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the Harz and Carpathian mountains, and the uniformity generally observable in all these, led him to expect a scene of a similar character in that which he was about to visit; but the reality far exceeded his expectations; for, if the structure of the cave, and the variety and beauty of the stalactites resembled those he had elsewhere witnessed, the majesty of equinoctial vegetation gave an individual character and indescribable superiority to the entrance of the Cavern of the Guacharo.

The entrance is a vaulted arch, eighty feet broad and seventy-two feet high; the steep rock that surmounts this opening is covered with gigantic trees, mixed with creeping and climbing plants and shrubs, brilliant with blossoms of the richest colours, and the most varied forms'. These form natural festoons, which hang before the mouth of the cave, and are gently agitated by the passing currents of air. What a contrast between such a scene and the gloomy entrances to the caverns of northern climes, crowned with oaks and sombre larches! But this luxuriant vegetation was not alone confined to the exterior; the traveller, on following the banks of this subterranean stream into the grotto, beheld them with astonishment, adorned for thirty or forty yards with the Praga palm-tree, plaintain-leaved hcliconias, eighteen feet high, and arums that resembled tree, in their size!

It was not found necessary to light their torches till they had reached the distance of 430 feet, owing to the continuous direction of the cavern, which allows the light of day to penetrate thus far; and when this began to fail, the hoarse pries of the nocturnal birds, whence the place derives its name and celebrity, began to be audible from' a distance. The Guacharo is about the size of a common fowl, and resembles in form the vulture tribe, with a beak surrounded by stiff hairs: its plumage is of a dark blueish gray, mixed with small streaks of black; white large heart-shaped spots, bordered with black, mark the head, wings, and tail; it is strictly a nocturnal bird, and is almost the only one which does not prey on animals, its food being fruits. The shrill, discordant noise made by thousands of these birds, brought from the inmost recesses of the cave, and reverberated from the arched roofs, form a clamour of which it is impossible to form an idea. Their Indian guides, by fixing torches to the onds of long poles, showed the travellers the nests of the bird, which were constructed in funnel-shaped holes, with which the roof of the grotto was pierced in all directions, and generally at about sixty feet above their heads.

There is an annual destruction of these birds by the Indians, who obtain from their young an oil much used in that country. They bring down the nests by means of long poles, and many thousands of the old birds are killed while endeavouring to defend their helpless progeny; they keep hovering over the heads of their enemies uttering the most discordant cries. The young that fall with the nests are immediately opened, and a thick layer of fat that is found in their intestines is melted down in pots of clay, and is known by the name of guacharo butter (Manteca or Aceite) it is half liquid, transparent, without smell, and may be kept a year without becoming rancid, and, according to the Baron who ate it at the convent, where no other oil is used, it imparts no disagreeable taste or smell to the food dressed with it. The habits of the bird, excluded from daylight, using little exercise, and feeding'on vegetable food, account for the production of this quantity of fat in a manner analogous to that in which geese and oxen are known to become large by similar modes of treatment; the quantity of this oil obtained, bears but a small proportion to the carnage thus made annually by the hunters; they do not obtain more than 150 or 160 bottles, of about sixty cubic inches each, of pure manteca; the rest, which is less transparent, is kept in earthen vessels.

There are two causes why this destruction of the birds at the oil-harvest, as it is termed, have not extirpated the race; one is, that the Indians are prevented by superstition from penetrating very far into the interior of the cavern, and the other, that neighbouring caverns, too small to be penetrated by man, afford a place of security to them to breed and multiply in; at least it appears that no perceptible diminution of their numbers has been observed.

• For the sake of our botanical readers, we may state, that among these the Baron enumerates a Dendrobium (family Orchides), with golden flowers, spotted with black, and three inches long! A Bignoma, with a violet blossom; a purple Dolichos, and a magnificent Solandia, the deep orange flower of which has a fleshy tube, four inches long.

