The glass becomes of a bottle-green color, which on cooling, changes to a brilliant green, similar to that produced by oxide of chromium. The reaction on charcoal is precisely similar. Tin renders the color somewhat darker. * * * * * 31. Vanadic Acid, VaO^{8}. Behavior with Borax on Platinum wire in the oxidizing flame. Dissolves to a clear glass, which is colorless when only a small quantity of acid is present, and yellow when containing a larger proportion. in the reducing flame. The yellow color of the glass changes to a brown when warm and a chrome-green on cooling. Behavior with Mic. Salt on Platinum wire in the oxidizing flame. As with borax. in the reducing flame. As with borax. * * * * * 32. Oxide of Chromium, Cr^{2}O^{3}. Behavior with Borax on Platinum wire in the oxidizing flame. Affords an intense color, but dissolves slowly. A small proportion colors the glass yellow when warm, and yellowish green when cold; a larger addition produces a dark red color when warm, which, on cooling, becomes yellow and finally a brilliant green with a tinge of yellow. in the reducing flame. A small quantity of the oxide renders the glass beautifully green both when warm and when cold. A larger addition changes it to a darker emerald green. Tin produces no change in the color. Behavior with Mic. Salt on Platinum wire in the oxidizing flame. Dissolves to a clear glass which has a pink tinge while warm, but on cooling becomes dusky green, and finally brilliantly green. in the reducing flame. As in the oxidizing flame, except that the colors are somewhat darker. Tin produces no further change. * * * * * 33. Arsenious Acid, AsO^{3}. Behavior with Borax on Platinum wire in the oxidizing flame. No reaction. in the reducing flame. No reaction. Behavior with Mic. Salt on Platinum wire in the oxidizing flame. No reaction. in the reducing flame. No reaction. * * * * * 34. Tellurous Acid, TeO^{2}. Behavior with Borax on Platinum wire in the oxidizing flame. Dissolves to a clear colorless glass which, when treated on charcoal, becomes grey and dull from particles of reduced tellurium. in the reducing flame. As in the oxidizing flame. Behavior with Mic. Salt on Platinum wire in the oxidizing flame. As with borax. in the reducing flame. As with borax. * * * * * 7. EXAMINATIONS WITH CARBONATE OF SODA.