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constructed, the sum of the three angles is the same as in the original triangle; and moreover that of the angles of these two triangles which are at a common point, that belonging to the new triangle is not greater than half that of the old, while another of the angles of the new triangle is equal to their difference. And if these operations be applied in like manner to the last consame relations to the second; and so on. Whence it follows, that the described process may be continued, till two of the angles of the last-resulting triangle are together less than any magnitude that shall have been assigned; and consequently the third or remaining angle may be made to approach, within any magnitude however small it may be chosen to assign, to the sum of the three angles of the original or any of the intervening triangles.

distant from the angular point than the point assigned within
the angle; in either of these cases the assumption made above
will have been allowed" (p. 28). To which the answer seems to
be, that to know by what necessity attendant on the constitution
of the straight line, the several results here taken for granted
will take place, is precisely the object which it was in question
to attain. The apparent application of the proposed principle instructed triangle, a third triangle will be constructed having the
the 20th Proposition of Euclid's Eleventh Book, is a mere error
of Euclid's, and corrected by the Arabs, and subsequently by
Legendre and probably others, through a very simple alteration
in the construction. Euclid's straight lines will fail to meet,
whenever his greatest angle exceeds half the angle cut off, by not
less than a right angle, Thus if the angles composing the solid
angle were 70°, 80°, and 130°, neither by cutting off one of the
smaller angles nor the other, could Euclid's intended construc-
tion take place.

All this is irrefragable; but not so the inference next taken
20. Professor Thomson. of Glasgow, proposes to take as an for established, which is that the third angle last mentioned
Axiom, that "if a triangle be moved along a plane, so that its approaches within any magnitude however small it may be
base may always be on the same straight line, its vertex describes chosen to assign, to the sum of two right angles. That it
a straight line equal to that which is described by either extre- approaches it (that is, that the angle continually grows larger) is
mity of the base." In which there are two things demanded, certain; but that it approaches to it within any magnitude how-
where either would be enough. For if it could be established ever small, is the point which, as in so many parallel instances, is
that the locus of the vertex is a straight line, every thing else taken for granted without sufficing proof. The weakness in the
might be demonstrated without premising that the lines described actual case, is in the fact that the base or side opposite to the
are equal; as has been done in kindred cases by Clavius and continually increasing angle, becomes itself of unlimited length.
others. Or if it could be established that the distances between If the resulting triangles had been all on the same base, the
the first and last situations of the travelling points respectively inference might perhaps have been conceded to be good. But it
are equal, this would suffice for the author's own demonstration, is precisely because by the extension of the base to an unlimited
without asking whether the vertex had been always in the join-magnitude the progress of the operation is removed from human
ing straight line. But how the equality of these distances is to eyes, that the force of the inference is diluted and done away.
be established, does not appear. One way of trying to proceed, Just as fast as the diminution of the two acute angles appears to
would be to show, that if the line on which the base of the induce a necessity for the obtuse angle's approximating to the
triangle travels (and of part of which the base is composed), sum of two right angles, does the increase of the length of the
instead of a straight line were a circular arc, the vertex would sides hold forth an augmented probability that the angle may
travel farther than the point in which the straight line from the after all evade increasing by the quantity required to make it
vertex to the centre cuts the base, if on the convex side, and less attain to two right angles in the end. To argue that when the
far if on the concave; which is easily done, by proving that if acute angles are nothing, or the lines coincide, the third angle
not, the straight lines that ought to be the radii of the circle will make a straight line, is substituting for what really happens,
would not meet. And this would throw the responsibility on what by the construction is not to happen. The demonstration
establishing, that the radius of a circle may be increased till a is therefore finally of the same strength as Franceschini's and
portion of the circumference approaches within any assignable others that have been mentioned. There is evidence of a per-
difference to a straight line of given length; in other words, that petual approach towards a given magnitude; but there is not
there cannot be three points not in a straight line, through which evidence of the degree and rapidity of approach which are
a circle may not be described. Which involves Euclid's necessary to insure arriving at it."
Axiom.

