The lakes of cochineal may be known from those of the dye-woods by their solubility in ammonia, a liquid which purples but does not dissolve the colours produced from the latter. 69. CARMINE. A name once given only to the fine feculences of kermes and cochineal tinctures, now denotes generally any pigment which resembles them in beauty, richness of hue, and powdery texture. We have, therefore, blue and other coloured carmines, though the term is usually confined to the crimson and scarlet lakes of cochineal. As at present commonly understood, carmine is that preparation of cochineal which contains the most colouring matter and the least aluminous base. Hence it is the richest, deepest, most intense, and most permanent. Although not to be classed as durable, yet by reason of its extreme depth, carmine is more stable than the weaker crimson, scarlet, and purple lakes. When well-made, pure, and employed alone and in body, it has been known to retain its colour for years, especially if protected by oil or varnish. In tint with white lead, however, it has no stability; and though little affected by impure air, in glazing it is soon discoloured and destroyed by the action of light. Of great power in its full touches, it possesses considerable clearness in the pale washes, and works admirably. In landscape, carmine is seldom used, the colour being chiefly valued in flower painting and illumination. 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