gives countenance to the opinion. That such was the expectation of the bees, receives still further countenance from the situation of these royal cradles; they were constructed upon the edges of the combs, as I believe the natural cradles of royalty always are; not formed by the breaking down of workercells, as is the case when artificial cradles are constructed. Admitting this to be a sound view of the matter, it would seem not improbable, considering the populousness of the stock, and the warmth of the weather, that, had I removed the queen a day or two earlier or a day later, one or more royal cradles would have been perfected; as in the first case there would most likely have been a formation of artificial ones, and a consequent raising of artificial queens; in the latter case there might have been a tenanting of the natural cells of royalty, and a maturation of natural queens. In both these respects I was disappointed; no queen was raised, and yet, though no substitute for the old one was presented to the family, there was no abatement of their watchfulness, nor any relaxation of their diligence. "The circumstance under which this family of bees was placed, appeared to offer a favorable opportunity for ascertaining the age to which the life of the working bee as well as that of the drone might extend. I knew that all the young workers were hatched within three weeks after the removal of the queen, and all the drones within twenty-four days of that time. I carefully watched the proceedings of the family during the remainder of the year, but till the close of autumn nothing different was noticeable in their proceedings from what world have taken place if the queen had been with them, excepting that there was no massacre of the drones, nor any deposition of fresh ova; both the store and the brood-cells were richly furnished with honey. The hive was situated in an upper apartment of my dwelling-house, well protected from cold-the quicksilver in Fahrenheit's thermometer, which hung near them, seldom ranging below 45, and never lower than 43 degrees. The drones began to decline in number towards the end of October, and by the middle of November not a single drone remained. Soon after their extinction there was a gradual but manifest diminution of the workingbees. They continued decreasing till the 30th of December, when only thirteen remained alive: these were quite active on the morning of that day, but before night two of them had expired; the other three, when I retired to rest about eleven o'clock, were moving briskly about upon the comb, but when I rose next morning, (31st,) they also had closed their career. Apprehending when the family became very much reduced, that so small a number of bees would be unable to maintain a due degree of heat; I not only surrounded the hive with a thick coating of wool, but kept a fire in the apartment night and day, which preserved a regular temperature of between 50 and 60 degrees Fahrenheit. "From this detail it will, I think, appear pretty evident, that the average life of the drone is about four months, while that of the working-bee is extended to about six months. "On the extinction of the family I took from the hive nearly twelve pounds of fine liquid honey. "The result of this experiment, as respects the length of the working-bee's life, fully confirms, so far as a single experiment can do, the opinion which I had previously formed, and it receives additional strength from another that was instituted by Reaumur. He marked 500 bees in April with red varnish, and saw them alive a month afterwards; but in the succeeding November not one of them could be distinguished. This circumstance, standing alone, cannot be regarded as conclusive; for, in the first place, the red varnish might have peeled off, prior to his last observation; and, in the next place, it is possible that none of the marked bees might have been spring bred; but, taken in conjunction with the facts detailed as having been noticed by myself, illustrating as they do the theory which precedes them, I think it may be received as strongly confirmatory of the opinion that the working-bee's life is much shorter than has usually been supposed, as it seems highly probable that at least some of the bees marked by Reaumur, if not all, were the produce of the spring laying, and whether or not the varnish and the bees had disappeared together, r.o doubt he observed in November a very manifest diminution in the populousness of the family. "It now only remains that I should advert to the longevity of the queen-bee, and upon this point the evidence which we possess is sufficiently ample to justify a decisive statement. The experiments of Huber, Della Rocca, Dunbar, and Golding, have clearly proved that her majesty sees many generations pass away before she quits the stage herself. Huber, though he only speaks positively of her life being extended to two years, was