air spirits

Brett Zimmerman on spirit beings in Melville’s Mardi (1849):

Taji believes, then, that the cosmos is a vast hierarchy of both physical existents and metaphysical essences (referred to in the book as “shades,” “spirits,” “seraphs,” “angels,” and “archangels”). …The vision Babbalanja reports, in chapter 188, is very much like the otherworldly imaginings of Taji: 

'These,' breathed my guide, ‘are spirits in their essences; sad, even in undevelopment.  With these, all space is peopled;—all the air is vital with intelligence, which seeks embodiment.’

Herman Melville: Stargazer pp40-41

UPDATE:  More of the same, in Pierre (1852):

Ah, thou rash boy! are there no couriers in the air to warn thee away from these emperilings, and point thee to those Cretan labyrinths, to which thy life's cord is leading thee? Where now are the high beneficences? Whither fled the sweet angels that are alledged guardians to man?

From Scenes Beyond the Western Border:

 Ah!  it was enough to freeze into palpable shape the ministering spirits of the air.
(September 1851)

The air, methinks, is fanned by seraphic spirits on their winged errands of Peace!
(January 1852)

 C.—Then, every senti[m]ent of my soul has ears, in which air spirits supernaturally whisper distracting, sonorous thoughts:— in darkness, with long unrest, it verges madness...
(March 1853)

A gentle air rustles the grass or leaves; the running waters too, give music: and then, they seem the voices of gentle spirits, which may in this hour of calm and loveliness awake to Eden memories.  (August 1853)