Italian translation of an article from the burlington magazine (1962 pp 60-62), written in connection with the controversy concerning picture cleaning at the national gallery, london. Points out the scientific methods should not be an alternative but merely an adjunct to aesthetic and historical criteria. Lists factors which make the removal of a picture's varnish difficult, undesirable or impossible. Discusses the idea of safe cleaning mixtures. Comments on the general belief that cleaning methods in the past were more harsh than those of today, saying that 19th-century picture cleaning in the national gallery was rarely more than surface cleaning. Warns against the dangers of cleaning. 9 references.