À l'anglaise, à la française, are used elliptically for à la modo française, à la mode anglaise, after the French fashion, after the English fashion. RÉSUMÉ OF EXAMPLES. Ce cavalier a mis pied à terre. his horse. Vous n'osez mettre le pied chez You dare not set your foot inside his lui. house. Mettez ces enfants à l'abri de la Shelter those children from the rain. pluie. Vous avez mis votre manteau à l'envers. Ce monsieur se met toujours à l'an- Hier nous nous mimes à table à dix yesterday? 14. We sat down to table at six o'clock. 15. Do you intend to commence boarding? 16. I intend to board with Mr. L. (chez M. L.). 17. When do you commence your journey? 18. We commence our journey to-morrow morning. 19. Did your son commence laughing? 20. No, Sir, he commenced weeping. 21. Why do you not commence working? 22. Because I am going to commence reading. 23. Does that lady dress after the English fashion? 24. She dresses after the Italian fashion. 25. Are those ladies well dressed? 26. They are extremely well dressed. 27. Will you not place yourself in the shade? 28. I will place myself in the sun, I am very cold. 29. Is your coat inside out? 30. No, Sir, it is right side out. 31. Is this the right side of this cloth (l'endroit)? 32. It is the wrong side (l'envers). 33. Are you not dressed after the English fashion? 34. I am dressed after the Italian fashion? 35. You are well dressed. KEY TO EXERCISES IN LESSONS IN FRENCH. 1. Votre beau-frère qu'a-t-il à faire ? 2. Il a des lettres à écrire. That horseman is come down from 3. A-t-il besoin de travailler? 4. Oui, Monsieur, il a besoin de travailler. 5. A-t-il l'intention de lire mon livre? 6. Il n'a pas l'intention de lire votre livre, il n'a pas le temps. 7. Votre sœur a-t-elle honte de marcher? 8. Ma soeur n'a pas honte de marcher, mais mon frère a honte de danser. 9. Votre cousine a-t-elle quelque chose à dire ? 10. Ma cousine n'a rien à dire, elle a peur de parler. 11. Est-il tard? 12. Non, Madame, il n'est pas tard, il est de bonne heure. 13. Avez-vous envie de lire la lettre de ma sœur ? 14. Avez-vous le courage d'aller à la guerre ? 15. Je n'ai pas le courage d'aller à la You have put your cloak inside out. Pourquoi vous mettez-vous à l'om- Why do you go into the shade? Ces enfants se mirent à rire. Je vais me mettre en pension. I will commence boarding. guerre. Nous allons nous mettre en voyage. We are going to commence our journey. 29. J'ai le temps de lire son livre. 30. Le menuisier a-t-il envie de vent. 5. Avez-vous mis votre frère au fait de cette affaire ? 6. Je ne l'en ai pas mis au fait. 7. Ne l'avez-vous pas mis à même d'étudier? 8. Je l'ai mis à même de s'instruire, s'il EXERCISE 132. parler? 31. Il a envie de travailler et de lire. 32. Votre fils a-t-il EXERCISE 37 (Vol. I., page 182). 1. Who wants bread? 2. Nobody wants any. 3. Do you not want your servant ? 4. Yes, Sir, I want him. 5. Does your gardener take care of your garden? 6. Yes, Madam, he takes care of it. 7. Does he take good care of his old father? 8. Yes, Sir, he takes good care of him. 9. Is your boy ashamed of his conduct? 10. Yes, Sir, he is ashamed of it. 11. Are you afraid of this horse or of that? 12. I am neither afraid of this nor of that. 13. Does our servant take care of your things? 14. He takes good care of them. 15. Are you afraid EXERCISE 38 (Vol. I., page 182). 1. Avez-vous besoin de votre domestique? 2. Oui, Monsieur, j'ai besoin de lui. 3. Votre beau-frère a-t-il besoin de vous ? 4. Il a besoin de moi et de mon frère. 5. N'a-t-il pas besoin d'argent? 6. Il n'a pas besoin d'argent, il en a assez. 7. Votre frère est-il faché de sa conduite? 8. Il est bien fâché de sa conduite, et bien faché contre vous. 9. A-t-il bien soin de ses livres ? 10. Il en a bien soin. 11. Combien de volumes a-t-il ? 12. Il en a plus que vous, il en a plus de vingt. 13. De quoi le jeune homme a-t-il besoin? 14. Il a besoin de ses effets. 15. Avez-vous besoin de vous reposer? 16. Votre frère n'en est-il pas étonné? 17. Il en est étonné. 18. Avez-vous envie de lire les livres de votre frère ? 19. J'ai envie de les lire, mais je n'ai pas le temps. 20. Avez-vous le temps de travailler? 21. J'ai le temps de travailler, mais je n'ai pas le temps de lire. 22. Le jeune frère a-t-il soin de ses effets? 23. Il en a bien soin. 24. Ce petit garçon a-t-il peur du chien? 25. II n'a pas peur du chien, il a peur du cheval. 26. Avez-vous besoin de pain ? 27. Je n'en ai pas besoin. 28. Êtes-vous content de la con29. J'en suis content. 30. Votre frère a-t-il duite de votre frère? envie de lire mon livre ? 