The subsequent experiments of Berzelius, however, cleared away the obscurity in which the subject was still involved. He showed that this mineral not only contained in its composition a small portion of the _neutral fluate of alumina_, but he demonstrated the presence of a _sub-phosphate_ of that earth, to no inconsiderable an amount. Much has been said of the error committed on this occasion by Davy, in overlooking thirty-three per cent. of phosphoric acid; but the _phosphate of alumina_ is a body that might very easily have escaped notice at a period when mineral analysis was in a far less advanced state than it is at present. On the 16th of May 1805, Davy communicated to the Royal Society a paper "On the method of analyzing Stones containing a fixed Alkali, by means of the Boracic Acid." This method was founded upon two important facts: first, on the considerable attraction of boracic acid for the different simple earths at the heat of ignition; and, secondly, on the facility with which the compounds so formed are decomposed by the mineral acids. The processes are extremely simple, and the method must be considered as having advanced the art of mineral analysis. For this and his preceding papers, the President and Council of the Royal Society adjudged to him their Copley medal. In 1806, Mr. Poole, having consulted Davy on the subject of a Mine occurring near Nether Stowy, received from him the following letter, which is interesting from the political opinions it displays. TO THOMAS POOLE, ESQ. MY DEAR POOLE,