18. It was suggested to them, whether they did not wish to make any
use of their knowledges; for it is not enough to be delighted with
knowledges, because knowledges have respect to uses, and uses ought
to be their ends; that from knowledges alone no use results to
themselves, but to others with whom they are willing to share or
communicate them; and that it is not at all meet for a man who wants
to become wise to stand still in knowledges alone, inasmuch as
these are only instrumental causes, meant to be serviceable for the
investigation of matters which ought to belong to the life. But they
replied that they were delighted with knowledges, and that to them
knowledges were uses.

19. Some of them, also, wish to appear, not as men, like the spirits
of other earths, but as crystalline globes. Their wanting to appear
so, although they do not, arises from the circumstance that the
knowledges of immaterial things are in the other life represented by
crystals.

20. The spirits of Mercury differ entirely from those of our Earth,
for the spirits of our Earth concern themselves not so much about
[immaterial] things as about worldly, corporeal, and terrestrial
things, which are material. For this reason the spirits of Mercury
cannot be together with the spirits of our Earth, and therefore
wherever they meet them they flee away, for the spiritual spheres that
are exhaled from both are almost contrary. The spirits of Mercury have
a common saying, that they do not want to look at the sheath, but at
things stripped of their sheath, thus at interior things.

21. There appeared a flame of considerable brightness, which blazed
cheerfully, and this for about an hour. That flame signified the