of opinion, I believe, that it might reach to four or five; and three latter naturalists, by marking their queens, have traced them from hive to hive, through a period of nearly four years; a coincidence, in point of time, which, while it justifies the opinion of Huber, speaks strongly in favor of the diligent and acute observations of Della Rocca, Dunbar, and Golding. Della Rocca's queen had accidentally lost a leg in being hived, the others were distinguishable by having had one of their antennæ clipped, neither of which bereavements revented the fulfilment of every royal function." CRYSTALLIZATION. THE particles of matter are so small that nothing is known of their form, further than the dissimilarity of their different sides in certain cases, which appears from their reciprocal attractions during crystallization being more or less powerful, according to the sides they present to one another. Crystallization is an effect of molecular attraction, regulated by certain laws, according to which atoms of the same kind of matter unite in regular forms-a fact easily proved by dissolving a piece of alum in pure water. The mutual attraction of the particles is destroyed by the water; but if it be evaporated, they unite, and form in uniting, eight-sided figures called octahedrons. These, however, are not all the same. Some have their angles cut off, others their edges, and some both, while the remainder take their regular form. It is quite clear that the same circumstances which cause the aggregation of a few particles would, if continued, cause the addition of more; and the process would go on as long as any particles remain free round the primitive nucleus, which would increase in size, but would remain unchanged in form, the figure of the particles being such, as to maintain the regularity and smoothness of the surfaces of the solid and their mutual inclinations. A broken crystal will, by degrees, resume its regular figure, when put back again into the solution of alum, which shows that the internal and external particles are similar, and have a similar attraction for the particles held in solution. The original conditions of aggregation, which make the molecules of the same substance unite in different forms, must be very numerous, since of carbonate of lime alone there are many hundred varieties; and certain it is, from the motion of polarized light through rock crystal, that a very different arrangement of particles is requisite to produce an extremely small change in external form. A variety of substances in crystallizing combine chemically with a certain portion of water, which in a dry state forms an essential part of their crystals; and according to the experiments of M. M. Haidinger and Mitscherlich, seems in some cases to give the peculiar determination to their constituent molecules. These gentlemen have observed, that the same substance, crystallizing at different temperatures, unites with different quantities of water, and assumes a corresponding variety of forms. Selenate of zinc, for example, unites with three different portions of water, and assumes three different forms, according as its temperature in the act of crystallizing is hot, lukewarm, or cold. Sulphate of soda, also, which crystallizes at 90 degrees of Fahrenheit, without water of crystallization, combines with water at the ordinary temperature, and takes a different form. Heat appears to have a great influence on the phenomena of crystallization, not only when the particles of matter are free, but even when firmly united, for it dissolves their union and gives them another determination. Professor Mitscherlich, found that prismatic crystals of sulphate of nickel exposed to a summer's sun in a close vessel, had their internal structure so completely altered, without any exterior change, that when broken open they were composed internally of octahedrons with square bases. The original aggregation of the internal particles had been dissolved, and a disposition given to arrange themselves in a crystalline form. Crystals of sulphate of magnesia and of sulphate of zinc gradually heated in alcohol till it boils, lose their transparency by degrees, and when opened are found to consist of innumerable minute crystals, totally different in form from the whole crystals; and prismatic crystals of zinc are changed in a few seconds into octahedrons, by the heat of the sun; other instances might be given of the influence of even moderate degrees of temperature on molecular attraction in the interior of substances. It must be observed, that these experiments give entirely new views with regard to the constitution of solid bodies. We are led from the mobility of fluids to expect great changes in the relative positions of their molecules, which must be in perpetual motion even in the stillest water or calmest air; but we were not prepared to find motion to such an extent in the interior of