therefrom, becomes a leading principle in the history of man." With these words-which derive their charm from the depth of the feelings from whence they sprang-let a brother be permitted to close the general description of the phenomena of the universe. From the remotest nebula, and from the revolving double stars, we have descended to the minutest animal forms of sea and land, and to the delicate vegetable germs which clothe the naked precipice of the ice-crowned mountain summit. Laws partially known have enabled us in some degree to arrange these phenomena; other laws of a more mysterious nature prevail in the highest sphere of the organic world, in that of man with his varied conformation, the creative intellectual energies with which he is endowed, and the languages which have sprung therefrom. We have thus reached the point at which a higher order of being is presented to us, and the realm of mind opens the view here, therefore, the physical description of the universe terminates; it marks the limit, which it does not pass.—HuмBOLDT's Cosmos.'

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THE aid which astronomy has afforded us in navigating the ocean, and making ourselves acquainted with the surface of our own planet, is a beautiful and striking instance of the light which one department of knowledge affords to another. A mere allusion to the familiar facts that the latitude and longitude of places are determined by observations of the celestial phenomena, such as the altitude of the sun, the occultation of stars, lunar distances, and the immersion and emersion of the satellites of Jupiter, will be sufficient to bring to mind the peculiar mode and full extent of this assistance. But the process of mutual illustration does not stop here. Navigation and geography, which have been so extensively promoted by the aid of astronomical science, have repaid the benefit by carrying the astronomer to those regions of the earth where he had an opportunity of witnessing phenomena in the heavens, which have enabled him to perfect his calculations. Dr. Halley, who himself undertook a voyage to St. Helena to make a catalogue of the southern stars, and who there observed a transit of Mercury over the sun, pointed out to the attention of astronomers the advantages to be derived from accurate observations of the transits of Venus, in enabling

them to determine the distance of the sun from the earth; and the object of the first voyage of Captain Cook, it is well known, was to observe a phenomenon of this kind, which could be seen to most advantage from some place in the South Sea.

But astronomy has not only been of service in making us acquainted with the geography of our planet, she has extended her assistance in a way which could scarcely have been antecedently imagined, she has thrown a light upon the darkest pages of history. All the motions of the solar system are performed with periodical regularity. From their first creation the heavenly luminaries have rolled along through the silent deserts of space, with that admirable precision, with that exquisite harmony of movement which, though inaudible, may well be called the music of the spheres; and this unerring precision enables the astronomer, not only to predict with confidence the position of the heavens at any future period, but to calculate backward and to determine the relative places of the celestial bodies at any given epoch in the past ages of the world. It is easy to imagine how this circumstance may be rendered available to purposes of historical research.

Fortunately for this end the superstition of mankind, in past times, long connected the appearances of the heavenly bodies, particularly the eclipses of the sun and moon, with their civil and political affairs; and as their historians have frequently recorded such astronomical phenomena of the kind as took place near the times of the events which they narrate, it becomes possible for the astonomer to verify in some degree their accuracy, and to fix, amidst conflicting testimonies or dubious evidence, the precise time—the year or even the day— when the event occurred. The precession of the equinoxes is another phenomenon which has furnished similar assistance. Independently of its use in guiding the chronologist through the obscurity of the past, there is something powerfully striking to the imagination in a cycle of changes like this, expanding itself after a period of twenty-five thousand years, and marking with infallible accuracy the flight of ages. A French philosopher has styled it a secular dial,-a dial of centuries,-invented by Providence to reveal its mysteries to studious man.

Thus the astronomer establishes, amidst the uncertainty of antiquity, a chain of fixed and certain facts; he carries into the darkness of fabulous ages and dubious events, a series of luminous points, which diffuse sufficient light to afford glimpses at least of their true history. He even (to use the words of a fine poet) attempts to

"Break through time's barrier and overtake the hour
That saw the heavens created."

We are indebted, amongst others, to Sir Isaac Newton for this application of astronomical knowledge. The same admirable intellect which penetrated space, and measured worlds only just visible to the eye, exerted its powers also in piercing the shadowy regions of time, and fixing epochs which had previously vacillated before the sight, and eluded the pursuit of the chronologist and the historian.-BAILEY'S ' Discourses, &c.'

PRESERVED meats are out of favour just now. We hear of little except condemned canisters, which the Admiralty unfortunately have in store. It is the more proper, then, to state, that the evidence before the jury went to show that it is possible to preserve meat in canisters without undergoing any change, for a great length of time. We had hashed beef, which was excellent, dating back to 1836; we had boiled beef fifteen years old, preserved in canisters, and many other specimens, none of which were changed. It is clear, therefore, that the canister-process of preserving is good, provided you keep a sharp eye on the contractors, and upon those who act under them.