21. The demonstration presented by M. Legendre in the earlier editions of his "Eléments de Géométrie," consisted in first establishing that the three angles of a rectilinear triangle cannot be greater than two right angles (which may be passed over as irrefragable and liable to no remark), and afterwards proceeding to show cause why they should not be less. But the evidence offered on this latter point, depended on taking for granted that two straight lines (D E and B E in fig. 35 a in the Fourth Edition, and probably in the subsequent editions as far as the Eighth inclusive) meet when they make with a third straight line (DB) angles of which one (as ED B) is, or may be made to be, less than a right angle, and the other looks less than a right angle, but without further proof.

24. Another demonstration, or step towards a demonstration, presented by the same author (See Note II. p. 279, 12ème édition), consists in representing, that if any angle less than two right angles is bisected, all perpendiculars to the bisecting straight line must meet the sides, because otherwise there would be a straight line shut up between the lines that make an angle, which is repugnant to the nature of the straight line." On which it is sufficient to observe, that the existence, cause, and origin of this repugnance, are precisely what it was demanded to demonstrate.

25. The next paragraph in the same page is directed to establishing the sort of postulate assumed in the last, viz. that a straight line cannot be shut up within an angle. The argument appears to be, that either of the straight lines which make an angle, being 22. In the Seventh Edition another attempt was made to show prolonged both ways, will divide the infinite plane in which it that the lines must meet; but what is advanced as the proof exists into equal parts, and any other straight line must do the involves the same fallacy as that of the Bolognese Professor.t same; but a straight line that should be shut up [renfermée] 23. This was withdrawn in the Ninth Edition, and a new the sides in any direction however prolonged, would cut off more within the angle, without being able to escape from it by cutting demonstration offered in the Twelfth. The new one depended on one side and less on the other; therefore a straight line canupon taking in any triangle an angle that is not less than any not be shut up within an angle. Whoever examines this closely, other in the triangle, and a second that is not greater (See 12ème will see that it would equally prove that two straight lines canédition, p. 20, and Plate,; bisecting the side opposite to the second not be parallel to one another; for in that case it might equally angle, and drawing a straight line from the angular point to he urged, that if the one divides the infinite plane into two equal the point of bisection; cutting off in this straight line and its pro- parts, the other must cut off more on one side and less on the longation a part from the angular point equal to the side opposite other. The whole is consequently a mal-reasoning, arising from to the first-mentioned angle (viz. that angle which is not less than overlooking Plato's observation (See Note to Prop. IV. of Book any other in the triangle), and in this side and its prolongation), that quality of magnitude can only be predicated of things towards the same hand a part equal to double the straight line finite. between the angular point and the point of bisection formerly mentioned, and joining the extremities of the two parts thus cut off. It is not difficult to show, that in the new triangle thus last

"The first Six and the Eleventh and Twelfth Books of Euclid's Ele-
ments; with Notes and Illustrations. By James Thomsom, LL.D. Pro-
fessor of Mathematics in the University, Glasgow, 1834. Notes, p. 358."
+ Elém. de Géom. Par A. M. Legendre, 7ème édit. p. 280. Note II.
Not less and not greater are substituted for the greatest and least of the
original. The demonstration is plainly intended to be applicable to any
triangle; but the terms in the original would not apply to an equilateral
triangle, nor to any kind of isoscoles.

26. The nex in order is the so-called analytical proof, which professes to demonstrate that if two angles in one rectilinear triangle are respectively equal to two in another, the remaining angles are necessarily equal. If two angles of a triangle and the that individual triangle are determined; that is to say, they can side between them are given, the rest of the sides and angles of severally be oni of one certain magnitude and no other. Hence, said the advaurs of this demonstration, the angle opposite to the given side is a function of the two angles and the given side; their meaning by this term being, that a quantity is a function of other quantities, when on those other quantities being fixed and determined in magnitude, the first quantity is necessarily

fixed and determined in magnitude, or is what Euclid in his Book of Data would call given. "Let the right angle be represented by unity or 1, and then the angles will all be numbers somewhere between 0 and 2; and since the third angle is a function of the two other angles and the side between them, it will follow that the side cannot enter as an element into the determination of the magnitude of the angle." And this, they said, because the side is heterogeneous with the other quantities which are numbers, and no equality can be compounded or made to exist between them.t

LESSONS IN GEOLOGY.-No. L.

