Odostomia we have a genus which is not fairly represented, on account of the excessively critical character of its species. Five genera of Gasteropoda, three of Lamellibranchiate acephala, three of Palliobranchiate acephala, and three of hard Echinodermata, all having members in the Scottish portion of the regions explored, are without representatives in the English western and southern provinces. On the other hand, seven genera of Gasteropoda and eight of Lamellibranchiate acephala having English representatives, are altogether wanting on the western and northern coasts of Scotland. All our brachiopods found within the area explored are Scottish species; the number of monomyarious Lamellibranchiata is slightly in favour of Scotland over England, which, however, shews a considerable majority of dimyaria. The proportion of Gasteropoda in the Scottish seas is, however, so great, that the total number of testacea is in favour of the north. This is to be attributed partly to the greater variety of depths and ground, and partly to the presence in the north of isolated colonies of arctic forms which swell the ranks of the inhabitants of those regions to beyond their natural proportions.

Whirlwinds produced by the Burning of Cane-Brakes.

Mr Olmsted read to the American Association, at New Haven, a paper on whirlwinds produced by the burning of cane-brakes in the south. The canes in Alabama often grow to the height of 35 or 40 feet. They are cut down, and, after drying for about six weeks, fire is applied to them in several places. As soon as the canes begin to burn, the air that is confined in their cells, and the watery vapour, burst them asunder. They generally explode through several cells at once, and thus are split in one continued line. Those explosions, in burning a large cane-brake, produce a continued roar, like the discharge of musketry from an immense army. On account of the dry, combustible nature of the cane, when kindled, the fire advances with great rapidity, giving out flames of the deepest red, the intensity and richness of which colour are incomparably finer than the flames which arise from the combustion of any other kind of wood. Together with the flame, there ascends a very dense, black smoke, resembling that which arises from burning camphor, or from the chimneys of gas-works or factories where bituminous

coal is used. This smoke also far surpassed, in its dense, deep black colour, any thing ordinarily observed.

The cane-brake visited by Mr Olmsted covered a space of 25 acres, and was set on fire at the part most distant from him. "Whirlwinds were now observed in the hottest part of the fire. They did not unite in one column, but were scattered throughout the fire, and several were formed at the same time. The first were on a comparatively small scale. Their height was from 30 to 40 feet. To these succeeded others on a larger scale, until they reached the height of more than 200 feet, and the flame and smoke which formed their columns were perfectly distinct from the general mass which arose from the fire. They appeared rather to increase in size and frequency toward the latter part of the burning,' and many were formed on the ashes after the fire had to a great extent gone down.

Among the whirlwinds there were several points of difference, by which they might be classed under four heads. The most common one was that which was stationary over a part of the fire which was hotter than the neighbouring portions. A second variety was that which had a progressive motion, and advanced over the burnt track, throwing up ashes and cinders, and thus making its course through the fire. Some of these emerged from the flames. This was probably the case with a number, although, having nothing to mark them after leaving the fire, they became invisible. One, however, passed near enough to us to be observed, and attracted our attention by its rustling sound, and by the leaves which it carried up. This was about 15 or 20 feet high. At the time this passed us we had moved from our first station, and were about 300 yards from the fire. These whirlwinds differed from the others in form, being very wide at the top, and contracting to a point at the bottom, like a top or a spindle; or, more exactly, they were of the form of the upper cone of an hour-glass. An interesting phenomenon which attended some of the whirlwinds might render it proper to arrange them under a third class. In these the flame was violently whirled at the base; then above succeeded a dark interval, where the flame seemed to be ex

tinguished entirely, but towards the top it broke out anew. It was a mixed whirling of flame and smoke, the smoke occupying the central portion. The dark interval where the smoke was unconsumed was greater or less, as the flame above approached to, or receded from, that beneath. There were a number of this class. The fourth kind were formed of immense columns of smoke, so narrow and lofty that they resembled towers of several hundred feet, or trunks like those of trees in form, extending into the sky. The rotary motion was obvious throughout their entire length. These columns of smoke were generally straight, but sometimes bent at the top by the wind. In connection with the whirlwinds there were several other facts of interest observed during the burning of the cane. We noticed the direction of the wind was changed. At first it was from the north-east, and continued in that direction in the upper part of the atmosphere, as was evident from the way in which the columns of smoke were bent. But shortly after the commencement of the burning the air beneath blew in all directions towards the centre of the fire. The columns of smoke were not bent for more than a hundred yards; hence up to that height the wind blew in all directions towards the centre of the fire. These whirlwinds revolved on their axes from right to left, and from left to right, without any prevailing tendency to one direction more than to the other. Frequently the same whirlwind would change the direction in which it revolved, and would again return to its first course. In a few instances this was repeated several times. The charred leaves of cane being thin and light, were driven off in considerable quantities. They were carried up frequently without being burned, and were sometimes found at a distance from the place of the fire. But considering the extent of the fire, few cinders were carried up. The combustion was very complete."-American Annual of Scientific Discovery, 1851, p.

