The interests of the Prince of Sansevero also extended to medical science. In the underground workshops of his palace, he developed a number of medicines which worked various cures, which seemed veritable “miracles” to all and sundry. Of his ability to “bring to new life those on the point of death, which vulgarly is called resurrecting the deceased”, we find a description in the Lettera Apologetica.

In 1747 he saved Luigi Sanseverino, Prince of Bisignano, from a death which seemed inevitable “to the most skilled Professors”. “The Author began the disparate and difficult work making use of his secret arts, and in the course of a few weeks not only beat and tamed the ferocity of the illness, but returned him to perfect health, even freeing him from some discomfort, which had troubled him in the past”. The same “portentious event” occurred again around three years later in the person of Filippo Garlini, resident in Rome, whose treatment the Prince supervised by letter. “The most renowned Professors of the medical art” gave “shining testimony” to this remarkable recovery.

As in the case of many other inventions of di Sangro’s, the fomulae for the medical remedies he devised are unknown. The cures gave him his “remarkable fame” as a miracle-worker, so much so that even Minister Bernardo Tanucci – despite not having a good opinion of the Prince – had to affirm in a letter of 1752 that the Duke of Miranda, afflicted by a “malign fever” and “furious with the doctors” who were unable to cure him, called in Raimondo di Sangro, “famous for [having] resurrected Bisignano”.