_Walls._--As a rule it is desirable as far as possible not to disturb the general flatness of wall surfaces, and to avoid all patterns which obtrude themselves too prominently upon the eye, or cause the space, whether covered with paper or painted decoration, to be broken into groups of ornament, or into distinct lines cutting it transversely or horizontally. The wall surface may be divided either by a chair or frieze rail and be treated in different shades of colour with good effect; or the upper portion may be covered with good artistic painting, which will add to the beauty and picturesqueness of the room. Where the upper space is covered with paper or distemper, the pattern or colouring should offer no startling contrasts, and the lower portion may be painted and varnished, so as to be readily cleaned. The colour of the wall surfaces of the different rooms must naturally depend upon the purposes for which the rooms are used, as the apparent warmth and pleasurable appearance of the room is materially enhanced or detracted from by the treatment of the wall-colouring; and while it is necessary to treat the surface of one room as a background for pictures, it may be desired to have another brighter and more decorative; but wherever possible, in passages, halls and staircases, it is desirable to varnish as much of the wall surface as possible, so as to render it non-absorbent and readily cleaned. In the selection of paper or other hangings, and in the arrangement of all ornament in wall or panel decoration, it becomes a matter of importance to select none which shall have distinct and strongly marked patterns, in which the ornament stands out and repeats itself in endless multiplication and monotony. All staring patterns should be avoided. Almost all papers may now be considered practically free from arsenic; the largest printers of machine-printed papers now use little or no arsenical colours; the principal manufacturers of block-printed papers allow on colours with a known trace of arsenic to enter their factories; and, as the colours of this class of paper-hangings are more thoroughly bound with size than those which are machine-made, they are to be recommended for house decoration in preference to the cheaper kinds, as being to a certain extent more lasting.