31. Il n'a pas envie de lire votre livre, il est fatigué. 32. Ce jeune homme est-il fâché contre vous ou amis ? 33. Il n'est faché ni contre moi, ni contre ses vous besoin de mon dictionnaire ? 35. J'ai besoin 1. Did the gentleman alight this morning? 2. No, Sir, he would not alight, he had no time. 3. Have you put that insolent person out of doors? 4. No, Sir, but I forbade him to set his foot in my house. 5. Did you shelter those little children from the rain? 6. I sheltered them from the rain and the wind. 7. Have you enabled your son to study medicine (la médecine)? 8. I have enabled him to study medicine, if he 9. Have you put on your coat inside out? 10. I have not put it on inside out, but right side out. 11. Did you put yourself in a passion? 12. No, Sir, I did not become angry. 13. Did you sit down to table at four o'clock naire et de celui de votre frère. wishes to do so. EXERCISE 39 (Vol. I., page 183). 1. Does your mother like reading? 2. Yes, Miss, she likes it much better than her sister. 3. What hat does your nephew wear? 4. He wears a silk hat, and I wear a straw hat. 5. Does that lady love her children? 6. Yes, Sir, she cherishes them. 7. Do you furnish those merchants with goods? 8. I furnish those merchants with goods, and they give me money. 9. Do your companions like fine clothes? 10. Our companions like fine clothes and good books. 11. Are you looking for my brother? 12. Yes, Sir, I am looking for him, but I do not find him. 13. Does your brother lose his time? 14. He loses his time and money. 15. Do we always lose our time ? 16. We lose it 17. Do you owe much money? 18. I owe enough, but I do not owe much. 19. Do you sell your two houses to our physician? 20. I sell only one, I keep the other for my sister-in-law. 21. Do you receive money to-day? 22. We receive but little. 23. Does your joiner finish his work early? 24. He finishes it late. 25. At what hour does he finish it? 26. He finishes it at half-past twelve. 27. very often. We finish ours at twenty minutes to ten. EXERCISE 40 (Vol. I., page 183). 1. Votre compagnon aime-t-il la lecture ? 2. Mon compagnon n'aime pas la lecture. 3. Votre père aime-t-il les bons livres ? 4. Il aime les bons livres et les bons habits. 5. Devez-vous plus de vingt dollars? 6. Je n'en dois que dix, mais mon frère en doit plus de quinze. 7. Avez-vous tort de finir votre travail de bonne heure? 8. J'ai raison de finir le mien de bonne heure, et vous avez tort de ne pas finir le vôtre. 9. Recevez-vous beaucoup d'argent aujourd'hui ? 10. Je n'en reçois guère. 11. Donnons-nous nos meilleurs livres à ce petit enfant ? 12. Nous ne les donnons pas, nous le gardons parceque nous en avons besoin. 13. Vendez-vous vos deux chevaux ? 14. Nous ne vendons pas nos deux chevaux, nous en gardons un. 15. Finissezvous votre travail ce matin ? 16. Oui, Monsieur, je le finis ce matin de bonne heure. 17. Votre beau-frère aime-t-il les beaux habits? 18. Oui, Madame, il aime les beaux habits. 19. Cherchez-vous mon neveu? 20. Oui, Monsieur, nous le cherchons, 21. Perd-il son temps? 22. Il perd non-seulement son temps, mais il perd son argent. 23. Combien d'argent a-t-il perdu aujourd'hui ? 24. Il a perdu plus de dix dollars. 25. Votre menuisier finit-il votre maison ? 26. Il finit ma maison et celle de mon frère. 27. Vendez-vous de bons chapeaux? 28. Nous vendons des chapeaux de soie, et les chapeaux de soie sont bons. 29. Quel âge votre compagnon a-t-il ? 30. Il a douze ans et sa sœur en a quinze. 31. Votre frère aime-t-il la viande ? 32. Il aime la viande et le pain. 33. Recevez-vous vos marchandises à deux heures? 34. Nous les recevons à midi et demi. 35. Nous les recevons à une heure moins dix minutes. come ? EXERCISE 41 (Vol. I., page 207). 1. Where are you going, my friend? 2. I am going to your father's; is he at home? 3. He is this morning. 4. Whence do you 5. We come from your house and from your sister's. 6. Who is at our house? 7. My neighbour is there to-day. 8. Where do you intend to take these books? 9. I intend to take them to the house of the physician's son. 10. Are you wrong to remain at home? 11. I am not wrong to remain at home. 12. Has the watchmaker good ? watches at home? 13. He has no watches at his house, he has some in his warehouse. 14. To whose house do you take your books ? 15. I take them to the binder's. 16. Do you go to the Dutch captain's 17. We do not go to the Dutch captain's, we go to the Russian major's. 18. Is he at your house or at your brother's? 19. He lives at our house. 20. Do we not live at your tailor's ? 21. You do. 22. Whence does your painter come? 23. He comes from his partner's house. 