solids. That their particles are brought nearer by cold and pressure, or removed farther from one another by heat might be expected; but it could not have been anticipated that their relative positions could be so entirely changed as to alter their mode of aggregation. It follows, from the low temperature at which these changes are effected, that there is probably no portion of inorganic matter that is not in a state of relative motion. Professor Mitscherlich's discoveries with regard to the forms of crystallized substances, as connected with their chemical character, have thrown additional light on the constitution of material bodies. There is a certain set of crystalline forms which are not susceptible of variation, as the die or cube, which may be small or large, but is invariably a solid bounded by six square surfaces or planes. Such, also, is the tetrahedron or four-sided solid, contained by four equal-sided triangles. Several other solids belong to this class, which is called the Tessular system of crystallization. There are no other crystals which, though bounded by the same number of sides, and having the same form, are yet susceptible of variation; for instance, the eightsided figure with a square base, called an octahedron, which is sometimes flat and low, and sometimes acute and high. It was formerly believed, that identity of form in all crystals not belonging to the Tessular system, indicated identity of chemical composition. Professor Mitscherlich, however, has shown that substances, differing to a certain degree in chemical composition, have the property of assuming the same crystalline form. For example, the neutral phosphate of soda and the arseniate of soda, crystallize in the very same form, contain the same quantities of acid, alkali, and water of crystallization; yet they differ so far, that one contains arsenic, and the other an equivalent quantity of phosphorus. Substances having such properties are said to be isomorphous, that is, equal in form. Of these there are many groups, each group having the same form, and similarity, though not identity of chemical composition. For instance, one of the isomorphous groups is that consisting of certain chemical substances called the protoxides of iron, copper, zinc, nickel, and magnanese, all of which are identical in form, and contain the same quantity of oxygen, but differ in the respective metals they contain, which are, however, nearly in the same proportion in each. All these circumstances tend to prove, that substances having the same crystalline form must consist of ultimate atoms, having the same figure, and arranged in the same order; so that the form of crystals is dependent on their atomic constitution. All crystallized bodies have joints or cleavages, at which they split more easily than in other directions; on this the whole art of cutting diamonds depends. Each substance splits in a manner and in forms peculiar to itself. For example, all the hundreds of forms of carbonate of lime split into six-sided figures, called rhombohedrons, whose alternate angles measure 105.55 degrees and 75.05 degrees, however far the division may be carried; therefore, the ultimate particle of carbonate of lime is presumed to have that form. However this may be, it is certain that all the various crystals of that mineral may be formed by building up six-sided solids of the form described, in the same manner as children build houses with miniature bricks. It may be imagined that a wide difference may exist between the particles of an unformed mass, and a crystal of the same substance-between the common shapeless limestone and the pure and limpid crystal of Iceland spar, yet chemical analysis detects none; their ultimate atoms are identical, and crystallization shows that the difference arises only from the mode of aggregation. Besides, all substances either crystallize naturally, or may be made to do so by art. Liquids crystallize in freezing, vapours by sublimation, and hard bodies, when fused, crystallize in cooling. Hence it may be inferred that all substances are composed of atoms, on whose magnitude, density, and form their nature and qualities depend; and as these qualities are unchangeable, the ultimate particles of matter must be incapable of wear. PALM OIL. BY DR. HENRY M'CORMACK. THE palm oil of commerce is obtained from the Cocos butyracea, which we are told is a native of Brazil. Now we find that the greater part, if not the whole of the palm oil in use, comes from the coast of Africa, by way of Liverpool and London. Then the cocos butyracea is either a native of Africa, which I take to be the case, or otherwise, the officinal palm oil of the Edinburgh Pharmacopoeia, is procured from the African palm. This I know to be the case, from having seen the plant and its oil upon the spot, up the river Sierra Leone. It is stated in our dispensaries, that the palm oil tree furnishes a yellow succulent