The travellers in continuing to explore the cave, followed the banks of the stream which issues from it, and is from twenty to thirty feet wide; they pursued this course as far as the hills formed of the calcareous depositions admitted When the torrent wound among high masses of stalactites they were often obliged to descend into the bed of the stream, which is only about two feet in depth; on its banks they observed great quantities of palm-tree wood, the remains of trunks the Indians made use of to climb to the nests which they could not otherwise get down.

Still pursuing the course of the river, the cavern preserving the same width and height to the distance of 145* feet from the mouth; the travellers, on turning round, were struck with the singularly beautiful appearance which » hill, covered with the richest vegetation, immediately fronting the entrance of the grotto, presented; this, brilliantly illuminated by the sun's rays, and seen through the vista of the dark cave, formed a striking contrast to the surrounding obscurity; while the large stalactites depending from the roof were relieved against the luminous background of verdure. After surmounting, with some difficulty, an abrupt rise in the ground where the stream forms » small cascade, they found that the cave diminished in height to forty feet, but retained its original direction, here a blackish mould was found, either brought by the rivulet, or washed down from the roof by the rain-water which penetrates the crevices of the rock; and in this, to the delight of the travellers, they found seeds growing, which had been brought thus far into the cave by the birds, but so altered by the deprivation of light, that they could not even recognise the species of plant thus produced under such unfavourable circumstances It was found impossible to persuade the Indian guides to advance further; the cries of the birds, rendered still more horrible by the contraction of the cave, had such an effect on their minds, that they absolutely refused to proceed; and to the regret of Humboldt and his friend, they were compelled to retrace their steps.

In the district of Lasco, in Mexico, between the villages of Chamacasapa and Tchnieotepee, there is a suite of caverns in limestone mountains, through which also subterranean rivers pass.

The peculiar liability of limestone rocks to be perforated with caverns and fissures, causes frequent examples of the rivers and streams traversing countries where they abound, to be suddenly ingulfed and afterwards to reappear. Besides the examples just given, and the mention made of one in Okey Hole in another part of this paper, we may cite in our own country the Manifold, which passes beneath the limestone hills about three miles south-west of Ectonmine in Staffordshire, and after a passage through caverns four miles in length, re-appears near Ham. The Hamps river breaks out from the ground near the same place; the Ribble, the Greta, and several others, are also subterranean streams.

We have thus endeavoured to give our readers an account of a few of the principal features that render these natural excavations interesting. In a subsequent Number we shall perhaps renew the subject of Caverns, with a description of some of the most celebrated artificial caves, cut in rocks, for the purposes of religion, interment, habitation, concealment, &c.

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UNDER THE DIRECTION OF THE COMMITTEE OF GENERAL LITERATURE AND EDUCATION APPOINTED BY THE SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE

THE MICROSCOPE.

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THE MICROSCOPE. No. I. The invention of the Microscope disclosed to the eye of the philosopher, the naturalist, and the curious inquirer into the wonders of the creation, a new world of minute animals, the existence of which was until that time unknown. By the power of this instrument, it was discovered that every drop of impure water contained thousands of living creatures, some of which, although invisible to the naked eye, yet bore the same proportion to others, still more minute, that the gigantic whale does to the smallest inhabitant of the deep.

» • In the infancy of the knowledge acquired by this instrument, the rapid and apparently hostile movements of the larger kind of these creatures among their smaller companions, induced a belief that they devoured each other; but later observations have rendered it nearly certain that they exist entirely on vegetable food.

In addition to this demonstration of the immensity in number of the animal kingdom, the structure of vegetables, and the hitherto invisible parts of human and comparative anatomy were made clear to the eye, and the theories of philosophers were in some cases established, and in others proved to be without foundation. In this manner this most curious instrument was productive of effects as useful as they were interesting. The corallines and sponges had long been considered as belonging either to the vegetable or mineral kingdom, but by means of the microscope, their little architects were at last discovered, and their minute cells proved to be the habitations of living creatures; and the great theory of' the circulation of the blood was made as palpable to the eye, as the most simple visible truth.

