In the anonymous eighteenth-century baedeker, which used to be sold at the entrance to Palazzo Sansevero, are briefly set out the procedures Raimondo di Sangro used to obtain silk and wax from some vegetable species. The Prince showed these strange materials to travellers on the Grand Tour curious to observe the results of his experiments.
The wax, made “without the natural aid of bees”, was obtained “from various common herbs and flowers”, which were boiled in water duly prepared with “a number of salts”. From this process resulted “a kind of oil, which, when collected and boiled again, takes on the consistency of pure wax”. This wax, white in colour, could be worked exactly like bee’s wax.
In 1752, di Sangro made a discovery which could have been – as Giangiuseppe Origlia commented in 1754 – of “great utility […] for society”. He managed to thread the so-called “vegetable silk”, produced into a few woolly purses from a plant called “Apocynum”. Because of the “extreme shortness” of the filaments of this plant, no-one before him had managed to obtain material. They were of such perfection as to “rival those made with common silk”. Using plant silk, the Prince produced also sheets of “paper like that from China”.