In cases in which the nature of the stain is not known, it should be attacked first by sponging with cold water, provided, however, that the fabric would not be injured by water. If the stain is not removed by cold or warm water, chemicals should then be applied. Often the behavior of a stain, when treated with cold water, will give some indication of its nature; for example, a grease spot will not absorb water. Hot water should be avoided in treating unknown stains until after other substances have been tried, since hot water will set many stains and make their removal more difficult..

Gums

See "resinous substances," page 301.

Silver Nitrate

See "ink (marking)," page 295.

Varnish Stain Removal

See "paint and varnish," page 299.

Whitewash Stain Removal

Whitewash stains should be treated in the same way as alkali stains (page 288).

Wine Stains

See "fruit and berries (fresh),"page 291. When the stain is first made sprinkle salt on it to keep it from spreading.