The latest in a new wave of book-length plugs for a specific medication (Interferon, p. 472; A Remarkable Medicine Has Been Overlooked, p. 914)--but far too gung-ho to be a reliable guide to one of the biggest drug-use disputes going. Dimethyl sulfoxide has been used in the US since the mid-Fifties as an industrial solvent; a cheap byproduct of the paper-making process, its main use is in veterinary medicine, but it has been F.D.A.-approved for treatment of human interstitial cystitis (a relatively rare condition). Much of the work in this country is being done in Oregon, by Stanley Jacob and Robert Herschler, the physician and chemist who are the major proponents of DMSO; Tarshis got his material from their ""exclusive files."" They, and others, have apparently found the drug useful as a pain reliever, an anti-bacterial and anti-inflammatory agent, a diuretic, and a carrier of other drugs. It is thus receiving attention for its possibilities in treating soft-tissue injuries (lots of big-time athletes endorse it here); it may also be helpful in treating arthritis, and head and spinal trauma. So there is enough of a story--enough solid research completed or underway, enough question of the F.D.A. response--for Tarshis to have told it straight . . . without building up DMSO use (make sure it's pure, go easy at first) or downplaying DMSO's side-effects (an unexplained breath odor, possible eye-lens changes with heavy use, potential birth defects). Why, typically, stoop to: ""'I've always used DMSO on serious cuts,' says a Bozeman, Montana man, 'and they have always healed in less than half the time'""? The truly remarkable question of DMSO is worth solid coverage--which it doesn't get here.