Hold vapor

Hold vapor was an abjuration spell that allowed the caster to surround and capture any vapor or cloud that was visible and within the range and capacity of the spell.

Effects
This spell created a spherical barrier with a radius of 20 ft (6.1 m) plus an additional 10 ft (3 m) for each experience level the caster had attained, at a range of up to 10 yd (9.1 m) per level of the caster. Hold vapor could contain breath weapons, cloudkill, fog cloud, incendiary cloud, the choking smoke from pyrotechnics, and similar gaseous hazards. Creatures in gaseous form (e.g., air elementals, djinns, or vampires) could also be captured, held, and prevented from transforming out of their vaporous state, but they had repeated opportunities to break out.

The caster had to maintain a steady chant to keep the barrier from fading away. Silence, interruption for more than one minute, or moving outside the range of the spell would cause the barrier to dissipate. The spell lasted for one hour or until the caster stopped chanting, whichever occurred first. The containment sphere was stationary and could not be moved even by natural and magical winds. Creatures and objects passed through the barrier as if it were not there. Once the barrier dropped, the contained vapors settled according to its nature and the prevailing conditions.

Origins
Hold vapor originated from the spellbook known as the Book of Bats, a tome of mysterious origin.

Components
This spell required the caster to chant the verbal component to maintain the barrier. A somatic component was also required, and the material component was a small balloon or bladder.