It has been erroneously stated that the finest carmines cannot be made in England, owing to a want of clearness in the atmosphere and a scarcity of sunshine. For many years, however, they have been produced in this country, not only finer than any foreign preparations, but equally good in winter as in summer.
Carmine is sometimes sophisticated with starch, vermilion, and with alumina not formed in the process of manufacture. Occasionally also, a portion of the animal matter of the cochineal from which it has been obtained is left mixed with it. These accidental or intentional impurities may mostly be detected by heating the carmine with liquid ammonia, which entirely dissolves the colouring matter and leaves the impurities in an insoluble state.
70. CRIMSON LAKE
Is a cochineal pigment containing more aluminous base than carmine, and is consequently weaker in colour and less stable. Deficient in much of the depth and brilliancy which belong to the latter, it is more commonly employed and more generally useful. This lake is of service in mixing tints, to impart richness, in flower painting and illumination, and is, like all cochineal colours, of greater utility in water than in oil. With cobalt and gamboge it yields an excellent gray, and with cobalt alone a fine purple for heather. Distant hills may be strengthened with a tint of French blue and lake, and Vandyke brown with the crimson will be found admirable for a rich coloured foreground. Many other beautiful tints, unexceptionable in an artistic sense, are afforded by crimson lake on admixture. It should be remembered, however, that not one of them is permanent as far as the lake is concerned. All cochineal pigments are more or less affected by strong light, which weakens their tints, and in time deprives them of colour; and it is not by being compounded that a fugitive colour is rendered durable.
71. SCARLET LAKE
Is prepared in the form of drops from cochineal, and is of a fine transparent red colour and excellent body, though, like other lakes, it dries slowly. Discoloured and destroyed by strong light both in water and oil, and not permanent in tint with white lead or in combination with other pigments, it possesses the common attributes of cochineal lakes. Yet when well prepared, used in sufficient body, and not unduly exposed, it has been found to last a lengthened period; but it ought never to be employed in glazing, nor at all in works that aim at high reputation and stability. It is in general tinted with vermilion, which has probably been mixed with lakes at all times to give their scarlet hue and add to their weight; for upon examining with a powerful lens some fine pictures of ancient masters, in which lake had been used in glazing, particles of vermilion were apparent, from which lake had evidently flown. Unfortunately, these lakes are injured by vermilion as they are by lead, so that glazings of cochineal over vermilion or lead are particularly apt to vanish. This effect is very remarkable in several pictures of Cuyp, where he has introduced a figure in red from which the shadows have disappeared, owing to their having been formed with lake over vermilion. The scarlet hue of this lake should properly be imparted to it during the process of manufacture, and not by subsequent mechanical admixture.
72. PURPLE LAKE
Is a species of crimson lake with a purple cast, transparent and deep-toned, and useful in shadows: in other respects resembling that pigment. Red being its predominant colour, we have preferred classing this so-called purple among the reds, in spite of its name. On the whole it is more durable than crimson lake.
73. FLORENTINE LAKE
Differs from scarlet lake only in the mode of preparation. Formerly the lake so called was extracted from the shreds of scarlet cloth. The same may be said of Chinese Lake.