163.

A Chemical Examination of the Metals and Alloys known to the Ancients. I. History. II. Analyses of Ancient Alloys, A. Coins struck prior to the Christian Era. B. Analyses of Ancient Arms and Cutting Instruments. C. Table of Mean Composition of the Specimens analysed. D. Deductions. By J. ARTHUR PHILLIPS, Esq., F.C.S.*

I. History.

Among the arts cultivated by mankind in the infancy of the world, metallurgy appears to have held a very prominent situation; for we read that Tubal Cain was an instructor of every artificer in brass and iron,† and consequently these, together with their uses, must have been well known to the antediluvians.

It is also probable that they were not the only metals in use at this remote period; for the extraction of iron from its ores, of itself indicates great metallurgical skill and experience, as from the refractory nature of the materials employed, a very intense heat and skilful manipulation must have been necessary to its production. From these considerations, we may infer that this metal could not have been discovered until the arts had attained a great degree of perfection, and long after the discovery of some others requiring less complicated apparatus and a lower temperature for their reduction. It would be quite impossible, after the lapse of so many ages, to trace the exact order in which the metals became known; but it appears natural to suppose that those which are found in a native state, were the first to attract the attention and exercise the ingenuity of mankind; and consequently, that gold, silver, and copper, were among the first with which the ancients became acquainted.‡ This, however, is but conjectural, as in the first mention of silver, Abraham is described as weighing unto Ephron, four hundred shekels of silver current money with the merchant, §

*The above is an abstract of a memoir published in the valuable Quarterly Journal of the Chemical Society of London, for October 1851. † Cen. iv. 22.

It is true that iron is sometimes found in the native state, as large masses of meteoric origin have been occasionally met with. These, however, occur but seldom, and in quantities far too small to have supplied this metal for the uses of the arts. § Gen. xxiii. 16.

thus indicating that in those days, it was not only well known, but commonly used as a medium of exchange, for which purpose it was estimated by weight.

In the time of Moses, at least six metals were known, as in his direction for the purification of the spoils of the Midianites, he says, "Only the gold and silver, the brass, the iron, the tin, and the lead, every thing that may abide the fire, ye shall make it pass through the fire, and it shall be clean ;"* thus shewing that the metallurgical arts had at that period attained considerable perfection, and that the metals were of frequent occurrence and constant employment. Of the processes practised in the early ages of the world, little can at present be known; but it would appear likely, from some passages in the sacred writings, as well as from the somewhat confused and obscure accounts of profane authors, that they differed but little from those which are employed at the present day.

That silver was at a very early period purified by means of lead, the following passages would seem to indicate: "The house of Israel is to me become dross all they are brass, and tin, and iron, and lead, in the midst of the furnace; they are even the dross of silver." And again, "the bellows are burned, the lead is consumed by the fire, the founder melteth in vain." We also read of silver being purified in a furnace of earth. Strabo quotes Polybius as speaking of a silver ore which after being washed seven times, was melted with lead, and became pure silver.

That tin was not only well known, but also highly valued at the time of the Trojan war, we learn from Homer, who calls it xaooiregos, and mentions it as forming part of the armour of Agamemnon§ and shield of Achilles.|| to make which, Vulcan is represented as throwing into the crucible brass unconquered, xaooiregos, and honoured gold and silver.

Among the ancient Greeks and Romans, the workers of metal had attained a pitch of excellence, in some instances scarcely to be surpassed in the present day; but although many proofs of their skill have come down to us, in the form of coins, statues, and implements of war, yet their authors afford but scanty information relative to the methods em

*Numb. xxxi. 22. † Ezek. xxii. 18.

Jer. vi. 29. § Iliad, 2. || Iliad, 18.