24. Where do you take my shoes and my waistcoat ? 25. I am taking your shoes to the shoemaker's and your waistcoat to the tailor's. LESSONS IN GEOGRAPHY.-XXII. EUROPE. Position on the Earth's Surface. The continent of Europe forms the north-western part of the Old World, or great triple continent in the eastern hemisphere, and lies wholly within the northern hemisphere, to the north-east, east, and south-east of the British Isles. It is situated almost wholly within the north temperate zone, with the exception of some of the extreme northern parts of Norway, Sweden, and Russia, which lie within the north frigid zone. The small map of the world on the plane of the horizon of London (see page 197) will show how favourably Europe is situated for commercial relations with the rest of the world, as it lies almost in the centre of the hemisphere which contains the greatest part of the land on the earth's surface, and is thus conveniently placed for carrying on an active export and import trade with all other parts of the daries.-Europe is bounded on the north by the Arctic Ocean; on the south, by the Mediterranean Sea, the Sea of Marmora, the Black Sea, the Sea of Azof, and the chain of Mount Caucasus; on the east by Asia, which is separated from it by the chain of the Ural or Oural Mountains, the river Ural, and the Caspian Sea; and on the west by the North Atlantic Ocean. Extent, Length, Breadth, etc.-This continent extends from lat. 36° 2' N. to lat. 71° 10 N., and from long. 9° 32′ W. to long. 68° E. Its greatest length, from Cape St. Vincent, in Portugal, to the north-eastern extremity of Russia in Europe, is about 3,500 miles; while its greatest breadth in a straight line from North Cape, in Norway, to Cape Matapan, the southern extremity of Greece, is about 2,450 miles. The most northerly point of Europe is usually considered to be the North Cape, in lat. 71° 10′ N. and long. 26° 1' E.; the most southerly point is Tarifa Point, near Gibraltar, in lat. 36° 6' N. and long. 5° 21' W.; the most easterly point is the head of Kara Bay, the southernmost extremity of the Kara Sea, which lies to the south of Nova Zembla, very nearly in lat. 68° N., long. 68° E.; and the most westerly point is Cape Roca, near Lisbon, in lat. 38° 47′ N. and long. 9° 31′ W. The surface of the land in Europe contains, according to the latest estimate, more than 32 millions of square miles, or more exactly 3,812,200 square miles; and its population is upwards This number, of 280,000,000, or more exactly 283,000,000. however, must be taken only as an approximation, on account of the constant increase, day by day, owing to the excess of the births over the deaths in every 1,000 of the population. Hence, there are in this continent on an average about 73 inhabitants to every square mile; but as Russia in Europe is reckoned to contain above two millions of square miles, or more than half of the continent, and to have a population of about 64 millions, or less than one-fourth of that of the whole continent, it follows that in Russia there are on an average about 30 inhabitants to every square mile, and in the rest of the continent on an average about 122 inhabitants to every square mile. The surface of the inland seas belonging to Europe is estimated at nearly 1 millions of square miles, or more accurately at 1,370,000 square miles, distributed in the following proportions:-The White Sea, in the North of Russia, 45,000; the Baltic, lying between Sweden and Russia, having Germany on the south, and Denmark at its entrance, 135,000; the Mediterranean Sea, lying south of Europe, 870,000; the Black Sea, south of Russia, 180,000; and the Caspian Sea, or Great Inland Lake, 140,000. The part of the Atlantic Ocean which flows between Great Britain and the continent, is called the German Ocean or North Sea; its passage on the south is called the English Channel, and at the narrowest part the Strait of Dover, which is about 20 miles across, and is reckoned 200 feet at its greatest depth. The entrance to the Baltic, or East Sea, is by a channel of which the part between Norway and Denmark is called the Skager-Rack, and the part between Sweden and Denmark the Cattegat. In the latter part there are three straits called the Sound, between Sweden and the Danish island of Zealand, about 2 miles wide; the Great Belt, between Zealand and Fünen, about 8 miles wide; and the Little Belt, between Fünen and the peninsula of Jutland, or Continental Denmark, about three-quarters of a mile wide. In the northern part of the Baltic are the Gulfs of Bothnia, Finland, and Riga. On