BY THOS. W. JENKYN, D.D., F.R.G.S., F.G.S., &c.

CHAPTER V.

ON THE CLASSIFICATION OF ROCKS.

SECTION IV.

ON THE TERTIARIES.

THE term "Tertiaries," as applied to certain beds, has a reference to the three grand divisions into which the fossiliferous rocks have been distributed by geologists. If you will consult the tabular view given in the commencement of this chapter, you will find that, taken in an upward direction, all the rocks from the Silurian to the Permian are called PRIMARY; that all the rocks from the Trias to the Chalk are called SECONDARY; and that all the beds between the Chalk and the Recent, or what I have called Post Pleistocene are called TERTIARY.

The tertiary rocks are generally divided into three, or rather four distinct groups, called, as viewed downward, the Pleistocene, the These terms were Pleiocene, the Meiocene, and the Eocene.

introduced and invented by Sir CHARLES LYELL. The reasons of this distribution are founded on the proportion which the fossil shells of each group bear to the species now living. All the recent rocks, called in our last lesson Post Pleistocene, might have been called Anthropozoic, that is, human-life rocks, but for the fact that their lower division contains fossils of all the existing species of shells, without any remains or traces of the human race. Sir Charles Lyell takes the fossils of this division of recent rocks as his standard in grouping the other beds downward to the chalk. All the different beds downward to the chalk, contain different proportions of the shells called present, modern, or recent. The Greek word for recent or new is kaivog, kainos, and the feminine kaun kainee. It has been the arbitrary custom of English scholars to write the Greek at as a diphthong, thus æ, and the x as c. Hence the uncouth word cane, now generally written cene and pronounced seen. Hence, the above names are pronounced as if written Ply'-sto-seen, Ply'-o-seen, My'-o-seen,

E'-o-seen.

The beds which contain the greatest abundance of living or recent shells., i.e. from 90 to 95 per cent., are called Pleistocene, from λoroc, pleistos, most. The beds which contained some smaller proportion than this, but more than the inferior beds, are called Pléiocene, from πλwv, pleión, more. The next underlying beds, as they contain only from 35 to 50 per cent., are called Méiocene, from pun, meiôn, fewer or less. The lowest of these

beds in which are only about 3 per cent. of species identical with the present, are called E'ocene, from noc, ceos, dawn, as if in this group we find the first indication or dawn of the existing species, since no recent or present species have been discovered in any of the secondary or the primary formations.

As the geological designations of these rocks are founded on their respective proportions of fossils identical with the recent fauna, you will perhaps find that the following summary explanation of them will answer every purpose in your efforts to learn the science.

shells.

1. The Pleistocene {most recent, or containing most of recent very recent, or having a large number of recent shells.

2. The Pléiocene

3. The Méiocene

4. The E'ocene

middling recent, or having a small proportion of recent shells.

somewhat recent, having some few indications of the present race of shells.

These groups are ascertained partly by their lithological character, and partly by their paleontology, or their fossil contents.

1. THE LITHOLOGICAL CHARACTER OF THE TERTIARIES.

The lithological character of a bed means the kind of material, sandy, clayey, flinty, or limy ingredients of which the rock is composed. The upper group of the Tertiaries are called Pleistocene, and are thus divided into minor formations.

I. THE PLEISTOCENE.

1. The Boulder Formation, or Drift. 2. The Norwich Crag.

3. Cavern Deposits and Osseous Breccia. 4. Sicilian Limestone.

I. THE BOULDER FORMATION, OR drift. The drift, or boulder formation, Las been described in a preceding lesson as being found associated with freshwater strata and marine beds, and as having been formed about the close of the pleistocene period. The mineral ingredients of this formation exhibit every where a confused mixture of the ruins of adjacent lands, and an immense number of stones, some angular and rugged, others rounded and smoothed, and brought to their present position from very remote districts, by the agency of icebergs. In the Eastern counties of England, this formation supplies specimens of almost every known rock. It extends from Scotland as far south as to Muswell Hill, near London, and no trace of it is found farther south. The best place to study it in England, is in the cliffs of the Norfolk coast, where it presents a section from 50 to 70 feet high, and about 20 miles in length. In that section it consists of clay, loam, and sand, partly stratified and partly unstratified. It contains pebbles and boulders of porphyry, greenstone, lias and chalk. These are found everywhere interspersed, but especially in the Till.

