The present paper wishes to be a kind of historical revival of an “old book” that is hardly available especially to young generations of researchers and students. A bit of confusion is present also in Wikipedia. The topic is the “Mie problem” and the book is a famous “Optical Properties of Metal Clusters” by Kreibig and Vollmer (Springer 1995), red with the eyes of 2024. Young generations often know well the detail of their studies and experiments but lack dramatically of an historical and wide perspective on their job, and it’s a pity. Technics but a little of “cultural heritage” which may be able to clarify views and put into a wider context a research work. This paper may be useful as a step toward a more conscious way of working on metal nanoparticles.