« AnteriorContinuar »
LESSONS IN BOTANY.-X.
The names of his twenty-four classes, including cryptogamic
plants as the twenty-fourth, are as follows :SECTION XX.-FURTHER CLASSIFICATION OF
1. Monandria-one stamen. 2. Diandria-two stamens. 3. VEGETABLES.
Triandria—three stamens. 4. Tetrandria—four stamens. 5. All the general principles we have discussed hitherto, and Pentandria-five stamens. 6. Hexandria-six stamens. 7. taken advantage of, have merely furnished us with the means of Heptandria-seven stamens. 8. Octandria-eight stamens. dividing vegetable growths into three sections; the question, 9. Enneandria-nine stamens. 10. Decandria-ten stamens. therefore, presents itself, how we are to continue the division, 11. Dodecandria-eleven to nineteen stamens. 12. Icosandria how arrange the classification of the hundreds of thousands of —twenty or more on the calyx. 13. Polyandria-twenty or plants which exist ? Various methods have been at different more on the receptacle. 14. Didynamia—four, two long, two times proposed for accomplishing this. We shall not mention short. 15. Tetradynamia—six, four long, two short. 16. them in the order of their organisation, nor shall we fully describe Monadelphia-stamens joined by their edges into one body. them, such not being the object with which these papers are i 17. Diadelphia-stamens joined into two bodies. 18. Polywritten. We shall mention the general principles involved in adelphia-stamens joined into many bodies. 19. Syngenesiaeffecting some of these classifica
stamens joined by their anthers tions, and shall point out in what
into a cylinder. 20. Gynandriarespects certain classifications are
stamens adherent to pistil. 21. better than others.
Moncecia—flowers bearing pistils Of all the different schemes of
exclusively, and flowers bearing classification which have ever been
stamens exclusively, on the same proposed or carried into execution,
plant. 22. Diccia—flowers bearing that of the celebrated Swede, Linné
pistils exclusively, and flowers bearor Linnæus, has undoubtedly at
ing stamens exclusively, on different tained to the greatest popularity.
plants. 23. Polygamia — flowers Indeed, so firm is the hold it has
bearing stamens exclusively, or taken of popular appreciation, that
pistils exclusively, or either parno inconsiderable number of those
tially, on one or many plants. 24. who study Botany still fancy they
Cryptogamia. have nothing better to learn than
In the annexed illustration, a rethe number of pistils and stamens
presentation is given of the fleshy which are contained in different
rhizome, leaves and flower of the flowers, totally unconscious of all
Iris Florentina, or White Iris, a natural alliances. Suppose that
· beautiful variety of the family some eccentric ethnologist should
Iridacece, and a native of Southern adopt the grotesque idea of classify
Europe. It flowers in May. Acing human faces according to the
cording to the division adopted by number of wives the individuals of
Linnæus, this plant belongs to the each race were in the habit of mar.
first order Monogynia (having one rying. Suppose that in reference
pistil), of the third class Triandria to this master-idea the ethnologist
(having three stamens). should arrive at the conclusion, that
From an inspection of this arinasmuch as Mussulman Turks, and
rangement, we observe that up to Mussulman negroes, and Mussulman
the eleventh class the number of Kalmucs, and Malays, all marry a
stamens alone furnishes the distincgreat many wives, that for this
tive sign, after which other circum. reason Turks, and negroes, and
stances are taken cognisance of. Kalmacs, and Malays, must all be
These circumstances are sufficiently similar races of men. Would not
indicated in the list of classes given such a classification awaken a smile
above; but it is desirable to preat its grotesque whimsicality and
sent the reader with the derivation would it not be considered an
of these terms. It will be remememinently false classification, not to
bered that the stamens are the male say absurd ?
organs of the flower, and the names Yet this is almost the parallel case
given to the first eleven classes are to that of Linnæus, when he effected
compounded of the Greek words for his celebrated artificial division of
the numerals, one, two, three, four, plants according to the number and
five, six, seven, eight, nine, ten and portion of the male and female parts
twelve, and the Greek noun avnp (stamens and pistils) of flowers.
