people of Greece, Egypt, &c. did, at some period of their his tory, make their edge-tools of bronze, is sufficiently plain from the use they made of them in religious matters, and from their being frequently found in the ruins of their most ancient cities but they were fallen into disuse in the reign of Porsenna, 500 years before Christ.* And it is probable that the nations on the western side of Europe, long before the commencement of the Christian era, had begun to disuse brass in arms, because we know that in the time of Caius Marius, the Cimbrian cavalry wore steel cuirasses; and that the people of Gaul, Spain, and Britain, were acquainted with the art of manufacturing iron in Cæsar's time. 6. The era in which edge-tools of bronze were in use in Britain, cannot perhaps be ascertained with any degree of certainty. There can be no reason to suppose that iron was introduced here while bronze was used in Greece: or that the Germans should be acquainted with it before the Britons. But when iron became plentiful amongst the Greeks, as it unquestionably was in the time of Lycurgus, 900 years before Christ, it would certainly be cheaper amongst the Phoenicians than either copper or tin: if, therefore, they traded to Britain at that time, it would be their interest to barter steel for the goods they came for; and that of the Britons to receive it for edge-tools, in preference to copper. The disuse of bronze tools, and the introduction of iron ones into this country, was probably gradual. But from the above reasons, I would conclude that bronze began to give way to iron here, nearly as soon as it did in Greece; and, consequently, that all the Celts, spear-heads, swords, &c. found in our island, belong to an æra 500, or at least 400 years before the time of Christ, for iron then seems to have been general among all the people along the shores of the Mediterranean Sea. 7. The circumstance of implements similar to our Celts having been found in Herculaneum, merely proves that the scite of that city was once tenanted by men ignorant of the use of iron; and we know from Dionysius Halicarnassensis, that it was founded about thirty years before the Trojan war. Also the various culinary and kitchen implements of bronze that abound in its ruins, prove nothing more than that the ancients had discovered that in warm climates copper or bronze is better adapted Since this paper was written, I have found a reference to bronze weapons in Pliny. Speaking of the medicinal qualities of iron, he says:-"Est et rubigo ipsa in remediis : et sic Telephum proditur sanasse Achilles, sive id area, sive ferrea cuspide fecit. Ita certe pingitur dicutiens eam gladio." He doubted whether this healing rust was scraped off a bronze or an iron sword, because he knew that in the heroic age, bronze was in use in weapons. He could have had no difficulty in concluding that it was not of bronze, from any use to which that metal was applied in arms in his time; for his own accounts of iron sufficiently refute such a notion; and in the chapter from which this extract is taken, he says:- "Medecina è ferro est et alia, quam secandi," from which it is plain that surgical instruments were made of it in his time.-Nat. Hist. xxxiv. 15. Hygin. 101. Paus. Arc. lxv. 4. Ovid. Metam. xiii, 172. Trist. v. 2, 15. Remed. Am. 47, &c. for such purposes than iron. I apprehend too, that nothing more can be inferred from the fact, that both Celts and undoubted Roman antiquities have been met with at Ladbrook, in the middle of the town of Old Flint, than that the Britons had occupied that situation either as a fortress or a town before the Romans settled in it. 8. That the Celts were not imported into Britain is plain, from moulds for casting them in, and pieces of crude bronze being found in places where, from the cinders that were with them, they appeared to have been cast. If the bronze of which they made them was imported, it is probable that the people who supplied them with it exchanged it for tin, one of the articles of which it was composed. But it cannot be supposed that a people, whose country abounded with copper, should be ignorant of the art of working and smelting it, at a time when they were mining and manufacturing tin, lead, and iron. The æs, which Cæsar says they imported, and the xaxapata, which Strabo mentions, were probably nothing more than vessels of copper or bronze, which foreign merchants bartered among them for hides and metals. 9. It has been shown that the sceptre or rod of Moses, and many of the utensils of the tabernacle of the Hebrews, were of brass; but none of them of iron. The Greeks and Romans borrowed a great part of their religious worship out of Egypt, where it is probable bronze, as the first metal which assisted in the arts of civilized life, was held in religious veneration; and iron, as a more modern discovery, in religious abhorrence. We accordingly find in Hesiod, that iron was prohibited in certain religious rites; and Accennius, on the word "ahenis" in the following lines from the Æneid, "Falcibus et messæ ad lunam quæruntur ahenis says: "Quia nefas id ferreis facere." Does not this custom justify the supposition that the "aurea falx," with which Pliny says the Druids, at certain seasons, cut the misletoe, is an error for "ærea falx?" and, consequently, that bronze implements were antiquated in his time in all common uses in Britain, and only employed in the religious rites of the Druids? 10. The extracts, I have given out of Homer and Aristotle, prove that the Phoenicians were in the habit of bartering their toys and baubles for valuable commodities in Greece and Spain; I would, therefore, infer, that they exchanged trifles of that sort amongst the Britons for tin; and, consequently, that the articles of jewelry, found in our most ancient tombs, are of Phoenician manufacture. SIR, ARTICLE III. A Method of fixing Particles on the Sappare. (To the Editor of the Annals of Philosophy.) Oct. 24, 1823. WHEN the species of minerals are ascertained by their physical qualities, they mostly undergo no injury, or but a very slight one; as that attending the determination of their hardness, the colour of their powder, their taste, &c. This is certainly a material advantage, and would highly recommend this method, was it constantly adequate to its purpose. That it is not so, however, we have a proof in the great errors into which have fallen those best skilled in it. Mr. Werner, its principal and most distinguished professor, was unable by its means to discover the identity of the jargon and the hyacinth; of