes on, spreading through all the smaller branches and twigs. It passes from them through the petioles to the leaves. They are ready to receive it, and arranged so that the light of the sun may fall on every one. Beautiful leaves! Their parts are orderly and regular! They have two sets of organs on the upper surface, the mid-rib and network of veins, through which their sap must pass from the stem; and another set on the under surface, for the altered sap to return to the stem. The sap, therefore, enters on the upper surface. Let us see how it is acted upon. The light of the sun is one of the important agents; its influence causes all the stomata (mouths) of the leaf to open. The sun's heat is another agent; it causes the greater part of the water in the sap to pass away, through the open stomata, in the form of vapour. Ion. Just as the perspiration passes through the pores in my skin, I suppose. P. Yes, in the same way. The air is the next important agent; it enters the leaves, and supplies the sap with some of its gases. The most important part of the air to the plant is that called carbonic acid gas, with which you are already acquainted. Ion. I know that part of the air very well. You told us that our breath is carbonic acid. You said, that in our lungs the carbon from our impure blood unites with the oxygen from the pure air. The oxygen and carbon together form the breath which comes out of our mouths. P. True; and just as the oxygen and carbon are united in your lungs, so they are separated again in the leaves (which I called the tree's lungs). The carbonic acid of the air enters the leaves, the carbon is then united with the sap, and the oxygen is set free again, to enter the lungs of more animals, and unite with more carbon. L. That is very curious. We reject the carbon from our lungs, and the trees absorb it. P. And when this carbon is united with the sap, it makes it thick and nutritious. The nutritious sap then passes through the vessels on the under-side of the leaf, through the petiole again, back to the body of the tree; there it forms material for the opening blossom, or for the ripening fruit and seeds, or for the growth of new sap-wood, or for the for- same degree of light and heat. mation of heart-wood. You know how to prove that the carbon absorbed by the leaves forms material for the wood. W. Yes; because coal, which was once wood, and charcoal (or burnt wood), are nearly all carbon. P. Let us now make a summary of this lesson. We said that a plant cannot live without its root, because that organ procures the sap. Now, we know that it cannot live without leaves, because they perfect the sap. You know, too, how much the leaves depend on the light, heat, and air. You know, Willie, that we have in our green-house what are called tender annuals, which require very much heat and light. P. There is one more point. I told you that in the broad leaves of the water-lily the stomata are on the upper surface-perhaps you can now tell me why. Ion. Yes, because it would be no use to have stomata on the under side; the oxygen, which is separated from the carbon of the carbonic acid, would not easily pass through into the water, I suppose. P. Right. I said that the upright leaves of the flags in our garden have the same number of stomata on both W. Yes; now I see one rea-sides of their leaves-perhaps son why plants cannot grow in you can give me the reason for dark courts and alleys. As that also. there is no light to act upon them, the leaves cannot open their mouths and breathe; and it is the same in the shady side of the garden-there is not light or heat enough for the plants, I suppose. P. And there is a reason why plants will not grow even in London streets, and in other crowded cities, where there is light. It is because, from the quantity of smoke, and the number of inhabitants breathing the air, it contains too much carbon; then the stomata get choked up. L. Unless you can get a very strong light and heat to open the pores more, and to make the plant live and breathe faster. P. Not all plants require the L. I think I can-because, as the light shines equally on both sides, the green cells of the tissue are as closely packed on one side as on the other-thus, there are the same number of spaces between them, for the pores. You may know that, because both sides are of the same colour. P. True. You say that one side of a leaf is of a bright colour because the action of the light causes the number of green cells to increase. Perhaps you can tell me why celery and asparagus are SO white. W. I can. Because, when the gardener cultivates them he covers them over with earth; thus he keeps the light from them. Ion. And that, I suppose, is the reason why, if you pull up the long stalk of mustard and cress, the part underneath the ground is white. P. Yes. And you may remember that in our lesson on celery, I told you that the whitened (blanched) stalks are fit to eat because they have not the poisonous quality of wild celery. This is from the same cause that prevents their becoming green. From want of light and heat they are not strong enough to form the green sap which contains the poisonous quality. Will you have another question? Ion. Yes, please—that is, if you think we can answer it. P. Try! When you go to a forest you will find that the outside trees are finer than those inside. Again, if you examine one of those trees you will find that the outside leaves are of a brighter colour, and more numerous, and thus the branches are larger. If you cut the tree down and examine the trunk, you will find that the circles of wood are much thicker on the side most exposed to the light. Perhaps you can tell me why? W. That is very easy to un derstand. The leaves on the outside of the tree have more light and heat than the others, therefore they digest more sap. Then the sap forms more wood on that side. P. True; and for the same reason the outside trees of the forest are finer, and contain harder wood than the others. One