[[The death of fire is birth for air, and the death of air is birth for water.]] (Kahn 41, cp. DK, S 76).
“Fire lives the death of earth and air lives the death of fire; water lives the death of air, earth that of water.” (R 76a)
One of the primordial realities of life is that one thing passes into another. Fire epitomizes this, as it burns trees and shrubs to the ground, turning them to some smoke and ashes (air and earth). But it too eventually runs out of energy. The thin air becomes thick with smoke until it dissipates. Then of course, the humid heavy but invisible air, containing the vapors of water, rises upward invisibly to form storm clouds, which can water down upon the earth.
The first version of the fragment, used by Kahn and Sweet, is traced through Plutarch, who is thought to be a reliable source. The second, traditionally more common rendition, comes from Maximus of Tyre. There is a considerable difference between the two. The first mentions only three elements. The second lists four. As we have seen, for example in Fragment 38, Heraclitus in places only mentions three elements (omitting air). There has thus been some discussion about whether he acknowledges air as an element. If these sources are to be trusted, then Heraclitus does view air as an element. It is listed in both of these texts. (See Kahn, pp. 153ff. for a discussion of the legitimacy of the attributions.)
The oppositions of death and life play out at the elemental level as the death and birth of one element from another — in order fire, air, water (in version one) or fire, earth, air, water (in version two).
We see a dialectical interplay of concepts. But we don’t get the typical ordering of oppositions we might expect if we were just speaking of conceptual juxtapositions: fire<->water: earth<->air, which work more like black<->white or up<->down. Here, in the second rendering in particular, we see an ordering that makes sense based on some empirical observations. Fire lives from consuming earth (trees, bushes, and whatever else). When fire is extinguished we are left with air. Air, transmitting evaporation into clouds, may be seen to give us rain clouds and water. Not mentioned here are the lightening storms of which Heraclitus speaks in Fragment 38, in which, of course, fire also rains down from the sky, which for its part can again consume the earth.