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a wise economy.

what we ought. You may overwork yourself for months with anticipated from the following equation, the resulting nitrogen out feeling it much, but you will one day pay the penalty; draw is of the same volume as the original cyanogen :a bill upon your constitution if you like, but it is sure to come

C,N, = C, + N, due in time, and a heavy pay-day it will be.


+ 2. There are many aspects of economy: there is the political

When a solution of ferrocyanide of potassium is added to a economy of the nation, the social economy of home, and the personal economy of life. It is of course pretty certain that in solution of a sesquisalt of iron, the well-known Prussian blue is each of them there will be differences of opinion as to method,

precipitated. but as to the wisdom of economy in itself no thoughtful people stage of its preparation given. If it be required in its pure

Hydrocyanic acid (HCN) has been alluded to, and the first will be at issue for a moment; and economy in relation to personal life will to a great extent be regulated by taste and state, dry calcium chloride is added to the above solution, and feeling. It would be foolish for one who had no ear for music experienced persons, and only then for some good reason.

the liquid distilled. This must never be attempted save by

It to spend years in the hard toil of trying to play well on an instrument, and for one who had no eye for distance to learn liquid, which gives off vapour, a breath of which would be fatal.

is the most powerful poison known. It is a limpid, colourless perspective. We must be judges to a great extent of our own powers, and a true economy consists in physically, mentally, and in cases where death has not resulted, the treatment is to

The poison seems to attack and prostrate the nerval system, and morally making the best of ourselves.

As political economy advances, and men become interested in pour cold water down the spine.
it, we may hope for the day when it will be the aim of society to leaves of many plants it is found in minute quantities.

The acid has the odour of almonds, for in the kernels and bring as easily as can be within the reach of the multitude good art, good scientific appliances, and good things of every kind,

There are other compounds of carbon and nitrogen into which 80 that these may not become the prerogative and appanage oxygen enters, but they become too complicated for an elemenonly of the rich or great, but may be made available by all. And tary study of chemistry. concerning personal economy, let that be no selfish or epicurean density, 38). — A porcelain tube is passed through a charcoal

Bisulphide of Carbon (symbol, CS,; combining weight, 76 ; thing, but an economy which embraces home, children, em, furnace in an inclined position; it is packed with charcoal ; ployers, servants, and secures for all as much as may be gained of health and joy, wisdom and wealth. Many may be found occasionally, into its upper end, pieces of sulphur are thrown, who blame everybody but themselves for their failures in life, and then the tube is stopped up by a cork. The sulphur is whereas it often happens that the said complainants commenced vaporised, and combines with the carbon, forming the bisul. life easily and even luxuriously, whilst others had to exercise phide of carbon. A glass tube attached to the lower end of some little self-denial and care; or, perhaps, they wasted is kept cool. Here there collects a mobile liquid of a very

the porcelain tube conducts the vapour into a condenser, which precious opportunities for advancement and improvement which high refractive power, and possessing a fetid odour. It dissolves never recurred again. It may sound strange to some, that economy is not so much fire," for when a bottle of it breaks, the bisulphide rapidly

sulphur and phosphorus. This latter solution is the “Fenian saving as spending ; but it is the making careful and clever use evaporates, depositing

the phosphorus in so finely divided a state, of the faculties within us and the opportunities without us. In the science of life and duty perseverance and energy often come

solvent on that it soon spontaneously ignites. It also acts as

gums and india-rubber. to untimely ends, because they are not united in fellowship with


There are four elements which closely resemble each other, LESSONS IN CHEMISTRY.-XIII.

and which, from the fact that they combine directly with the

metals to form salts, have received the name of halogens, "saltCOMPOUNDS OF CARBON WITH NITROGEN AND SULPHUR- producers.” “These elements are chlorine, bromine, iodine, and

fluorine. CARBON formas other compounds than those with oxygen and CHLORINE (symbol, CI; combining weight and density, 35.5). hydrogen already described. It enters into combination with —Chlorine is the most prominent member of the group. It is chlorine, but the four products will not require attention until very widely disseminated through Nature, in combination with We reach organio chemistry. Only one compound is known with sodium, with which metal it forms common salt (NaCl). nitrogen. It is

Preparation. There are two ways by which this gas may be Cyanogen (symbol, CN; combining weight, 26; and the density obtained :has been found to be 26, and therefore its true symbol is C,N,). 1. Dilute sulphuric acid with its own bulk of water ; allow it -It was discovered in 1814 by Gay Lussac, and derives its to cool, then to fourteen parts of this in a Florence flask ada name," a producer of blue," from the fact that it is the chief four parts of common salt, intimately mixed with three parts of agent in the production of Prussian blue. When bodies which black oxide of manganese. This reaction will ensuecontain carbon, nitrogen, and potash are heated together, a 24,50, + 2NaCl + Mno, = Na,so, + MnSo, + 2H,0 + 2Cl. remarkable salt, the cyanide of potassium (KCN), is formed, which is characterised by crystallising in large yellow tables.

