Εικόνες σελίδας
[ocr errors][ocr errors]

1. aštoc, a, ov, worth, worthy; roMA. aš. of great value. 2. Avvov, wwog, o, Hanno, the Carthaginian general. strepage (from rspac, beyond), transported, carried over; trečov (from resoc), of foot-soldiers; it reig (itrirevc) horsemen, cavalry. 3. Smpac (>mp, oc) the Seres, an Indian people who produced silk ; Zmy (infin. of Żaw, I live), to live ; XaA6atovc, the Chaldeans; ratgarov erm, literally, above the hundred years; so with either number the article is used when a whole is contemplated in construing into English you must drop the article in such cases: 8vovy (from 3too, I live, 8toc, Wife), to live. 4. (3:00 at, to have livet'; Aeyerat, is said. 5, ers\evrmos (from rooc, an end), came to an end, died; OAvuoriac, adoc, ), an Olympiad, a period of five years; the Greeks reckoned time by Olympiads as we date from the birth of Christ, A.D. : 8woug, having lived; erog Év, &c., one gyear to eighty, that is 81 years. 6. stars, said ; Nspov, ovoc, č, the Roman emperor Nero; aret)\sig (from atrstMew, I threaten), threatenest. 7. Skoxaarikog, ov, Ö, an idler, a witling ; atropov, being in straights ; strutrpaoxe, sold. 8, sporn 9sic (sporaw, I ask), being asked ; són, said, answered. 9. Östyua, aroc, ro, a specimen; treptépépé (trept and £epw) carried about. 10. Yuyvooks, pronounce the same judgment; trooc xapw arowy, doing nothing for favour. 12, apsaxsw, to please, wish (try) to please all. A 13. ataxvvov (aloxvvopal), reverence. 14, soatratav, to deceive, cheat. 15. ayvost, be thou ignorant. 16. gkurorouoc, ov, Ö, a leather cutter, from oxvroç, ove, ro, a hide, loather; svyevng, well-born; apxer, ar. suov, literally begins from me, that is, with me; traveral, comes to an end. 17. atrskpwaro (atro and kpwoo), answered; extric, hope; Katyap, for. * 19. osperat, is carried, flows ; ex80Xm, mg, j, a falling out of; asypt, up to, down to, tintić.

21, sécAavvet, marches.

[merged small][ocr errors][ocr errors][merged small][merged small][merged small]

4. 'O exov vovy, let him who has mind; p.mptoard (ongog, a bean ; the Greeks reckoned with beans, as the Latins did with pebbles, calculi, whence calculate), calculate.

5. §uskwxws (kwxww, I hinder), tried to hinder; 3atrio 6m vat, to be baptized; 3atrro, I dip; spxm, comest thous?

6. Bagrađers (3aorača, I carry), bear; oitwg, thus; avarxn. (ava, wy, tropow, I foll), fill up, fulfil.

7. Kavymouc, swg, ), boasting; ovvetónoic, swg, ), conscience; ‘atrāorng, mroc, j, simplicity; sixtkpweig, ac, ), sincerity; oapkukog (oapá, flesh), fleshly: aveotpap, we have behaved (conducted) ourselves, we have acted; treptogorspoc (trept, denoting abundance), more exceedingly.

8. Trapak}\maic, soc, i. exhortation, comfort; trapapov6-ov, ov, ro, solace, soothing ; kotvovua, ag, à, community; trysvpia, arog, spirit; a r\ayxvov, ov, 70, bowels ; ouxt puptoc, ov, o, pity ; tr}\mpwordre (trampoo, Ifill), fulfil; pps.unre (ppsvec, the mind), that ye desire, aim at, love; avpubvXot (buxn, the soul), being of the same soul, of one soul; spuésta, ag, à, strife; kevodošta, (revoc, empty), vainglory; ratstvodpoovyn, mc, i (rarelvoc, humble), lowliness of mind ; })ovgewoi, thinking, considering; torspexsw, to be superior; okotrovvreg (gkorstv, to look, hence strugeotrew, to overlook, whence our word bishop).


The pronouns are among the oldest words in every language. Consequently, if in two languages the pronouns are found to have strong marks of resemblance, we may safely conclude that those two languages are akin to each other. Such marks of resemblance may be found by comparing the Greek and the

[ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small]
[merged small][ocr errors][merged small]


[ocr errors]

the man himself.

