Susan Rothwell, age 10, of Victor, New York, for her question:

Is Irish moss useful?

Irish mosses are reddish seaweeds called carrageens. They look like leafy little trees growing on the ocean floor. But actually they are alga plants, with no true roots or stems. Several different carrageens grow off the coasts of Ireland and Northern Europe and also off the eastern shores of North America. Their juicy foliage is stuffed with material like gelatin. The people of Europe have used this material in all sorts of ways since ancient times. They still gather tons of Irish moss from the seas, and so do we.

People used to think that this gelatin was a useful food. But experts now say that it has little or no nourishment, however, we use it as gelatin to thicken desserts and gravies. For centuries, these carrageen seaweeds have been used to cure and soften leathers and to add smoothness to woven fabrics. Many things we use need gelatins to keep them soft and pasty. So Irish moss is used in such items as face creams, soaps and shampoos and dozens of other pasty products.