elementals and fuels

Thanks to MarkH for this lovely find.

For example, in energy production, solid fuels, some renewable, some not, are extracted from the earth and made to produce energy in a variety of forms. Principally coal, but also wood, peat and dung are burned, and uranium is reacted, to produce heat. This ‘fire’ energy is then usually transformed to mechanical, then to electrical energy. The other two of the four elements are usually called in to assist in this double transformation: water and vapor in the steam turbine. Actually, in most modern steam turbines ‘super-critical’ pressures and temperatures are used, under the influence of which the distinction between liquid and vapor disappears and these two elemental states of matter are reduced to a kind of intermediate mush. Under these conditions, one might ask oneself (if not the students): What is happening to those other elementals, the sylphs and undines, when their physical sheaths are subjected to this kind of treatment? (Masters, Brien: Science in Education, p 236.)

Waldorf education science education. Yes, what is happening to these elementals?