by the use of pure silver powder. The sheet of tinfoil was employed as before, and amalgamated with mercury, the greater part of which was drained off the surface of the foil, and then pure silver in the form of an impalpable powder (known as silver-bronze powder), was freely dusted all over the amalgamated surface. The fine silver particles became rapidly amalgamated or dissolved by the mercury, and when the sheet of glass was slid on and pressure applied, an amalgam of pure silver coated the glass, greatly improving the brilliancy and colour of the mirror. This method seemed likely to have a great future, but before it got into use, a process suggested by Liebig some years before was developed and applied in a practical form by Professor Henry Draper. By this method of working, which he used for the silvering of glass mirrors for reflecting telescopes, Professor Draper entirely dispensed with the tinfoil and mercury process, and deposited pure silver direct on to the glass from its solution. This was a far more perfect mode than my own of putting pure silver on to the glass, and quite put an end to my process. At the present day all glass mirrors are silvered by one or the other of several modified forms of Leibig's admirable invention.