Seventhly:--Be decided, but temperate, in your contrasts of colour. It would obviously exceed the limits of these notes to attempt in them to enter upon the principles of the "harmony of colour;" they must be studied from treatises specially devoted to the subject. Such study must, however, be accompanied by constant experiment and practice; for it would be as foolish to expect a man to be a good performer upon any instrument, because he had learnt the theory of music, as it would be to suppose that he must necessarily paint in harmonious colouring, because he studied the theory of balance in combination. To the experienced eye and hand, functions become intuitive, which, to the mere theorist, however profound, are toil and weariness of spirit. Such are a few of the rules, by attention to which the illuminators of old achieved some of their happiest effects, and which can never be safely disregarded by those who would emulate their efforts. In taking up the class of substances on which illumination, as applied to general decoration, may be best executed, we meet, firstly, with one occupying a somewhat intermediate position,--viz., tracing-paper. I term its position intermediate, because, it may be wrought upon in either oil or water colour; and because, when so wrought upon, it may be either mounted on paper or card, and so made to contribute to book or picture enrichment; or attached to walls or other surfaces, brought forward in oil-colours, and be so enlisted in a general system of mural illumination. How this may best be done technically will be hereafter described; here I may notice only the use which may be made of this convenient material, by many not sufficiently advanced in design or drawing to be able to invent or even copy correctly by free hand, and yet desirous of embellishing some particular surface with decorative illumination. For instance, let it be desired to fill a rectangular panel of any given dimension with an illuminated inscription. Take a sheet of tracing-paper the exact size, double it up in both directions, and the creases will give the vertical and horizontal guidelines for keeping the writing square and even: then set out the number of lines and spaces requisite for the inscription, fixing upon certain initial letters or alphabets for reproduction on an enlarged scale, from this work, or any other of a similar kind, and making the height of the lines correspond therewith. Then lay the tracing over either the original or the rough enlargement, and trace with pen, pencil, or brush, each letter in succession, taking care to get each letter into its proper place, in reference to the whole panel, to the letter last traced, and to the other letters remaining to be traced. When this is completed, trace on whatever ornaments may best fill up the open spaces and harmonize with the style of lettering. When the tracing is completed, with a steady hand pick in all