§ 111. PREFositions coxstruED witH

Qué, out; out of. Stad, after ; to; acQIuffet, without ; outside cording to, of 9tádist, next; next to. $8et, by; near; with. 9teóft, together with. £8tnutem, within. $)6, over; at. (śntgegett, towards; oppo- ©ammt, together with site to. &eit, since. Öegenitóer, over against. $on, from; of. ©emää, conformably 3u, to, at. with. 3umiber, against; COIN is. Joit, with. trary.

§ 113. PEEPositions construED witH THE AccusATIVE.

av6pwtrou ruveg SOIne Islen. interrogative rig av6pwaroc, which man? | relative Ö apoptotroc &c, the man who. Upossessive 6 splog trarsp, my father. Pronoun syw, I; ov, thou; oil, of himself.

[ocr errors]


[ocr errors]

(3) Prepositions construed with (4) Prepositions construed with


[ocr errors]

We now give again the prepositions governing the several cases respectively, with their proper definitions: subjoining, also, some few observations on such of them as seem to require further explanation, And first, we mention those construed with the genitive.

Øutd, through. ©ombet, apart; without

ğüt, for; the place of lim, about; around

@egem or gen towards. #Bibet, against.

Soğme, without. § 115. PREPositions coxstruED witH THE DATIVE or


QItt, on ; at ; near, lieber, over; above.

2Iuf, on ; upon. 1Inter, under; among

$intet, behind. $or, before.

3rt, in, or into. 3misden, betwixt; be

9tećen, beside. tween.


These prepositions govern either the accusative or the dative; but not without a difference of signification: for, when motion towards, that is, motion from one point to another, is indicated, the accusative is required: when, however, motion or rest in any given place or condition is signified, the dative is used; thus, bet Rnabe sauft in ben Öarten, the boy runs into (motion towards) the garden; bet &nabe (àust in bem (Satten, the boy runs in (motion within) the garden. This is the general principle; which will be found, with more or less distinctness, everywhere to prevail in the use of the prepositions of this class.

[blocks in formation]
[ocr errors][subsumed][merged small][ocr errors][merged small][merged small][ocr errors][ocr errors][ocr errors][ocr errors][ocr errors][ocr errors][merged small][ocr errors][merged small][merged small][merged small][ocr errors][merged small]


HAwixG, finished our preliminary consideration of tae metals which yield yellow or white precipitates with hydrosulphuric acid, or hydrosulphate of ammonia, I purpose now leaving the metals for a time, and discussing the chemical properties of certain non-metallic elements. Oxygen shall be the subject of discussion and experiment in the present lesson. When I inform, you that oxygen constitutes, at least, threefourths of the crust of the globe and its living inhabitants, you will admit that it must be an important element. Oxygen, by combination with other bodies, may assume the condition of solid, liquid, or gas, but obtained separately, it is always gaseous; therefore we shall have to obtain it and examine it under the form of oxygen gas. There are several methods of generating oxygen gas, but only one capable of being followed by a student who is unsupplied with special instruments. This process I shall describe with a view to its adoption; the others I shall afterwards mention, with the object of making their theory understood. First, let us begin by deasribing the instruments necessary. You will require either a large test tube, about half or threequarters of an inch in diameter, made by preference of German glass, as being more infusible than our own ; a bent glass tube, and a pneumatic trough, or its substitute, and a receiver. You will require, in point of fact, an arrangement bike the fol


[merged small][ocr errors]

or such a substitute for it as your ingenuity, stimulated by your necessities, will easily supply. I need scarcely indicate that your distillatory apparatus being small (i.e. the test tube), yeur receiving bottle must be small also. In the present case, ounce or ounce-and-a-half phials will be of sufficient dimensions. Scarcely more necessary is it to remark, that the distillatory apparatus, as indicated above, will require some sort of support not represented in the diagram, and that the regular pneumatic trough may be dispensed with, by using a basin ims the receiving bottle being prevented slipping by means of some heavy material, such as lead, brick, &c., placed in the basin, and indicated by the letter B in our sketch. So much then for the apparatus.

Fig. No. 2.

The substance we shall require as the oxygen-yielding material, is a mixture of two parts by weight of the salt termed chlorate of potash, and one part by weight of peroxide (black oxide) of manganese; the substance procurable in commercial circles, under the simple name “manganese.” If the student should by chance live in a remote place, where old chemical terms still dominate, the druggist will inform him that he does

not keep such a material as chlorate of potash; if the student ask for it under the name of oxynuriate of potash, he will be more successful.

