incombustibleness

Fourthly, in its _incombustibleness_, in that it would not burn in the fire; nay, though I kept it a good while red-hot in the flame of a Lamp, made very _intense_ by the blast of a small Pipe, and a large Charcoal, yet it seem'd not at all to have diminish'd its extension; but only I found it to have chang'd its colour, and to appear of a more dark and duskie brown colour; nor could I perceive that those parts which seem'd to have been

Micrographia Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses with Observations and Inquiries Thereupon Robert Hooke 1669