2. If hydrochloric acid be added to black oxide of manganese,

the effect will be the liberation of chlorine, thusTo produce this, substances rich in nitrogen-such as hoofs, hide-clippings, woollen rags, dried blood, etc.

,-are heated in an

Mn0, + 4HCI MnCl, + 21,0 + 2C1, iron pot with two and a half times their weight of potassium The gas is greenish yellow, hence its name, and is about two carbonate. The resulting potassium cyanide is now dissolved and a half times heavier than air. When submitted to a out by water and allowed to crystallise. It is commonly called pressure of four atmospheres, it becomes a liquid, which as yet the prussiate of potash. When iron, or any of the proto-salts has never been frozen. The gas is best collected in the usual of iron, is added to a solution of this prussiate of potash, way, but the water must be warm, for cold water absorbs twice large four-sided tables are deposited, which are ferrocyanide its bulk of the gas. Such a solution is a very convenient way of potassium. When ten parts of this salt are dissolved in of keeping chlorine for test purposes. The bottle may be four times their weight of warm water, and distilled with seven labelled " Chlorine water,” and kept well stoppered and in the parts of sulphuric acid diluted with twice its weight of water, dark, for light causes the chlorine and the hydrogen of the the first portion of the liquid which comes over is a dilute solu- water to combine. On account of its weight, the gas may also țion of hydrocyanic or prussic acid (HCN). Mercuric cyanide may be collected by passing the delivery tube to the bottom of the be made from this by saturating the solution with red oxide of jar. mercury, and then evaporating. If this salt be heated, it is It will be found to possess a most irritating odour, and decomposed into cyanogen and mercury; and thus it is, we get if breathed in any quantity may produce ulceration of the the compound. It is found to be a transparent, colourless gas, lungs. Since it does not combine directly with oxygen, poisonous and inflammable; its flame is edged with purple; chlorine is not combustible; but its most distinctive being soluble in water, it must be collected over' mercury. is its great affinity for hydrogen. If, therefore, If the gas be passed through fron tubes at a high temperature, introduced into a jar of the gas, it will burn it is decomposed, charcoal is deposited, and, as might be fame. The combustion is due to the combining of


with the hydrogen of the fat, forming hydrochloric acid (HCI). It is chiefly noted as a powerful bleacher, being the active The carbon comes away unburnt as smoke.

principle in bleaching powder, which is a mixture of calcium Bodies rich in hydrogen will frequently take fire when chlorits (CaCl) and hypochlorite (CaC1,0,), and is made bý plunged into a jar of this gas. This is the case with a piece allowing chlorine to enter the top of a chamber in which are of paper dipped in turpentine. Metals in a finely divided trays of well-slaked lime one above the other. The gas falls state are violently attacked by the gas. Copper leaf and by its weight, and is absorbed by the lime. antimony, powdered and slightly warmed, even take fire, the Chloride of lime, as this compound is usually called, emits result being in every case a chloride of the metal.

the odour of hypochlorous acid. When exposed to the air, The peculiar affinity chlorine possesses for hydrogen gives it the carbonic acid gradually displaces the chlorine which is given off. power of bleaching. If grass and fabrics dyed with vegetable This makes this body a valuable disinfectant, as the quantity colours be dipped into a jar of the gas, they will become white. of the gas emitted is so small as not to be injurious, and yet This will be found to be the case only when the articles are effective. The best mode of using it is to dip cloths in a moist; then the chlorine, taking the hydrogen of the water, solution of the powder, and bang them up. liberates the oxygen, which, being in its nascent state, is much This substance is used as the great bleacher. The calico, etc., more active, and attacks the colouring matter, thus bleaching is boiled in lime-water and a weak solution of caustic soda, to the body. This may be well illustrated by dissolving some remove the grease of the manufacture and the "dressing.” It indigo in sulphuric acid, and adding to a dilute solution some is then soaked in a solution of two and a-half per cent of of the chlorine water above mentioned. The colour entirely bleaching powder in water. But the action is not discernible disappears. The difference between writing ink and printers' until the fabric is "soured” or dipped in a weak solution of ink is shown by introducing each into a jar of this gas; the sulphuric acid and water. Thus the chlorine is liberated in the former is bleached.