[ocr errors]

The mixture of chlorate of potash and black oxide of manganese should be effected, if possible, by rubbing the two togo in a mortar; mere incorporation, however, with the lade of a knife will answer sufficiently well. You will not do amiss by preparing at least an ounce of this mixture, and preserving it properly labelled in a bottle. The operation of generating oxygen will frequently be required in the course of future experiments, and students who do not possess a gasometer must prepare the gas little by little as it may be required. Pour about a tea-spoonful of the mixture into the test tube, replace the cork, arrange the apparatus, and apply heat. Oxygen gas will come over rapidly, but the first portions being necessarily contaminated with atmospheric air previously exästing in the apparatus, must be thrown away; all subsequently collected is pure oxygen gas.

Collect six or seven bottles full of it, and before proceeding to try any experiments, follow me in discussing the theory of its production, and the nature of gases generally. What, then, is a gas 2 I know of no definition which is logically distinctive. The definition long received was, “a permanently elastic #tid,” but it is incorrect. Nevertheless, the expression per

manently elastic fluid, although not sufficiently general in its

significance to comprehend all gases, indicates the most salient property of so many, and applies so perfectly to the gas under consideration, that we may profitably discuss its meaning. I have therefore to inform you that oxygen gas is permanently elastic; that is to say, neither cold nor pressure, nor both comined, nor, in short, any other agency, has yet succeeded in condensing oxygen gas into a liquid or a solid condition. Now many gases equally transparent and colourless as oxygen have been condensed into liquids, and even solids. I dare say, most people have observed the bubbles which escape from ginger-beer, soda-water, champagne, &c. These bubbles are due to the presence of a transparent, colourless gas, named, carbonic-acid ; it has not come under our notice yet, but it speedily will. By the application of intense cold and pressure, this gas may be converted into a solid, having the aspect of Snow. A similar result has been accomplished in the instance of many other gases; therefore, it follows that the neatly turned definition, formerly accepted as characteristic of gases, is no longer admissible. Oxygen gas, however, has resisted £very attempt at liquefaction or solidification ; yet analogy leads us to suppose that, if we could apply sufficient cold and sufficient pressure, a similar result would ensue.

Abandoning all logical definition of a gas as hopeless, it is still in our power to entertain a good, general appreciation of the leading characteristic of gases, by remembering that persistent elasticity, under common circumstances, is the special feature by which they are contradistinguished from vapours; the latter being readily condensed. For example, steam, or aqueous vapour, is the result of the application of heat to water. We all know that steam is elastic, or else what would be the use of expansion gear in a steam engine But it is not permanently elastic under ordinary circumstances, for immediately on coming into contact with the air, or any material sufficiently cold, it condenses into water. When thus condensed, it folls a position analogous with a liquefied gas; and when, on the further application of cold, ice results, we have a condition analogous to that of a solidified gas.

Perhaps some such question as this occurs to you. How am I to reconcile the apparently incongruous statements that oxygen can only be procured as a gas, and that three-fourths of the material elements of our globe are composed of it There is no contradiction involved in these statements; as a constituent of the solid and liquid matters of the globe, oxygen is combined, and chemical combination, you are well aware, produces wonderful changes. Both clay and flint contain a vast amount of oxygen, the latter nearly fifty per cent; but the oxygen existing in combination, its solidity is attributable to that circumstance.

Experiments with Oxygen Gas.-Proceeding to examine systematically the properties of oxygen gas, attend to the following directions.

(1.) Having uncovered a bottle full of the gas, pour into it a little transparent lime-water, and agitate; not the slightest change results.

(2.) Immerse in another bottle a slip of moisteried litmus paper, and another of moistened turmeric paper; not the slightest discoloration of either slip takes place, thus demonstrating that oxygen gas is neither acid nor alkaline.

(3.) Take a splinter of wood, such as a bit of lath, or, a long brimstone match, ignite the end, wait for a few seconds until an incandescent coal has formed; blow out the flame and plunge the glowing though not flaming extremity into a bottle of oxygen gas. Immediately the wood bursts into flame, thus indicating the presence of a gas different from any already noticed in these lessons. It is thus proved by this experiment that oxygen gas is a supporter—a very powerful supporter—of combustion. It is moreover proved by the same experiment that oxygen gas is not a combustible, because, although causing the stick to burst into flame, itself does not. Remem: ber how diametrically opposed these qualities are to those of hydrogen. If the mouth of the receiving bottle be large enough, the preceding arrangement may be varied as follows.

Fig. No. 3.

Instead of a slip of wood use a piece of wax taper, attached, as represented in the accompanying diagram, to a bent piece of copper or brass wire. Proceed in other respects exactly as in the experiment just detailed.

Fig. No. 4.

