To make stannate of soda, proceed thus. Melt together 2 parts of caustic soda and 1 part of finely powdered tinstone (native oxide of tin). Add to the melted mass a small quantity of hot water, allow to settle, and pour off the clear liquid; this can be evaporated to form the liquid stannate. On further evaporation the liquid will commence to crystallise, and after cooling the crystals may be strained off, washed once or twice with a little water, and dried. The liquid poured off from the crystals should be evaporated to dryness and added to the next melt; the part insoluble in water may also be added so that there may be no waste. Tin crystals (stannous chloride) are formed by boiling tin with hydrochloric acid until no more will dissolve, and then evaporating and cooling the solution; the tin crystals will then separate out.