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.