Whatever some persons may affect, a true knowledge of the art of painting is by no means an easy acquirement; it is not a natural gift, but demands much reading and study. Many there are, no doubt, who may be able to descant speciously enough, perhaps, on the perfections and defects of a picture; but, on that account alone, they are not to be regarded as real judges of its intrinsic merit. Know then, that, in selecting the most remarkable productions among the vast number exhibited in the CENTRAL MUSEUM, I have had the good fortune to be directed by the same first-rate connoisseur who was so obliging as to fix my choice in the GALLERY OF ANTIQUES. I mean M. VISCONTI. Not confining myself either to alphabetical or chronological order, I shall proceed to point out to you such pictures of each school as claim particular notice. ITALIAN SCHOOL. N. B. _Those pictures to which no number is prefixed, are not yet publicly exhibited_. RAFFAELLO. N° 55. (Saloon.) _The Virgin and Child, &c._ commonly known by the name of the _Madonna di Foligno_. This is one of the master-pieces of RAPHAEL for vigour of colouring, and for the beauty of the heads and of the child. It is in his second manner; although his third is more perfect, seldom are the pictures of this last period entirely executed by himself. This picture was originally painted on pannel, and was in such a lamentable state of decay, that doubts arose whether it could safely be conveyed from Italy. It has been recently transferred to canvass, and now appears as fresh and as vivid, as if, instead of a lapse of three centuries, three years only had passed since it was painted. Never was an operation of the like nature performed in so masterly a manner. The process was attended by a Committee of the National Institute, appointed at the particular request of the Administration of the Museum. The _Madonna di Foligno_ is to be engraved from a drawing taken by that able draughtsman DU TERTRE. N° ( ) _The Holy Family_. This valuable picture of RAPHAEL'S third manner is one of the most perfect that ever came from his pencil. It belonged to the old collection of the crown, and is engraved by EDELINCK. Although superior to the _Madonna di Foligno_ as to style and composition, it is inferior in the representation of the child, and in vigour of colouring. N° ( ) _The Transfiguration of Christ on Mount Tabor._ This is the last production of RAPHAEL, and his most admirable _chef d'oeuvre_ as to composition and grace of the contours in all its figures. It is not yet exhibited, but will be shortly. This picture is in perfect preservation, and requires only to be cleaned from a coat of dust and smoke which has been accumulating on it for three centuries, during which it graced the great altar of St. Peter's church at Rome. Among the portraits by RAPHAEL, the most surprising are: N° 58. (Saloon.) _Baltazzare Castiglione_, a celebrated writer in Italian and Latin. N° ( ) _Leo X._