fibre of the cloth, and the bleaching is effected. Sometimes This property of chlorine makes it valuable as a disinfecting this process is repeated, and finally the articles are thoroughly agent. It attacks the hydrogen of the noxious gas, and thus washed in water to remove all traces of the acid. destroys it.

Chlorous Acid (C1,02).-To prepare this gas, three parts of Hydrochloric Acid (symbol, HCl; combining weight, 36.5; arsenious acid, and four of potassium chlorate, density, 18-25).—This liquid is also called muriatic acid, or are made into a paste with water ; sixteen spirit of salt; is water largely impregnated with the gas parts of pure nitric acid (specific gravity, 1.24) hydrochloric acid, which is prepared by gently heating common are added; the whole is placed in a small flask, salt and sulphuric acid in a flask :

which is filled up to the neck with the mixture, NaCl + H,So, 3 HCI + NaHSO..

and a very gentle heat applied by means of a The gas which comes off is colourless, 1.27 times heavier collected in dry bottles by displacement. The

water-bath. The yellow-green gas may be than the air, and possesses a pungent odour.. In contact with greatest care is required in its manipulation, the air it combines with the moisture, giving rise to white fumes. At a pressure of 40 atmospheres it becomes a clear Cent., and also if it come into contact with

as it explodes at a temperature of about 56° liquid. Its composition may be determined both synthetically any very combustible body. Its formation is and analytically by the eudiometer. If equal volumes of due to the deoxidisation of the chloric acid chlorine and hydrogen be introduced into the instrument, on in the potassium chlorate. the passing of the spark they combine, forming HCl. There is

Peroxide of chlorine (C1,0.) is a gas which no diminution of volume. Thus, H + Cl = HCI

explodes as soon as it touches organic or com1 + 1 = 2.

bustible bodies. It is prepared by pouring If now a series of electric sparks be passed, some of the gas equal parts of sugar and potassium chlorate,

sulphuric acid on potassium chlorate. Mix is again decomposed,

and the unaltered acid may be removed each in powder ; then pour upon them a few drops of sulphuric by allowing a few drops of water to rise up through the mercury; acid ; the whole will ignite. On this principle the first attempt these absorb the undecomposed HCl. The remaining gas is at matches was founded. found to be equal volumes of H and Cl. These gases, when mixed in equal proportion, will combine, with an explosion, in bottom of a tall glass fall of water (Fig. 43), also add a few

Place a piece of phosphorus about the size of a pea at the sunlight. Large quantities of this acid are made as a bye product in sulphuric acid

to the bottom of the glass. The phosphorus enters

grains of potassium chlorate ; through a long tube pour a little the manufacture of sodium carbonate. In this, its commercial into combustion with the peroxide of chlorine as it escapes. state, it is very impure, since it contains iron in the form of a chloride, to which its yellow colour is due, and also sulphuric of chlorine gas be passed through a strong solution of caustic

Chloric Acid (HCIO,).—This acid forms chlorates : if a current acid and arsenic. The result of the action of hydrochloric acid on metals is potash, the following reaction ensues :

3C1, + 6KHO that chlorides of the metals are formed. Their various salts

KCIO, + 5KC1 + 3H,0, may be found by replacing the

H in the HCI, according to the potassium chlorate and chloride being the result ; as the latter atomicity of the metal. tion may be at once detected by a few drops of silver nitrate. sium chlorate was used in the preparation of oxygen. The presence of a chloride in a solu- is more soluble, therefore it can easily

be separated from the

chlorate by crystallisation. It will be remembered that potasThe white, curdy silver chloride falls. Aqua regia is a mixture of nitric and hydrochloric acids, chlorate when giving off oxygen be stopped, the residue will be

Perchloric Acid (HCIO). If the decomposition of potassium which is capable of dissolving both gold and platinum.

