MR. SWEET'S FOOD FOR SOFT-BILLED BIRDS (SYLVIADÆ).--The birds of this sort, though the finest songsters and most interesting of all the feathered tribe, have been less known or noticed than others, probably owing to the greater number only visiting us in summer, when the trees are so densely clothed with foliage that birds are not easily seen, and when heard sing are generally considered by those who hear them to be either blackbirds or thrushes, or some of the more common singing birds. When they are seen the greater number of them receive the general appellation of white-throat, without distinction, though this is rather singular, since they are all very distinct when examined, and their songs are all very different. If you speak to a bird-fancier or bird-catcher about any of them, you might as well talk of a bird in the wilds of America, for they know nothing of them. Many of them are therefore difficult to be procured in the neighbourhood of London, though most of them are plentiful there. With care, the whole of them may be preserved in good health through the year, and many of them will sing through the greater part of the winter if properly managed. They require to be kept warm; the room in which they are should never be allowed to be below temperate, or they will suffer from it, particularly the tender sorts; at first the cold will make them lose their sight, after which they seldom recover. The redstart and nightingale are most subject to this; it sometimes also happens to the fauvette, and also to the whinchat.