In Madrid, the whole of the middle classes, and, indeed, all excepting the very highest ranks, live in stories, or flats, as they are called in Scotland,--each story being a distinct house. The outer door of every house in Madrid is of an enormous strength, more like the door of a prison, or of a convent, than of a private dwelling house; and in the centre, there is a small window, about six inches long by two broad, grated with iron, and with a sliding shutter. When one rings at the door of a Spanish house, the answer to the bell is a voice, which calls out “_Quien es?_”--who is it? or who comes? and the person wishing to be admitted, must answer “_Gente de paz_,”--literally, People peace. But this assertion does not content the person within, who then shoves aside the shutter and peeps through; and the usual colloquy is carried on through the grating, before the door be thrown open, unless the person without, be known to the servant within. One cannot help endeavouring to account for the origin of so singular a custom; and perhaps the truest guess that can be made, is, to refer it to the suspicion, and feeling of personal insecurity, which are the offspring of bad government, of political persecution, and religious inquisition. The window shutters of the houses are as massive as the doors; and the glass of the windows is purposely so bad, that it is impossible to see into a house from the opposite side of a street: three panes, however, are always of good glass, so that one may be able to see out.