Εικόνες σελίδας
PDF
Ηλεκτρ. έκδοση

** $$ home Dot **** 2the inhabitants of Aluca; "he Veientes go to aid the Sabines;

[ocr errors]
[ocr errors]
[ocr errors]
[ocr errors]
[ocr errors]

Luas gel telureur maria tx* pre

11€ LouT

AKET TO THE EXIRCISES IN THE 1.*eliver it entre lepi anc esleri,

LATIN LESSONS.

By J548 R 11123, DD. parte superinte ut leur TUCLE, DATE LTE

(Cretávard from page 59, T. IV.) ::. *** ut nuruts fat and p..

Vol lil. 7.12-ExcLISE-LATIN.

Reiptt.cae interest; ne reier?; Lorun interest; omnium unit. ' * * ortere: ; Des de est; & II: Tetersaruto esse certiorem me ***** }LE VZ 1"11* 0.73 lec: LES; maritun ra.ere cercet fec.: matrem filia tua; animi T:UNILL, 22.5 tbt KE KIÍLIOS; bali saepe corfusi sunt arini; temporis et urces

6*255 senatum regisa aiposer; me suscepti degoui taedet; boni

sarum miserentur ; buus taede: riiae; te usorem habere mihi hotels in Batu resit in mentem ; praeteritarus reordatur; rei militaris es peri

tes; e Esciane tecti est Dens taal cocs. rei te faciam certiorem;

1.:erarum appetens puer fet sap ens; piscibas scatet mare; mius 11.47 **""}ft 19 rt 3 peor est ingenu 8910r iva; a plurimis à vitise magai aestimantur; quanti 11.6.2014 3** 1.3.d buke botum emisu : non arcu$ assis me faciunt; nostrum est

MED.ee to superase, taum obsegai; prod. bonis est accesatus ; capitis damna. ... $121.Com selsgb.tur; clares urbis poiesiaus suae fecerunt hostes.

1* 1 Le Tares in: dikwa gharam 11,* . L. anda

Vol. III. p. 95.-LATIx-ExGLISK. une ur" :*** G. 't eramus Caesar said to Dumnoris that be pardoned the past misdeeds of - Lidt'i tu wink* ; but his brother Diritiscus; the abandoned womin cursed both; physi

. w lublatis titt of beveral cians, while tber miciser to the wbole body, cure not even the 1.1.5 Sert Hart state of that, by sa jest part; Venus was married to Vulcan; Gabinius is reviled; ned at bow" t In CVEK WIL Zon with each I tare reproved Trebatius because he does not regard his health

| suffcectly; the unwilirg are not easi's persuaded; I am of this 1117 isnt veel te ronko spread in i opinion; a good citizen makes to the republic a present of his

115 XT**** U kentin of all private hatreds; the Germans are given to labour and hardships : kitera semua last but it rundt. They are also found made" war on Gaul; certain sigas precede certain things ; father

a urbe ius, in a cidriet near Nice, in dangers; the physician applied remedies to the wounds; Cather 1.mam in vrt tarks of the Pyrenees, and among compares small things with great; the consul preferred the

infety "ULT forur . Ara Minor, and may be traced of all to the safety of individuals': I set before myself all things : * nem énDE :tract of country which extends be esteemed his love for his son less than ebe public good; Quin:

1 X-teem : the borders of Western India. tius Fabius alone survived the slaughter of his family at Cremera; 100 Lembit Lit same calcareous nature are found in the senate bestowed honours on ilustrious men; the virgin mare Lorenz m 1. ERTIL S R.DUE MURChison has lately ried him whom Caecilia had had for a basbaod; tby keepers have slavi 1 1 punes rezz before the Geological Society of London, given thee the name of madman; the name of that disease is is 13 de ceps's of India and those of Europe

. neatid, read, discussed, and

handied by the orator ; Atcibiadesa batean 1194 10. suks super one of the chief connecting avarice ; my name is Arcturus; I have deliberated and determined 352-tez verside, ar.d dear one hundred degrees purposes kept his mind on the wateh ; majesty and love done