In directing the attention of the observer to the different objects in nature or art, which are most worthy of notice, or most curious in their structure, we shall point out, in the first instance, such as occur in what has hitherto been considered the lowest state of animated nature,—the infusoria;, or animalcule (very small animals), which, as already noticed, are found in stagnant waters, both fresh and salt, but more particularly in stale vegetable infusions.

The smallest creature yet discovered, is the monad, monas termo, so called from monas, unity, and terma, an end; since it has been supposed to be the end, or lowest limit, of animal life. The group of small figures like grains of sand to the right of the top of the circle, represents several species of this genus; the form of the whole is that of half-transparent globules of different sizes. At first sight, they seem to be without the least appearance of mouth, or any trace of organization whatever; but the recent discoveries of Professor Ehrenberg, of Berlin, have proved that we have no right to conclude organization does not exist, merely because our limited powers of sight are incapable of perceiving it; for even this, the smallest of the infusory animals, which all naturalists had hitherto considered to be a perfectly simple body, nourished entirely by absorption, has been proved, by the patient experiments of Dr. Ehrenberg, to be at least in possession of four distinct stomachs.

; The method employed to discover the vessels in these curious creatures, is extremely ingenious and simple; it consists in nothing more than supplying them with vegetable colouring-matter for food. After many experiments, it was found that indigo, carmine, and sap green, answered the purpose better than any other substance.

The method of applying it ia this:—a drop of.

water containing the animalcuhe, being placed upon the slip of glass usually employed when examining these objects, a small quantity of a solution of the colouring-matter is added to it, by means of a camelhair pencil. Another drop of clear water is then placed near the first, and this last drop is brought under the microscope; so that, by drawing a fine point from one to the other, some of the animalcula: from the coloured drop will escape into the clear water, and their stomachs and alimentary canal being filled with the coloured liquid, will be thus rendered perfectly visible.

In employing these coloured liquids, it is absolutely necessary they should be perfectly pure and unadulterated; the least mixture of metallic substances will either kill the animalcule, or, at least, cause the colouring-matter to be rejected.

The rolvox, or whirler, on the same side of the circle, but lower down, is larger than the monad; and one species, volvox globator, is of sufficient size to be visible to the naked eye. The curious movement of these creatures is sure to attract the attention of the observer; they are almost constantly rolling round, with a greater or less, degree of swiftness, as if turning upon an axis.

The genus vibration, so called from the vibrating, or wavy motion of all its species, which differ extremely in form, as may be seen by referring to the figures at the top of the circle, is very interesting; one species appearing like groups of animals attached to each other, and assuming various arrangements.

The Proteus, or changeable animalcula, is continually altering its shape in the most curious manner; the figures in the engraving, on the left, near the top, will explain, much better than any description, the different forms the same individual can assume.

The creatures we have already described, are, in proportion to their size, of considerable thickness or plumpness of figure; the next in order are comparatively flattened, or else cupped, or somewhat like a shallow bag; and some are furnished with appendages like tails, or partially covered with the appearance of hair'.

We now come to a higher class in the scale of animation, the Polypi, many feet, so named from the number of cirri, or feelers, which surround their mouths, and are figuratively termed feet; some are fixed to solid substances, and others are perfectly free in their movements. An instance of the former is shown on the right hand at the bottom of the circle; it is called Vorticella scnta, and the engraving beneath the circle is a greatly-magnified representation of the internal arrangement of its organs of life, as shown by Dr. Ehrenberg.

The Rotifer, or Wheel-insect, on the right hand in the circle, belongs to this class, and is extremely curious and puzzling in its construction; when in motion, it seems to be impelled by means of two wheels, one on each side of the front part of the body; these wheels appear as if they turned upon an axis, but if this were really the case, it would imply their complete want of connexion with the body of the animal, a thing utterly impossible. The truth seems to be that the minute feelers, with which the felloes of these delicate wheels are furnished, are moved with so much rapidity as to deceive the eye, and prevent the true motion from being perceived.

The slender worm-shaped figures on the left of the engraving, are called Microscopic Eels, and are readily found in sour paste or stale vinegar; they appear to be more perfectly organized than any of the other objects represented.

