I have come across references to a mysterious figure named Bern(h)ard de Callen, a "baron from Austria." Presumably, he would be more commonly known as "von Callen or von Kallen"
According to an anonymous letter written from Paris to Samuel Hartlib in 1643, de Callen had apparently already spent more than 20,000 Reichthalers in his alchemical pursuits. He appears to have travelled regularly, for he was present in France and also the Netherlands in this same year.
I have been able to find a couple of other manuscript references concerning him (Hartlib had some choice words concerning this gentlemen in his Ephemerides, for example), but I have not been able to find any mention of him in contemporary printed literature, with the exception of a short alchemical tract that was printed under his name in 1653 and again in 1656. See http://www.gbv.de/du/services/gLink/vd17/14:697032Q_001,800,600
I am looking for any further information concerning this gentleman, biographical or otherwise. Can anyone help? Does his name ring any bells for anyone out there?
At risk of leading you off on a wild goose (or rather wild raven) chase, can I draw your attention to the phrase 'Corvus Deplumatus', 'The Plucked Raven', which appears in the title of his second tract?
I do know that this was the title of a Jesuit religious drama and I think there is also a musical setting of it (there's probably something about it in Grove).
It seems rather a strange term, especially in a Jesuit context - can Adam shed any light?