The Barddas of Iolo Morganwg, Vol. I., ed. by J. Williams Ab Ithel, , at sacred-texts.com
There are five elements, and from them, and their conjunction, are all things, living and dead, that is to say: calas; fluidity; breath; uvel; and nwyvre. From calas is every corporeity, namely, the earth, and every thing hard; from fluidity are moisture and flux; from breath are every wind, breeze, respiration, and air; from uvel are all heat, fire, and light; and from nwyvre every life and motion, every spirit, every soul of man, and, from its union with the other elements, other living beings. From nwyvre, in its simplicity, apart from every thing else, is God, for God is nwyvre, and is incapable of variety, or change, or death, or corruption, or diminution, for there can be no place where He is not, or time in which He does not exist.
Different names are given to the elements in other Books, that is, earth, water, air, fire, and nyv; and in other Books, thus, namely, &c. From the union of calas with water is a body; from the union of water with firmament, 1 darkness; from the union of firmament, or air, with fire, heat; from the union of fire with nyv, moving energy, and every motion from place to place; and from nyv are all life and its characteristics, namely, understanding, memory, awen, affection, hatred, sorrow, joy, &c.
383:1 p. 382 Al. "air."