Scientific American 24, 1.3.1851
SCARLET. - Dip the cloth in a solution of alkaline or metallic salt, the in a cochineal dye and let it remain sometime, and it will come out permenently colored. Another method. Hald a pound of madder, half an ounce of cream tartar, one ounce of marine acid, to a pound of cloth. Put it altogether and bring the dye to a scalding heat. Put in your materials and they will be colored in ten minutes.
The dye must be scalding hot. Rinse your goods in cold water as soon as they come from the dye.
[We copy the above from an exchange, in order to point out the errors, for assuredly they are very great. It is stated above that the cloth should "be dipped into a solution of alkaline or metallic salts." This is wrong; if the cloth were dipped into a solution of common salt, it would not answer. Metallic and alkaline salts are entirely different. To dye a good scarlet, let the cloth be well cleansed from all grease and dirst, and put into a tin or clean copper vessel as much clean water as will cover the cloth well. Put in one ounce of ground cochineal for every pound of cloth, and boil it five minutes, then add a wine glass full of the chloride of tin, one ounce of cream of tartar for every ounce of cochineal, stir all up, and enter the cloth all as free and loose as possible; boil for one hour, and a beautiful scarlet is the result. After this, rinse the cloth in clean cold water and dry in a warm place.