What is more important than all other preserved provisions, is the article to which I must next request attention. A great deal of interest was excited when the contents of the Exhibition first became known,-and it did not diminish afterwards,-by a certain meat-biscuit, introduced among the American exhibitions from Texas, by Mr. Gail Borden. We were told that its nutritive properties were of a very high order; it was said that ten pounds' weight of it would be sufficient for the subsistence of an active man for thirty days,-that it had been used in the American navy, and had been found to sustain the strength of the men to whom it had been given, in a remarkable degree. Statements were made to us, which have since been corroborated, that it would keep perfectly well without change, under disadvantageous circumstances.

Colonel Sumner, an officer in the United States' Dragoons, who had seen it used during field operations, says he is sure he could live upon it for months, and retain his health and strength. The inventor, he says, names five ounces a-day as the quantity for the support of a man; but he, Colonel Sumner,

could not use more than four ounces, made into soup, with nothing whatever added to it. The substance of these statements may be said to amount to this, that Borden's meat-biscuit is a material not liable to undergo change, is very light, very portable, and extremely nutritious. A specimen, placed in the hands of Dr. Playfair for examination, was reported by him to contain thirty-two per cent. of flesh-forming principles; for it is a composition of meat, the essence of meat, and the finest kind of flour. Dr. Play fair stated that the starch was unchanged, that, consequently, there could have been no putrescence in the meat employed in its preparation, and that the biscuit was "in all respects excellent." It was tasted; I tasted it-the jury and others tasted it; and we all found nothing in it which the most fastidious person could complain of; it required salt, or some other condiment, as all these preparations do, to make them savoury. This meatbiscuit, as I said just now, was reported to be capable of keeping well, and this might well be true,-because no foreign matter had been introduced into its composition; there was no salt to absorb moisture, and nothing else to interfere with the property of flour, or of essence of meat.

These biscuits are prepared by boiling down the best fresh beef that can be procured in Texas, and mixing it in certain proportions with the finest flour that can be there obtained; it is stated that the essence of five pounds of good meat is estimated to be contained in one pound of biscuit. That it is a material of the highest value there can be no doubt; to what extent its value may go, nothing but time can decide; but I think I am justified in looking upon it as one of the most important substances which this Exhibition has brought to our knowledge. When we consider that by this method, in such places as Buenos Ayres, animals which are there of little or no value, instead of being destroyed, as they often are, for their bones, may be boiled down, and mixed with the flour which all such countries produce, and so converted into a substance of such durability that it may be preserved with the greatest ease, and sent to distant countries, it seems as if a new means of subsistence was actually offered to us. Take the Argentine Republic-take Australia, and consider what they do with their meat there in times of drought, when they cannot get rid of it whilst it is fresh; they may boil it down, and mix the essence with flour (and we know they have the finest in the world), and so prepare a substance that can be preserved for times when food is not so plentiful, or sent to countries where it is always more difficult to procure food. Is not this a very great gain ?-LINDLEY'S Lecture before the Society of Arts on the Exhibition of 1851.'

MINERAL matter, unlike animal and vegetable substances, cannot, in its original or natural state, be modified by man for his use. While he can obtain important varieties of animal substances, by treatment of the animals themselves, or by perpetuating certain varieties of them, and can by culture produce valuable modifications in plants, or their parts, no skill of his can alter the natural condition of an ore in the mine. His power commences with that of discovering the mineral matter required by him.

Mineral substances have thus to be regarded, industrially, as essentially connected with the means of extraction, and the after processes by which they are rendered available for use. While plants and animals differ in various regions of the earth, and the traffic connected with the raw materials they afford is adjusted to this difference, mineral matter of the same character may be discovered in any part of the world, at the Equator or towards the poles; at the summit of the loftiest mountains, and in works far beneath the level of the sea. granite of Australia does not necessarily differ from that of the British Islands; and ores of the metals may (the proper geological conditions prevailing) be found of the same general character in all regions. Climate and geographical position have no influence on the composition of mineral substances.

The

Though geographical position has no influence on natural mineral substances, except so far as modifications may be produced by the action of the atmosphere, it may nevertheless constitute a most important element among those on which depend the actual uses of those substances. All other conditions being equal, it may decide their extraction or non-extraction. Even important minerals may be so situated as to be unproductive of advantage to those endeavouring to obtain them for use. No doubt, geographical position may be modified by the labour of man, and so that the mineral matter in the same locality, which could not be profitably raised at one time, may bo most advantageously worked at another.

The condition of man, therefore, occupying different areas on the earth's surface as nations, becomes an element of the utmost importance as regards the useful extraction of mineral substances. The conditions under which such divisions of mankind may exist, their laws and customs, are important to the development