sometimes called _China_ or _Chinese Ink_, is chiefly brought from China in oblong cakes, of a musky scent, ready prepared for painting in water. Varying considerably in body and colour, the best has a shining black fracture, is finely compact, and homogeneous when rubbed with water, in which, when largely diluted, it yields no precipitate. Without the least appearance of particles, its dry surface is covered with a pellicle of a metallic appearance. When dry on the paper, it resists the action of water, yet it will give way at once to that action, when it has been used and dried on marble or ivory, a fact which proves that the alummed paper forms a strong combination with the ink; possibly a compound of the latter on an aluminous base, might even be employed in oil. Different accounts are given of the mode of making this ink, the principal substance or colouring matter of which is a smoke black, having all the properties of our lamp black; the variety of its hues and texture seeming wholly to depend on the degree of burning and levigating it receives. From certain Chinese documents, we learn that the ink of Nan-king is the most esteemed; and among the many sorts imported into this country, we find those of the best quality are prepared with lamp black of the oil of Sesame; with which are combined camphor, and the juice of a plant named _Houng hoa_ to give it brightness of tone. According to an analysis by M. Proust, the better kinds contain about two per cent. of camphor. By some, the pigment known as Sepia has been supposed to enter into their composition. _Liquid Indian Ink_ is a solution for architects, surveyors, &c. 293. IVORY BLACK is ivory charred to blackness by strong heat in closed vessels. Differing chiefly through want of care or skill in preparing, when well made it is the richest and most transparent of all the blacks, a fine neutral colour perfectly durable and eligible both in water and oil. When insufficiently burnt, however, it is brown, and dries badly; or if too much burnt, it becomes cineritious, opaque, and faint in hue. With a slight tendency to brown in its pale washes, this full, silky black is serviceable where the sooty density of lamp black would be out of place. It is occasionally adulterated with bone black, a cheaper and inferior product.