Dr. Scheinberg's suggestion is of course entirely appropriate, and his screening test deserves much more attention and use. It will be difficult, however, to convince physicians to employ it routinely in all infants, inasmuch as Wilson's disease at most will be found in 8 to 10 of 1,000,000 persons tested. The rarity of the disorder does not argue against routine screening, for the detection of a case prior to the onset of symptoms and signs might spare grief and expense which would amply justify the time and effort involved in its detection.