nebelkappen

Der Jung Misner, a minnesinger, seems to be the earliest written witness to this word (Vil manig laster dat ich sihe/in miner nebelkappen “many wretches that I see/in my ‘mist-cape’ ”) to be found in the Codex Manesse 339 verso from Zürich, and dated to the early 1300s.    

  

And in the Heldenbuch we read, Von den gezwergen:

“Zû dem erstenließ er die zwerglin werden vmb des willen, das das lant vnd gebürge gar wiest vnd vngebawen was, vnd vil gutes von silber vnd gold edel gestein vnd berlin in den bergen was. Darumb machte got die gezwerg gar listig vnd wyse das sie übel vnd gût gar wol erkanten vnd warzü alle ding gût waren Sie wisten auch warczü die gestein gut waren. Etliche steyn die gebent grosse sterck.  Etlich machtent die vnsichtber die sie bey in trügent. Das hieß eyn nebelkap.”

Illustrations of Northern Antiquities (1814) On the Teutonic Romances H.W. Weber :

“First, he produced the dwarfs, because the mountains lay waste and useless, and valuable stores of silver and gold, with gems and pearls, were concealed in them.  Therefore God made the dwarfs right wise and crafty, that they could distinguish good and bad, and to what use all things should be applied.  They knew the use of gems - that some of them gave strength to the wearer, others made him invisible, which were called fog-caps."

What it is, in a nutshell can best be seen from Johannes Aventinus (1477-1534) who somewhere has:

 

 “ist noch ein sprichwort bei den Kriechen von diesem fingerl (ring des Gyges) wie bei uns von den nebelcappen.”

 “It is still a byword with the Greeks of this ring (ring of Gyges) as with us of the nebelcappen.”