present in such abundance, under favorable circumstances, that the difficulty disappears. In the Public Garden at Berlin he found that workmen were employed for several days in removing in wheelbarrows masses of fossil infusoria. He produced from the living animals, in masses so large as to be expressed in pounds, tripoli, and polishing slate, similar to the rocks from which he had originally obtained the remains of such animals; and he declares that a small rise in the price of tripoli would make it worth while to manufacture it from the living animals as an article of commerce. These results are only curious; but his speculations, founded upon these and similar facts, with respect to the formation of such rocks, for example, polishing slate, the siliceous paste, called kiesselguhr, and the layers of flint in chalk, are replete with geological instruction.

"As the discoveries of Professor Ehrenberg are thus full of interest for the geological speculator, so have they been the result, not of any fortunate chance, but of great attainments, knowledge, and labor. The author of them had made that most obscure and difficult portion of natural history, the infusorial animals, his study for many years; had travelled to the shores of the Mediterranean and the Red Sea in order to observe them; and had published a work far eclipsing anything which had previously appeared upon the subject. It was in consequence of his being thus prepared, that when his attention was called to the subject of fossil infusoria, (which was done in June, 1836, by M. Fischer,) he was able to produce not loose analogies and insecure conjectures, but a clear determination of many species, many of them already familiar to him, though hardly ever seen perhaps by any other eye. The animals, (for he has proved them to be animals, and not, as others had deemed them, plants) consist, in the greater number of examples, of a staff-like siliceous case, with a number of transverse markings; and these cases appear in many instances to make up vast masses by mere accumulation without any change. Whole rocks are composed of these minute cuirasses of crystal heaped together. Professor Ehrenberg himself has examined the microscopic products of fifteen localities, and is still employed in extending his researches; and we already see researches of the same kind undertaken by others, to such an extent, as to show us that this new path of investigation will exercise a powerful influence upon the pursuits of geologists.

"It may be further added, that even since the council adjudged this medal, Professor Ehrenberg has announced to the Royal Academy of Sciences, of Berlin, new discoveries; particularly his observations on the organic structure of chalk; on the fresh-water infusoria found near Newcastle and Edinburgh, and on the marine animalcules observed near Dublin and Gravesend; and, what cannot but give rise to curious reflection, an account of meteoric paper which fell from the sky, in Courland, in 1686, and was found to be composed of confervæ and infusoria."*

⚫ Convervæ are unread-like flowerless plants. Infusoria are minute animalculæ, such as are found in solutions.-ED.

REVIEW.

Natural Philosophy. (Laws of Matter and Motion,) by W. & R. Chambers, Edinburgh.

THE little treatises now publishing under the title of "Chambers's Educational Course," promise to

effect an important revolution in the school education of the country; they are not however mere dog. matical school books, nor yet are they only applicable to the young, but may rather be considered well digested hand books of literature and science, useful as a reference, and as a guide to all persons, giving in plain language the most valuable truths. Several subjects have been already published on history, natural philosophy, &c.; with the latter subjects only we have now to do, and have chosen to justify and illustrate our opinion by that on the "Laws of Matter and Motion," for it is upon these that all the arrangements of material substances, causes of phenomena, and working of nature's changes depend.

The authors have in this little treatise considered matter in all its properties, relations, and varieties; its laws while at rest, and when in motion; in its various attractions and its repulsions; the gravity of some kinds, the imponderable nature of others; on action and re-action; the composition and resolution of forces. Thus the whole together contains the more valuable elements of the mechanical and the chemical sciences explained briefly, and yet fully; clearly, and yet scientifically. The following is on the destruction of matter :

"Particles of matter are never destroyed or lost, although they may disappear from our immediate observation. Under certain circumstances the particles may be again collected into a body without change of form. Mercury, water, and many other substances, may be converted into vapor, or distilled into close vessels, without any of their particles being lost. In such cases, there is no decomposition of the substances, but only s change of form by the heat; and hence the mercury and water assume their original state again on cooling.

are

"When bodies suffer decomposition or decay, their elementary particles, in like manner, neither destroyed nor lost, but only enter into new arrangements, or combinations with other bodies. When a piece of wood is heated in a close vessel, such as a retort, we obtain water, an acid, several kinds of gas, and there remains a black, porous substance, called charcoal. The wood is thus decomposed or destroyed, and its particles take a new arrangement, and assume new forms; but that nothing is lost, is proved by the fact, that if the water, acid, gasses, and charcoal, be collected and weighed, they will be found exactly as heavy as the wood was, before distillation. In the same manner, the substance of the coal burnt in our fires is not annihilated; it is only dispersed in the form of smoke, or particles of culm, gas, and ashes or dust. Bones, flesh, or any animal substance, may in the manner be made to assume new forms, without losing a particle of the matter which they originally contained. The decay of animal or vegetable bodies in the open air, or in the open ground, is only a process by which the particles of which they were composed, change their places, and assume new forms.