the west of France and north of Spain, lies a part of the Atlantic called the Bay of Biscay. South of Spain, between Europe and Africa, lies the entrance to the Mediterranean, called the Strait of Gibraltar, which is about 13 miles broad in the narrowest part, and about 1,000 feet deep. The length of the Mediterranean is estimated to be about 2,300 miles, and its greatest depth upwards of 6,000 feet, or more than a mile and a furlong. Its waters are more salt than those of the Atlantic, from which a strong current runs continually into the former. The tides in the Mediterranean, owing to its narrow entrance, are very small, and in many places the ebb and flow are scarcely perceptible. The Gulf of Venice, or the Adriatic Sea, is an arm of the Mediterranean which lies east of Italy and south of the Austrian dominions; and the Archipelago (anciently the Egean Sea), another arm between Greece and Asia Minor, studded with islands famous in ancient history. The waters of the Archipelago communicate with those of the Sea of Marmora (anciently the Propontis) through a narrow channel or strait called the Dardanelles (anciently the Hellespont), about half a mile in width at its narrowest part; those of the Sea of Marmora with those of the Black LESSONS IN ARITHMETIC.-XXXI. SHORT METHODS OF REDUCTION WITH REFERENCE TO MONEY. considerable use. 9. To find out how much a Given Sum per Day amounts to in a Year. There are 240 pence in a pound, and 360 = 240 +120, or 240 + 2; and therefore one penny per day amounts to one pound and half a pound in 360 days. Sea (anciently the Euxine Sea) by the Strait of Constantinople WE proceed to explain two or three artifices which are often of (anciently the Thracian Bosphorus), which is still narrower than the former; and those of the Black Sea with those of the Sea of Azof or Azov (anciently the Palus Mæotis, the Maotian Fen) by the Strait of Yenikale (anciently the Cimmerian Bosphorus, i.e., the Cimmerian Ox-Ford), about a mile and a half wide. The eastern part of the Mediterranean adjoining Turkey in Asia is called the Levant (from the French, levant, rising), because to the inhabitants along the northern and southern shores of the Great Sea the sun appears to rise in that quarter of the horizon. The waters of the Caspian Sea or Lake are not superficially (that is, on the surface of the land) connected with those of the Mediterranean, being separated from them by the Caucasian chain of mountains. Owing to the indentation of the continent of Europe by seas, bays, and gulfs, it has a greater line of seacoast, in proportion to its size, than any other continent on the For 6d. + 3d. 9d., and therefore 6d. a day amounts to £9 in 360 days, face of the globe; and lying almost wholly within the north temperate zone, it is better adapted for the health, convenience, and commercial intercourse of its inhabitants. Hence its superiority in point of power, intelligence, and wealth to all the other continents. The total length of its sea-coast is estimated at about 17,000 miles, or rather more than two-thirds the circumference of the globe. In the north of Europe there are only two peninsulas worthy of particular notice, namely, the Great Scandinavian Peninsula, which includes Sweden and Norway, and lies between the Baltic Sea and the North Atlantic Ocean; and the Peninsula of Jutland, which includes Continental Denmark, and lies between the Cattegat and the North Sea. It is joined to the continent by the Isthmus of Schleswig or Slesvig, which is about 25 miles wide. In the south of Europe there are three peninsulas of great importance in history, namely, the Iberian or Spanish Peninsula, including Spain and Portugal, which lies between the Mediterranean and the Atlantic, and is separated from the rest of Europe by the mountain chain of the Pyrenees stretching from the Bay of Biscay to the Gulf of Lions; and Greece (anciently the Peloponnesus, the Island of Pelops), sometimes called the Morea, which is joined to the mainland called Hellas (anciently Achaia) by the Isthmus of Corinth, this isthmus being only about four miles wide at the narrowest part. To these peninsulas may be added the Crimea, which is the most southern part of Russia, and which is joined to the mainland by the Isthmus of Perecop, a neck of land only about five miles wide at the narrowest part. SUMMARY OF BOUNDARIES. Adriatic, or Gulf of Venice, N. of Mediterranean. Archipelago, N.E. of Mediter. ranean. Baltic Sea, N. of Germany. English Channel, S. of England. Genoa, Gulf of, S. of Piedmont. Kara Sea, N. of Russia. Levant, E. of Mediterranean. White