For this reason, in 1771 his father found himself forced to send to Leopold II, Holy Roman Emperor, Grand Duke of Tuscany, a letter in which he asked him to admit his son freely to the Collegio della Sapienza di Pisa (which later became today's Scuola Normale di Pisa):[2] «Royal Highness, Eusebio Valli, Florentine citizen, residing in Monterchi, servant and subject of H.R.H reverently exposes: how he wishes to apply himself to the studies of Philosophy and Medicine at the University of Pisa; but since his father does not have sufficient financial support to be able to keep him in that educational condition, he begs H.R.H to deign to confer him a place as a pupil at the Collego della Sapienza of that city...» «Altezza Reale, Eusebio Valli, cittadino fiorentino, dimorante in Monterchi, servo e suddito dell’A.V.R.

[6] Eusebio followed in the footsteps of great masters such as Luigi Galvani from whom he learned the art of physiology, of which the latter was the spokesperson, and Alessandro Volta, whose influence led Valli to study phenomena like “animal electricity” or “bioelectricity”.

After his death numerous streets and squares have been dedicated to the great Eusebio Valli in Tuscany and two large marble plaques commemorate him respectively in his birthplace in Casciana Alta and in his paternal house in Ponsacco.

His tomb, situated in the Cristóbal Colón Cemetery, bears the epigraph: “victima de su amor à la humanidad" ("a victim of his love for humanity").

[5] During his stays in the Middle East and Asia Minor, Valli worked out a theory according to which the etiopathogenetic development of the plague required the so-called “principle of affinity”, that is to say, a sort of predisposition to the disease.

Luigi Galvani, one of Eusebio's leading figures, published some applications of various metals to frogs and this prompted a large number of other Italian scientists to share and discuss these researches.

Valli became a respected exponent in this field throughout Europe; he gave public lectures on Galvani's experiments and published articles on this topic in various Italian and foreign cities, including Lausanne, Paris, London.

In 1793 he published a volume of 300 pages entitled Esperimenti sull'elettricità animale (Experiments on animal electricity), which at the time constituted one of the most organic analyses of all the problems of galvanism.