gate, beyond a large paved courtyard, are thirty-two buildings, divided into equal groups by three direct and three transversal streets, intersecting each other at right angles. These vast buildings contain stalls for the shelter of the animals, and 123 places where the carcases are cut up after having been killed in the interior court, situated in the centre of the ranges of sheds. Both the sheds and the yards are carefully paved, and the ground, on an inclined plane, communicates with the sewers. ance. Everywhere water is in abund The slaughter-house is frequented daily by some thousand slaughtermen and butchers. The work begins, according to the season, at four or six in the morning, and is continued until about one o'clock. At two o'clock the retail butchers come and make their purchases of the carcass butchers, who buy the animals at the cattle-market, have them killed and cut up, and sell them on the spot dead and dressed for the shops. One hundred and eighty numbered carts, all exactly of one weight, carry the meat from the slaughterhouse to the different quarters of Paris. Before going through the gate they pass by the office of the octroi officers, and stop on a weighing-machine, and thus the exact quantity of meat they take away is recorded. The octroi or town duties payable on the spot are 11 per cent. per kilogramme ? 2 Of this sum 2 per cent. is reserved specially for the liquidation of the cost of the immense buildings which have relieved the inhabitants of Paris of a pestilent nuisance. A saw is never used in the slaughter-house; the only instruments employed are the knife and an axe made wholly of iron, in order to avoid the contingency of the handle coming off. The slaughtermen handle it with marvellous dexterity. With this weapon, apparently so 3 unwieldy, they sever from one end to the other the vertebral column of an ox, with such precision that the spinal marrow is separated into two parts exactly equal. Among the butchers are five Jews, who, in accordance with their law, never stun an animal, but always kill it by cutting its throat. In general these butchers, whose trade is to kill, have a horror of seeing the animals suffer, and always do their best to despatch them at the first blow. No part of a dead animal is thrown away; all is turned to account. At the slaughter-house itself, in the first court, is a building divided into two compartments furnished with large boilers, where the sheep's feet and calves' heads are prepared and made ready to be placed as we see them at the butchers' doors in pails of well water. The grease is carefully preserved, and a place has even been built for the purpose of melting it; but it does not seem yet possible to make use of it. The fat of sheep, when of good quality, is used in the making of candles. The feet of oxen furnish an oil used in clockmaking. The large intestines of the ox are bought by the pork butchers; the small ones are sent to Spain, to become the cases of sausages highly prized beyond the Pyrenees; the thin intestines of sheep are made into harpstrings, the bones into animal black. All that is absolutely useless for anything else is added to the manure, of which about 16,000 francs worth are sold annually at the central slaughter-house alone. In order to encourage the provincial carcass butchers to profit by the rapidity of the railways and to send. meat to Paris, in conformity with the decree of police, of the 3d of May and of the 24th of August 1849, a public auction has been opened for meat sent direct by the departments. This auction mart now occupies a portion of the Central Hall, and is divided into two distinct parts, one for wholesale, and the other for retail transactions. Although but recently introduced, this sale by auction has already produced excellent results, and it increases in importance every day. "Government, and Life of Paris," by M. DU CAMP. 1. METRE, a French measure rather more than an English yard; there are 1608 metres to an English mile. 2. KILOGRAMME, a French weight, about two lbs. English. 3. VERTEBRAL COLUMN, the back-bone, so named because the bones and joints fit into each other. 4. FRANC, a franc is worth about 10d. English money, and 25 francs are about a sovereign. THE AIR. THE greatest part of air is nitrogen,1 there being about four times as much of that as of oxygen.2 Although the proportion is small, yet the quantity of this gas in the whole of the air is great, for you must remember that the atmosphere is perhaps forty-five or fifty miles high. It is calculated that in the atmosphere over every acre of land there are seven tons of carbonic acid gas.3 Continual additions are made to the carbonic gas in various ways. Every fire adds to it; for the carbon in the burning of wood, coal, and other substances unites with the oxygen and forms carbonic acid gas. Thus fire lessens the oxygen, and at the same time adds to the carbonic acid. If a lighted candle be placed on a plate, and covered with a glass jar, it will burn brightly at first, because there is enough oxygen in the jar; but soon it will burn dimly, and go out. The reason is that the carbon of the candle unites with the oxygen to form carbonic gas. If, as the candle is about to go out, you lift the jar, the flame will brighten again, because you let out carbonic acid gas which has fallen to the bottom of the jar, and fresh air comes in to supply oxygen. If you put two candles, one a long one and the other a short one, under the same jar, the short one will be first extinguished. All fires then lessen the oxygen in the air, and add to the carbonic acid gas. The quantity of carbonic gas breathed out in twentyfour hours is considerable. It is calculated that a fullgrown man breathes out in twenty-four hours more than two pounds of carbonic acid gas, and in this there is not less than half a pound of solid carbon or charcoal. He throws off therefore from his lungs in the course of a year, nearly 200 pounds of charcoal-considerably more than his weight. As all animals, from the elephant down to the smallest insect, breathe out carbonic gas, the supply of it to the air from this source must be great. Animals also take oxygen from the air with every breath. It becomes a part of their blood. You could not live, if the blood did not constantly receive oxygen from the air as it passes through the lungs. Death is caused by drowning because oxygen cannot enter the blood. The water prevents it from doing so. You see how proper it is to speak of oxygen as the lung-food of the body. Now, mark how the air which you breathe out differs from that which you breathe in. That which you breathe out has less oxygen and more carbonic acid gas. The nitrogen is not altered, for as much comes out as goes in. I will tell you a story of an emigrant ship called the T Londonderry. The ship was crowded with emigrants, and many of them were on deck. There came on a storm, and the captain ordered all to go into the cabin. They were here very much crowded, and fresh air came to them only through an opening in the deck. As the waves broke over the vessel, sea-water dashed down through this in great quantities. The captain ordered that tarpaulin (that is, a cloth through which neither water nor air can pass) should be nailed over the opening. The people below suffered dreadfully for want of fresh air. The poisonous carbonic acid gas increased every time each person breathed, and no pure air could get to them. They cried out in their distress, but the noise of the storm prevented their being heard. At length one of the emigrants succeeded in forcing a hole through the tarpaulin. He told the captain that the people were dying for want of air. The tarpaulin was taken up at once. Many were dead, and many were dying. The fresh air saved many, just as letting fresh air into the jar revived the expiring flame of the candle. The Viceroy of Bengal,5 Surajah Dowlah, having taken Calcutta in June 1756, thrust one hundred and forty-six English people into a loathsome dungeon known as the Black Hole, where in one night, as they could get but very little fresh air, the greater part of them died of suffocation. All animals then in breathing, and all fires in burning, add to the carbonic acid gas, and lessen the oxygen. What, then, is there to hinder the air from becoming more and more loaded with carbonic acid gas, and less and less supplied with oxygen? Here, now, is a wonderful and beautiful provision of our Creator. He has provided means for constantly taking carbonic acid gas |