(an'-ear), genitive avdpos (an'-dros), The cases are remarkably similar THE IRIS, AN EXAMPLE OF THE LINXEAN CLASS TRIANDRIA,
Icosandria is formed of in all that relates to our argument,
the same Greek noun, and EikOOL for although it is the manner of a
(i'-ko-si), the Greek for twenty; Mussulman gentleman to have several wives, whereas it is the polyandria from the same Greek noun avnp and the adjective wont of a lady flower to have several husbands; yet this cols | Tolus (pol-use), much or many. The term didynamia means lateral discrepancy does not affect the general deduction. two-powered, from the Greek 8vo (du'-o), two, and duvauis
Nevertheless, the artificial classification of Linnæus has ac- (du-na-mis), power; the reason why the term is applied will be quired a celebrity so great, and is so interwoven with popular seen by referring to the explanation given above. Monadelphia botanical ideas, that it cannot be dismissed with the casual means one brotherhood, from the Greek movos (mon'-os), one, notice we have already afforded it. Let us, therefore, proceed and aden pos (a-del-fos), brother, because all the stamens are conto examine the general principles on which it is based.
nected together. Syngenesia is another term signifying a growIn the first place, Linnæus divided plants into cryptogamic ing together, from the Greek ouy (sune), together, and yeivouai and flowering, as we have done. The department of crypto- (gi'-no-mi, the g hard), I grow. Gynandria signifies woman-man, gamic Botany was, however, very imperfectly known to Lin from the Greek yuvn (gu'-ne, 9 hard), woman, and avnp, genitive næus ; it was to the classification of flowering plants that his avopos, a man, because the pistils and stamens are attached. chief efforts were directed, and it is on his mode of effecting Monoecia signifies one-housed, from the Greek povos, one, and Oikos this that his botanical fame depends. Linnæus arranged all (oi'-kos), house, for a reason which will be evident. Polygamia flowering plants ander twenty-three classes, founded on the num- signifies many-married, from the Greek nolus, many, gauos ber and arrangement of the male parts (stamens) of the flower. (gam'-os), marriage; the meaning of which term will also be VOL. I.
Example of “ Slow" Movement.
2: Before and after an intervening phrase : Thou, who didst put to flight
Talents || without application || are no security for progress in Primeval silence, when the morning stars
learning. Exulting shouted o'er the rising ball;
3. Wherever transposition of phrases may take place :0 Thou, whose word from solid darkness struck That spark, the sun, strike wisdom from my soul!
Through dangers the most appalling || he advanced with heroic
intrepidity. * Moderate." There is something nobly simple and pure in a taste for the cultiva
4. Before an adjective following its noun: tion of forest trees. It argues, I think, a sweet and generous nature, Hers was a soul || replete with every noble quality. to have a strong relish for the beauties of vegetation, and a friendship
5. Before relative pronouns, prepositions, conjunctions, or for the hardy and glorious sons of the forest. There is a grandeur of thought connected with this part of rural economy. It is worthy of
adverbs used conjunctively, when followed by a clause depending liberul, and freeborn, and aspiring men. He who plants an oak looks
on them : forward to future ages, and plants for posterity. Nothing can be less A physician was called in || who prescribed appropriate remedies. selfish than this. He cannot expect to sit in its shade, and enjoy its The traveller began his journey || in the highest spirits ) and with ebelter ; but he exults in the idea that the acorn which he has buried the most delightful anticipations. in the earth shall grow up into a lofty tree, and shall keep on flourish
6. Where ellipsis, or omission of words, takes place : ing, and increasing, and benefiting mankind, long after he shall have ceased to tread his paternal fields.
To your elders manifest becoming deference, to your companions | frankness, to your juniors || condescension.
7. Before a verb in the infinitive mood, governed by another How does the water come down at Lodore ?
verb:Here it comes sparkling,
The general now commanded his reserve force | to advance to the And there it lies darkling;
aid of the main body.
Exercise on Rhetorical" Pauses.
Industry || is the guardian' of innocence.
Hononr || is the subject of my story.
The prodigal || lose many opportunities ' for doing good.