? * Deler t. sge on the north flank of the well agree, nor tarry

in one abode ; the father gare luis son a dog; Carpatia 925 Libe, jeudate with its southernmost the Rhine approaches the ocean ; you do not know what man you De veez Elu 11 TL use of the Bramahpoolra" in the suitable to a marriage ? he villas, built along the pleasant places

of the river, stand on its margin; the world obeys God, and the 3241 forates a ser.ge of mountains near Suggsville, seas and the lands obey him, and the life of man obess the.com: *: ava: care iuired fee: brigh, are entirely in indgreed

between mejorarus and myself (comme ile de proteipity va uni tuues, copy Sussex, the blue clay that the le my house

and be on his guara Against me, but it is berduan ant bautum.gton, and the calcareous to form that the Sible brought three books to Tarquininen 1* que us a: Latvari atd Bogner, abound in bus; it is sooliste to allow what you can prerent ; neither the plane *r*. test been briefs stated in this lesson right hand of Ceres; ebe Parthians had isken the standarde from

sa a un para: a fierce the number, the Crassus; Caesar betrothed the granddaughter of Atticus, to e List mitt lit bucies and in visible agents Tiberius Claudius Nero; it is advantagecus to the country itself to

2. Las esse pu: priprese. Se ination of our Earth's have citizens who perform what they owe to their parents; no fool ***! Julius tell ** 2.1106Edappreciable eren br nor distonest person can be well of Caesar made to his country

var ita & ATTAQUE Esses produced by their own homes het ecartels nenses the praise and the glory of othered these t's best operats

, and ask ** who common in no time to not heard of the watchings (vigiliae) of Demons; ******** mbros tine Be Lime writt to pass the most in the school or pythagoras silence was imposed on disciples for

1:1 ty means of thenes let us always live as if we thought we had to give an account; 3.13.45 Bilaries have contri: in india lasciviousness and corbwere like gladiators rather than 1.-*st am surel meg ture of the

globe, generals ; if my son sing at all he sins against me; we wish to be &C DIRA, and whales, ribe not only for ourselves but for our children, our relatives, our

Hostale postat pege of the itiends, and, above all, for the commonwealib; I recommended *** Bla". I: 40%. 211: niedem peace to Pompey and the senate; who is a winess of this thing?

Bolos ta liriekes; 60 is bar is Celsus doing, I wonder i what do you wish? I do not under ** ***** *3 meio e con ur.d se

sland what is the meaning of a varice in old age ; virtue is the only

iting which men can neither gire not receive as a gift : it is base se lets Luke uue

season. I because now to make it has in mot mend; 'Pausauias wen: to hapes

Issey chose this place as their residence; Caesar left behind fire

[ocr errors]
[ocr errors]
[ocr errors]
[ocr errors]

cohorts to protect the camp; sleep is very like death; a physician dilegerunt; tibi subvenit medicus, sed mederi non potest; domo ministers to a sick body; but who cures the mind ? ihe lion has a me reliquerunt praesidio; vae mihi! quid facio ? imperio Galterrible voice; Egypt was added to the Ronjan empire; he is liberal Pico Italia est adjecta; fratris ingenium longe antecellit meum; w bo takes from himself what he gives to another; the genius of si peccas, tibi peccas; cave leonem; portae liber adjacet; copiae the Greek poets far excelled the poets of other nations.

fluminis ripa, insistunt; mihi convenit liber; hostibus signa

detrahent milites; impiis non est bene; mali malis maledicunt; Vol. III. p. 95.-ENGLISH-Latin.

in doctum esse con convenit tibi; prae curru currit equus ; bona omnia sibi ipsi proponunt; maximos forti duci honores deferret

senatus ; volentibus multa facile persuadentur; vulneribus tuis Nomen tibi est Roberto; filio nomen do Roberto; simillimus remedia' medicus adhibebit; Angli student laboribus; est in peripatris est filius tuus; alteri seris, non tibi; est mihi ager; divitias culo pater (patri est periculum); mulieri supplicanti condonavit ; mihi affert ager; mihi auxilio advenerunt amici; ludos sibi uepril virginem mihi uxorem adjungam.

[blocks in formation]

I may

SING

he may we may

praise

PLUR.

