perhaps through a connection "Saltpeter".
Well, i didn't give myself much hope when i started looking for this - but it is amazing what one can find with a bit of Googling.
So proposal for a new connectionSaltpeterHumberstone and Lara Saltpeter worksChilehaus.
Built for Henry Brarens Sloman (1848-1931). He made his fortune in Chile in Saltpeter mining. On returning to Hamburg he commissioned the "Chilehaus" naming it after the source of his wealthMammoth Cave
. "Saltpetre deposits were discovered on the cave walls and this valuable nitrate was removed and sent to be processed in gunpowder factories between 1809 and 1819." (AB eval)
The following could be included - but the "Saltpeter" is of course synthetic - albeit for the same purpose as the "real thing"! The AB does however comment in its Comparative analysis "Santa Laura Saltpeter Works, Chile (2005, (ii), (iii) & (iv)) is similar in responding to the world-wide demand for fertilizer but not in terms of the combination of hydroelectricity and electro-chemical processes."
So the connection with "real" salpeter could be that it was built to replace it with a synthetic product?Rjukan/Notodden
"Rjukan was formerly a significant industrial centre in Telemark, and the town was established between 1905 and 1916, when Norsk Hydro started saltpetre (fertilizer) production there. Rjukan was chosen because Rjukanfossen, a 104-metre waterfall, provided easy means of generating large quantities of electricity" (wiki)