Your attention has already been directed to the vast extent of this formation in North America, and in the northern parts of Russia and Germany, and also to the Alps as another centre from which these erratic blocks have been carried by icebergs. You find the same to be the case in your own country, as instanced in the mountains of Galloway, Cumberland and North Wales.

Though the drift is, comparatively, a most recent formation, "toute quantité formée d'une manière quelconque d'une autre you are not to expect to find it always resting on some other quantité."-Lagrange, Théorie des Fonctions Analytiques. "Il faut donc que l'angle c soit entièrement déterminé, lorsqu'on con- tertiary strata. In many places, and especially in Scotland, it is nait les angles A et B, avec le côté p; car, si plusieurs angles o pouvaient found to rest immediately on some of the older rocks, and is correspondre aux trois données A, B, p, il y aurait autant de triangles différents qui auraient un côté égal adjacent à deux angles égaux, ce qui est im-covered by stratified beds of sand and clay which are usually possible: donc l'angle c doit être une fonction déterminée des trois quantités without any fossils. A, B, p; ce que j'exprime ainsi, 0=: (A, B, p)."

"Soit Pangle droit égal à l'unité, alors les angles A, B, C, seront des nombres compris entre 0 et 2; et puisque c=: (A, B, p), je dis que la ligne p ne doit point entrer dans la fonction . En effet, on a vu que c doit être entièrement déterminé par les seules données A, B, p, sans autre angle ni lign quelconque, mais la ligne p est hétérogène avec les nombres A, B, C; ets on avait une équation quelconque entre A, B, C, P, on en pourrait tirer la valeur de p en A, B, C; d'où il résulterait que p est égal à un nombre, ce qui est absurde: donc pne peut entrer dans la fonction 4, et on a simplement c=p: (A, B)."-Legendre, Elém. de Géom. 12ème édit, Notes. p. The entire passage is inserted at the end of these notes in English, that our stuents may be able to judge for themselves of the merits of this controversy.

281.

Such a position is represented by the diagram, fig. 1, page 263, where a represents the ancient rock, and d, e, b, various beds of the tertiaries.

11. THE NORWICH CRAG.

On each side of the river Yare, within five miles of the city of Norwich, are seen beds of sand, loam and gravel, which are called by the country people CRAG, or gravel. These beds abound with the shells of animals, marine, freshwater, and land. The strata have every appearance of having accumulated at the bottom of the sea near the mouth of a large river. This formation is found in patches of different thickness, and covered with a denso mass

[graphic]

bones there. The preservation of such bones is due to the slow but constant supply of stalactite matter brought into the caverns the ca by water infiltrating from the roof.

Cavern breccias are found in every part of the world, but at San Ciro, in Sicily, there is one of great interest. It is about 20 feet high, 10 wide, and 180 above the sea. Within it there is an ancient sea-beach formed of pebbles of different rocks brought thither from very distant places. Broken corals and shells mingle with the pebbles. Under a mass of breccia were found an immense quantity of bones of the mammoth, &c., in a dark brown calcareous marl, and many of the bones were worn as if rounded by the action of the waves. This bed of breccia is about 20 feet thick, and under it is a bed of sand filled with sea shells of recent species.

III. CAVERN DEPOSITS AND OSSEOUS OR BONY
CONCRETIONS.

When rounded pebbles and gravel are cemented together into a hard stone, the mass is called a conglomerate, and sometimes, plum-pudding stone; but when such a cemented mass is composed of angular and unworn fragments of rock and other materials, it is called, from the Italian, Breccia.

In mountainous districts, many fissures are found, into which animals seem to have fallen from time to time, or into which they have been washed by floods. These animal remains are frequently found covered with alluvial matter and with fragments of rocks which have been detached by frost. The whole mass is then formed, by stalactite infiltration, into what is called a bony or

Osseous breccia.