Oxides of Chlorine.--Although these elements do not combine found not only to contain potassium chloride and chlorate, but by direct means, yet in indirect ways five compounds have been acid, which acts on the chlorate and decomposes it, but not on

also perchlorate. It may be separated by means of hydrochloric produced :Hypochlorous acid HCIO Chloric acid

the perchlorate. From this salt the acid itself may be got.

нсіо, Chlorous acid нсіо, , Perchloric acid • HCIO.

Compounds of Chlorine and Nitrogen.--If chlorine be passed Peroxide of chlorine. 01,0,

into ammonia, as has before been said, nitrogen is liberated; Hypochlorous Acid (HCIO).—The prefix "hypo" is from the but after a certain quantity of sal-ammoninc has been produced, Greek inep, under, or beneath, signifying that this acid has less drops of an oily liquid begin to form. These are supposed to oxygen in it than chlorous acid. It may be obtained by shaking be the terchloride of nitrogen (NCI), the most explosive and op mercuric oxide with chlorine water. The reaction is

the most dangerous of chemical compounds. The experiment HgO + 2C1,

should never be attempted, unless all the apparatus used be of C1,0 + HgCl,. The C1,0 is hypochlorous oxido. This combines with an atom an iron mask. *A drop of this substance in a porcelain capsale

lead, and the operator dressed in a strong suit of leather, with of water, foring the hydric salt, or the acid

was touched with the top of a fishing-rod; the violence of the 1,0 + C1,0 = 2HCIO.

explosion drove some of the

porcelain through the bottom of the vodour, and is extremely weak, carbonic chair, which was of thick wood. A kindred compound of nitrogen

jecting it from its combinations. with iodine, which is not so explosive, will be noticed.

Fig. 43.


which it is attached to the seed-vessel ; embryo straight in the

axis of a fleshy albumen. SECTION LVI.-PRIMULACEÆ, OR PRIMEWORTS.

The Primulaceæ principally inhabit the temperate regions of Characteristics : Calyx free or rarely adherent; corolla mono- the northern hemisphere, especially in Europi and Asia. They petalous, hypogynous or perigynous, regular; stamens inserted not only please the eye by the beauty of their flowers, but also upon the corolla, their number equal to

contribute something to the resources of the parts of the corolla and opposite to its

medicine. The common primrose (Prilobes; ovary unilocular; placenta central,

mula vulgaris) is well known to all from free; ovules curved, seldom reflexed; fruit

its yellow flowers and broad green leaves, capsular; seeds numerous, dicotyledonous,

which are seen in the hedges in sheltered albuminous.


nooks even before the departure of winter. The Primulacece derive their name from

The cowslip (Primula veris) is distinguished the genus Primula, so called because its

by the smallness of its flowers, which form species flower in the spring. They are for

an umbel (Fig. 205). The flowers of this the most part herbaceous, annual or peren

plant act as a sedative, and are used in nial, having a ligneous or tuberous rhizome.

making a kind of wine of a soporific chaThe stem is usually subterraneous and

racter. The auricula, or bear's ear, as it






SATIVA). short. The leaves are in

is called in some parts of some species radical and

the Continent, is employed fasciculated, in others cau

by the inhabitants of some line and opposite, or verti

parts of the Alps as a cillate, or alternate, and

remedy for consumption. devoid of stipules. Flowers

It is equally good with all complete, either solitary or

others proposed at different arranged in umbels on the

times as a remedy for that summit of a shaft, or soli

disease. tary, or arranged in cymes

All the members of the springing from the axilla

primrose tribe are in great of the leaves, occasionally

repate as ornamental terminal in spikes. Calyx

plants, more especially the monosepalous, usually five

auriculas. From these partite. Corolla rotate,

plants, which are natives of campanulate, or infundibuliform, or bilabiate, contorted in æsti- | the Alps, horticultural skill has developed several varieties. The vation, sometimes absent. Ovary composed of as many carpels cyclamen (Cyclamen Europeum) possesses radical leaves, which as there are lobes to the calyx. Placenta for the most part are covered with white spots above, and red on their lower surglobular, and communicating with the summit of the

ovary by face; the corolla has a roseate tint, and in all the species of this arachnoid filaments. Style and stigma simple. Fruit a cap- genus the tube of the corolla is turned towards the ground, sule transversely or longitudinally dehiscent. Seeds ordinarily whilst its limb or free portion is directed towards the sky. fixed by the central hilum or eye of the seed, the point at the root of the cyclamen, or sowbread, is eaten greedily by the



wild boars of Sicily. The name cyclamen is derived from the ovules pendent; fruit bacciform or capsular, indehiscent, Greek kuklos (ku’-klos), a circle, in allusion to the shape of the loculicidal ; seeds pendent, dicotyledonons, albuminous; stem corm or bulb-like root.