It is not to be expected that the whole of the

* See the lower part of the circle.

A.

ereatures represented in the circle are to be found in one drop of water, or even at one season of the year, or in the same country; it is only by constant attention to the subject that the observer can be expected to meet with the greater number of the forms represented above. The readiest mode of obtaining them is by placing in a number of open-mouthed phials, half filled with water, bits of straw, peppermint, dead leaves, and other vegetable substances, and after a few days, if the weather is mild, or the room in which they are placed tolerably warm, a drop taken from any of them, and placed under the microscope, will exhibit some of these curious creatures; and, in general, the longer the infusions are kept, the more numerous the animalcule will be; stagnant puddles in leaden gutters are the most likely places to meet with the wheel insects, especially in warm weather.

As, when speaking of any object, allusion is frequently made to the number of times it is magnified, it will be well always to bear in mind the meaning of this expression. When any thing is said to be magnified nine times, that is, so as to appear nine times its real size, it is not to be supposed that the object will appear nine times the length, and nine times the width, for that would be eighty-one times its natural size; but three times its length, and three times its width; this may be illustrated by the annexed diagram.

The square A is the original size of the object which is magnified to three times its length, and as much in width; but, by inspecting the diagram, it will be clear that the representation is nine times the natural size. The same rule, of course, applies to every other proportion.

To discover how much an object is magnified, we have to divide the number of inches at which it can be seen most clearly by the naked eye (which is on the average eight), by the distance at which the image is perfect under the magnifying glass; so that if the distance at which we are obliged to hold the glass from the object is one inch, it is magnified eight times in length, and eight times in height, or actually sixty-four times. If the distance is half an inch, its appearance will be twice that size, and so on.

The above calculation only holds good when single lenses or glasses are employed: to calculate with exactness the magnifying power of a compound microscope, is not quite so simple an operation, and it is necessary to know the foci of the different lenses of which the instrument is composed.

A method, however, which approaches nearly to the truth, may be very easily put in practice; it is as follows. When observing the magnified appearance of the object through the microscope with one eye, let the other, instead of being closed, be directed to a common rule, marked with inches, and held at such a distance as to be clearly visible, that is, about eight inches; then, by comparing the enlarged appearance seen by one eye, with the inches as seen at the same time on the rule by the other, the power of the instrument may at once be seen, if the real size of the object is known. Thus, if its length is one quarter of an inch, and it appears, when seen through the glass, to be equal to two inches, as seen on the rule by the naked eye, it is clear that it is magnified eight times in length, or sixty-four times in magnitude.

He that smarts for speaking truth hath a plaster in his own conscience. Fuller.

Wb are not disarmed by being disincumbered of our passions. Burke.

HOW HE MUST LIVE THAT LIVES WELL. He who neglects his duty to himself, his neighbour, or his God, fails in something that should make life commendable. For ourselves, we need order; for our neighbour, charity; and for our God, our reverence and humility; and these are so linked one to another, that he who lives orderly cannot but be acceptable, both to God and his fellow-creatures. Nothing jars the world's harmony like men who break their ranks. One turbulent spirit will disturb even the calmest kingdom. We may see the beauty of order in nothing more than in some princely procession; and though, indeed, the circumstances and ceremonies belonging to state are not intrinsically necessary to government, yet, by a secret working in the minds of men, they add a reverence to it.

Did every man keep his own life as he ought, what a state of concord would a world, a kingdom, a city, a family be? But, being so infinitely disjointed, it is necessary that some should afford their help, and be charitable. If none were to repair the breaches, how soon would all lie levelled in demolishments? Love is so excellent, that, though it be but to one's self alone, yet others partake and find the benefit. Without charity a man cannot be sociable, and take away that, and there is little else that a man has to do in the world. How pleasant can good company make his life beneath! Certainly, if there be any thing sweet in mere humanity, it is in the intercourses of beloved society, when every one shall be each other's counsellor, each other's friend, and mine, and solace: and such a life as this I take to be the most pleasing to God, as well as to man. But yet this cannot be truly pleasing, unless a man be careful to give to God the honour that he owes him.

