silver in solution. The learner must not imagine them, however, to be the only tests. There exist others, of which the following are important : There are other tests; but we may simply pass them over; the best have already been indicated-more would be needless at present. Method of obtaining Silver in a Metallic Form from a Silver Solution.-Not every metal, as I have already stated in the preceding lesson, readily admits of being recovered from its solution in a metallic state. Silver is embarrassed with fewer difficulties than any other in this respect, many efficient processes existing by which it may be obtained in a pure metallic condition. Amospheric Railway.-An important application of the vacuum principle was made some years ago in the construction of atmospheric railways. Vallance, an Englishman, apars to have been the original inventor, in 1824; but it was Solution of iodide of potassium-known in certain country only in 1831, that the first atmospheric railway was construc-shops under the name of ydriodate of potash-throws down ted in Ireland, by the engineers Messrs. Ciegg and Samuda. from salts of silver a palish-yellow precipitate. Metallic copThe principal details of this principle of railways is represented per, immersed in a solution of silver-or, at any rate, in a in fig. 101. A cast iron pipe MN, is placed between the rails, solution of nitrate of silver, throws down the metal in a finelythe whole length of the road. In the interior, there is a piston divided metallic form. A, with a rod of about ten feet long terminated by a counterweight B. The first carriage is connected with the piston-rod by an iron plate c. To allow of the play of this plate as the piston advances, a longitudinal slit is made along the whole length of the pipe; this is covered by a continuous band of leather, so that when the train is in motion, it is gradually raised as it proceeds. In fig. 102, a transverse section of the pipe, and of the parts now mentioned, is represented; where x is the piston rod; c the plate which connects it with the train; E the covering valve, at the instant when it is opened to admit of the passage of the plate c. The prime mover of the train is the atmospheric pressure. For this purpose, the extremity Nit of the pipe remains open, while the other extremity м is shut, and is put in communication with a powerful exhausting machine, or air-pump, driven by a steam engine. In the front of the piston, therefore, the air is rarefied, and the pressure is thus reduced to one-third or one-fourth of that of the atmosphere, whilst in the rear of the piston, the whole of the atmospheric pressure is permitted to act. The piston, therefore, advances in the direction of N M, drawing after it the whole of the train. It is necessary that the valve which closes the longitudinal aperture or slit in the pipe should only be raised to admit of the passage of the plate o, when the piston is passing; if this precaution were not taken, the air would find its way into that part of the pipe which is in advance of the piston. This object is attained by means of a disc fixed on the piston-rod and projecting into the longitudinal slit of the pipe, so as to raise the valve E. K is a piece or part of the first carriage in the train, which shuts this valve as the train proceeds on its journey. In the figure, the parts of the piston are exhibited on a scale twice the size of that of the carriages. LESSONS IN CHEMISTRY.-No. XX. BEFORE resuming our active consideration of the metal silver, I feel it desirable to draw the reader's attention to a fact, which I trust, however, he will have already recognised and given it due consideration. He can scarcely fail to have seen that the preceding lesson, although totally devoid of showy experiments, contained several aggregative groups of facts of the highest importance. The learner should master them one by one, and every one. It is not for me to tell him how this mastery is to be effected. Different people have different methods. Some persons depend on frequent reading; some on frequent writing; some rely on frequent experiments. Any plan that accomplishes the end is good; but I would recommend the following as an accessory at least. Write each little aggregation of facts in large characters on a large piece of paper, and stick or pin those pieces of paper in your bed-room, or some other part of the house where you must see them every day. It is astonishing how, in this way, deductions become impressed on the mind, absorbed, as it were, unconsciously by the recipient. Nor is the result to be marvelled at, when we reflect on the mind's susceptibility to external images and impressions. Who is there amongst us who can recall a house, which we have often seen, except with all the accessories of trees and flowers, and other local objects in relation to it at the period of our last view? Who is there, who, after having seen a certain room, with its accessories of furniture, does not feel the mental impression to be violated by any alteration? Thus it is. The mind unconsciously takes a sort of daguerreotype image of things ground us: houses, furniture, faces, and chemical deductions printed or written on a sheet of paper. Once for all, the facts must be learned. The plan which we have followed in the preceding lesson furnishes an epitome of the chief tests for Reduction by Copper.