Summary The anniversary of the death of Pietro Tacchini (1838?1905), one of the pioneers of solar physics in Italy, is commemorared by this account of his major creation, the Società degli Spettroscopisti Italiani (1871). Established to promote cooperation among solar spectroscopists engaged in the study of the solar chromosphere, it was the first scientific Society devoted to spectroscopy and its astronomical applications. Its journal, the Memorie, collected most of the important works on solar physics by Angelo Secchi SJ (1818?1878), Tacchini (...) himself, and many other protagonists of the newly born astrophysics. A brief history of the Society and its development draws on many previously unexploited archival sources, in order to show its role in raising astrophysics to the status of a scientific discipline, in the context of the astronomical research of that time in Italy and abroad, especially in the USA. (shrink)