"The decay and decomposition of animals and vegetables beneath the surface of the earth, fertillise the soil, which nourishes the growth of plants and other vegetables; and these, in their turn, form the nutriment of animals. Thus is there a perpetual change from death to life, and as constant a succession in the forms and places which the particles of matter assume. Nothing is lost, and not a particle of matter is struck out

Ar the meeting of the British Association, in the year 1835, Mr. Mallet enumerated the following experiments to obtain a cheap and yet good substitute for hemp rags, for affording a pulp fit for paper-making, which has long been a desideratum with the manufacturer. Many attempts have been made to procure one, but the difficulties of finding one such as would suit the required conditions, and the duty and cost of the hemp-rags, have induced adulteration to a vast extent in the paper manufacture. Much of the letter-paper now in use owes its apparent thickness, and stiff, close texture, to an intimate admixture of the pulp or vegetable fibres with a cream of plaster of Paris or whiting. Brown paper is adulterated with ground clay, and, for similar purposes, currier's shavings, chopped wool and hair, cotton-flyings, thistle-down, and other similar materials, have been occasionally tried; but from none of them has good paper ever been made; and amongst the many experiments that have been attempted with them, being the only one that has been brought into successful use, is that of the manufacture of paper from straw, which answers tolerably for some purposes, though not for writing on, and is now made in some few places very extensively.

Under these circumstances, it appeared probable that nature might afford some vegetable fibres, of a texture sufficiently fine for making paper, and which had never undergone any manufacturing process; and on looking around, the confervæ of freshwaters, and also certain varieties of turfs or peats, suggested themselves. The former was soon found too fragile, and its structure unfit to resist the action of the bleaching re-agents.

It is generally known that a peat-bog, and especially those of Ireland, consists of various strata, varying in density and other properties in proportion to their depth. The top surface of the bog is usually covered with living plants, chiefly mosses, heaths, and certain aquatic or paludose plants; immediately beneath this lies a stratum varying from only two or three inches to four or five feet, according to the state of drainage of the bog, of a spongy, reddish-brown, fibrous substance, consisting of the remains of vegetables, similar usually to those living on its surface, in the first stage of decomposition.

The chemical state of this stratum is nearly that of some of the papyri found in moist places in Herculaneum; that is to say, having long been exposed to the action of water, at nearly a mean temperature, the vegetable juices have nearly all been converted into ulmin-geine, or impure extractive matter, and the fibres remain nearly untouched, together, probably, with some of the essential oils of the original plants. It, therefore, seemed that, if these fibres, which were apparently sufficiently fine for the purpose, could be separated from their

coloring matters, the object would be nearly, if not entirely attained; to this, therefore, attention was directed, and was attended with success. It is unnecessary here to enter into any detail of experiments, or into any elaborate disquisition as to the principles concerned, in making a white pulp from this material, either as regards the manufacturer or the pure chemist; presuming these to be already understood, the process may be briefly stated as follows:

The proper description of turf being selected, is soaked in cold water until all its parts are softened, and, to a certain extent, disintegrated; it is then bruised in a suitable engine, in cold water, which is continually agitated and renewed, so that all pulverulent matter (or new dust while the turf is dry), may be washed off. The so far cleansed fibres are then partially dried by strong pressure, in hair bags, under the hydraulic press, or by other suitable means, and then by suitable sieves and winnowing; all roots, sticks, or other gross matter incapable of being bleached, are removed. The fine, uniform, brown fibres, or rather minute stems, leaves, &c. &c., are then placed in proper vats, and digested in the cold; that is, at ordinary temperatures, with a very dilute solution of caustic, potass, or soda; preferring that made from what is called, in commerce,"black potash."

