4. What is to be observed about _Succinum_ or Amber? whether it be an
Exsudation of the Sea? whether it be seen to float upon the surface of the
Sea? whether it be soft, when 'tis first cast on shore? At what season of
the year, and in what manner 'tis taken up, &c?
5. What is to be observ'd in the Digging of _Sal Gemmae_ in _Poland_? what
is the Depth of the Mines, stored with this Salt? what their distance from
the Sea, &c?
6. What truth there is in that Relation concerning Swallows being found in
Winter under waters congealed, and reviving, if they be fish'd and held to
the fire?
7. Whether there be in the _Bodnick Bay_ a Whirl-pool, as is related to be
in the Sea of _Norway_, which is commonly call'd the _Maal-stroom_? And
whether there be any Signs, that speak the communication of those Gulphs by
subterraneous passages; as the Jesuit _Kircher_ affirms in his _Mundus
Subterraneus_ T. 1. p. 146?