With the exception of nitric acid, acids do not generally produce stains upon white fabrics but often change or destroy the color of dyed materials. However, cotton and linen fibers are destroyed readily by some acids, especially by those of greater concentration or strength. Dilute acids do not attack wool and silk fibers to any great extent unless they are allowed to dry on the cloth and become concentrated, but they do sometimes affect the color of the fibers. It is essential, therefore, that acid spots on textiles be neutralized at once by some alkaline solution. For this purpose any one of the following should give good results:

1. Water. Rinse the spot several times in a large volume of water. This treatment serves to stop any further action of the acid on the fabric, but usually has no effect on any discoloration due to the acid.

2. An alkaline substance, such as washing-soda, ammonia, or borax. Apply an alkali to the acid spot. The alkali forms a salt with the acid and this must be removed later by rinsing or sponging with water. The acid should be neutralized completely with the alkali or the discoloration may reappear after a while. Either of the following alkalis may be used: (a) Ammonia. If the spot is slight, neutralize it by holding it in the fumes from an open bottle of strong ammonia. (6) Sodium bicarbonate (baking soda). Sprinkle this on the stain-on both sides, if possible-moisten with water, and allow to stand until the acid is neutralized (shown in this case by the ceasing of the effervescence); and remove the excess by rinsing with water.