(1) Pulverize chalk thoroughly, and mix with distilled water in the proportion of 2 lb. to the gal.; stir well, and then allow it to stand about 2 minutes, during which time the gritty matter will have settled to the bottom; then pour the chalky water into another vessel, being careful not to disturb the sediment, and allow the fine chalk to settle to the bottom; pour off the water, and place the chalk in a warm oven to dry. This is an excellent powder for restoring silver, and it is also useful as a base for other polishing powders.

(2) Spanish whiting treated in the same manner, with a small quantity of jewellers' rouge added, makes a powder that is a little sharper than the prepared chalk, and which is well adapted to cleaning polished steel articles.

(3) A third powder, and one that is still sharper than either of the above, is made of rottenstone treated in the same manner as the chalk. The addition of bone black to any of these powders will prevent their discolouring leather.