fruit, with a fibrous pulp, containing a hard cartilaginous kernel, which last, by grinding and maceration, furnishes the oil. I shall now state the real process by which it is prepared, from which it will be seen that an error must have crept into our accounts on the subject. The palm tree growing on the coast of Africa, furnishes at the base or origin of its leaves, clusters of a yellow succulent fruit. Each of these bears some resemblance to a grape shot. The bunches are of different sizes, and the fruit composing them of different shapes, as might be expected from their reciprocal pressure, although naturally round, when not exposed to it. The pulp of this fruit is soft, and of a bright yellow color-it is from this that the oil is obtained. Within it lies inclosed a hard and thick-shelled stone, of a dark color, within which is contained a firm white kernel of a pleasant oily flavor. This kernel also affords an oil, which is not yellow, but white-and not fluid, but concrete even in Africa. I need hardly say that the yellow palm oil is quite fluid while in Africa, and that it is not until it has been exposed to the cold of our temperate regions, that it becomes solidwhereas the oil of the kernel, as I have said, is always concrete, or nearly so. Both the white and the yellow oil are obtained by expression. The latter is procured in immense quantities in Africa, where it is partly consumed by the negroes along with their rice and pepper, or fried with their fish; and partly exported to Europe, where its principal use is in the manufacture of soap. It continues to possess a pleasant fragrant odour for a long time after its extraction, and holds the same importance among the necessaries of an African, that olive oil does among those of an Italian or Spaniard. It affords an amusing spectacle to a new comer to witness a number of merry negroes squatting on their hams round a calibash of rice. They seldom use a spoon, but knead the grain into huge balls, which they roll over in a mixture of pepper, salt, and oil, and then pitch them with unerring aim and surprising velocity into their mouths, whence they almost seem to descend unbroken into the stomach. The white oil is only used as an ointment for the skin, which it keeps nice and soft, while it at the same time prevents too great an excretion of perspiratory matter. Not content with the hue that nature had given them, I have sometimes seen fond mothers mix this oil with something like lampblack and rub their children over from head to foot, giving them a singularly lustrous appearance, especially in the sun. The palm tree is one of the most stately in the African forest, towering above the rest, as the lofty pine does at home over its fellow trees. Parrots are said to be fond of the fruit. I have geen it given to them after they were newly caught. Indeed the strong arched beak of this bird seems to render it peculiarly fit for tearing the fibres of fruit asunder. The preceding statement affords but a trifling addition to our knowledge, but as every thing helps to swell the great mass, I may be permitted to bring it forward. MISCELLANIES. Electrical Experiment.-Air is constantly blown from an electrified body, whether they be in a state of positive or negative electricity: thus a wheel placed on either of these will yet revolve always the same way, or in a direction opposite to the ends of the bent wires. In like manner a thick tapering wire will still project a stream of air, as indicated by the turning of a small wheel of card. Hence the explication of a seemingly paradoxical fact, that any hot body will cool faster if kept electrified. To make this experiment in a satisfactory manner, gild a very large mercurial thermometer, having a ball perhaps of an inch or an inch and a half in diameter, and a long stem bearing only 30 or 40 degrees; suspend the instrument from an insulated stand, at the distance of two or three yards from the prime conductor, with which it communicates by a silver thread, apply the hand to the bulb of the thermometer and heat it up to 20 degrees above the temperature of the room, and note the time it takes to fall to the proper point, repeat the operation, and then keep turning the machine, and the mercury will be found to sink down in less than half that time. Cleaning of Engravings.-Put the engraving on a smooth board, cover it thinly with common salt finely pounded; pour or squeeze lemon-juice upon the salt so as to dissolve a considerable portion of it; elevate one end of the board, so that it may form an angle of about 45 or 50 degrees with the horizon. Pour on the engraving boiling water from a tea kettle, until the salt and lemon-juice be all washed off; the engraving will then be perfectly clean, and free from stains. It must be dried on the board, or on some smooth surface gradually. If dried by the fire or the sun, it will be tinged with a yellow color. Any one may satisfy himself of the perfect efficacy of this method, by trying it on an engraving of small value. Detection of the Traces of Writing fraudulently erased.