Bern, Burgerbibliothek, Cod. 402

blown upon

...to take [it]. At the same time, it does not have fire that remains, nor [is it affected] by outward breaths. For then the wick, being porous and dry, draws up the moisture, and the oil itself is what burns. But coal and wood cannot burn unless they are blown upon, because of their earthy and viscous nature. For the pores of all such things are dense, through which the pneuma opens and acts upon the fire. And as more and smaller separated [parts] fall upon it, it happens the more. For this reason, those who break up coals sometimes bring them together and blow upon them. For when they come together from small [pieces], the flame is created as if by a stream. And fire-sticks original: "πυρεῖα" — devices used to kindle fire by friction do the same thing through friction. And they take thin kindling for the woods and blow upon the coals. And the coal itself, when blown upon, is inflamed more and faster, just as in smithies. This, therefore, would not seem to be acting unreasonably with the pneuma. For fire itself is a certain nature of pneuma. Since the differences in combustible and flammable things are many, for this reason, their powers are different, and not every [thing] is able to do the other thing faster. For instance, coal provides light just as the flame does. But this [the coal] and the lamp are not the same. Nor would this one [the lamp] be burning and blazing in the same way. But the purer they are, the more they lack earthy or watery [elements], nor do they have within them that which obstructs the passage through which smoke and vapor original: "ἀναθυμίασις" — exhalation/fumes pass. For this reason, the flame of green [wood] appears redder than that of dry [wood], because it contains more of that [moisture]. Through which, being seen through, it takes on its color, just as the sun does when the air is thick. But the coal...
Why coals and woods are inflamed when blown upon.

the fire is a certain nature of pneuma

that the powers of combustible things differ.

Why the flame of green woods appears redder.