Notwithstanding the large number which must have perished from accident or neglect, or have been wilfully destroyed, the number of richly illuminated manuscripts still existing is surprisingly great. Most public, and many private collections oontain numerous examples, and copies aro eagerly purchased at very high prices whenever offered for sale. The Vatican, the Imperial Libraries of Vienna and Paris, and the British ,Museum are especially rich in examples of the various schools and periods; the monasteries of Italy, and the libraries of Oxford, Cambridge, and Trinity College, Dublin, also possess numerous and important, though less various collections.
We have now to speak of what are popularly known as Miniatures— the small portraits executed on ivory, either for decorative purposes, or to place in cabinets, lockets, or brooches. Miniatures painted in (manic' are noticed under EXAM ELS.
Although of later date than the works of which we have been speaking, portrait miniatures are by no means of recent introduction. portraits were among the embellishments introduced by the mediaeval miniatori in the manuscripts executed by them for noble patrons ; and after the decline of the practice of illuminating books, the production of portrait miniatures for placing in lockets, frames, or cabinets, seems to have quickly grown into fashion. Ivory was early adopted as a more suitable ground than vellum for independent works, and its adoption led to a change in the technical processes. In medimval miniatures, body colours—or colours rendered opaque by the admix ture of white were alone employed, and the ground or vellum was entirely concealed, the brilliancy of effect being obtained by the colours themselves. In modern portrait miniatures, the painters have very generally employed transparent colours, at least for the flesh tints ; finding that the peculiar texture and semi-transparency of the ivory by showing through the tints of transparent colours caused them to " bear out," as it is termed, with great brilliancy, besides imparting an exquisite softness, and much of that "inner light" which is so pleasing in carnations.
The ivory for miniatures is cut in very thin sheets, so as to retain as much as possible of its semi-diaphonous character, and when mounted, is" backed" by some perfectly white material. The painting is executed in water-colours, but by a process differing entirely from that known as water-colour painting. Ivory having a smooth and non-absorbent surface,
the colour cannot be floated on in washes, or flat tints, laid one over another. The flesh tints and other parts requiring great delicacy of finish, are therefore entirely dotted, stippled, or hatched upon the surface. In the draperies and back-grounds, the colours are however often washed in with flat tints, the inequalities of tint or surface being afterwards got rid of, and the whole worked up by careful stippling. A mezzotinto scraper, and sometimes an eugraver'a point or needle, is used for removing lights, securing diie graduation of tints, &c. Gum is the only vehicle used with the colours besides water. Formerly, it was usual to execute the drapery and background of miniatures in body-colours, but the value of the ivory surface is thus lost, and the brilliancy lessened ; while the general balance and harmony are almost always injured by the combination of opaque with transparent colours. The use of opaque colours has therefore been almost entirely abandoned by the best English miniature painters ; though retained by French artists, who, it must be confessed, have employed them with great tact and skill.
Until of late years miniatures were almost invariably confined to the face and bust of a figure. They now often comprise the entire person, with all the accessories common to a " whole-length " portrait on canvas, and are painted on a sheet of ivory of a size which almost removes them from the class of minatures. The process is, however, the same in these as in the bust portrait, where the adoption of a larger scale does not call for a somewhat larger handling. Sheets of ivory of sufficient size for these large miniatures—as we must call them for want of a more appropriate term—cannot, of course, be cut from the diameter of an elephant's tusk, as are those for miniatures of the ordi nary size. They are, in fact, thin veneers sawn from the circumference of the tooth, as described under IVORY, steamed and flattened under hydraulic pressure, and fastened with a composition of india-rubber to a mahogany panel. Some of these large paintings on ivory, as executed by Mr. Thorburn and others, have a broad and masterly effect ; but they are after all hardly to be regarded as miniatures, and certainly do not possess the special characteristics of works of that class.