-Professor Gazzari, of Florence, having been frequently appointed by the tribunals to give professional evidence on trials of this nature, instituted experiments on the subject, which, by showing him the possibility of removing not only the ink, but also the materials employed in its removal, proved that cases might arise when the fraud could not be detected in any other manner than by examining the condition of the paper or other material written on. For this purpose optical means were tried in vain, and immersion in water did not show such a difference in the absorptive power of the written and unwritten parts, as happens in the employment of certain sympathetic inks; but on exposure of the inspected paper to a moderate fire, the paper which, in consequence of the corrosive effects of the ink, was in those parts altered in its nature, was unequally acted on by the process of carbonization, and thus the number and length of the lines, and often the whole of the erased portion were distinctly revealed. LONDON:-Printed by D. FRANCIS, 6, White Horse Lane, Mile End-Published by W. BRITTAIN, 11, Paternoster Row. THE ELECTROTYPE; OR, ENGRAVING BY VOLTAIC ELECTRICITY. ' We have already, in page 199, given an account of this curious processs; since that time we have made many experiments upon the subject, as well as read the papers published by its original discoverer, Mr. Spencer, of Liverpool. So much attention have these last discoveries now excited, that we believe a fuller description of the process, hints for its success, and an account of the simple apparatus employed, will be acceptable to our readers, especially when we premise that the medals thus formed are exquisite in delicacy and sharpness, and so easy to manufacture, that it is impossible to err in the process, or to fail in its fulfilment. It is but fair, as well as more satisfactory, to explain it in Mr. Spencer's own words, more especially as they are so plain and explicit, as to leave us nothing more to desire. The following paper, (with the exception of the description of apparatus,) is abridged from his papers, read before the Liverpool Society : My first essay was a piece of thin copper-plate, having about four inches of superficies, with an equalsized piece of zinc, connected together with a piece of copper wire. I gave the copper a coating of soft cement, consisting of bees' wax, resin, and a red earth-Indian or Calcutta red. The plate received its coating while hot. On cooling, I scratched the initials of my own name rudely on the plate, taking special care that the cement was quite removed from the scratches, that the copper might be thoroughly exposed. This was put in action, in a cylindrical glass vessel about half filled with a saturated solution of sulphate of copper. I then took a common gas glass, similar to that used to envelope an Argand burner, and filled one end of it with plaster of Paris, to the depth of of an inch. In this I put some water, adding a few crystals of sulphate of soda, to excite action, the plaster of Paris serving as a partition to separate the fluids, but sufficiently porous to allow the electro-chemical fluid to permeate its substance. "I now bent the wires in such a form that the zinc end of the arrangement should be in the saline solution, while the copper end should be in the cupreous one. The gas glass, with the wire, was then placed in the vessel containing the sulphate of copper. "It was then suffered to remain, and in a few hours I perceived that action had commenced, and that the portion of the copper rendered bare by the scratches was coated with the pure bright deposited metal, whilst all the surrounding portions were not at all acted on." The various cuts introducing our present number, will render evident the foregoing and following experiments. Fig. 1 represents the apparatus used by Mr. Spencer, as above mentioned; A is a glass, or other vessel, holding about a pint. B is a wooden cover, fitted on the top of it. C is the lamp glass, fixed in the middle of the cover, and furnished with the plaster of Paris bottom. D is a wire having a piece of zinc at the bottom of it, and a wooden cup, F, for the sake of convenience of connection at the top. E is a second wire passing through the wooden top, and bent below, where it has the plate of copper fastened to it. If the two wires, D and E, are soldered, or tied tightly together, the mercury cup may be dispensed with. Fig. 2 represents a common drinking glass, having a sheet of plaster of Paris across it, and fastened there by a little liquid plaster poured round the edges, which not only keeps it firmly fixed but prevents leaking from one side to the other. A is the glass or tumbler. B is the sheet of plaster. C is the plate of zinc, connected with