more word on the stomata of the leaves. If you twist a branch round, so that the lower surface of the leaves be turned towards the sun, they will gradually work back to their natural position. If prevented from doing this, they will wither and die. L. That reminds me of my little geranium in the nursery window-its leaves did almost the same thing. Willie turned round the pot, so that the front of the leaves was turned towards the fire-place, and in a few days the leaves turned their front (or upper) side to the light again. If the plant could have spoken to Willie, it would have said, "You don't know how much my health depends on my leaves!" Ion. And it might have added, "You don't know how much my leaves depend on the light and heat." TO-DAY. DON'T tell me of to-morrow; THE TUDORS. HENRY VIII. P. You heard something of Henry last week. You heard that he had good abilities and learning, and might have become a good king, but for the want of good education. He had not been taught to govern his bad passions; he was accustomed to gratify every wish, therefore his passions governed him. He would not, and at last he could not be happy until his desires were fulfilled. Thus Henry spent the first two years of his reign in the indulgences of pleasure. In the year 1511, Henry joined the kings of other nations in Europe in a league against France, and this was the first instance of England taking part in the disputes of other nations on the Continent. This event was the beginning of a bad course: the English Government, by meddling with the affairs of other nations, have since wasted immense treasures and the lives of thousands. In the year 1512, war was declared against France. In the next year a sea-fight took place; a battle was also fought by land, which was called "the Battle of the Spurs." It was so called because as soon as the French came in sight of the English army they unaccountably turned round and spurred their horses to flight. The next year, however, peace was made. The French king, to please Henry, entertained him in France; and the festival he gave him was so splendid that the place was afterwards called "the field of the cloth of gold." Both kings spent large sums of money on that occasion. In the year 1513, a great battle was fought with the Scots on Flodden Field, in Northumberland. This was a most disastrous battle for Scotland. King James IV. was himself slain, with a number of nobles, abbots, and gentlemen; in all about 10,000 men. The wars of Scotland and France being over, Henry devoted himself to pleasure again. But to pay for his indulgences he required a large amount of money. As he could not procure this lawfully, he oppressed his subjects, and acted unjustly in many ways to procure it. But the trouble of forcing his subjects to pay his unjust demands was too great; it interfered with his enjoyments. For instance, he attempted to raise taxes without the consent of the Parliament, and an almost general insurrection took place. Such opposition was very "troublesome " to the king, who wanted to live at ease and enjoy himself. He therefore entrusted the business of procuring money to a man named THOMAS WOLSEY, who had lately grown into favour. Wolsey was as remarkable a character in the reign of Henry VIII. as Thomas à Becket was in the reign of Henry II. Let us look into his history. ficence. Never were there such famous " games" as those carried on between Henry and Francis. Both were handsome young men, fond of "chivalry and feats of arms," and they sent a challenge through all the courts of Europe that they were ready, on the plains of Picardy, to answer all comers that were gentlemen at tilt and tournay. Thus they spent a whole fortnight in feats of arms and gay carousals. Thomas Wolsey was born at Ipswich. So clever was he that he became "Bachelor of Arts" at the age of 14; and was called "the boy bachelor." In course of time he became a clergyman; by his pleasing manners he gained the favour of his patrons, and at last became chaplain to King Henry VII. Being employed on important business by the king, he executed it with such dispatch and success, that the king also was highly pleased with him, and made him DEAN of Lincoln. When Wolsey was introduced to the young King Henry VIII., he saw at once how to please such a master. He did not disdain to dance, sing, laugh, and amuse himself with the worst people of Henry's court, until the king began to think him "a good fellow." He was made Bishop of Winchester; afterwards he became Archbishop of York; then he was made Lord Chancellor of England; and at length he re-cester, and Hereford; and had ceived a Cardinal's cap. As a cardinal, Wolsey acquired immense power, wealth, and influence; he was thus able to gratify his royal master's wishes, to procure him the supplies of money he required, and to enable him to indulge in almost unbounded extravagance. The French and English kings became great friends, made great pageants, and indulged in games of "tilt and tournay," which were sustained with the most gorgeous magni While the king was thus enjoying himself, his industrious servant, Cardinal Wolsey, persevered in supplying him with money. He extorted it from the people by means of benevolences; he procured a large sum from the people, and another amount from the House of Commons. Wolsey also took care of his own interests, by increasing his own riches and titles at the same time. In addition to the offices already mentioned, Wolsey had the bishoprics of York and Durham. He "farmed" the bishoprics of Bath, Wor the control of the richest offices of the church. Thus his own revenue was supposed to be as great as that of the Crown. He took care to live in splendour almost equal to that of Henry; he built for himself the magnificent palace of Hampton Court, and was waited upon by a train of servants and retainers, as if he were going to revive the feudal system in the church. He was indeed a great "churchbaron." But, bad as the king and his |
