As far, therefore, as space will allow, paintings should be kept separate: larger rooms, or fewer pictures, are what is wanted.[B] From this digression, pardonable, let us hope, because in the interests of art, we will pass on to a consideration of marrone pigments. 276. BROWN MADDER is an exceedingly rich marrone or russet-marrone brown, bearing the same relation to the colour marrone that raw umber bears to the colour citrine. One of the most valuable products of the madder root, it has supplied a great desideratum, and in water especially is indispensable, both as a local and auxiliary colour. Of intense depth and transparency, if made with skill, it affords the richest description of shadows, either alone or compounded with blue, and the most delicate pale tints. Being quite permanent, a good drier, and working most kindly, it is a pigment which cannot be too strongly recommended to the landscape painter's notice. Containing a large proportion of red, it is eligible, with yellow or blue, for mixed orange or mixed purple of a subdued tone. It may be used tolower red curtains or draperies, and for the darkest touches in flesh. Mixed with cobalt, it forms a fine shadow colour for distant objects; and with indigo or Prussian blue and black, is serviceable for the shades of those nearer the foreground. It is similarly useful when mixed with black, and will be found advantageous in rusty iron, as anchors, chains, &c. For the deepest and richest parts of foregrounds it may be employed alone, as also for deep dark cracks and fissures, or strong markings in other near objects, as boats and figures. With French blue, or cobalt and white, a set of beautiful warm or cold grays may be obtained, in proportion as the brown or blue predominates. Compounded with blues and bright yellows such as aureolin, it gives fine autumnal russet greens. A good purple for soft aerial clouds is furnished by cobalt and brown madder, or for stormy clouds by the brown, Prussian blue, and black: an equally good slate colour is obtained from cobalt, sepia, and the brown. For glazing over foliage and herbage, a mixture of the madder with aureolin or gamboge is adapted; and for brooks and running streams compounds of this brown with raw Sienna, cobalt and raw Sienna, Vandyke brown, and French blue, will each be found useful. Black sails are well represented by burnt Sienna, French blue, and brown madder; and red sails by light red or burnt Sienna with the brown. 277. MIXED MARRONE.