dry cleaning, process of cleaning fabrics without water. Special solvents and soaps are used so as not to harm fabrics and dyes that will not withstand the effects of ordinary soap and water. Dry cleaning began in France about the middle of the 19th cent., at first in small plants, where it was done by hand; with the development of specialized machinery it has become an important industry. The danger of fire—at first a constant menace because of the large amounts of flammable materials in use—was largely overcome by concentrating the work in specially designed plants and by the use of a high-boiling petroleum product still commonly used in the United States. Newer chlorinated hydrocarbon synthetic solvents, such as perchlorethylene, are nonflammable but require precautions against their toxicity and danger to the ozone layer. The process for dry cleaning ordinary fabrics is to place them in revolving washers where they are washed with the cleansing fluid and a special soap, rinsed with pure cleansing fluid, and then spun to remove most of the fluid. They are then dried with warm air in a tumbler. Delicate fabrics are done by hand. The cleansing fluids are reclaimed and used again. Unusual stains are given an expert test to determine the proper solvent; special stain removers include chloroform, ether, and carbon disulphide.