-First of all, we have seen that admits of being thrown down from a solution in nitric acid by immersion of a piece of copper. The metal may be precipitated in such a condition of fine powder, that the metallic character is scarcely recoverable. However, if a little quicksilver be thrown into the vessel in which the powder is deposited, and agitated, the quicksilver and the silver will combine, forming a sort of metallic paste, to which the term silver amalgam is applied, amalgam being the general expression indicating the composition of any metal with quicksilver. If this amalgam be strongly heated in a crucible, or even the bowl of a tobacco-pipe, all the quicksilver will escape in vapour, and all the silver will remain as a sort of button. The reader will easily see, that instead of simply evaporating away the quicksilver, and allowing it to go to waste, as in our experiment, the process of distillation might have been had recourse to; in which case the quicksilver would have been recovered. Supposing this to have been accomplished, we should have exactly copied the procedure of the gold and silver metallurgist, who extracts gold almost universally, and silver from certain ores by the process of amalgamation, as it is called: that is to say, he first brings the gold or silver particles in contact with mercury or quicksilver under favourable conditions; accomplishes their union, and finally, distilling away the quicksilver, leaves the noble metal pure. Of all the machines devised for the purpose of conducting amalgamation on the large scale, Berdan's, of which a diagram, fig. 5, is appended, is the best. It consists of cast-iron basins (their number variable), in each of which rotate two cast-iron bolts-the rotation being effected by motion imparted to the basins. Into each basin is piaced a portion of the ore to be crushed and amalgamated along with water and quicksilver. The machine being now set in motion, the ore is speedily reduced to powder; and, coming into contact with the quicksilver, amalgamation is effected. But the chief peculiarity of the machine consists in this. Under each basin is a fire, which, heating the contents, the mercury comes in contact with the metal, hot and expanded-conditions under which its combining agency is greatly exalted. Although metallic silver may be readily obtained from a solution of its nitrate by precipitation with copper, nevertheless this plan is not frequently had recourse to in practice. Far more usual is it to throw it down as a chloride, by the addition of hydrochloric acid, or solution of common salt, and subsequently extract from this chloride its contained silver. Two processes may be adopted for accomplishing this: the first is reduction by fusion with a carbonated alkali; the second is reduction by contact with metallic zinc. Before trying this process, let us examine, a little more attentively than we have done, the substance chloride of silver. To this end, let the student prepare some, by the addition of a solu tion of common salt to a solution of nitrate of silver. The operation will be most conveniently performed in a Florence flask; and the solution of common salt should be added, little by little, until no further precipitate results. The precipitate being white, assimilates, so far as relates to colour, with thousands, nay, tens of thousands of other substances; but certain physical appearances presented by it are so peculiar, that it might be proportions, the result is rendered turbid, from the refusa, as it were, of the generated chloride to deposit itself. Fig. 6. Let the student now take the flask in which the mixture has been effected, and agitate it circularly, fig. 6. Thus treated, he will find the diffused particles of the precipitate soon aggregate into one curdy mass, and, depositing, will leave the supernatant liquid clear. Thus we not only have a good characteristic of chloride of silver, but we have a means of practically separating it in the course of analysis; but the test of ultimate appeal for chloride of silver is hartshorn-liquor ammonia in which it readily dissolves, although totally insoluble in nitric acid. Other White Precipitates occurring in Silver Solutions, and how they may be distinguished from the Chloride.