Sea, N. of Russia. SUMMARY OF PRINCIPAL STRAITS. nople, N.E. Sea of Marmora. St. George's Channel, Irish Sea. SUMMARY OF PRINCIPAL PENIN- Crimea-Russia. Italy-New Kingdom of Italy, North Sea, or German Ocean, E. Scandinavia-Sweden and Norway. Hence, to find how much a given sum per day amounts to in 360 days, we have only to reduce the sum to pence, and add half the number of pence to the result. This will give the number of pounds to which the sum will amount in 360 days. To find the amount in one year (365 days), we must add 5 times the sum per day to the pounds found by the first part of the process. Thus 6d. a day is £9 2s. 6d. a year; == and therefore to £9 2s. 6d. in 365 days. Thus 7d. a day will amount to £10 10s. in 360 days, = For 7d. (× 7d.): 10 d., which corresponds to £10 10s. for the 360 days. Adding 5 x 7d., or 2s. 11d., we get £10 12s. 11d. for a year. EXAMPLE.-Again, to find how much 2s. 6d. a day amounts to in a year. == 2s. 6d. 30 d. 301d. + (30 d.) = 45 d., and hence in 360 days 2s. 6d. amounts to £45 15s., and therefore, in 365 days, to £45 15s. + 5 (2s. 6d.), or to £46 78. 818. 10. To reduce a Given Sum of Money to the Decimal of a Pound. 18. = = £16 = £180 = £.05. Hence, to reduce any number of shillings to the decimal of a pound, multiply the number by 5, and cut off two decimal places. Thus 23 shillings are 1·15 of a pound. Again, by calculation, we find that a farthing is 0010416 of a pound. Now the difference between this decimal and 001 is 0000416, or very nearly '0000417; and ·001 = Hence, Now (0010000417) 23023+0009591023 to three But (001+0000417) 24024 × 0010008025 to three decimal places. Hence, for sums of 24 farthings and upwards, we must add one to the number of farthings, and then cut off 3 decimal places as before. This we may do until the number of farthings is large enough to cause more than one to be carried to the 3rd place of decimals. Thus 7 d. 31 farthings; and therefore, when reduced to the decimal of a pound, it is, correctly to 3 places, 032. Now 47 (0000417)=0019599, which still only adds 1 in the 3rd decimal place; and therefore, as far as 48 farthings (one shilling), the above rule holds. As soon as a shilling is reached, we find the decimal of a pound by the rule first given. EXAMPLE. Reduce 13s. 81d. to the decimal of a pound. Find how much the following sums per day amount to in s year : NITROGEN: SYMBOL, NATOMIC WEIGHT, 14 — DENSITY, 14. NITROGEN is the chief constituent of the atmosphere, of which it forms four-fifths. From being an element of nitric acid, Chatal gave the gas the name here adopted, following the example of Lavoisier. The French chemists call it azote, from its inability to support life. It exists in almost all animal and in many vegetable products. 1. Pass air through a porcelain tube containing copperturnings, which is surrounded by red-hot charcoal. The heated copper combines with the oxygen, and the nitrogen is received in a gas-holder. 2. In a capsule of Berlin ware (Fig. 31) float a piece of phosphorus on water; and, after having ignited it, place over it a bell-jar. The phosphorus takes all the oxygen to form phosphoric acid (PO), a solid, which is readily absorbed by the water, the gas remaining in the jar being nitrogen. 3. The oxygen may be absorbed from the air slowly, either by suspending in the jar a stick of phosphorus-in this case phosphorous acid (P,O,) is gradually formed-or by placing in capsule a mixture of iron-filings and sulphur moistened with water. The experiment is arranged as the last, but must be untouched for at least twenty-four hours; by that time all the oxygen in the jar will have been absorbed by the mixture, and the water, rising to fill the place of the absorbed gas, will be found to occupy one-fifth of the jar. There are other ways of obtaining nitrogen from its compounds, thus: if chlorine gas be passed into water impregnated with ammonia, the reaction will be = 4NH, (ammonia) + Cl, 3NH Cl (sal-ammoniac) + N. Care must, however, be taken that the ammonia be in excess, lest one of the most explosive of bodies-the chloride of nitrogen -be formed. Properties.