The Oleacec are trees or shrubs having opposite petiolate SECTION LVII.-EBENACEÆ, OR EBENADS.

leaves without stipules. Flowers ordinarily complete and disCharacteristics : Calyx free; corolla hypogynous, monopeta- posed in a panicle, cyme, or fascicle. Calyx persistent, four lous; stamens sometimes equal in number to that of the lobes partite, sometimes absent. Corolla sometimes absent, composed of the corolla, and alternating with them, sometimes double or of four petals, ordinarily coherent, infundibuliform or campanuquadruple in number ; ovary many-celled, uniovulate ; ovules late, valvate in æstivation. Anthers attached by their posterior pendent from the summit of the central angle; fruit bacciform; side, ovules ordinarily twin. Fruit in some cases an unilocular seeds few in number, or occasionally one, dicotyledonous, albu- drupe, as in the olive; sometimes a bilocular berry, at other men cartilaginous, radicle superior. Trees or shrubs possessing times a bivalved capsule, or, lastly, a dehiscent capsule. Tho an aqueous juice, and furnishing a wood which is very dense. Individuals of this natural order have alternate leaves which embryo occupies the axis of a central albumen; radicle superior.

The Oleacece inhabit temperate regions, especially in the are coriaceous, entire, and without stipules. Flowers often in, northern hemisphere. They are rare in Asia and tropical complete, regular, axillary. Calyx three to six partite and America. The greater number of ash species (belonging to this persistent. The corolla is caduceous, urceolate, slightly coria- natural order) are natives of North America. The lilacs have ceous, three to six partite, imbricated in æstivation. Stamens passed into Europe from the East. This natural order is in. inserted at the base of the corolla, rarely in the receptacle. teresting in the double respect of agriculture and horticulture. The berry is globular or ovoid, sometimes dry, in which case it The cultivated olive (Olea sativa, Fig. 208) is a tree devoid of opens by splitting.

beauty, but whose utility is immense. It is a native of southern The Ébenaceæ are found in tropical Asia, the Cape, Australia, Europe. Its drupaceous fruit, the olive, is too well known to and tropical America ; a few species are met with in the Medi- need prolonged description. The pericarp of this drape is terranean district.

charged with a valuable oil, which is obtained by subjecting the The members of this natural order are celebrated for the fruit to heavy pressure. In the manufacture of soap and for hardness of their wood. Ebony, the wood of the Diospyrus culinary purposes olive oil is unrivalled. ebenus, has been celebrated from all antiquity for the darkness

The American olive (Olea Americana) bears edible drupes, as of its hue, general beauty, and manifold uses. The ancients is also the case with many exotic species. The most celebrated obtained it from Ethiopia ; at present our supplies are chiefly of these is the Chinese olive (Olea fragrans), the flowers of which drawn from the eastern coast of Africa, especially Mozambique, are mixed by the Chinese with the leaves of their tea. Ebony is either uniformly black or marked with white and yellow stripes. It is a remarkable fact that the wood of the Ebenacece only becomes black in aged trees; the wood of young LESSONS IN ARITHMETIC.-XXXV. plants is white. The appended diagram (Fig. 206) of a sprig of

SIMPLE INTEREST. the Diospyrus hirsuta, a member of this natural order, illus. 4. When money is lent, money is paid to the lender for the trates the more evident characteristics of the Ebenaceæ.

use of it. The sum lent is called the principal, the money paid SECTION LVIII.-AQUIFOLIACEÆ, OR HOLLYWORTS. for the loan is called the interest. The sum paid for the use

Characteristics : Calyx free, four to six partite ; corolla hypo. of the principal ought evidently to depend upon the time during gynous, almost monopetalous; stamens four to six, alternate which the borrower has the use of it. Interest is therefore with the petals ; ovary two to six or many celled, úniovulate; generally paid at so much per cent. per annum; that is, for ovule pendent; fruit drupaceous ; seed dicotyledonous ; embryo the use of every £100 of principal, so much is paid for its ase straight at the summit of an abundant fleshy albumen ; radicle during one year. superior ; leaves opposite, simple, without stipules. The Aqui

