On the occasion of the <<Journees d'Automne 1991>> of <<La Societe Francaise de Metallurgie et de Materiaux>>, as an introduction to the fourth theme <<The history of metallurgy through the archeological findings>>, Professor Andre Guinier member of the Institute, delivered a very appreciated lecture on <<The part of theory and experiment in metallurgy progress>>. The author, distinguished physicist well known for his works in crystallography especially on X ray diffraction use applied to structure study and for his very significant discovery of the Guinier-Preston zones in light alloys, put his thoughts forward on the origin and the development of metallurgy. He emphasizes the exceptional importance of observation and experimentation but he adds the essential contribution of scientific theories; he asserts that progress results only from the jointing of the two processes: the former enriching the latter. At last, he ends his speech by an appeal to young metallurgists who, in his opinion, must be inspired by the lessons of the past: let them avoid the exclusive resort to theoretical abstraction, let them rely on the always on the alert curiosity and on the intuition of the experimentation. The Reading Committee of <<Les Memoires et Etudes Scientifiques de la Revue de Metallurgie>> keenly hoped to publish this lecture. Our readers, members of the Scientific Community will benefit from this dense paper full of the experience of a scientist.
