Be very careful when treating unidentified stains. To start with you need to find out what the fabric is made of. Egg yolk works wonders on washable, coloured fabrics. After treating the stain, rinse with cold water. White, starched fabrics should be dabbed with eau de Cologne or spirits. Then treat with a solution of ammonia and bile soap, and leave to soak overnight if necessary. For wool, use cornmeal, potato flour or vinegar and potato starch. Heat these ingredients in water, and then moisten the stain. Once dried, the stain can simply be brushed away. Use a piece of clean linen soaked in vinegar to wipe stains from velvet. Then wash in clean water.