Limestone hills often abound with a series of caverns with low and narrow passages from one suite to another, which hold a tortuous course through the interior of the mountain. These caverns and passages seem to have served, at some early period, as the subterranean channels of springs and rivers. In tho ter-period as the Norwich crag.

tiary period, these channels had become and remained open for the homos and shelters of animals which perished and left their

II. THE SUBAPENNINE BEDS,

The A'pennines, composed chiefly of secondary limestone, are a chain of hills which commence at the base of the Ligurian Alps and extend through the whole length of Italy. At the foot of these mountains and on each side of them, is found a series of tertiary strata which forms a line of low hills between the central ridge of mountains and the Adriátic on the east side, and the Mediterranean on the west.

The strata of these low subapennine hills consist generally of light-brown or blue marl, covered by a yellow calcareous sand and gravel, imbedding fossil shells. The marl is very aluminous, containing much calcareous matter and scales of mica. Near Parma it attains a height of about 2,000 feet, abounding in marine shells. Near Sienna, the yellow sand conglomerate rests immediately on the Apennine limestone, and at St. Vignone (pronounced Vinion) it passes into a calcareous sandstone. As this yellow sand formation is superimposed upon the marl, it represents the deltas of rivers and torrents which gained upon the bed of the sea where the blue marl had been previously deposited. Geologists now acknowledge that all the subapennine tertiaries do not belong to the same period. The beds indicate three distinct geological eras.

1. The beds of Piedmont, e.g. at Superga, are Meiocene. 2. The beds of North Italy, Tuscany, and the Seven Hills of Rome, are Pleiocene.

3. The Tufaceous formations about Naples, Ischia, &c., are Pleistocene, and Post Pleistocene.

III. THE MEIOCENE.

1. The Faluns of Touraine.

2. Part of Bourdeaux.

3. Part of the Molasse of Switzerland.

I. THE FALUNS OF TOURAINE.

In French Brittany, near Dinan and Rennes, and also in the provinces bordering on the river Loire, there is a tertiary formation called by the peasantry Faluns (faloons). It consists of shelly sand and marl, and is used for agricultural purposes. Some of the shells and corals are entire, some are rolled, and others are in comminuted fragments. In some places, as at Doué, near Saumur, these sands and marls form a soft building stone, which is composed of broken shells united by a caleareous cement, and which looks much like a mass of the coralline crag in Suffolk.

This formation exists in scattered patches of slight thickness, and very rarely exceeding 50 feet in depth. They are frequently found to rest on a great variety of older rocks, such as gneiss and clay slate. In other districts, as between the Seine and the Loire, they repose upon the upper freshwater limestone of the Parisian tertiaries. At some points south of Tours, the shells are stained a ferruginous colour, like those of the red crag in Suffolk.

The fossil shells indicate that these Faluns were formed partly

on the shore itself at the level of low water, and partly at very moderate depths, not exceeding ten fathoms below that level.

II. PART OF THE BOURDEAUX BED3.

Immense deposits of tertiary rocks are found in the country which lies between the Pyrenees and the Gironde river. Seven hundred species of shells have been found in these beds, and they all indicate that this division of the Meiocene strata is older than the Faluns of Touraine.

III. THE MOLASSE OF SWITZERLAND.

In Savoy we find, at the northern base of the great chain of the Alps, and throughout the lower country of Switzerland, a soft green sandstone, which is probably one of the oldest Meiocene groups hitherto discovered. It is associated with marls and conglomerates and is called "molasse," derived from "mol," soft, as the stone is easily cut in the quarry. It is of very great thickness, and might perhaps be divided into several formations.

No rocks of the Meiocene period are found in England.

IV. THE EOCENE.

The Eocene group of rocks is divided by Sir Charles Lyell into three subdivisions, which he calls the Upper, the Middle, and the Lower Воседе.

[blocks in formation]

III. THE LOWER EOCENE.

1. Lower sands with marine shelly beds.
2. Do. with lignite and plastic clay.

I. THE UPPER EOCENE is represented in the upper marine beds of Paris, the Fontainebleau sandstone and millstone, the Kleyn Spawen beds, the Berlin tile clay, the tertiary strata about Mayence, and the freshwater formations in Auvergne.