-Solutions of oxalic, tartaric, sulphuric, sulphurous, carbonic, and many other acids, as well as their combinations, yield white precipitates when projected into silver solutions; but these may be readily determined not to be the chloride, by means of nitric acid and ammonia. The reader may try experiments with some or all of these tests, if he pleases; but their fuller description more properly belongs to another part of our subject. Meantime, it may be as well to point out that the only two white silver is easily recognised; and therefore, by negative evidence the former. Having procured some chloride of silver, let the student expose a portion of it to sun-light; and, remarking the blackening which ensues, let him associate this appearance with the substance chloride of silver-and, indeed, with silver salts-all of which, if exposed to the direct agency of light, in contact with organic matter, assume a dark tint. Resuming now the process of extracting silver from its chloride, proceed thus. Collect a portion of chloride; squeeze it between blotting-paper until nearly dry; mix it with twice its weight of carbonate of soda (washing soda), and fuse it in a crucible or tobacco-pipe bowl. Chloride of sodium and metallic silver will result, as rendered evident by the appended diagram: The chloride of sodium, being soluble, may be removed by washing, then leaving the silver pure. Process of Reduction by Zinc. -A far more generally applicable and elegant method of obtaining metallic silver from its chloride consists in agitating it with a sheet of metallic zinc immersed in water, slightly acidulated with hydrochloric acid. Treated thus, chloride of silver is rapidly decomposed, with the formation of chloride of zinc and the liberation of metallic silver. If the materials, i. e. zinc, acid, and water, be all quite pure, then the resulting precipitated silver will be chemically pure also, and may be freed from any adherent chloride of zinc by copious ablution. This plan of obtaining silver from chloride of silver is of frequent occurrence in the laboratory, where the valuable precipitate continually accumulates as the result of testing; and, in this way, the student may obtain all the silver contained in what remains of the nitrate of silver which he has dissolved for the purpose of experiment. LESSONS IN ITALIAN GRAMMAR.-No. XX. BY CHARLES TAUSENAU, M.D., Of the University of Pavia, and Professor of the Italian and German Con. Fu uc-cí-so con un col-po di pi-stô-la. Con sem-bián-te tur- Si netta, he wipes himself handkerchief, pocket-handkerchief. When the preposition with denotes company, society, union, community, connexion, or when it denotes the instrument or means by which something is effected, it coincides with the use of con in Italian. In the former case, the words together | Fazzoletto, with, besides, to, or similar ones, and in the latter, the words by means of, by agency of, by dint of, by, through, are frequently equivalents of with, and are translated by con; e. g. an-dá-re col fra-tél-lo, to go with the brother; si as-so-ciò con un mer-Occhio, eye (coda dell' occhio, cán-te, he entered into partnership with a merchant; és-se-re, the lesser or external canthus stá-re con ú-no, to be with one, to belong to one, i. e. to one's or angle of the eye; guardar family, company, &c.; con chi stá-te voi? with whom are you? uno colla coda dell' occhio, to (ie, in whose service are you? or with whom are you on a look at one from the corner visit? or with whom do you stay and take dinner? &c.); vên- of one's eyes, generally from go con voi, I come with you; com-but-te-re col ne-mi-co, to fight contempt, also from suspiwith the enemy; con-giu-gne-re un sog-gêt to col sú o pre-di-cá-to, cion or envy, to look askance to join a subject to its predicate; con-cer-tá-re ú-na cô-sa con or cast a suspicious glance -no, to concert a thing with one; pa-ra-go-nd-re ủ-na cô-sa con at one, to look at one un' al-tra, to compare one thing with another; con qué-ste má- with an evil eye, not to like ni, with these hands; con gran fa-ti-ca, with great pains; con one). fro-de ed in-gan-no, with fraud and deceit; con un col-lêl-lo, with Temperare, to mix, dilute. a knife; con un scu-do gua-da-gnár-ne tre, with one crown or Vino, wine. dolar to gain three; la-vo-rá-re col-la li-ma, col pen-nél-lo, col| Favorite, please. scar-pel-lo, to work with the file, with the pencil, with the Fenir, to come. chisel; fa-re u-na cô-84 con pia-té-re, con do-to-re, con fa-ci-li-ta, | Me, me. con dif fi-col-tà, con de-stréz-za, con buôn gar-bo, to do a thing | Meco, with me. with pleasure, with grief, with ease, with difficulty, with skill, with good grace. The adverb in-sie-me, together, very frequently has the preposition con after it, and exactly coincides with the English together with; e. g. in-siê-me con lui, together