Prosperity Il gains friends, adversity | tries them.
Time || once passed || never returns.
He that hath no rule ' over his own spirit, is like a city' that is
broken down, and without walls. As if a war waging,
Better' is a dinner of herbs | where love | is, than a stalled ox || and Its caverns and rocks among;
hatred therewith. Rising and leaping,
The veil || which covers ' from our sight | the events of succeeding Sinking and creeping,
years, is a veil' woven by the hand of Mercy.
Blessed || are the poor in spirit.
Silver and gold || have I none.
Mirth || I consider' as an act, cheerfulness || as a habit of the
mind. Mirth || is short ' and transient, cheerfulness || fixed ' and Eddying and whisking,
permanent. Mirth || is like a flash of lightning, that glitters' for Spouting and frisking,
a moment: cheerfulness || keeps up a kind of daylight ' in the Turning and twisting
Some || place the bliss ' in action, some || in ease;
Those || call it pleasure, and contentment || these.
The habitual tendency of young readers being to hurry, in
reading, their pauses are liable to become too short for distinctDizzying and deafening the ear with its sound.
ness, or to be entirely omitted. In most of the above examples,
the precision, beauty, and force of the sentiment, depend much And so never ending, but always descending,
on the careful observance of the rhetorical pauses. The student Sounds and motions for ever and ever are blending,
may obtain an idea of their effect, by reading each sentence All at once and all o'er, with a mighty uproar; And this way the water comes down at Lodore.
first, without the rhetorical pauses-secondly, with the pausing
as marked. VI.-APPROPRIATE PAUSES.
Rule on the “ Oratorical" Pause. The grammatical punctuation of sentences, by which they are
The “oratorical” pause is introduced into those passages divided into clauses by commas, although sufficiently distinct which express the deepest and most solemn emotions, such for the purpose of separating the syntactical portions of the structure, are not adequate to the object of marking all the
as naturally arrest and overpower, rather than inspire utter
ance. andible pauses, which sense and feeling require, in reading aloud. Hence we find, that intelligible and impressive reading
Examples. depends on introducing many short pauses, not indicated by The sentence was--DEATH ! There is one sure refuge for the comunas or other points, but essential to the meaning of phrases oppressed, one sure resting place for the weary-THE GRAVE., and sentences. These shorter pauses are, for the sake of dis
It was the design of Providence, that the infant mind / should tinction, termed - rhetorical.”
germ of every science. If it were not so, the sciences Powerful emotion not unfrequently suggests another species the field | a place ' wherein it may grow, regale the sense 1 with its
could hardly be learnt. The care of God || provides ' for the flower of of pause, adapted to the utterance of deep feeling. This pause fragrance, and delight the soul | with its beauty. Is his providence mometimes takes place where there is no grammatical point less active over those, to whom this flower offers its incense ?-No. Ford, and sometimes is added to give length to a grammatical | The soil' which produces the vine || in its most healthy luxuriance, is false. This pause may be termed the “ oratorical,” or the not better adapted to that end, than the world we inhabit, to draw Danze of “ effect."
forth the latent energies of the soul, and fill then 'with life' and The length of the rhetorical pause depends on the length of vigour. As well might the eye | see without light, or the ear / hear the clause, or the significance of the word which follows it. The
| without sound, as the human mind | be healthy and athletic | withfull " rhetorical pause" is marked thus ll, the “ half-rhetorical
out descending into the natural world, and breathing the mountain
air. parise” thus |, and the short “ rhetorical pause” thus '.
Is there aught in Eloquence | which warms the heart ? She draws Rules for “Rhetorical” Pauses.
her fire' from natural imagery.' Is there aught in Poetry | to enliven The “ rhetorical” pause takes place, as follows:
Is there 1. Before a verb when the nominative is long, or when it is the natural world || is only the body, of which she is the sou
the imagination ? There is the secret' of all her power.
aught in Science to add strength and dignity' to the human miemphatic :
books, Science ' is presented to the eye of the pupil, as it we Life | is short, and art | is long.
dried ' and preserved 'state. The time may come,
structor' will take him by the hand, and lead him ' by the running triangles only, but for any triangles, whether symmetrical or streams, and teach him all the principles of Science, as she conies not, that are upon the same base and between the same from her Maker; as he would smell the fragrance of the rose, with
parallels. Thus, the triangles L F G, M F G are each of them out gathering it.
