4. Brighten it in a large bath of boiling water, containing 4 pounds of
soap, and 1 pound of a cream-consistenced salt of tin, containing nearly
half its weight of the muriate of tin, combined with as much nitric acid
of spec. grav. 1·288. This strong nitro-muriate having been diluted with
a little water, is to be slowly poured into the bath of soap water, and
well mixed by stirring. The pieces are now put in, and winced through it
for one half, or three quarters of an hour.