4340. Vignette is a French term, designating the ornamental engraving, without a border, which is sometimes placed in the title-page of a book, at the head or termination of a chapter, &c.
4341. Xylography is the art of engraving upon wood; etching, mezzotinto, aquatinta, are varieties of the art of engraving upon copper. Until within these few years, copper and wood were the substances employed by engravers for book illustrations. For certain purposes, wood (box-wood) continues in the highest repute: but copper has been in a great measure superseded by steel, where a large number of impressions is required.
4342. Electrography is a newly-discovered electrical process, by which one copper plate may be expeditiously produced, in fac simile from another.
4343. Glyphography is a somewhat similar process, by which, through the action of the voltaic battery, plates may be obtained from drawings, affording impressions ad libitum.
4344. Lithography is the art of taking impressions from drawings or writings made on prepared and highly-polished calcareous stone.