lately called _Factitious Ultramarine_, is a specially fine preparation of M. Guimet, presenting the nearest approach to the natural product of any artificial ultramarine, both in transparency, purity of hue, and chemical characteristics. Equalling in depth and power the ordinary French ultramarine, it possesses greater clearness, beauty, and brightness; and has, in a subdued degree, that quality of light in it, and of the tint of air, which forms so distinguishing a feature in the native blue. 133. FRENCH ULTRAMARINE, or _French Blue_, is a rich deep colour, but less transparent and vivid than the preceding variety, which is preferable in unmixed tints. For compound hues, French blue is sufficiently well adapted, and is extremely useful. With aureolin and burnt Sienna, or Vandyke brown, it affords valuable autumn greens; and with lamp black, or lamp black and light red, good stormy clouds. A sombre gray for distant mountains is furnished by French blue and madder brown, with a very little gamboge; and a deep purple for sunsets, by the blue and purple madder, or Indian red and rose madder. With cadmium and orient yellows, sepia, viridian, and many other colours, this ultramarine is of service. 134. NEW BLUE Is confined to water-colour painting, and is an artificial ultramarine, holding a middle position between French blue and permanent blue, being less deep than the one and less pale than the other. It may be said to hover in tint between a rich ultramarine and cobalt. 135. PERMANENT BLUE Is a pale ultramarine, with a cobalt hue; and, in spite of its name, less permanence than belongs to the richer and deeper sorts. What Antwerp blue is to Prussian blue, this is to French blue--that is, as regards colour. With respect to durability, however, permanent and Antwerp blues cannot be compared; the former being a weakened variety of a stable, and the latter a weakened variety of a semi-fugitive, pigment. Hence permanent blue justifies its name, although that name would be more suited to the brilliant, or French, ultramarine. 136. GENUINE ULTRAMARINE,