(4.) Perform the following comparative experiment: take two bottles full of oxygen, and open them. Place one to stand during a few seconds open upon a table—mouth upwards of course. Hold the other for a similar period open, and inverted, as represented in the diagram; finally, by means of an ignited stick, test either bottle for the presence of oxygen. The upright bottle will be found still to contain it; from the other it will have departed; thus we prove that oxygen gas is specifically heavier than the atmosphere. Nevertheless, it is only heavier by a very slight amount; calling atmospheric air one or unity, the specific gravity is one and onetenth and a little more—how much this “little more may be, chemists are not agreed upon.

[blocks in formation]
[ocr errors]

purity, without any halo surrounding it; a reddish halo. however, envelopes the flame which is generated under similar treatment in protoxide of nitrogen, or laughing gas. Moreover, oxygen gas is devoid of taste, whereas, protoxide of nitrogen is perceptibly sweet.

Although we have succeeded in finding the characteristics which distinguish oxygen from all other gases, it is far too important an element to be discussed in this one lesson. In my next I shall describe another series of experiments, having for its object the teaching of the various relations of oxygen to other bodies. This lesson I shall terminate with an examination of the changes which ensue in the mixture of oxide of ymanganese and chlorate of potash, as causes, concomitants, or results of the evolution of oxygen gas.

First, them, let me remark, that although peroxide of manganese contains, as its name indicates, a great deal of oxygen ; although it is frequently employed alone as an oxygen-yielding material; yet, used as we have used it in combination with chlorate of potash, it does not undergo the slightest change. There are some instances of chemical decomposition determined or aided by mere contact with a body that undergoes no change in itself. Chemists designate this sort of action “catalytic;” they might as well term it “incomprehensible” at once. However, not to weary you with mere names, remember that the oxide of manganese determines, we know not why or how, an evolution of oxygen gas from chlorate of potash at

[ocr errors]

138. Fractions may also be subtracted, like integers, by setting them down, when the sign of the subtrahend is changed, one after the other, without reducing them to a common denominator.

[ocr errors]

139. To subtract an integer from a fraction, or a fraction

from an integer.

Change the sign of the subtrahend, and write it after the minuend; or, put the integer into the form of a fraction, and then

a much lower temperature than would otherwise be necessary. proceed according to the general rule for subtraction of fractions.

Chlorate of potash, if heated alone, evolves all its oxygen, provided the temperature to which it is exposed be sufficiently high out it is almost too high for glass to bear ; hence, the agvantage of mixing the chlorate with oxide of manganese. In the following diagram I shall leave out the oxide of manganese altogether.

5 Oxygen —- 6 Oxygen 1 1 Chloric ~40 (evolved) Chlorate acid 1 Chlorine S. / =48 Of =76 -36 K potash 1 Oxygen / 124 1 Potash -8 –48 1 Potassium — 1 Chloride ={0 of potassium =76

LESSONS IN ALGEBRA.—No. IX. (Continued from p. 118.)


137. RULE.—Change the sign of the subtrahend, that is, of the fraction to be subtracted ; and then proceed as in addition of fractions.

[merged small][ocr errors]

Here, reducing the fractions to a common denominator, they

[ocr errors]

h h— 10. From A subtract in. Ans. – — m or Žny O y 3/ bd–-ch 11. From 4g-H. : subtract 3a– 7" Ans. a+ #. b— —b 2b–2c 12. From 1-1- *E* subtract too. Ams. 1-H °. d d d d— d—b 13. From a+3h— * subtract 3a–h-F 5b—5d Ans. 4–2a+* * e ,-- d —ca:—bd—b 14. From * take +y. Ans. ac-cr-00-by, b C bc —d by— da: 15. From a—-b take 6 © Ans. gy--by-ca-Eda. e 3C 2:y & C 'ad-l-ay—bc—Hez 22-4-3d 17. From a- -* take 3d. Ans. a- 2x+3dy. 3/ 2 2y a—h a—b 18. From 2+y take a-. Ans. r—-y— −. a:—y a—b a 3–y?–10a–H108 19. From TIOT take 2-Hy” Ans. 102–H10y 4y—2c ..., 33–69 20. From 2––. take +a++a. Ans. e-a. l 2 y—2a: 21. From — subtract –. Ans. */ e 22 $/ 2-y i I 2y—a: 22. From z subtract 2y’ Ans. 2xy 2 O2 *3–8°s: 23. From to subtract –, Ans. & 2-y 3/z acy:

« ΠροηγούμενηΣυνέχεια »