the Mirror.)

Many books, especially those printed in the 17th century, have no other designation either of printer, bookseller, or even city, but merely marks or signs. The anchor is the mark of Raphelengius, at Leyden; and the same with a dolphin twisted round it, of the Mantuii, at Venice and Rome; the Arion denotes a book printed by Oporrinus, at Basil; the caduceus, or pegasus, by the Wechelliuses, at Paris and Frankfort; the cranes, by Cramoisy; the compass, by Plantin, at Antwerp; the fountain, by Vascosan, at Paris; the sphere in a balance, by Janson, or Blaew, at Amsterdam; the lily, by the Juntas, at Venice, Florence, Lyons, and Rome; the mulberry-tree, by Morel, at Paris; the olive-tree, by the Stephenses, at Paris and Geneva, and the Elzevirs, at Amsterdam and Leyden; the bird between two serpents, by the Frobeniuses, at Basil; the truth, by the Commelins, at Heidelberg and Paris; the Saturn, by Collinaeus; the printing press, by Badius Ascensius, &c.

P.T.W.

THE NATURALIST.

DIFFERENT COLOURS OF THE EGGS OF BIRDS.

It is a remarkable fact in the economy of nature, that of those birds whose nests are the most liable to discovery, and whose eggs are most exposed to observation from the form of the nests, the eggs are of that colour which is the least different from the surrounding objects; whilst those birds whose eggs are of a bright and positive colour, hide their nests in the hollows of trees, or never quit them, excepting in the night, or sit immediately that they have laid one or two eggs. It is also to be observed that of those species which build an exposed nest, and the females of which alone perform the duty of incubation, the colour of the female is much less bright than that of the male, and more in harmony with the objects by which she is surrounded during the period in which she sits upon her eggs. It would seem, therefore, that those birds which lay a brightly-coloured egg have the instinct to make a close nest, or to place it in the least exposed situations; while those which lay a sober-coloured egg are less solicitous to conceal it from the notice of their enemies. M. Gloger, a German naturalist, has paid great attention to this curious circumstance, and has very recently published an elaborate memoir, in a work printed at Berlin, in which he notices the habits of all the species of birds indigenous to Germany, in confirmation of the theory. Our limits will not allow us to notice the particular species which he enumerates; but it may be sufficient to excite attention to this subject, to mention, that the birds which lay an egg perfectly white (the most attractive of colours) make their nests in holes of the earth, and cavities of trees, such as the kingfisher and the woodpecker, or construct them with a very narrow opening, as the domestic swallow; that the same coloured egg is found amongst the birds which scarcely quit their nests in the day, as hawks and owls; and that such birds as doves, which only lay one or two eggs, and sit immediately after, have their eggs white. The bright blue or bright green egg belongs to birds which make their nests in holes, as the starling, or construct them of green moss, or place them in the midst of grass, but always well covered. The eggs of many gallinaceous birds, that make their nests carelessly in the grass, are of a pale and less decided green, such as those of the partridge and pheasant. Of the mixed-coloured eggs, those of which white forms the ground belong to birds that make very close nests. Speckled eggs, with a dark or dirty ground, belong to the largest number of species. Almost all the song birds lay such eggs; and building open nests, they almost invariably line the inside of them with materials of a harmonious colour with the eggs, so that no evident contrast is presented which would lead to their destruction.—Companion to the Almanac.

EFFECTS OF SEA AIR.

Those who frequent the sea-coast are not long in discovering that their best dyed black hats become of a rusty brown; and similar effects are produced on some other colours. The brown is, in fact, rust. Most, if not all, the usual black colours have iron for a basis, the black oxide of which is developed by galls, logwood, or other substances containing gallic acid. Now the sea-air contains a proportion of the muriates over which it is wafted; and these coming in contact with any thing dyed black, part with their hydrochloric (muriatic) acid, and form brown hydrochlorate of iron, or contribute to form the brown or red oxide, called rust. The gallic acid, indeed, from its superior affinity, has the strongest hold of the iron; but the incessant action of the sea-air, loaded with muriates, partially overcomes this, in the same way as any acid, even of inferior affinity to the gallic, when put upon black stuff, will turn it brown.—Ibid.

THE DUGONG, THE MERMAID OF EARLY WRITERS.

Of all the cetacea, that which approaches the nearest in form to man is undoubtedly the dugong, which, when its head and breast are raised above the water, and its pectoral fins, resembling hands, are visible, might easily be taken by superstitious seamen for a semi-human being.—Edinburgh Journal.

SPIDERS.

Live and grow without food. Out of fifty spiders produced on the last day of August, and which were kept entirely without food, three lived to the 8th of February following, and even visibly increased in bulk. Was it from the effluvia arising from the dead bodies of their companions that they lived so long? Other spiders were kept in glass vessels without food, from the 15th of July till the end of January. During that time they cast their skins more than once, as if they had been well fed.—Redi, Generat. Insect.

Spiders are excellent barometers: if the ends of their webs are found branching out to any length, it is a sure sign of favourable weather: if, on the contrary, they are found short, and the spider does not attend to repairing it properly, bad weather may be expected.—Times.

SWARMING OF BEES.

The ingenious President of the Horticultural Society, Mr. T.A. Knight, has been led from repeated observation to infer, that, in the swarming of bees, not a single labourer emigrates without previously inspecting its proposed future habitation, as well as the temporary stations of rest where their numbers collect soon after swarming.—Philosophical Magazine.

THE CHAMELEON'S ANTIPATHY TO BLACK.

Whatever may be the cause, the fact seems to be certain, that the chameleon has an antipathy to things of a black colour. One, which Forbes kept, uniformly avoided a black board which was hung up in the chamber; and, what is most remarkable, when it was forcibly brought before the black board, it trembled violently, and assumed a black colour.—Oriental Mem.

RULES FOR THE WEATHER.

A wet summer is always followed by a frosty winter; but it happens occasionally that the cold extends no farther. Two remarkable instances of this occurred in 1807-8 and 1813-14. With these exceptions, every frosty winter has been followed by a cold summer.

The true cause of cold, or rather the direct cause, is to be found in the winter excess of west wind, every winter with excess of west wind being followed by a cold summer; and if there is no cold before, or during a first excess, then a second excess of west wind in winter occasions a still colder summer than the first. It also appears, by repeated experience, that cold does not extend to more than two years at a time.

Again, if the winter