This section is from the "Henley's Twentieth Century Formulas Recipes Processes" encyclopedia, by Norman W. Henley and others.
(See also Bones, Shell, and Horn.)
The article is placed for 24 hours in water, 1,000 parts of which carry 100 parts of vinegar (acetic acid, 6 per cent), and from 1 to 5 parts of aniline red. As soon as it acquires the desired color pour off the liquid, let the ivory dry, and polish with Vienna lime.
Wash the article first in potash or soda lye and then put into a neutral solution of silver nitrate. Drain off the liquid and lay in the direct sunshine.
Put the article in a weak solution of triple gold chloride and then into direct sunshine.
For a different shade of red (from the first given), place the article for a short time in water weakly acidified with nitric acid and then in a solution of cochineal in ammonia.
Leave for several hours in a solution of lead acetate, rinse and dry. When quite dry place in a solution of potassium chromate.