Present Tense Present Tense Present. 2. obe tu, loben, to praise. lobend, praise thou

praising 3. lebe er, let

him praise 1. loben wir,

let us praise 2. lebet ihr,

praise ye. 3. lobou fie, let

thcm praisc

they may

PLUR SING.

praise.

Perfect Tense.

Perfect gelobt sabei, to gelobt, praised. have praised.

PLUR. SING.

praised.

gelobt,

we have
you have
they have

Present Tense.

Present Tense. i lich lobe, praise.

ich lobe, 2 tu lobest, thou praisest. tu lobest,

thou mayst 3 er lobt, he praises.

er lobe, 1 vir loben, we praise. wir loben, 2 ihr lobet, you praise.

ibr febet, you may 3 sie leben, they praise. sic loben, Imperfect Tense.

Imperfect Tense. 1 ich lebte, I praised. ich Tobete, I might 2 tu lebtest, thou didst praise. ou lebetest, thou mightst 3 er lobte, he did praise.

er lobete,

he might I wir lobten, we did praise. wir lobeten, we might 2 libr lobtet, you did praise.

ihr lobetet, you might 3 lite lobten, they did praise. Fie lobeten, they might Perfect Tense.

Perfect Tense. 1 lich babe I have

ich babe

I may have 2 tu bat thou hast tu habet

praised, &c. 3 ler hat he has

er babe i wir baben

wir baben 2 lihr habet

ihr habet 3 sie haben

sie haben Pluperfect Tense.

Pluperfect Tense. lich hatte I had

ich Vätte I might have 2 ru hattest thou hadst

tu hättest praised, &c. 3 er batte he had

er hätte 1 wir batten

wir bätten 2 ihr hattrt

ihr hattet 3 sie hatten

sie hätten First Future Tense.

First Future Tense. First Future. lich werte I shall ich werte (if) I shall ich würde iu wirst

thou wilt bu wertest praise, &c. tu würrest 3 er wird

he will
er werte

er nurte 1 wir werden

we shall
wir iverton

wir warten 2 ihr wertet

ibr wortet

ihr würtet jie werten they will fic werten

fic würden Second Fulure Tense. Second

Future Tense. Second Future 11ich werte

I shall ich werte (if) I shall in würte tu wirst thou wilt tu wertest have praised du würdest he will er werte

&c.

cr würde I wir werden we shall

wir werden

wir wülten 2 ihr wertet

ihr werdet

ihr würtet (3 sie werden they will

sie werten

sie würten

SING.

gelobt,

praised

gelebt,

PLUR.

we had you had they had

[blocks in formation]

$ 81. The Mixed CONJUGATION

Perfect Participle, and at the same time, partaking of the New

Form, in that they assume, in the same parts, the lense-sign (Embracing the Irregular Verbs properly so called). te and the participial ending t. These are they which, strictly

speaking, are the irregular verbs of the language, and accordThere are a few verbs (sixteen in all), which have a sort of | ingly, they are here so classed. They will be found, also, mixed conjugation; partaking of the old Form, in that they in the general List of (so called) * irregular" verbs, which, chauge their radical vowels to form the Imperfect Tense and the for the sake of convenience, we have inserted.

IMPERFECT.

PAST

1

PARTI

IMPERATIVE.

A CONSTANT SUBSCRIBE: " Which is the better of the two?" is most simple, practical, and complete Guides to a thorough knowlede of the
dative case. The word to, after a word signifying motion, must generally the Exercises, with numerous relerences to the Grammatical Kulos, price

ZIG-ZAG (Spalding): His geometrical trisection of an angle won't do; bir
TIRES OF THE MIXED CONJUGATION. other queries are exceedinzly smail.-G. B. (Stanchester) is right; he will tal

the mutter put right at p. 83. f the same volime. See the 1st No. olvi.
iv.-W.R. C. (Stepney, The Stadium differs in different places and be
diffrent anrient writers.-J. C.C.: We really cannot well advise without

fi ore definite information; of in town, a perfonal interview would save
PRESENT

immense trouble.-AN ADMIRER: See past Notices to Correspondents.INFINITIVE.