The principal and interest upon it added together constitute foliaceæ are evergreen ligneous plants, with petiolate shining the amount. leaves. The flowers are regular, axillary, and small, usually If the borrower pays the interest to the lender at the expirawhite or greenish in colour. Calyx persistent, imbricated in tion of every year (or as soon as, according to the agreement, æstivation, as is also the corolla. Anthers adnatant; ovules' it becomes due), he will evidently have to pay the same sum pendent at the summit of the central angle of each cell, and each year. But if he omit to do this, and retain it until he reflexed; fruit composed of agglomerated drupes.

returns the principal, he will, year by year, keep in his possession The Aquifoliaceæ are nowhere abundant, but they are more a continually increasing sum belonging to the lender, upen plentiful in north and equatorial America and the Cape of Good which (if the agreement be so made) interest must be paid. Hope than elsewhere. In tropical Asia and in Eirope they are In the first case the interest is said to be simple ; in the comparatively rare.

second, compound. Most of the species of this natural order contain a bitter 5. To find the interest upon a given sum for a given time at a extractive principle, to which the denomination ilicine is given, given rate per cent. and which in certain species is associated with varying propor- The interest for one year upon any given sum is obtained tions of an aromatic rosin and a glutinous matter termed viscine. (see Art. 2 (1) in preceding lesson, page 362) by multiplying by Some species are purely tonic, whilst others are purgative and the rate per cent., and dividing by 100. emotic; a few are stimulant.

The interest for one year having been found, the simple in. The common holly (Ilex aquifolium, Fig. 207) is a small tree terest for any number of years is obtained by multiplying the distributed between the forty-second and fifty-fifth parallels of one year's interest by the number of years. north latitude, and which in cold climates is only an unpretend- EXAMPLE 1.—Find the interest on £780 10s. for 1 year at ing shrub. It grows in greatest perfection in the mountainons 5 per cent. The answer is to £7803, or £4484. forests of castern Europe. In gardens it is cultivated for the

40 ) 1561 ( £89 Os. 60.-Answer, sake of its pretty red berries and the deep green of its glossy leaves. By force of culture many varieties of the holly have been obtained, some hearing leaves devoid of spines, some having black, yellow, or white instead of red berries. Holly leaves were once employed as a febrifuge; they owe their medicinal properties to a principle termed ilicine, which admits of being extracted. Ilicine has been proposed instead of quina as a remedy for intermittent fever. From the inner bark of the holly the substance birdlime is obtained.

SECTION LIX.-OLEACEÆ, OR OLIVEWORTS. Characteristics : Calyx free; corolla hypogynous, regular, composed of four petals, free or coherent ; stamens two, inserted

on the corolla ; orary two to five celled, bi- or pluri-ovulate;



1 20


240 240



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3 6 9

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14 f

Or, by decimals, são £780:5 = 5 :: £7.805.

8. If a given principal produce a given interest in a given time, 7.805

to find the rate per cent. 5

Dividing the whole interest by the number of years gives us

the interest on the principal for one year. 39.025

We can then, by the Rule of Three, find the interest upon 20

£100 for one year, i.e., the rate per cent.

EXAMPLE.— The interest on £274 for 5 years being £47 195., 0.500

find the rate per cent. 12

£274, i.e., 960 x 274 farthings, produce £47 19s., i.e., 46032 6.000

farthings in five years, and therefore 198942 farthings in one year. Therefore £39 Os. 6d. is the required interest.

Honce, by Rule of Three, EXAMPLE 2.-Find the interest on £176 17s. 3 d. for 7 years

As 960 274 : 44922 : : 100 : rate per cent. and 9 months at 8 per cent.

46032 x 100

Therefore the rate per cent =
The interest for one year is 8
£176 173. 3 d.

5 X 274 x 960

= } = 3 per cent.-Answer. And since 7 years 9 months = 71 years, the answer is

EXERCISE 54.-EXAMPLES IN SIMPLE INTEREST. 77 * 8 * (£176 178. 3d.) * 100. The operation may be performed thus :

Find the interest of the following sums :

8. d. £176 17s. 30.

1. 525 0 at 4 per cent. for one year. 8

2. 874 16

at 5 100 ) £1414 188. 4d.

3. 1539 12

at 52

4. 2288 16 14.14

5. 1286 14 7 at 7%

6. 7671 19 5) at 41
7. 476 16 0 at 6

for 3 years 6 months.

