To those much acquainted with art, it will be thought of the utmost importance to obtain any recipes of the time of Rubens and Vandyke. Such we are in possession of--contained in a manuscript in the British Museum--of which we may expect the publication entire. It may be interesting to give some account of this MS. and its author. The manuscript is entitled "Pictoria, Sculptura, Tinctoria, et quæsub alternarum artium spectantia, in Lingua Latinâ, Gallicâ, Italicâ, Germanicâ conscripta, a Petro Paulo, Rubens, Vandyke, Somers, Greenberry, Jansen, &c.--Fo. xix. A.D. 1620; T. de Mayerne." Theodore Mayerne, the author, was born at Geneva, 1573. "He selected the medical profession; and after studying at Montpelier and Paris, accompanied Henri Duc de Rohan to Germany and Italy. On his return he opened a school, in which he delivered lectures to students in surgery and medicine. This proceeding, and the innovation, as it then appears to have been, of employing mineral specifics in the healing art, excited a spirit of opposition which led to a public resolution, emanating from the faculty at Paris, in which his practice was condemned. His reputation rapidly increased from this period. He had before been appointed one of the physicians in ordinary to Henry IV. In 1611, James I. invited him to England, and appointed him his first physician. De Mayerne enjoyed the same title under Charles I. He died at Chelsea, leaving a large fortune, 1655."... "Dallaway, in his annotations on Walpole, after noticing the influence of De Mayerne's medical practice on the modern pharmacopoeia, remarks that 'his application of chemistry to the composition of pigments, and which he liberally communicated to the painters who enjoyed the royal patronage,--to Rubens, Vandyke, and Pelitot--tended most essentially to the promotion of the art. From his experiments were discovered the principal colours to be used for enamelling, and the means of vitrifying them. Rubens painted his portrait; certainly one of the finest now extant. It originally ornamented the Arundel collection: was then at Dr Mead's, Lord Besborough's, and is now (1826) at Cleveland House.'... A monarch who was so fond of painting as Charles I., was fortunate in having the assistance of a person who combined a love of art with a scientific knowledge applicable to its mechanical operations. It is not surprising that such an amateur as De Mayerne should enjoy the confidence of the first painters of his time; or that in return for the useful hints which he was sometimes enabled to give them, they should freely open to him the results of their practical knowledge. Such communications, registered at the time by an intelligent observer, threw considerable light on the state of painting at one of its most brilliant periods, and tend especially to illustrate the habits of the Flemish and Dutch schools."