When a man shall do these things, and perform his duty to his Maker, he shall find a peace within, which shall fit him for whatsoever befalls. He shall not fear himself, for he knows his course is order. He shall not fear the world, for he knows he has done nothing to injure it. He shall not be afraid of heaven, for he knows he there shall find the favour of a servant, of a son, and be protected against the malice and spleen of Satan. Let me live thus, and I care not though the world should mock at my innocence.

Feltham's Resolves.

St. Jerome relates that "the blessed Apostle John, living at Ephesus to extreme old age, was with difficulty carried to church in the arms of the disciples, and being unable to make a long discourse, every time they assembled, was wont to say nothing but this, 'Little children, love one another.' At length, the disciples and brethren who attended, tired of hearing so often the same thing, said,' Sir, why do you always say this?' Who then made this answer, worthy of himself, 'Because it is the Lord's

command; and if that alone be done, it is sufficient."

Dr. Lardner.

Friendship is not inconsistent with the spirit and princi pies of the Gospel. It is not indeed the subject ot an in junction, as if the formation of particular attachments were a duty to be practised: but it as certainly is not forbidden, as if it were a vice or a weakness to be avoided. In several passages of our Lord's teaching, the existence of friendship, and the natural disposition of the heart of man towards it, are recognised plainly and with complacency: and the example of his conduct, in admitting St. John to a special share of his intimacy and regard, is a proof that friendship needs not to be discouraged. Charity for all men, brotherly love for all our brethren in Christ, is unquestionably pre scribed to us: but such regard and good-will for all is not incompatible with a higher degree of affection for some. And surely if amongst the twelve, whom our Lord selected for his constant companions, there was one peculiarly distinguished as " the disciple whom he loved," we need not

scruple to love some more than others. Bishop Mant.

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NEWGATE. The annexed engraving is a representation of one of the principal entrances into London when it was a city begirt with walls, and is not only interesting as a picturesque view of an old portal of the city, but from its having been the principal prison of London, from the reign of Henry the Second to the beginning of the reign of George the Third.

The account given by Stowe, in his Chronicles of London, of the cause of the erection of this New-gate, —a name that the prison retains at the present time,— is so circumstantial and curious, that we cannot state the origin of this structure better than in his own words.

"This Gate was first erected about the reign of Henry the First, or of King Stephen, upon this occasion: the cathedral church of St. Paul being burnt about the year 1086, in the reign of William the Conqueror, Mauritius, then Bishop of London, repaired not the old church, as some have supposed, but began the foundation of a new work, such as men then judged would never have been performed, it was so wonderful for height, length, and breadth; as also in respect it was raised upon arches or vaults, —a kind of workmanship brought in by the Normans, and never known to the artificers of this land before that time. After Mauritius, Richard Beaumore did wonderfully advance the work of the said church, purchasing the large streets and lanes round about, wherein were wont to dwell many lay people,

which ground he began to compass about with a strong wall of stone and gates.

By means of this increase of the church territory, the high and large street stretching from Aldgate, in the east, to Ludgate, in the west, was in this place so crossed and stopped up, that the carriages through the city westward were forced to pass without the said church-yard wall, on the north side through Paternoster-row, and then south, down Ave Marialane, and again west, through Bowyer-row, to Ludgate j which passage, by reason of so often turning, was very cumbersome and dangerous to man and beast.

"For remedy whereof a New Gate was made, and so called, by which men and cattle, with all manner of carriages, might pass more directly from Aldgate, through West Cheap, by St. Paul's, and from thence to any part westward over Holborne-bridge, and through Iseldon to any part north and west."

This structure not only served as a portal to the city, but, like the other gates, the apartments above and on each side of it were used as places of confinement; and, as the New Gate was particularly strong and secure, criminals of the highest order were confined within its walls. Henry the Third, in the year 1218, issued an order to the sheriffs of London, to repair the prison called Newgate, for the safe keeping of his prisoners, promising the charges should be allowed to them upon their account in the Exchequer. In this prison Robert Baldock, Chan

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