This love of nature ; this adaptation of man' to the place assigned equal to the triangle PFG, which is on the same base, F G, and him ' by his heavenly Father; this fulness of the mind || as it des
between the same parallels, DE, K, and each of them would cends into the works of God, is something, which has been felt' by be equal to any triangle that may be formed by drawing lines every one, though to an imperfect degree, and therefore I needs no from the points F and G to any point in the straight line u k, explanation. It is the part of science, that this be no longer a blind produced both ways indefinitely. affection ; but that the mind' be opened to a just perception of Triangles also which stand upon equal bases and between the what it is, which it loves. The affection, which the lover first feels!
same parallels are equal to one another. Thus, the triangles for his future wife, may be attended only by a general sense of her
LNG, MO F, which external beauty ; but his mind 'gradually opens ( to a perception of
stand on equal the peculiar features of the soul, of which the external appearance | is only an image. So it is ' with nature. Do we love to gaze on the
bases, NG, F 0, and
* between the same sun, the moon, the stars, and the planets ? This affection in its bosom | the whole science of astronomy, as the seed contains
parallels, DE, HK, the future tree. It is the office of the instructor' to give it an
are equal to one existence and a name, by making known the laws which govern the
another, as are also motions of the heavenly bodies, the relation of these bodies to each
the triangles LNF, other, and their uses.
MOG, which are Have we felt delight' in beholding the animal creation,-in watching
E between the same their pastimes' and their labours? It is the office of the instructor!
parallels and stand to give birth to this affection, by describing the different classes of
on equal bases N F, animals, with their peculiar characteristics, which inhabit the earth, the air, and the sea. Have we known the inexpressible pleasure of G O.
And this is also as true of unsymmetrical triangles as of beholding the beauties of the vegetable world ? This affection can symmetrical triangles, for if we join the dotted line n P, the only expand ' in the science of botany. Thus it is, that the love of triangles L NF, PNF, are equal to one another, because they nature ' in the mass | may become the love of all the sciences, and are on the same base, NF, and between the same parallels ; the mind will grow and bring forth fruit | from its own inherent and since the triangle mgo is equal to the triangle L N F, it power of development.
must also be equal to the triangle P N F.
In Case 3, when two of the angles of the required triangle are
given, it is manifestly necessary only to make at two points in LESSONS IN GEOMETRY.-X.
the same straight line, and on the same side of it, two angles In our last lesson we considered the various series of data equal to the given angles, each having its opening turned necessary for the construction of an isosceles triangle: we will towards the apex of the other, and then, if necessary in order to now do the same for any kind of scalene triangle, or triangle of complete the triangle, to produce the sides of the angles that are which all three sides are unequal.
inclined to the side that is common to both. The student must A scalene triangle, as it has been stated, may be an acute- notice that when two angles of a required triangle are given angled triangle, an obtuso-angled triangle, or a right-angled without any special requirement as to their relative position, triangle. To determine any scalene triangle
, it is plain that we drawn, similar in form but of different superficial areas, all
an endless number of pairs of symmetrical triangles may be must have one of the following series of data. I. With regard to the sides without the angles :
satisfying the general requirements set forth in the data.
Thus, in Fig. 33, if A and B represent the given angles of the 1. The length of each of the three unequal sides.
triangle required, it is plain that to make a triangle having two 2. The length of two sides and the altitude of the triangle.
angles equal to the given angles A and B, we have only to make II. With regard to the angles without the sides :
at any point, c, in a straight line, x y, of indefinite length, the 3. Any two of the angles of the triangle.
anglo Y c E equal to A, and at another point, D, in the same III. With regard to the sides and angles combined :
straight line, the angle x D E equal to B, each angle having its
opening opposite or turned towards the apex of the other, as, in 4. The length of any two of the sides of the triangle and one of its this figure, the opening of the angle at c is opposite the apex » angles.
