The following we have seen in quite a number of exchanges :— 11 The article referred to is made of coke and other materials, and With such success and economy, that they can be afforded for about one-third the price which is now paid tor the common bricks made of clay. The manufacture,according to the specification, is effected by means of cast-iron moulds, the interior of which are the exact dimensions of the common brick; in this mould a certain quantity of duff or waste coal, powdered coke, charcoal, or cinders, is placed, and being carbonized, the amalgamated material swells to the exact torm required. When taken from the mould it undergoes a finishirg process, in which varnish is applied to the end or side having, while wet, a coating of powdered glass, with an admixture of a mineral coloring matter sifted over it. The brick is then vitrified, when a beautiful glaze of any required color is produced, and the article is ready for use. During the manufacturing process, the fumes are passed through water. The finishing process is oiily required for particular purposes, as in many instances the coke brick is equally available without it. The material is rendered fireproof by an application of the muriate of alumina, and is impervious to atmospheric influences by the nature ot its formation. When articles of coke fabric are required of extraordinary density, a variation in the filling material, and also an extraordinary amount of compression, are necessary; and then there is hardly any limit to the degree of solidity which may be obtained. It is further stated that there is no description of article used in the erection or ornamentation of buildings but may be produced of the material; thus columns of interior and exterior use, cornices, capitals of plain or ornamental design can be manufactured and supplied in a finished state." [Now, no one acquainted with the price of coke and clay can for a moment doubt, if he reflects, that this new material must be far more expensive to manufacture than brick. Common bricks can be vitrified in the same manner, and as clay contains a great quantity _ofalumina., bricks do not require to be rendered fire-proof, (for this they are already) by being dipped into a solution of chloride of alumina. Instead of such bricks being made for one-third less than common bricks, we believe, that they could not be made for double the price, and in every sense they must be inferior in quality. Ornamental brick can be made of clay,—they are now made.