After some time, nearly the whole of the geine and other extractive matter is removed, in combination with the alkali. The fibres are again pressed dry, or nearly so, from the digesting liquor, and are now found to be of a dark fawn color, in place of their former deep red brown. They are next transferred into an exceedingly dilute sulphuric acid, containing not more than fifty grains of acid of commerce to the quart of water. They remain in this at the common temperature for some time, generally about four hours, bnt varying with the kind of turf; this separates the iron and earthy matters from the fibre, and carries off the adhering portions of potass and of ammonia, if any exist in the turf, which is occasionally the case. The fibres are now washed with pure cold water, until they cease to give any acid re-action, and are finally pressed nearly dry, and immersed in a dilute solution of chloride of lime; in this they remain at common temperature until sufficiently white for the purpose of the paper-maker, and, on being removed, will generally be found fine enough, as to fibre, for immediate manufacture; but, if not, are to be reduced by the ordinary rag-engine, or other suitable machinery.

By this process it is calculated that aoout eighteen pounds weight of pure, white, fine pulp, may be procured from 100 weight of the raw or the native turf.

Returning now to the solution of the potass, which has carried off the geine, &c., and which is chiefly, in fact, a geinate of potass; it is treated with dilute sulphuric acid, slightly in excess, and filtered through a calico or linen cloth. The potass is taken up by the acid, and the geine and extractive matter precipitate, and are collected on the filter, from which, being removed, they are dried by a steam or water-bath, and become a valuable pigment.

Vandyke brown has long been known to painters in both oil and water colors. This is it, in fact, in its purest form; it is an extremely rich, glowing color, and valuable for its permanence, as scarcely any agent ordinarily met with is capable of affecting it.

When once perfectly dried, it becomes insolute in water, and, therefore, is not in the least deliquescent, but it is still soluble in alkalies; thus possessing two properties eminently fitting it for the uses of the paper-stainer and scene-painter, &c. &c. It is perfectly miscible with gum, mucilages, and with oils.

The liquid from which this color or bistre has been separated now contains various sulphates in solution, chiefly of iron, lime, and alumina; but the major part, sulphate of potass, or soda, whichever has been employed; if the former, Glauber's salt may be made from it, and if the latter, alum, as matters of commerce. The quantity of alkali used is small in proportion to the amount of fluid; but if the operations were very extensive, this economical use of them should be attended to.

After the fibre has been some time digested in the solution of chloride of lime, in most cases a resinous-looking matter floats upon the surface of the fluid in a very minute quantity. This, when a large quantity is operated on, may, by careful management, be collected, and is found to be a species of artificial camphor, mixed with some gum resin, and probably an essential oil. This substance, or mixture of substances, possesses some singular characters: it would seem probable that the artificial camphor is produced by the action of some fine chlorine upon turpentine, existing in minute quantity in the turf; and it is a curious subject for reflection, that chemistry should thus, as it were, recall into existence and decompose the turpentine existing in, and produced by trees or plants which have, for hundreds of years, ceased to have life, or to exist as vegetables. As the properties, so far as they have been ascertained, of this singular substance are purely chemical, it is unnecessary here to detail them. It is not to be procured from every specimen of red or surface turf.

Some specimens of turf have been met with, unfit, however, for paper-making, from which it would appear to be profitable to manufacture bistre and ammonia, from the very appreciable quantity of the latter they contain.

This fibrous red surface turf, when dry, is extremely tough, and is proposed being also applied as a substitute for mill-boards, or board-paper, for the use of engineers, &c. It is capable, when dry, of immense compression by the hydraulic press ;and as the fibres naturally lie nearly all in one plane, they thus arrange themselves, so as to give great toughness and flexibility to a plate of it when compressed. Accordingly, suitable masses of this turf are placed in a strong cast-iron, or other vessel, and the air exhausted; the vessel is then filled with a mixture of dilute solution of glue and molasses, at a boiling heat, which fills all the pores of the turf. The masses are then removed, while hot, and exposed to powerful pressure in a hot-press, in a similar way to hot-pressing paper, which reduces them to the required thickness, that of the original mass having been previously properly regulated. The plates so formed are found, when cold, to be hard, tough, and flexible, and will answer almost every purpose of mill-board. They are not injured by high-pressure steam. Many other substances may be used, according to circumstances, for filling the pores, previous to pressure-as fat, oils, boiling coal-tar, wax, &c. &c.

It is worthy of remark, that the substance pro

posed being used for all the above processes, is the worst turf for burning; so that the material which is worst, and nearly valueless as fuel, is the best and most valuable, by a fortunate coincidence, for manufacturers. If, therefore, as there is reason to believe, the lower strata of turf can, by certain modes of charring, be made a valuable fuel, and the upper and more recent strata are used for the purposes of the various manufactures above adverted to, there is strong ground of hope that, at a future period, the bogs of Ireland, instead of being contemplated, as hitherto, as a blot and stain upon her fair and fertile champaign, may be looked upon as one of the centres of her industry, and the richest sources of her wealth.