with him; insie-me con un' al-tro, together with another; -o in-sie-me con mi-o pá-dre, I together with my father." Porta, carry. Andar, to go, going, pace, Tempo, time (coll' andar del It is obvious that it is not allowed to translate with by con whenever this preposition does not represent any of the abovestated meanings; e. g. I am satisfied with him, só-no con-tên-to di lui; I am delighted or greatly pleased with you, mi ral-lé-gro | Fu ucciso, he was killed. di voi. In these cases, to translate with by con would com- Colpo, blow, knock, shot, pletely alter the sense. Só-no con-tên-to con lui, and mi ral-lé- | Pistola, pistol. gro con lui (di quál-che cô-sa) would mean: I am satisfied along | with him (i. e. as well as he), and I am delighted or greatly pleased along with you (i. e. as well as you I congratulate you on somethin). Con, with a noun following, frequently supplies the place of adverbial expressions; e. g. con pru-den-za, with prudence; con ci-vil-tà, with politeness; con so-brie-tà, with sobriety; con su-per-bia, with haughtiness, &c., for pru-den-te-mén-te, prudently; ci-vil-mén te, politely; so-bria-men-te, soberly; super-ba-mén-te, haughtily, &c. Con, before an infinitive, which in this case occupies the place of a real noun, is quite an idiom, and will be best translated by the prepositions by, through, by the conjunctions while, when, as, and particularly and, or by the present participle of the English verb; e. g. coll an-da-re a spás-so non si può ar-ric-chi-re, by taking walks (i. e. by idling) one cannot get rich; é-gli si sò con di-re......he excused himself by saying, saying, and said, while he said; é-gli fé-ee te-sta-mén-to con fár-mi e-ré-de di tútto il su-o, he made his will, and constituted (or constituting) me heir of all his property. EXERCISES.-ITALIAN-ENGLISH. scu Si nét-ta col faz-zo-lét-to. Guar-dár cól-la (con la) có-da dell' ôc-chio. Tem-pe-rár il ví-no coll' a-cqua. Fa-vo-ri-te di ve-nír con me (or me-co). Pôr-ta té-co (con te) la lan-têrna. E-gli lo pré-se sé-co (con se). Coll' an-dár del têm-po. It is also allowable to separate in-siê-me from con, and to place it after the case governed by con; e. g. con lui in-sie-me, together with him; me-co (i, e. con me) in-sie-me, together with me. The adverb in-sie-me-men-te also means together with, but it is not so much in use as in-siê-me con. Sembiante, visage, face, coun- tenance, air, Turbato, disturbed, alarmed, Mi disse, he told me. purpose, of purpose, de- Non s' accordano, do not match. Via di quà, away with. Con sua buona grazia, with your ence. Parlando, speaking (con rispetto COLLOQUIAL EXERCISES.-ITALIAN-ENGLISH. L' al-bero, m., the tree. man. Rie-co, rich. Il vi-ci-no, m., the neighbour. la vi-ci-ne, f. Il cu-gi-no, m., la cu-gi-na, f., the cousin. Il gio-va-ne, the young man, Il giar-di-nie-re, m., the gar In the place of con me, with me; con te, with thee; and con se, with himself, herself, itself, themselves, meco, teco, and seco, are frequently used; and in elegant style con as a mere expletive, con meco, con teco, con seco. The adjective már-cio, m., and már-cia, f., rotten, putrefied, vile, despicable, is sometimes nothing more than an augmentative, giving greater force to the word to which it is joined, and, in this case, somewhat similar to the English arch, chief, principal, very, E. B. « már-cia for-za, with all one's might; erê ti-co mar-cio, arch-heretic; a tú-o már-cio di-spêt to, in defiance of thee. Vivo, m., and ví-va, f, living, lively, brisk. the gardener's La giar-di-niê-ra, f., the female Ad En-ri-co, to Henry. gardener, wife. L'uô-mo, m., the male person, man, husband. La dôn-na, f., the woman, wife, Il sol dá-to, m., the soldier. Lo scul-to-re, m., the sculptor, Lo spec-chio, m., the looking- Lo scri-gno, m., the coffer, Lo scritto, m., the writing. Di Car-lo, of Charles. A Car-lo, to Charles. D' En-ri-co, of Henry. mól-to ric co. Di Mi-la-no, of Milan. E' di-belongs to-(.e. is of-) EXERCISES.-ITALIAN-ENGLISH. ENGLISH-ITALIAN, Our gardener is a good man. Your gardener's wife is a good woman. My friend is the uncle of this young man. I have bought this tree from your gardener. Our (female) neighbour has a very good son and a very good daughter Hast thou seen this poor man's child? My (male) cousin's looking-glass is very large. Thy (male) neighbour is the pupil of my father. My book is on the form. I have given my hat to this poor child. The book which I have received from a friend is lost. Louisa has lost her bonnet. Have you (sing.) found Charles's ring? Henry's father (i. e. the father of Henry) is very rich. John's garden is very small. William's friend has departed. My cousin has (i. e. is) arrived. We have received a letter from Louis; he is at Milan. Have you seen Francis and Ferdinand? Rodolph has departed for Venice. We have written