Dear Dr. Wolke: Can you please write something about the misuse of words in relation to foods?

-- R. L. Wolke

I'll be glad to. Thanks for giving me an excuse to do so, because writing about language in a food science column might otherwise appear to be out of place. But a reader's request is my command.

Technical words aren't the only ones that cause occasional trouble for food writers. Menu terminology does too. I'm the kind of guy who upon being handed a menu in a restaurant scans it for spelling errors. But even though the other day I actually saw "tuna tar tar" on a menu (honest!), this column won't be about spelling. Anybody can slipp up on that once in a while.

Well, maybe just one gripe about spelling: The word "restaurateur" does not have an "n" in it. In 18th-century France, before the word came into general use for the operator of an eating establishment, it referred to the proprietor of a stopping place along the road at which a traveler could rest his horse and perhaps score a meal, which might include an energy restorative or "restaurant" such as a bowl of rich broth. The soup chef or proprietor, often the same person, was afforded the honor of being called the restaurateur.

Okay, one more spelling gripe: the name of the shiitake mushroom is spelled with two i's. It does not begin with an Anglo Saxon four-letter word.

Melting: How many times have you heard or read that sugar melts in hot coffee or won't melt in iced tea?

Melting is the change of a solid into a liquid through the application of heat. And neither tea nor coffee is nearly hot enough. Every solid has its melting point, the temperature at which this solid-to-liquid transition takes place. Ice melts at 32 degrees, salt melts at 1,474 degrees, and iron melts at 2,800 degrees. Sugar (sucrose) will melt if you put it in a saucepan and heat it to 350 degrees, such as when making caramel, peanut brittle or other candies. But not when you add it to hot water.

What happens to sugar in coffee and to salt in your stew is not melting but dissolving, from the Latin dissolvere, meaning to come apart. The crystalline structures of solid sugar and salt do indeed disintegrate, the resulting submicroscopic fragments (molecules or ions) being liberated to swim freely around among the water molecules. The sugar and salt do not become molten lumps, liquefied by heat. They are present in dissolved form; they are "in solution."

Now don't write to tell me that melt is defined in your dictionary as "1. to change from a solid to a liquid state, generally by heat" and 2. "to dissolve; disintegrate." Lexicographers compile dictionaries with the express purpose of reflecting the current use of our changing language, not of ordaining what is right or wrong. That responsibility must be borne by sticklers such as I.

Melding: Many cookbooks tell us to combine ingredients, say, for a sauce, dip or salad dressing, then refrigerate them for several hours to let the flavors "meld." Do they? Is the fusion of flavors more fused after melding?

Meld is what is known as a portmanteau word -- a word invented by fusing two words of similar meaning. It was melded (if I may say so) from the words melt and weld, and means to blend, merge or unite. It could be used quite accurately as a synonym for dissolve, because dissolving is a true merging of one substance (the solute) into another (the solvent, which is usually water).

A computer search turned up more than 6,600 Web pages on which "meld" is used in conjunction with the word "flavor." Example: "Cook for another few minutes until the flavors meld." (Does a bell ring when they're melded?)

Flavors can certainly change, and in many cases improve, upon cooking, standing or mixing. For one thing, the physical acts of cutting or blending ingredients can release enzymes that generate tastes and smells that weren't there before. Everybody knows that a ragout tastes better on the second day. And many wines, of course, mature with age, although the chemistry of how this happens is undoubtedly quite complex.

It's too simple to suppose that substance A in ingredient X reacts with substance B in ingredient Y to produce some sort of new reaction product C with a unique taste. But if it is found empirically that the overall flavor improves, let's just make the most of it. Melding is probably as good a word as any.

Ultimately, however, the true blending and combining of the profusion of taste and smell signals that we sense when chewing a food takes place in the brain. Individual molecules of taste and smell act upon our taste and smell receptors, which then send messages to the cortex of the brain. There, they are combined with texture and "mouth-feel" signals from the nerves in our oral cavities to produce that consummate sensation of "Mmmm, good!" That's real melding.

Robert L. Wolke (www.professorscience.com) is professor emeritus of chemistry at the University of Pittsburgh and the author, most recently, of "What Einstein Told His Cook: Kitchen Science Explained" (W.W. Norton, $25.95). He can be reached at wolke@pitt.edu.