Besides "
Montepellusanus", during the thirteenth century (and beyond) the only supply of
saltpeter across Christian Europe (according to "De Alchimia" in 3 manuscripts of Michael Scot, 1180–1236) was "found in Spain in Aragonia in a certain mountain near the sea", (which can only be Catalonia):
saraceni apellant ipsum borax et credunt quod sit alumen. Et in Hispania invenitur versus Argoniam in quodam monte juxta mare. et apellant ipsum hispani alumen acetum activum. In fact in 1561,
Elizabeth I of England at war with
Philip II of Spain, became unable to import the saltpeter (of which the
Kingdom of England had no home production), and had to pay "300 pounds gold" to the German captain Gerrard Honrik for the manual "Instructions for making salpeter to growe" (the secret of the "Feuerwerkbuch" -the nitraries-). In 1783,
Giuseppe Maria Giovene and
Alberto Fortis together discovered a "natural nitrary" in a doline close to
Molfetta, Italy, whose name is
Pulo di Molfetta. The two scientists discovered that saltpeter formed inside the walls of the caves of the doline, under certain conditions of humidity and temperature. Prior to the discovery, nitraries were widespread all over the
Kingdom of Naples. Manure was collected by the government and used to make
saltpeter, which was a key ingredient for gunpowder. After the discovery, it was suggested that manure could be used for agriculture, in order to increase the production, rather than to make gunpowder. The discovery also generated issues; in particular, it was initially challenged by some scholars. Subsequently, chemist
Giuseppe Vairo and his pupil
Antonio Pitaro confirmed the discovery. This undoubtedly damaged producers of artificial saltpetre, and some scholars, most likely supported by the producers, tried to dismiss the discovery. Following the above discovery, naturalists sent by academies from all Europe came in large number to visit
Pulo di Molfetta, since the saltpeter was a fundamental ingredient in the production of
gunpowder and these deposits were of considerable strategic interest. Soon, the government started to extract saltpetre from
Pulo di Molfetta and today the
doline still contains the remains of the ancient plant used to extract saltpetre, making it a site of
industrial archaeology.
Pulo di Molfetta is currently not open to tourists. Shortly thereafter,
Giuseppe Maria Giovene discovered that saltpetre also formed in other caves of
Apulia. == See also ==