We examined specimens of the pulp, described as being yielded from peat, at the rate of eighteeen per cent. and have no hesitation in saying that it appeared to be white, pure, and perfectly suited to the manfacture of paper.

With respect to the bistre color, we were assured, by a very competent judge, that he considered it quite eligible for the use of the artist, the housepainter, and the paper-stainer. He also spoke favorably of the mill-boards, formed by the operation described; and had no doubt but that the other products from the combinations employed, such as alum, Glauber's salt, artificial camphor and ammonia, would fully answer the purposes of com

merce.

Ireland, we believe, is blessed with two millions of acres of bog (of which 1,300,000 are susceptible of drainage and cultivation*); and if it should be convertible into so many useful articles of consumption, how prodigious must be the sources of employment and improvement which it will open to the view of the statesman and philanthropist.

* According to Parliamentary returns: the greatest depth forty-five feet; and the average depth twenty-eight feet.

QUERIES.

23-Animal heat, whence is the origin of it? Answered on page 75.

24-How may shells be best cleaned? See page 95. 25-How are fossil woods cut and ground, so as to be fit microscopic objects? Answered on page 56.

26-Where can fossil animalcules be purchased? Of Mr. Pritchett, in Fleet Street.

27-Why does a fine needle float upon water? Answered on page 56.

28-Why does the wick of a floating chamber lamp always go to the side of the vessel of oil in which it is burning? Answered on page 56.

29-How are the fantoccini figures made and managed? Answered on page 311.

30-How is the canvass, used by oil painters, prepared? Answered on page 128.

31-How are the leads for ever-pointed pencils made? Answered on page 128.

32-Why does rotten wood give light in the dark? See page 72.

33-What occasions the singing (as it is called) of a tea kettle before boiling? Answered on page 72.

34-What occasions the rumbling noise we hear when hot iron is plunged into water, or steam let into a cold vessel? Answered on page 72.

35-In one of Mr. Childe's dissolving views snow appears to fall-how is it managed? Answered on page 271.

36-Why is it that certain ponds, lakes, and rivers, never freeze, even in the coldest winters? Answered on page 104. 37-What is the best method of bronzing iron or brass? Answered on pages 168 and 398.

38-What is the cause of magnetism? Answered on page 72.

39-Why is the rainbow a ring, and not a circular disc? Answered on page 72.

40-How are solar and lunar halos produced? See page 104.

AMONG the admirable Automata, which were once exhibited at Bullock's Museum, and many years afterwards at Leicester Square, was one which attracted more than ordinary attraction, and which was thought to have been one of the most complex of those wonderful machines, yet none of them was so simple in its moving powers. The Automaton alluded to was The Conjuror. The machine represented a cabinet: at the bottom of this was a drawer, into which a card could be placed. In the upper part of the cabinet was a pair of folding doors; and before it, at some distance, stood the figure of the conjuror, with a long white wand in his hand, and dressed in appropriate costume. The spectator had presented to him eight very thick cards, each with a particular question upon it; he was directed to choose one of the questions for solution to put into the drawer below, and then to close it. This put

into action the motive machinery. The figure of the conjuror moved its head, appeared to ponder for a moment on the answer to be given, waved his wand, and struck it against the small folding doors above him. These immediately flew open, and displayed, on a tablet within, the proper answer.In a short time the doors closed again, and the lower drawer was projected forwards, ready for the card that had been placed there to be removed, and another substituted.

The whole of the motions here are of obvious character; the heads and arms of the figure, the opening and closing of the doors, involves no very great complexity of wheel-work. The answers to the questions are given by means of magnetism in the simplest manner, and will be easily understood by the following description of the apparatus above represented, which has been called the

MAGNETIC CONJURING BOX. ONE of the two figures in our cut represents this box closed, and in use: it is to be supposed that the five of diamonds has been placed in the drawer seen at the lower part of the box, and that the folding doors have flown open, and shown within them a corresponding card. The other view displays the same box in section, the slides next the eye being removed. On the lower part, just above where the drawer slides in, will be seen a magnet, suspended and moveable round it. This carries with it the wire, which is seen running upwards through the box, and which bears upon it an eightsided prism or drum, each side of which corresponds with the loose cards which are to be put into the drawer, or else answers to any questions which may be written upon them. The eight cards, represented as squares in the engraving, have a magnetic needle passing through them, each in a different direction, and which is concealed by the paper covering them. When one of these is put within the drawer, and that closed, it will be brought beneath the revolving magnet in the box itself, and the latter magnet, being alone capable of motion, will range itself parallel to the fixed one in the card, consequently will draw round with it the drum or prism, which is fixed to the centre wire above, and according to the position of the magnet below so it will offer one or other of its sides to the folding doors, with the answer looked for.