1. The freshwater marls and limestones of Paris seem to have been formed in marshes and shallow lakes. Some of the siliceous rocks of this formation are used for millstones.

2. The upper marine sands consist of marls, micaceous and quartzose sand, with beds of sandstone abounding in marine shells.

The Upper Eocene is not found in England.

II. THE MIDDLE EOCENE is represented by the Paris gypsum, the beds of Headon Hill in the Isle of Wight, the Barton beds, and the Bagshot and Bracklesham sands.

Near Paris we find, below the upper marine sands, a series of white and green marls, with beds of gypsum lying under them, which are best developed at Montmartre, where its fossils were first discovered by CUVIER. The gypsum is quarried for the manufacture of the plaster of Paris.

In England, the Middle Eocene is developed in various instances.

1. In Headon Hill, in the Isle of Wight, we find beds of marl, clay, sand, and a friable limestone containing freshwater shells, These beds are seen in the sea cliffs, where some of the strata contain a few marine and estuary shells.

2. In the cliffs of Barton, the pure white sand without fossils, on which the freshwater series of Headon Hill rested, is found to repose on a marine deposit, in which 209 species of shells have been found. This is the newest purely marine bed of the Eocone series known in England.

3. The Bagshot sands consist chiefly of siliceous sand found about Bagshot and in the New Forest. They may be divided into three beds, the upper and lower being of light yellow sands, and the middle of dark green sands and brown clays, al! reposing on the London clay.

a

teeth.

4. At Bracklesham near Chichester, there is a bay, bounded by low cliff of blue clay and green sand, full of fossil shells and The lower Bagshot sands have supplied the boulders of sandstones which are frequently found in some of the chalk valleys, and which are called Sarsden stones, and Druid sandstone, as may be seen at Stonehenge in Wiltshire, and Kitt Kotty near Maidstone in Kent.

III. THE LOWER EOCENE consists of the London clay, the Sablés (sab-lé) of the Paris basin, the mottled and plastic clays of Hampshire and London, and the nummulites of the Alps.

In the Paris basin, just below the Calcaire grossier, are extensive deposits of sand, having in the upper portion some marine beds called "lits coquilliers," in which 200 species of shells have been found. At the very base of the tertiary system in France, are beds of sands and plastic clay abounding with fossil oysters. In the lower clays and sands layers of lignite are found.

1. The London Clay consists of a tenacious brown and bluishgray clay, with layers of concretions called Septaria, which are employed in manufacturing Roman cement. The best places to study this bed are Highgate near London, the Isle of Sheppey in Kent, and Bognor in Sussex.

2. Mottled or Plastic Clays are accumulations of sand, pebbles, and mottled clays. They are well developed in some of the railway cuttings about Reading, in Berkshire; in different parts of Hampshire; and especially about Blackheath and Woolwich. In many places it appears to be a mixture accumulated by the combined action of river and sea-water. At Poole, in Dorsetshire, this clay is used for pottery, and hence the term "plastic clay,"

3. The Nummulite of the Alps and Pyrenees. This is a cal- NOTES AND REFERENCES-a. Faire entendre raison au petit careous rock, consisting often of a compact crystalline limestone, B., induce little B. to listen to reason; L. S. 96, R. 4.-5. il full of nummulites or shells of the class Foraminifera, or ex- s'engagea une dispute, an altercation commenced; the verb is unitremely diminutive forms of shelly animals. As these fossils are personal.-c. from se mettre; L. S. 68, R. 3, also part ii., p. 96. very much like pieces of coin, and as nummus is the Latin ford. remit, delivered; from remettre; L. part ii., p. 102.-e. L. coin, and nummulus, is little coin, this rock is called Nummulite. S. 43, R. 6.-f. fit coudre, had it sewed; L. S. 31, R. 3.-g. In the Alps this rock is of great thickness. In many parts of causa, talked, spoke.-h from falloir; L. part ii., p. 92.-i. on Europe, Asia, and Africa, this group forms a very large part of se remit en marche, the march was resumed; L. S. 34, R. 1, 2.— the Tertiary formations. It is found in Algeria and Morocco; inj. the verb is unipersonal.-k. from atteindre; L. part ii., p. 78. the Carpathian Mountains; in the districts between Egypt and -7. qu'il, let it.-m. from suffire; L. part ii., p. 106.Asia Minor; and between Persia and India. restait, if there remained; the verb is unipersonal; L. S. 84, R. 4.-0. L. S. 77, R. 2.-p. L. S. 25, R. 2.-q. faire sauter, blow up.-r. from produire; L. part ii., p. 100.—s. la retenait, supported it.

