456 Academy of Sciences, Arts, and Belles Lei Ires of Caen. 



Academy in the sitting of the 10th November, of which the fol- 

 owiiig announcement is given in The Moniteur. 



" Caen, l^vh Dec 

 " An interesting discovery for tlie Arts has just been made in 

 oui- department. It is a new j)rocess for reproducing nd irifi/ii- 

 tum a desigu traced on a plate of porcelain. In this respect 

 it is a method analogous to lithography : but it has many advan- 

 tages over it. Ey means of tablets of porcelain impressions may 

 l)e tahen of the finest and most delicate sketches of the crayon 

 or pencil ; and lolig use of the plate will neither efface nor spread 

 the touches, as too often happens in the processes of mezzotinto 

 and lithography. 



" We will not undertake to describe exactly the new process. 

 We can only say that the lines traced with a particular metallic 

 composition on the polished surface of porcelain become incrusted 

 there bv a second baking without forming any indentation or re- 

 lief, and without being in the least enlarged or deformed. The 

 parts drawn have acquired a sort of asperity not sensible to the 

 touch, but which retain the ink perfectly, while that sul)stance 

 slides off the rest of the plate. It will be seen from this, that the 

 design is indelibly fixed. On the contrary, in lithography a thou- 

 sand accidents, the action alone of the press, may stretch and 

 render blurred the lines traced upon a stone, which, being porous, 

 must remain always more or less permeable to an ink of the same 

 nature as that with which the sketch is first made. 



" Thisdiscoverv was communicated to the Academy of Sciences, 

 Arts and Belles Lettres of Caen at its sitting of the 10th of No- 

 vember." 



I strongly suspect that the writer of the foregoing letter knows 

 nothing v.hatever of the discovery which he attempts to describe, 

 excepting only that porcelain tablets are to be substituted for the 

 stones now used in the lithographic art ; and this I take to be 

 the real discoverv, namely, that porcelain plates may be used 

 instead of stone, and the tracings be made with vitrifiable ma- 

 terials, instead of waxy or resinous. Every person acquainted 

 with printing knows that printers' ink w^ill attach itself to any 

 smooth surface (even to glass), unless the material be pervious to 

 and imbibed with water. It is the water that prohibits the ad- 

 hesion of the ink. Contrary to what this writer insinuates, it 

 seems likelv that the porcelain plates are used in their 7inglazcd 

 state, and that the only glazed parts are those which exhibit the 

 lines of the design. If this opinion be correct, it will follow that 

 the porcelain plates are to be preferred to stone; because, should 

 they get injured at any time by the touch of a greasy finger (which 

 often ruins a lithogra})hie design, by rendering the part adhesible 

 to the ink, when the ball is applied to it), they may be perfectly 

 restored to use by baking agaiu in the kilu. A. T. 