of the angle at D, and vice versû; and to complete the triangle 5. The length of one side of the triangle and two of its angles. 6. The length of one side of the triangle, its altitude, and one of its inclined to the common side, cd, until they meet. If we reverse
produce the sides, C E, D Е, of the angles at c and D that are angles adjacent to the given side.
the position of the angles, making the angle at c equal to the As in the construction of the isosceles triangle, the first case angle at B, and the angle at D is met by Problem VIII. (page 191), but the second brings equal to the angle at A, the us to
triangle assusnes the form shown PROBLEM XXIV.-To draw a triangle of which the length of by the triangle FC D in the two of its sides and the altitude are given.
figure. The triangles ECD, Let A and B (Fig. 32) represent the length of two of the sides FCD, are symmetrical and equal of the triangle required, and c its altitude. In any straight line, in every respect. The triangles DE, of indefinite length, set off FG equal to B, and by Problem X. K G H, LG H, shown by dotted (page 192), draw the indefinite straight line, k, parallel to lines, are also equal and sym. DE, at a distance from it equal to c, the altitude of the required metrical in every respect, and triangle. Then from r as centre, with a radius equal to a, draw satisfy the general conditions of an arc cutting i k in the point L. Join L F, LG; the triangle the data, although their super
X CC LFG is a triangle answering the requirements of the data, for ficial area is greater than the
Fig. 33. its sides, LF, F G, are equal to A and B respectively, and its area of the triangles E C D, FCD, altitude shown by the dotted line L N is equal to the given because the points G and i, at which the angles necessary for straight line c. The triangle M F G, drawn in the same way, is the construction of the triangle required are made equal to a also a triangle which meets the requirements of the data, for its and B, are taken on the indefinite straight line, xy, at a greater sides, MG, G F, are equal to A and B respectively, and its altitude, distance apart than c and D. shown by the dotted line mo, is equal
PROBLEM XXV.-To draw a triangle of which treo sides and The triangles L F G, MFG, are equal to each other in every one of the angles are given. respect, namely, the length of their sides, their altitude, and First, let the given angle be included between the given sides, their superficial area. They are upon the same base, pg, and and let the straight lines B, c represent the length of the giren betwoen the same parallels, D Е, I k, and they are what we may sides of the triangle required, and a the given angle included om kymmetrical triangles. From this we learn that symme between them (Fig. 34). Draw any straight line, X Y, of inde
triangles on the same base and between the same parallels finite length, and at any point, D, in x y, make the angle Y DE ial to one another; and this is true, not for symmetrical equal to the given angle A. Along D Y set off D F, equal to C,
and along D E set off D G, equal to B. Join G F; the triangle to A. If it be required to have the smaller angle opposite to OD 7 answers the requirements set forth in the data, as does the given side, the angle kho must be made equal to the larger also the triangle KDH, obtained by setting off D H along Dy angle B, and the same method of construction followed as indiequal to B, and D K along D E equal to c.
cated by the dotted lines in the figure. The triangles G DF, KDH are symmetrical and equal in every PROBLEM XXVII.—To draw a triangle of which one side, its respect; but if the position of the given angle had been required to be opposite to one of the given sides, instead of being included between them, a very different result would have been
We will suppose, firstly, that it is required to place the angle opposite the shorter of the two given sides. At the point L in the
B straight line of inde-
equal to c; and from straight line, x y, of indefinite length, and, by Problem X. Fig. 34.
N as a centre, with (page 192), draw the straight line D E, also of indefinite length,
a radius equal to B, parallel to it, at a distance from it equal to B. Set off Fg in describe the arc O P, cutting the straight line L m in the points XY equal to A, and at the point F in the straight line G F make 0, P. Join o N and Pn. Either of the triangles ONL, PNL, the angle G F H equal to the given angle c. Let Fl meet D E will satisfy the requirements of the data, for in the triangle in H.