X. 1.2. Liverpool: Suly Latin rell first, and then Greek. 'I'N ELEVE

(Birmingham): Here is a Frencka song for you:-
of the Indicatire
Indicat. Subjunci cigle.

DopCSALOGUE DE L'AMIT:é.
l'n ami tute choisiras

Sans te pregar actement. Pieran, to burn, id brannte idi brennte zebrannt brenne

Semblable à toi tu le voguras Prirsen, to bring, ich bradite ich brådite gebrad't

D'a, dl godis, de sentimeist. Tenica, to think, 10€ tadite id tichte qendt

A t'aimer tu le convieras

En vivant charitablement. Türfen, to be per- ich tarf, tu tarist, ich turite ic durfte seturit

Ton respe t tului prouveras mitted, er tarf

En le reprenant franchement. Savon, to have,

Junai. alisien tu ne voudras id babe, du fait er ich hatte ich bitte abt ube

Q ili prédre ton jugement. hat

Au beserin tu le dé endras Kennen, to koow, i linnte ich fenuite f.17

('ontre tous intrévidement. Kinnen, to be able, ich fan, tu fanuft, ich furnic ich fonnte izefonnt

1 xa parole tu croiras

Comme son entier dévouement. can, er fann 1.

Bruciup tu lui pardonneras Migen, to be als ich mig, til malit, ia merrte idy měchte bzeuiecht

Si vouluir qu'ii t'en fasse autant. lowed, may, er mit

@py pciues tu devineras

Pour les c nanler senlement, Ouren, to be id mur, tu muş, mußte ich müşte 'gemust

Lestiennes tu ne lui diras obliged, must, cr mus

Q1s'il y peut soulagement. Nennen, to name, id nannte ich nennte genannt

e femme iu respecteras Renren, to run, i rannte ich rennte gerannt

Et lilienue pareillement.

Avec lui tu partageras Senteni, to send ih jantte by jentete gerandt

Tous tes biens fraternellement. Bollen, to be ich all, tu sallit,

Et faisant ainsi tu seras obliged, shall, er roll

Sûr d'ê re niiné bien tendrement. Wenten, to turn, lid, wandte 'ich trentetegeminit

F. II. J. {Londen, and J. E. II. (Kidderminster;: Thanks.-J. DOWELL Wisjen, to know, ich weiß, tu weißt, ich wußte ich wußte gewußt wisse

(Birminghan): Thanks; the cause for a standing army is to keep the

balance of pauer in Europe, as * dl as for nation i defeuce. The second er reis

question is alaurd.-Cutts: We don't know thlleir-at-Law Society." Wollen, to be wil- ich will, tu willit,

J. RUTHERFORD Blick in): The correct answer to a question implying an
ling,
er will

allirmation is yes; and to one implying a negative, is 19.-NIL DE:TA
RANDOM asks too much of us.-W.B. Hudson (Lincoln): Series is buh

singu ar and plural; hence we can say both this series and these series -
$ 83. PARADIGMS OF IRREGULAR VERBS.

W. W. R. (Taunton and A L'ATUER Burnley): We cannot undertake 10

recommend one Assurance society more than another.-C, THOMAS (St. (1) In order to a better display of the irregularities of some Betting questione.-3. C. JOHNYTUSH: We mean that the wholer i norge of these verbs, we append the following paradigms. They will Texamene in French can be liad for 61. The specific gravity of silver, inge be found exceedingly convenient for ready reference. Some of and not hammered, 14 10 174, and hammered, 10 311; of to. pare and not these verbs, also have certain peculiar uses, which require spe-hardened, 7-291, and hardened, 7209; that ut water being 1.000. cial attention. For this reason we have, immediately after the

Alpha (Farringdon): To differentiate y=(1+x)(1+2), paradigms, added a series of explanatory remarks, with copious apply the formula dizil(17) =dotrdu, thus: examples illustrating the several ways in which they are dy=(1+x2)d1+x)+(1+r)*(1+x)= . employed.

(1+r) 4(1+x) dx+1+x)(1+21+)=

(1+x):4 1+x)(1+3)dr+(1+x)(1+r)(1+r)6rds AYSWERS TO CORRESPONDENTS.