FRENCH

READING S.-No. III.
LE SAPEUR DE DIX ANS.
SECTION VI.

b

ANSWERS TO CORRESPONDENTS.

-n. s'il

ANNA PRINGLE (Ferry Hill): She must try and beat the boys in the Four Bali question; neither they nor she have mastered it yet. She is very right about fractional questions and solutions; we are proud of her correspondence.-E. PHILLIPS (Machen): We are sorry that we can't give our correspondent the information he requires.

Le pauvre marchand voulut faire entendre raison1 au petit Bilboquet, mais il était entêté comme un cheval aveuGEORGE ISAAC E. (Nottingham); The Italian language has no nasal gle, et il s'engagea une dispute qui attira bientôt quelques sounds, and each vowel keeps its alphabetical sound irrespective of any soldats. Ils entrèrent pour s'informer du motif de la que- consonant that may follow; e. g. in the words tempo, time; sento, I feel; relle, et ils trouvèrent l'idée du tambour si drôle, qu'ils pronunciation of the vowel e, such as they have in French on the pronunciamento, chin, the consonants m and n have no influence whatever on the obligèrent le pauvre Juif à lui céder sa barbe, et l'union of each vowel preceding them. The combination gn, pronounced as in d'eux, Gascon et perruquier du régiment, tira des rasoirs de French, is the only exception, and approaches a nasal sound. This constitutes an important difference between the two languages, French being to sa poche, se mit à raser le malheureux marchands et a great extent a nasal language, and Italian a language spoken from the remit solennellement la toute à Bilboquet qui l'emporta chest. A great many examples in the first ten lessons, exclusively devoted en triomphe. En arrivant au régiment, il la fit' coudre have clearly illustrated this. The best Italian translation of the Bible, for to the explanation of the principles and mechanism of Italian pronunciation, par le tailleur sur un morceau de peau d'un tambour crevé, Protestant readers, is by Giovanni Diodati. The "Society for Promoting et sans rien dire de son dessein, il la mit au fond de son Christian Knowledge," 67, Lincoln's-inn-fields, and the " British and Foreign Bible Society," Earl-street, New Bridge-street, Blackfriars, have both pubsac. On en causas pendant quelques jours, mais il fallut lished this translation. The price varies from 3s. 8d., 4s. 8d., &c., according to bientôt penser à autre chose. On se remit en marche, et on ne the binding, and it may be had at the above-stated premises in Lincoln's-inn Fields, or at Bagster's, Paternoster-row. With regard to the Italian pensait plus au petit Bilboquet, quand on arriva à Moscou. Dictionary, we must refer you to former remarks, and only beg to repeat Alors il arriva d'affreux malheurs, le froid et la dévas- that the subject will be duly considered. tation privèrent l'armée française de toutes ses ressources,1 la famine l'atteignit, et bientôt il fallut se retirer à travers un pays désert et des neiges sans fin. Je ne veux pas vous faire un tableau de cet horrible désastre; c'est une chose trop vaste et trop épouvantable 12 à la fois, pour que je vous en parle dans cette histoire qu'il vous suffise de savoir que chacun s'en retournait comme il pouvait, et que c'est à peine s'il restait quelques régiments réunis en corps d'armée et obéissant aux généraux. Celui de Bilboquet était de ce nombre. Il était de l'arrière-garde,11 qui empêchait des milliers de Cosaques, qui suivaient la retraite de l'armée,1 de massacrer les malheureux soldats isolés. Un jour, ils venaient de franchir une petite rivière, et, pour retarder la poursuite des ennemis, on avait essayé de faire sauter deux arches d'un pont de bois qu'on venait de traverser; 16 mais les tonneaux de poudre avaient été posés si precipitamment," que l'explosion ne produisit que peu d'effet: les arches furent cependant démantibulées, mais toute la charpente appuyait encore sur une grosse poutre qui la retenait,18 et qui, si les ennemis fussent arrivés, bientôt permis de reconstruire le pont.19 COLLOQUIAL EXERCISE.