Join G H. The triangle F G H answers the requirements ONL the sides o N, NL are equal to B and c respectively, of the data, for it has a side F G equal to A, an angle G FH while the angle o L N is opposite to the shorter side on; and equal to C, and it is of the altitude - k, which is equal to the in the triangle PNL, the sides PN, NL are equal to B and c given altitude B. A triangle equal to the triangle G F H in respectively, while the angle PLN is opposite to the shorter every respect, and symmetrical with it, may be obtained by
making an angle at g, in the straight line F G, equal to c, and If it be required to place the angle opposite to the longer of following the same process of construction. the two given sides, it is manifest that we must set off L Q along
If the given angle be an obtuse angle, as c, the line which LX equal to B; and from Q as centre, with a radius equal to c, represents the altitude of the triangle required will fall on a describe an arc cutting the straight line L M in R. By joining point in x y without the line which is set off upon it equal to R Q, we get a triangle, R Q L, that satisfies the requirements of the given side. If it be an acute angle, as the anglez, the the data, the sides L Q, Q R being equal to B and c respectively, line representing the altitude of the triangle may fall between and the angle Q L R, which is equal to the angle A, opposite to the extremities of the line set off equal to the given side, as the longer side R Q.
No in the triangle NLM, which is drawn having the side L M The learner may make an endless variety of practical exercises equal to A, and the angle ML N equal to the given angle z; on this problem, by varying the length of the given sides and but whether this be the case or not depends entirely on the the opening of the given angle. Practice of this kind will be size of the angle and the relative proportions of the altitude and found to ensure neatness and accuracy in geometrical or given side. mechanical drawing, and will tend to render the draughtsman
In the construction of right-angled triangles, as one angle is skilfal in the use of his compasses and parallel ruler.
always necessarily known, less data are required than in the PROBLEM XXVI.-To draw a triangle of which one side and construction of obtuse-angled and acute-angled triangles ; thus tico of the angles are given.
any right-angled triangle may be constructed if we knowLet A represent the length of the given side of the required 1. The length of either of the sides containing the right angle (as triangle, and B and c the given angles, and first let both of the A B and ac in Fig. 37).
given angles be ad. 2. The length of either of the sides containing the right angle, and jacent to the given the side which subtends the right angle (as a B and B c, or ac and B C, side, or
in other in Fig. 37). words, let them be
3. The side which subtends the right angle, and the perpendicular at its opposite ex
let fall on it from the right angle (as a D and Bc in Fig. 37). tremities,
Thus, if the sides that contain the right angle be equal to P same side of it. and R, draw at right angles to each other A B and A c, and
Draw any straight make A B equal to P, and Ac equal to R, and join BC: ABC
D E equal to A. At equal to P, and the side that sub-
the point d make the tends the right angle equal to s,
angle E D F equal to draw BC equal to s; bisect it in the angle B, and at the point E make the angle D E F equal to c. E, and from E as centre, with the Let the sides DF, EF meet in the point F; the triangle F D E distance E B or Ec, describe the satisfies the requirements of the data; as will also the triangle semicircle B a C. Then from B as GDE, constructed by making the angle GDE equal to c, and centre, with a radius equal to P, the angle GED equal to B.
draw an arc cutting the semicircle Next, let one of the given angles be opposite to the given BAC in A. Join AB, AC; the side, as, for example, when the angle equal to the larger angle B triangle ABC will be the triangle B is required to be in this position. Take I k, in the straight required.
Fig. 37. line of indefinite length, XY, and at the point make the angle If the side which subtends the KHL equal to the angle c. Through K draw km parallel to right angle be given equal to s, and the perpendicular let fall 1 L, and at the point k in the straight line m K make the angle on it from the right angle equal to Q, draw Bc equal to s, bisect N K N equal to the angle B, and let the straight line k n meet it in E, and draw the semicircle B AC as before; through E draw the straight line L in N. The triangle NHK has the angle E F perpendicular to B C, and along it set off Eg equal to Q. I IN equal to C, and the angle 1 N K equal to B (for it is equal Through G draw G A parallel to bc, cutting the circumference to its alternate angle N KM, which was made equal to B), and the in A, and from a draw A B, AC, to the points B and c. The larger angle a n k is opposite to the side - K, which is equal altitude, A D, of the triangle A B C is equal to g.