the corundum and the sapphire; of his apatite and his spargelstein; and while he thus parted beings, as it were, from themselves, he forced others together which had nothing in common. The chemical method justly boasts its certainty; but it carries destruction with it, and often bestows the knowledge of an object only at the expense of its existence. The sole remedy which can be opposed to this defect is to reduce the scale of operating; and thus render the sacrifice which must be made as small as it is possible. M. de Saussure's* ingenious contrivance for subjecting the most minute portions of matters to fire, by fixing them on a splinter of sappare, appeared to fulfil the conditions of this problem, and to have accomplished all that could be desired. It has, however, been scarcely at all employed, owing to the excessive difficulty in general of making the particles adhere; and in consequence the almost unpossessed degree of patience required for, and time consumed by, nearly interminable failures. That such should be the case could not but be a subject of much regret, for besides economy of matter, of time, of labour, and the great beauty of deriving knowledge from so diminutive a source, and attaining important results with such feeble agents; reduction of volume became, in this instance, productive of increase of power, and thence, of an extension of the series of qualities by which substances are characterised. A slight alteration which I have made in M. de Saussure's process has removed the objection to it. To water, saliva, gum water, which he employed, the last of which is not sensibly * Journal de Physique, par Rozier, tome 45. superior to the former, I have substituted a mixture of water and refractory clay. Small triangles, or slender strips, of baked clay may be used in lieu of sappare, which is not at all times to be procured; or a little of the moist clay may be taken up on the end of a platina, or other wire, and the object to be tried touched with it. This way may be applied to pieces of the ordinary size, and supersede the use of the platina tongs. But a proceeding which I have only recently adopted appears to deserve the preference. Almost the least quantity of clay and water is put on the very end of a platina wire, filed flat there. With this, the particle of mineral lying on the table can be touched in any part chosen; for a moment or two it is dry, and may be taken up, and put into the flame, without the clay exploding, as not unoften happens when more of it is used. Particles of the least visible minuteness may be thus submitted to trial with the utmost facility. The contact of the particle with the wire may, in general, be so managed as to be extremely slight, as the slenderest point is sufficient to support it. However, when the utmost heat possible is desired, a fragment of a less conducting matter may, if deemed necessary, be interposed. There may be cases in which the presence of the clay is objectionable. I conceived that some of the body itself to be tried, would, on these occasions, supply its place. Flint was the least promising of any in this respect. It was selected for the expe riment. With a paste of its powder and water, pieces of flint were successfully cemented to flint, and some of this paste taken on the end of a wire, served, if not quite as well as clay, yet very sufficiently. After several times igniting and quenching in cold water, the reduction of very hard matters to subtile powder is attended with no difficulty. Earth of alum would perhaps be preferable to pipe-clay for making the triangles on strips, and for agglutinating objects to them. It would even have the advantage over sappare of being a simple substance. Some from the Paris shops acquired only little solidity in the fire; but I afterwards learned that it had been obtained from alum by fire. Since I have been in possession of this means of so effectually confining the subjects of examination as to be able to continue during pleasure to act on them, I have directed but little attention to the fusibility of matters. Quartz, whose fusion has been called in question by M. Berzelius,* has seemed to be quite refractory. On some few occasions when it has proved otherwise, the phenomena have neither corresponded with M. de Saussure's account, nor been always the same, which * De l'emploi du Chalumeau, p. 108. certainly admits of the fusion being attributed to an accidental cause. But I have found with much surprise that flint can be melted without difficulty; and even of a considerable bulk. Where the heat is most intense, a degree of frothing takes place; where it is less, there is a swelling of parts of the surface. The effects were the same with French and English flint, with black and with horn-coloured. Does flint, like pitchstone, contain bitumen, which, at a certain heat, tends to tumefy it? This might explain the smell from its collision, and the oil which Neumann obtained by its distillation, and to which no credit has been ever given. No doubt can, I conceive, be entertained of flint being a volcanic production. On this point I may speak again at a future opportunity. In using mere water, diamond, anthracite, plumbago, were particularly difficult of trial, as any adhesion they had contracted with the sappare was quickly destroyed by the combustion of their surface, while, as the intention in their case is not to subject to great heat, they may be so secured in the clay as at least very much to retard their escape. Here acting on very minute particles is essential, as when large pieces are employed, the effect is too slow to be perceptible. A pleasing way of demonstrating the combustion of plumbago, and of even exhibiting the iron in it, is to rub a little from the wetted point of a pencil on one of the clay plates mentioned in a former paper.* In trying diamond it was imagined that its glow continued an unusual time after removal from the fire. The present method afforded the means of making a comparison. A fragment of diamond, and another of quartz, chosen purposely of rather a larger size, were fixed near each other in the clay; and it was observed that the diamond was most luminous while under the action of the flame, and longer so after removal from it. Its being a very slow conductor of heat may occasion in part the latter quality. In the same way the unequal fusibility of two substances may probably, on some occasions, be ascertained; and serve, from deficiency of a better, as a means of distinction between them. I am, Sir, yours, &c. J. SMITHSON. * Annals for May. |