8. 781 16 10 2.98

at 4

for 5 12

9. 971 18 4 at 5

for 8 10. 1792 12 at 63

for 5

10 11.80

11. 3584 18 8

at 3

for 10 9 4

12. 7365 4 10} at 73

for 12

13. The interest on £781 16s. 10d. at 4 per cent. is £75 11s. 6}d.; 3.20

find how long the interest has been running.

14. The interest on £971 188. 4d. at 5 per cent, is £413 is, 3.d.; Hence the interest for one year is £14 25. 11:4. •2 farthings, and

find how long the interest has been running. for 71 years the interest is this sum multiplied by 7%.

15. The interest on £841 178. 90. at 4, per cent. is £113 6s. 0 d.; Another convenient method of working such a question would find how long the interest has been running. be to reduce the principal to the decimal of a pound, by the 16. What principal will amount to £308 7s. in 27 years at 4) per cent. ? rules given in Lesson XXXI., Art. 10 (Vol. II., page 270).

17. What principal will amount to £132 3s. in 21 years at 4 per cent. ? Now, 3:a.

18. What principal will amount to £247 10s. in 2 years at 5 per cent.? £.014

19. In what time will £537 16s. 8d. amount to £591 12s. 4d. at 178.

£.85 178. 3d.

21 per cent. ? - £.864 to 3 places.

20. If £575 in 3 years amounts to £600, what is the rate per cent. ? Therefore, for one year interest = 1 176.864 pounds

21. In how long will £2500 double itself at 4 per cent. simple interest? = 8 x 1.76864

22. If £293 7s, 6d. produces in 2) years an interest of 225 10s., what = £14.14912

is the rate per cent. ? 20

23. If £2475 8s. 4d. in 3 months produces an interest of £24 15s. 1d.,

what is the rate per cent. ?

KEY TO EXERCISE 53, LESSON XXXIV. (Vol. II., page 362). 11.7888

1. £15.
8. 5.14.

15. £23 per doz., 1.c.,
2. £13.055.
9. 10 per cent.

113 per cent. 10. 3 84 oz.

16. £1111 2s. 29d. 3.1552

4. 9933:37%, or 9:5612, 11. 583 per cent. 17. £1078 11s. 6-9533d., £14 28. 11 d. is the interest for one year, true to the nearest farthing; etc.

12. 7.01519, etc.

etc. and to find the interest for 7 years 9 months, this result must be 5. 21600.

13, 2s.

18. 2311 per cent. multiplied by 77, or £14.14912 by 7-75.

6. 18518.

14, per cent. is 19. 21000.

7. 8.21. 6. Given the simple interest upon a sum of money at a given

gained. tate per cent., to find the time during which the interest has been

LESSONS IN LATIN.-XXVI. We have evidently to find the interest on the principal for one year; then the number of years required will be the number

REGULAR VERBS-THE SECOND CONJUGATION. of times the given interest contains the interest for one year.

ACTIVE VOICE. 7. Given the AMOUNT of a sum of money at simple interest for

EXAMPLE.—Moneo, 2, I remind. given time at a given rate per cent., to find what principal has produced this amount.

Chief Parts : Moneo, monui, monịtum, monēre. EXAMPLE.-Suppose it be required to find what sum at 4.) per

Characteristic lettor, E long. cert. has produced an amount, £138 14s. 4d., in 2 years. The corresponding parts and signs having been given under

In two years £100 would amount to £109.
Hence we have the proportion,

the first conjugation, need not be repeated; in the Latin, the

student will easily make the alterations required by the difference As £109 : £100 : : £138 14s. 4d. : required principal; of conjugation, and the English is unaffected by conjugation. which, when worked out, gives as the result

MOODS, TENSES, ETC., of MONEO, I remind.
£127 5s. 310 d.
Hence we get the following

Indicalive. Subjunctive. Imperative. Infinitive. Participle.

Monore. Monens, Rule for determining what principal has produced a given Sing. Monco.


Moneas. amount in a given time, at a given rate per cent.

Mone, or monito.

Monet. Moncat. Monéto. Multiply the given amount by 100, and divide by the number Plu. Monêmus. Moned mus. obtained by the addition of £100 to the interest on £100 for Monētis. Moneatis. Monēto or monclõte.

Monent. Moneant. Monenlo,

3. .9683.



the given time.

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