(1+x)=(1+1) {4+4x+66+6x" }d= I'N ETUDIANT: The letter vis put at the end of words ending in a rowe!

(+6x+10.6°)(1+-2)*(1+x)dx. and coming before a word beginning with a vowel, whether a cmma intervepes or not; but it may be onnitted. The correction suggested was made in answer to another correspondent, vol. iji., p. 311, where the meaning of Xoupw (I rejoice) is given. The following is the translation of the lines of

LITERARY NOTICES. Ilomer: " For there is not anywhere a more miectable being than tran among all

FRENCH the creatures that breithe and crawl upon the earth." " And when the early rosy-fingered dawn appeared."

New ready, price 14. in stiit Wrapper, or 5x, strongly bound in clothing

the First Pait complete, consisting of the French and English, of Cassel.is only conjecture there may be some reasons of a local character: Oor beincan Chirierenny Numbers, and in form

one handsome luluine of eight hiusurs query , but can feminine noun to designate a man, The word des is used with a nominative case in a partitive or defi'ite senge to express some, any; me, des pommes, may be liad sepatule.

and thirty-two pages.' Price 86. 6d. bound in cloth, or the Two Divisions some appies, or 21mply opples. Sre vol. i., pp. 32 and 63. We do r.o: krow which a in the word anns our correspondent mean,

A COMPLETE MANUAL OF THE FRENCH LANGUAGE, by Professor De

, price questioned whether usaze, which is the only guide in languaze, does not ard the latter sanction enough to render it all wable.

it is conducted is admirally caleulated to accomplish ibe proposed chieren Tentias: We have not room for the complete parsing of the sentence laid down, and, secondly, the Principles are copiously illustrated by suitabies

In the first place, the Grammatical Principles of the Language are clear referred to, nor do we see any difficulty in it. AQUILA PULCHRA: The preposition ah is indispensable before rames of

Exercises of English to be turned into French. lizing agents, bu: is not used before those of lifeless instruments, which are

CASSELL'S LESSONS IN FRENCH, in a neat volume, price 2s. in etilf covers simply put in the ablative. Ad insulam could not be changed to insulæ, the

or 24.6d. neatly bound in cloth.

A KEY TO Cassell's Lessons in French, containing Translations of all be translated by ad, foliowed by an accusative, though the preposition is 15. paper covers, or 1s.6d. clvtb. omitted before the name of a town or small island. The French books mentioned are good aud cheap.

GERMAX
11. STTIB: We are now preparing an easy German reading book, which will
liebed srst, uider the title of " Lessons in German Pronunciation.” Monthly Paris, 1s. each.

CASSELL'S GERMAN DICTIONARY is now issuing in Numbers, at 34. each
alread; publ, bed an“ Eclectic German Reader," containing select
d extracts from German authors. Both these works have a dic- cloth.

Cassell's Lessons in German, price 25. in stiff covers, or 28. 6.1.
fail the words at the end.
E (Manchezter): All right.--SALOPIAN (Shrewsbury): We do not

Cassell's LESSONS IN Latin, price 2s. in stiff covers, or 2s, 6d. cloth, 10 OKAMUS (Aiuble, : Not.

Cassell's Key to tHE LATIN Exercises, now ready, price 19. in stil
covers, or ls. 64. cloth.

This forms one of the

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

f

[ocr errors]

LESSONS IN CHEMISTRY.-No. V.

terminating above in a sharp edge, will do). These prelimi

naries being arranged, place under the suspended and inverted ON HYDROGEN.

tumbler the tobacco-pipe stem delivering hydrogen gas. If The student will remember that in the first lesson he was told

Fig. 23,
to prepare a certain combination of tobacco-pipes, corks, and
large-mouthed bottles. They have not been employed hitherto,
and the learner may consequently think I have forgotten all
about them : not so.

It has been my especial object to arrange these lessons in
such a manner that manipulative details, or the directions

t
for conducting the mechanical part of operations (and che-
mistry is full of such), may be interspersed with a due pro-
portion of thinking philosophy. I shall continue to hold this
object in view, and therefore shall not set off the manipulative
part of chemistry by itself, but describe the manufacture of
every instrument when wanted.