a wire with the plate of copper at D. The wire is in the figure supported by a forked piece of wood on the top of the plaster division, but this is not necessary. Fig. 3 shows the wire and its two plates A and B, soldered together, and ready for immersion, with the exception of bending the wire. Fig. 4 is an apparatus for the same purpose, and of very similar construction to No. 1. A is the glass vessel. B the wooden top. C a tube formed of perous earthenware. D the piece of zinc. E the wire bearing the copper coin; and F the binding screw, which unites tightly the two wires together. Fig. 5 is an apparatus upon a larger but simillar construction. A is a square glass vessel. B a plate of copper holding several medals upon it, all of which are either united by soldering to the copper plate, or else united to it by a drop of quicksilver on the edge of the medal. C is a box made of plaster of Paris, fitting into the glass box A, but prevented touching the bottom of it, either by props underneath, or else projecting ledges at each end. D is the plate of zinc. E is the screw that binds together the two wires,-by this simple apparatus a number of objects may be made at once. "To Engrave in Relief on a Plate of Copper.Take a plate of copper, such as are in use among engravers. It is not essential that it should be highly polished. "Have a piece of copper wire neatly soldered to the back part of it, and then give it a coating of the cement already mentioned. This is best done by heating the plates as well as the wax; or, to level the wax after it has had a coat, hold the back part of the plate over a charcoal fire, or spirit lamp-taking care to hold it level. "Then write, or draw the design on the wax, with a black-lead pencil or a point. The wax must now be cut through with a graver, or a steel point→→→ taking especial care that the copper is exposed on every line. "It must now be immersed in dilute nitric acidsay, three parts water to one acid. It will be at on e seen whether it is strong enough, by the green color of the solution, and the bubbles of nitrous gas eliminated. Let it remain long enough to allow the exposed lines on the plate to be slightly corroded, that the wax (which gets into the pores of the copper during the heating process), may be thoroughly got rid of. Practice will determine this better than any rules. "The plate is now ready to be placed in the voltaic apparatus. After the voltaic copper has been deposited in the lines engraved in the wax the surface of the formation will be found to be rough, more or less, according to the quickness of the action, To remedy this, rub the surface with a piece of smooth flag or punice-stone, with water. Then heat the plate, and wash off the wax groundwork with spirits of turpentine and a brush. The plate is now ready to be printed from at an ordinary press. "To Deposit a Solid Voltaic Plate, having the Lines in Relief.-Take a plate of copper, lead, silver, or type-metal, of the required size, and engrave in it, to the depth requisite to print from, when in relief. "Contrary to ordinary engraving, the lines must be flat at the bottoin, and as nearly as possible of the same depth, when so engraved, (should the plate be copper or silver), heat it, and then apply a little bees' wax, (what is termed virgin wax is preferable,) mixed with a very small proportion of spirits of turpentine; and give the plate a coating of it. It may be laid on in a lump; and the heat of the plate should be sufficient to melt it. on the eve of cooling, the plate should be wiped clean, and all the wax taken off,-as sufficient will have entered the pores of the plate to prevent the voltaic copper from adhering. "Then solder a piece of copper wire. Wnen I "The plate must now receive a couple of coats of thick varnish on the back and edges, (a preparation of shell-lac and alcohol does very well.) prefer, if the plate is large, to imbed it with plaster of Paris or Roman cement, in a box the size of the plate, allowing the wooden edge of the box to project just as much above the surface of the plate, as you wish the thickness of the voltaic one to be. (Care must be taken, to keep the engraved surface of the plate clean.) "It is now ready to be placed in the apparatus to be deposited on. "Should the plate be lead, or what is still better, type-metal, the preparation of wax does not require to be given to the plate, as, when it is deposited on to the given thickness, applying heat is sufficient to loosen the plates." (Continued on page 405.) PHENOMENA OF SPRINGS. (Resumed from page 380, and concluded.) Mineral and Thermal Springs.-Almost all springs, even those which we consider the purest, are impregnated with some foreign ingredients which, being in a state of chemical solution, are so intimately blended with the water, as not to affect its clearness, while they render it, in general, more agreeable to our taste. and more nutritious |