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T. G. L: The result will be most conveniently illustrated by regarding the solution as hydrochlorate of protoxide of tin: to which solution nitric protoxide of tin, and converts it into peroxide. One portion of this peroxide acid being added, the latter becomes decomposed,-yields oxygen to the is precipitated, leaving an excess of hydrochloric acid to combine with the rest. Thus the hydrochlorate of peroxide of tin results.

or the acid employed was not sufficiently strong.

A. C. HILLARY: Probably the metal was not in the state of fine powder,

E. WILLIAMS: The result of such distillation would not be simply one chemical product, but many very complex products, whose investigation

would belong to the higher departments of organic chemistry.

D. B. C. (Hartlepool): We do not answer some questions for fear of giving

offence to some readers, especially when they refer to religious worship. -J. D. (Newcastle): High Dutch is German.-G. W. R. (Walnut-tree walk): The ch in archbishop is pronounced like ch in church.-MATHETES The Greek upsilon is generally replaced by y in English; as in cvv, with; astronomical day begins at the noon of one day, and terminates at the noon and in ovens, scythes, a Scythian.-H. WATKINS (Wolverhampton): The of the next day. The civil day varies in different nations; with ourselves it begins at midnight of one day, and terminates at midnight of the next day. -G. H. H. (Haslingden): See our answer to R. S. 8. (Glasgow).—A POOR STUDENT will get solutions of his questions in any treatise on Trigonometry. eût-DON QUIJOTE (Grahamston): We don't know any Spanish Dictionary about 8s. or 10s. that we can recommend.-B. H. (Bristol): See page 79, vol. iii. P. E., where the rule is that things without life are neuter. Now heart and hand apart from the body are without life, and therefore strictly neuter. But by poetic gender, as it is called, sex may be attributed to these nouns: in that case, we should call the heart feminine, and the hand masculine, that is, if we were writing poetry.-HOPEFUL: Very well, go on.

| 11. Que fut-elle bientôt obligée
de faire ?
12. Pourquoi l'auteur ne veut-il
point faire le tableau de cet
horrible désastre?

13. Que suffit-il de savoir ?
14. Où se trouvait le régiment
de Bilboquet?

15. Que faisaient les Cosaques?
16. Qu'avait-on essayé de faire
après avoir passé la rivière?
17. Pourquoi l'explosion n'a-
vait-elle pas eu beaucoup
d'effect?

18. Pourquoi la charpente du
pont ne tombait-elle pas?
19. Qu'est-ce que les ennemis
auraient pu faire, s'ils étaient
arrivés ?

given.

CIUS (Liverpool) should have had an answer if his address had been YOUNG WHITEBREAD wishes to know the proportion in which liquor potasse must be added to sugar of lead in order to produce the potash solution of oxide of lead so useful as a test for sulphur."

A slight amount of consideration will prove to our correspondent that the proportion will altogether depend on the strength of the liquor potass and of the lead solution. The best plan of procedure consists in disregarding solution until the desired result is accomplished. Thus, having taken some weighed or measured proportions, and adding liquor potasss to the lead solution of acetate of lead (sugar of lead), or still better,solution of trisacetate of lead (Goulard's extract), add to it by small quantities at a time liquor potasss until all the oxide of lead is precipitated. Then continue to add more until nearly, but not quite, all this precipitate is redissolved. By thus leaving a little oxide of lead, the operator is assured that liquor potasse has not been added in excess.

chemical experiments.
G. H. BALDING (Hastings) wishes to know how to make crucibles for
He is not sufficiently precise. What sort or
crucibles ? and what kind of experiments? The crucible adapted for one
use is totally unfitted for others. The chemist employs crucibles of clay-
casionally, gold; but he does not prepare those crucibles himself; they are
ware, German porcelain, blacklead-ware, iron, silver, platinum, and, oc-

the manufacture of various trades.

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