Perhaps the operative student may have observed ---at any
rate, he ought to have observed, for no phenomenon occurring
during the performance of a chemical operation and appertain-

(a) ing to it should remain unnoticed, I say he may have observed, that during the act of solution of the zinc in dilute sulphuric acid a certain gas was evolved. Now this gas is termed hydrogen ; it is the lightest ponderable body in nature, and the common method of procuring it is really that which the the apparatus be sufficiently delicate, the tumbler t will be

There student has already, followed, namely, by the operation of raised, thus proving the levity of hydrogen gas. dilute sulphuric acid upon the metal zinc : iron will answer are many processes of demonstration more elegant than this : nearly as well. Perhaps, moreover, the student may have several will be mentioned hereafter. There are none, howobserved that the hydrogen gas thus developed had a peculiar ever, of equal simplicity, as they require the use of apparatus smell; this, however, is a casualty-pure hydrogen is almost not yet described. devoid of smell. I need not describe on what the smell de. The next experiment to be mentioned shall have reference pends just at this time, further than stating that the cause is to the products of the combustion of hydrogen gas. For a sort of oil generated during the process of dissolving zinc in this purpose, ignite a jet of such gas as it emerges from dilute sulphuric acid.

the shank of the tobacco-pipe, and hold over the flame a wide. Let us now learn a few properties of this gas by experiment, mouthed bottle or tumbler, as represented in the following generalising these properties hereafter.

For this purpose,

diagram, fig. 24 :-
repeat the act of solution,-using zinc and dilute sulphuric

Fig. 24,
acid as before,-only let the solution be performed in the bottle
instead of an open dish, and stop its mouth with the perforated
cork, armed with its tobacco-pipe shank, immediately after
the zinc and dilute acid have been poured into it. It is
scarcely necessary to intimate that the mixture of sulphuric
acid with the predetermined quantity of water can scarcely,
with safety, be attempted in the bottle itself, on account of the
heat developed. It requires to be effected in an earthenware
basin, jug, cup, or something of that sort.

Having generated hydrogen in this way, we shall soon learn
one of its most prominent qualities : causing a flame to
approach the end of the tobacco-pipe shank, the hydrogen
which escapes will immediately take fire, proving that it is
combustible. In performing this experiment, it will be well
for the operator to place himself at some little distance from
the apparatus, because if the light be caused to approach the
extremity of the tobacco-pipe shank before the generated After the lapse of a few seconds, the vessel, previously dry, will
hydrogen has forced out all the atmospheric air which the be bedewed with moisture. Where does the student believe
bottle originally contained, an explosion will be the result: the moisture comes from? His first idea, perhaps, might be,
not dangerous in itself, but it may be destructive to the clothes that it comes from little particles blown out, as it were, from
by the diffusion of the dilute acid in spray. Every pheno- the liquid in the bottle. În our rough experiment, probably
menon, as I have before remarked, occurring during the a little is attributable to that source; but if every care be taken
performance of a chemical experiment is important, and should to dry the gas, still its combustion yields water-nothing but
never be passed unchallenged. In the present case, we do water. Hence hydrogen derives its name from vowp, water,
not stipulate for an explosion ; we will effect that purposely, and yèvvaw, I form; hydrogen, then, means the water-formet.
and by a convenient process, hereafter. Nevertheless, should If, instead of a tumbler, the student uses a large-mouthed
an explosion occur, it would only serve to anticipate a com- bottle (a soda-water bottle answers remarkably well), he will
munication of the fact, that hydrogen gas forms an explosive generally succeed in eliciting a roaring or singing noise, attri-
mixture when mingled with air in certain proportions. If butable to vibrations set up in the contained air by means of
an explosion occur, replace the stopper, and wait this time the burning hydrogen.
before applying the flame until all the atmospheric air has been The chemistry of gases is very delicate; I shall, therefore,
expelled. This period may be readily guessed at, or may be when describing these bodies (the term sounds oddly to an un-
insured, by giving the operation a little more time. Applying chemical ear, though it is correct) frequently require to men-
now the flame, the jet of hydrogen will burn tranquilly. tion instruments that the student neither has nor requires to