-The gas is colourless, inodorous, and tasteless. It is a little lighter than air, its specific gravity being 0.9713; its affinities are very low; it refuses to combine with other elements, except under peculiar circumstances. Hence it will not support combustion, and is fatal if breathed in a pure state; not that it has any poisonous qualities, but is incapable of supporting life. certain gases. THE ATMOSPHERE. alteration, either in volume or temperature, will be observed, and air will be formed. In every case, when chemical combination takes place, there is invariably either an alteration in volume or temperature, or both. 2. If air from water, or from melted snow, be analysed, it will be found that oxygen is present in almost double the proportion in which it is present in the atmosphere. This fact has been already alluded to, as caused by water being capable of absorbing more oxygen than nitrogen. If, however, the gases were chemically combined, the water must absorb them as one body-air, and they would appear in the water in the same proportion as in the atmosphere. The volumes of the gases in the air may be roughly ascertained by abstracting the oxygen from the air in a graduated bell-jar, by burning phosphorus as above described, being careful that the diminution of the volume be measured when the temperature has fallen to what it was at the commencement of the experiment. But the most accurate method is by the eudiometer (Fig. 32). The instrument is used thus: The tube is filled with water, then a portion is poured out. Place the thumb on the open end, and by properly inclining the tube, the air may be made to pass to the sealed end. The water is now made level, so that the air may be under no undue pressure, and the number of measures of it read off on the graduated scale. The open end is completely filled with water, and the instrument is inserted in a pneumatic trough; where hydrogen is passed into it, the quantity being at least more than half the air in the eudiometer. The instrument is again closed with the thumb, and the mixture of air and hydrogen got into the sealed end. The water in the two tubes is again levelled, and the volume of the mixture read off. The instrument is held firmly, as in the diagram, and the platinum wires, a and b, connected with the outside and inside coatings of a charged Leyden jar. The spark which passes in the tube, fires the mixture, and the oxygen in the air and the hydrogen combine to form water. The temperature is allowed to equalise itself, and the water is again levelled and another reading made. It will be evident that the difference between the two last readings will give the quantity of gas which has gone to form the water in the explosion. Now we know that this consisted of all the oxygen in the air, and some of the hydrogen we introduced; but we also know that onethird of the quantity must be oxygen, this being the proportion by volume of the gas in water. Hence we arrive at the quantity of the oxygen in the air with the greatest accuracy. To determine the composition of the air by weight, it is necessary to weigh the copper, in the first process given for the preparation of nitrogen, before and after the experiment, being careful to ascertain the quantity of air passed through the heated porcelain tube. Thus the composition of air is Next to these two gases, the most important ingredients in the atmosphere are vapour of water and carbonic acid gas. To determine their respective quantities, a system of U tubes (Fig. 33) is connected with an "aspirator," which is simply a vessel which has an opening at the top, and another at the bottom; it is filled with water, and when the lower tap is turned, it is evident that as the water flows out air is drawn in through the opening at the top, and by connecting it with the tubes, a current of air is made to pass through them. The first two, a and b, are packed with pieces of pumice stone, soaked with sulphuric acid. This retains all the moisture the air which passes through contains. It next traverses a system of bulbs, suggested by Liebig, which are partially filled with a strong solution of caustic potash. Here all the carbonic acid gas is absorbed, forming with the potash carbonate of potash. The air, however, in passing through the liquid, will take up some moisture, and thus destroy the accuracy of the experiment; therefore, this moisture is again absorbed by the sulphuric acid in the tube d. A fourth tube, e, similar to d, intercepts any moisture which may attempt to penetrate the tubes from the aspirator S. The t and the bulbs c are accurately weighed. Th 1. If 4 volumes of nitrogen and 1 of oxygen be mixed, no slightly opened, and the air slowly drawn th Around our globe rolls a gaseous ocean, which is a mixture of Oxygen and nitrogen greatly preponderate over the others, and are found in the proportion of 4 volumes of nitrogen to 1 of oxygen. The chief use of the nitrogen seems to be to dilute the oxygen. That the atmosphere is not a chemical compound, but a mixture, may be thus proved : |