a letter to Stephen in Paris. Have you (sing) seen thech of Louis? Has (i. e. is) your (sing.) uncle departed for Paris? Caroline's aunt is in London. Our (male) neighbour has a son, who is called Adolphus, and a daughter who is called Louisa. ENGLISH-ITALIAN. The nephew has gone with the general's son and daughter into the park to dine there. Next week they will go together into the countrý. A courier has arrived with the news of the conclusion of peace. The cousin came here with the express order to buy a horse and a coach. I have never offended him with one single word. In time, and with patience, one learns everything. Man ought to spend the first part of his life with the dead, the second with the living, and the third with himself. The world is filled with ungrateful persons: we live with the ungrateful, we work for the ungrateful, and we always have to do with the ungrateful. Nephew, ni-pó-te, m. VOCABULARY. They will go, vô-glio-no an-dd re Together, tút-ti in-sie-me One single word, ú-na só-la pa- Time, têm po, m. Ought to spend, de-ve pas-sá re Hô ve-dú-to l'om-brêl-la di vô-stro pá-dre. L'a-mí-co di First part, pri-ma pár-te, f. Second, se-con-do, m., se-cón- Living, vi-vo, m. Last, úl-ti-mo, m., úl-ti-ma, f. Peace, pd.ce, f. (i. e. news of Himself, se stés-so 80, m. To buy, di com-prá-re I have never offended him, i-o Is filled with, è piê-no di We work, si la-vó-ra And we always have to do, e si LESSONS IN GREEK.-No. XXII. ACCORDING to these general statements and explanations, the Third. λείπω. Number. THE POPULAR EDUCATOR. From this instance you learn that the Greek verb varies, or is modified in person, in number, in tense, in mood, and in voice. Accordingly, it is the business of the learner to become familiar with the verb in all these its modifications, so as to at once recognise every form he may meet with in reading, and be ready at first sight to assign its meaning. The task is not an easy one, but will yield to persevering application. The task, being difficult, must be undertaken in detail. Before we proceed to the general conjugation of the Greek verbs, we must present a peculiar form, namely, that of the substantive verb, or verb of existence, είναι, to be. About to be. G. plural. The English is only given in part, it being presumed that that u means I am, he can hardly fail to know that the the learner can easily supply the rest; thus, when he knows plural runs we are, you are, they are. Let it be premised that the significations given in the paradigms, or examples of conjugation, are sometimes only approximately correct; for the exact meaning the student must wait until he is familiar with the details of Syntax and other details, which will follow. The verb whose forms are given above, belong, it will be seen, to the class of the verbs in μι. There is another form, distinguished in part by accents, namely, είμι, I go, (εἰμί, I am); the conjugation of which will be given in its place under the verbs in μι, The second person of the present, ει, is more used than εις. In the imperfect, the second person, ης, often becomes ησθα, by the addition of a euphonic suffix; the third person is ŋy, more frequently than η. Instances are found, particularly in the first person singular and the third person plural, of another imperfect, which resembles the imperfect of the middle voice. S. ημην ησο ητο, Ρ. ημεθα ησθε ηντο. A middle imperative form is also found in the second person singular, namely, εσο, be thou, The entire present subjunctive, namely, ω ης y, &c., supplies terminations to all the verbs in w. The second and third person singular have the iota subscript, as seen above. The optative forms, ετην ετης ειη, lend their terminations την, &c., to the optative of the verbs in μι. For the form είημεν, ειμεν is used; and for είησαν, ειεν is much more common; ειεν is also found in the sense of well! very well ! be it so! The future, in all its moods, is a middle form ; its termination, σομαι, is that of all the middle verbs in the future. The original forms were οντος ουσας ουσαις Λουσι οντα. ៖ Α. οντα ουσαν So decline the participles in wv, of all the verbs. By the aid of prepositions various compounds of u are tive; as παρ-ειμι (adsum), I am present; απ-ε:μι (absum), formed, and these compounds are conjugated like their primiam absent; μετ ειμι (intersum), I am among; συν-ειμι (una sum), I am with, προς-ειμι (insum, accedo), I am near, I approach; περι-ειμι (supersum, superior sum), I survive, I am 1. 2. 3.That is, the first person, the second person, the superior; and others. The preposition remains invariable; third person. Before I make any remarks on this verb, I will explain the contractions, the rather because they will recur again and again. LIST OF CONTRACTIONS, WITH EXPLANATIONS. only the verb undergoes the conjugational changes. |