The letter N in the figure indicates the north pole of the magnets within the cards.

THE AELLOPODES.

ONE or two exhibitions lately in London, of carriages to be propelled by human means, have renewed a subject which in the time of the velocipedes engrossed universal attention. The projectors of many of these schemes unfortunately set to work with less knowledge than zeal-not calculating before hand, by strict mathematical principles, the result of their inventions, and forgetting that it is not those schemes that look prettiest on paper, nor even the most effective models either, that in practice are found best to succeed. Pseudo-mechanics too often forget that they cannot make power; all they can do is to apply to the best purpose the force given them, by, in the first place, generating as much as possible from given materials, and afterwards to lose as little as possible of it by friction; that is, by the weight, the bearings, and the complexity of their machinery, as the ultimate application of that force will allow.

We are led to these remarks by a most ridiculous machine, now exhibiting in London, called "The Aellopodes," the invention of a Mr. Revis, of Cambridge, who is so sanguine respecting its excellence as to suppose that it may be used with advantage for cross country posts, and afford a saving to the Post Office of £60,000 per annum. The machine consists of two wheels of about six foet diameter, fixed upon an axletree, bearing four cranks, with a smaller guide wheel, some feet in front. The motive power is a man's weight, working upon two treddles, (three or four treddles in the machine,) which are connected with the cranks on the axletree, by means of bent levers passing to the back of the carriage. The whole machine is twelve feet long, weighs, if we understand rightly, about 1 cwt., and costs £30 in its construction. The man who works it remains in a standing position,

holding a handle connected with the guide wheel in front, and treading alternately upon two of the treddles; the motion given to them is communicated by the bent levers to the cranks, and thence to the larger wheels, the friction of which on the ground causes the locomotion of the whole.

Mr. Revis says" that this carriage will go thirty miles an hour," and perhaps upon a floor it may do so readily; yet to accomplish even twenty miles upon the smoothest roads, must require the most toilsome and unremitted exertion-what will necessarily be the effect when upon one which is rough or muddy, where the friction will be four, or more, times greater? If such impediments to motion are found with an unloaded carriage, as it is evident with the increase of them whenever the carriage may be loaded with 2 or 3 cwt. of letters and newspapers, shows how little available the aellopodes are likely to be to any useful purpose, especially as on hilly ground the inventor himself does not expect it will pass over. Added to which, its expense of manufacture is great—its size exceedingly cumbrous-and its weight too much. When in motion producing such a rattling of iron-work as to be in the highest degree disagreeable, and to those travelling the same road by horse conveyance dangerous. Besides which, the motion (which is similar to ascending a very steep staircase, with steps eighteen inches high) is so laborious, that we believe it impossible for the most powerful man long to sustain it. The intense labor, indeed, at the treadmill shows such exertion, long continued, to be beyond human strength, and in the instance of this machine to go at a speed of thirty miles an hour, as each step propels it eighteen feet, the driver must take 8,800 such tremendous steps in that time, lifting up his body each step, eighteen inches, and altogether within one hour to a perpendicular height of two miles and a half.

MATERIALS USED FOR PAPER.

It was long after the art of writing was first invented, that mankind employed any substance analogous to our paper. Tables of stone, of metal, or of wood, served to register the most important events or laws-the letters being engraven upon them with sharp instruments. Many examples yet remain of this, particularly the Egyptian hieroglyphics, the Persepolitan cylinders, and the Babylonish bricks-engraven, indeed, with a language now unknown. Tablets, coated with wax, probably succeeded, for they are alluded to very frequently by the Roman writers. It must have been, however, at a much earlier period than the foundation of the Roman empire, that real paper was made by the Egyptians from the papyrus (a reed growing in the Nile), as their mummies, even from the most ancient period, have often had preserved with them rolls of the papyrus paper, graven with emblematic characters. This was the material employed by Virgil, Horace, Ovid, and other of the Roman poets, to write their important works upon; and, during this Augustian age, the quantity of papyrus paper imported from Egypt, yielded a large profit to the manufacturers. So great, indeed, at one time, was the consumption, that the demand became greater than the supply, and parchment was invented in Pergamos, Asia Minor, to supply the deficiency.This was about two centuries before the Christian ærni. It afterwards totally superseded the use of papyrus paper, and remained, throughout Europe,