The next experiment we will perform shall have reference have, a mern description of their form and mode of operation to the extreme lightness of hydrogen. It is this:-Attach being sufficiently instructive. Of this kind is Cavendish's to one end of a thin slip of deal, a drinking-tumbler, or Eudiometer, the instrument by which the truth that hydrogen other similar vessel, as indicated in the accompanying dia- by combustion with oxygen (for that is essential) yields water, gram at t, fig. 23, and to the other end of the same slip of deal nothing but water, was first determined. In the experiment any pan-like contrivance for the suspension of a counterpoise which we have performed, the hydrogen supplied itself with w; next, support the slip by a fulcrum f (an upright board, oxygen from the atmospheric air; but it would have been com. VOL. IV.

84

acrewed off at m', and the instrument attached to this point of Taking a piece of tin or iron, or other metal plate, fold it into

petent for the operator to have mixed it with oxygen previous | although not very correct in its results. The second method to combustion : and this is what

the chemist Cavendish did. is by exhaustion, as we have seen in the instance of Cavendish's Having effected a mixture of oxygen and hydrogen, and filled Eudiometer. The third method, now to be described, is by far with this mixture a thick glass vessel, as represented in the the most usual and most important.--collection by the pneu

: accompanying diagram, fig. 25, and since known as Cavendish's matic trough. If a bottle be taken, filled with water, and held

thus inverted over water, I need hardly say the water which it Fig. 25.

contains will not escape; but if a jet of gas be liberated under the mouth of the bottle, it follows, from a consideration of some ordinary laws of hydrostatics, that gas being lighter than water, the former will ascend and the latter will descend, until ultimately the bottle becomes quite filled with gas, but empty of water. For this elegant contrivance we are indebted to the in. genuity of Dr. Priestley. In my sketch, fig. 26, I have represented

Yig. 26. a common basin as the vessel in which the bottle is inverted, and I have represented the bottle as supported by the hand. I need not say this way of proceding is inconvenient; to give full effect to the operation one requires that the bottle shall stand without support, and that the vessel shall be large-one, in fact rather like a tub than a basin ; a vessel thus modified becomes the pneumatic trough. As relates to the bottle

or jar in which the gas is to be cola lected, it will stand quite well without any support provided its mouth be sufficiently wide ; if circumstances of any kind require the use of a narrow-mouthed bottle, it may be supported in dozens of ways, readily occurring to the

operator. The student need not expend one penny in the purchase of a paella matic trough, except he has to deliver public lectures, and requires display. The first wash-bowl, kitchen-tub, toot-pan

: or slop-basin he can lay hands on will answer sufficiently well

; and as for the support, I will now

just mention one that in many cases answers even better than a shelf. It is this.

Pig. 27. Eudiometer, he then caused an electric discharge to traverse a pair of wires a b, penetrating the glass stopper s, so that an electric spark should pass through the space ó': by this elegant contrivance the gas was ignited, and the sides of the vessel became bedewed with moisture, which on being examined was found to be water. As the experiment adverted to will scarcely be performed by any chemical novice, it would be a waste of time to describe in detail the construction and use of this beautiful instrument. I shall merely content myself, therefore, with observing that the stopper is screwed tightly down by means of a contrivance indicated in our diagram; and the foot m of brass is not permanent, but admits of being junction to of an air-pumpwill easily understand, that the air originally contained in the vessel being pumped out, a vacuum will ensue, and the stop-cock e

Fig. 28. being screwed on to a vessel containing gas, the latter will rush in. The method here described is not the usual one by which vessels are filled with gas; chemists accomplish the object far more readily by what is called the pneumatic trough, to be described presently. In the experiment of Cavendish, however, water would have been inadmissible as the filling agent, and mercury scarcely more eligible.

Methods of Collecting Gas.-Two methods of collecting gases have already come under our notice. Firstly, we collected hydrogen by simply inverting a tumbler over a jet, through which the gas was escaping. This method is usually called that of a displacement, and is sometimes had recourse to,

[graphic]
[graphic]
[graphic]
[graphic]
[ocr errors]
« ΠροηγούμενηΣυνέχεια »