Plutarch on Alexander's Bath and on Medea
A note to Pseudodoxia Epidemica, Book III, chapter 21

Then Alexander marching with his Army into the Countrey of Babylon, they all yielded straight unto him. When he came into the Countrey of the Ecbatanians, he marvelled when he saw an opening of the Earth, out of the which there came continual sparks of fire as out of a Well: and that hard by also the Earth spued out continually a kind of Maund or Chalky Clay somewhat liquid, of such abundance, as it seemed like a Lake. This Maund or Chalk is like unto a kind of Lime or Clay, but it is so easie to be set a fire, that not touching it with any flame, by the brightness onely of the light that cometh out of the fire, it is set a fire, and doth also set the Air a fire which is between both. The barbarous People of that Countrey, being desirous to shew Alexander the nature of that Naptha, scattered the Street that led to his lodging, with some of it. Then the day being shut in, they fired it at one of the ends, and the first drops taking fire, in the twinckling of an eye, all the rest from one end of the Street to the other was of a flame, and though it was dark and within night, lightened all the place thereabout. Alexander being in Bath at that time, and waited upon by a Page called Steven: (a hard favoured Boy, but yet that had an excellent sweet Voice to Sing) one Athenophanes, an Athenian, that alwaies nointed and bathed the King, and much delighted him with his pleasant conceits, asked him if he would see the trial of this Naptha upon Steven: for if the fire took and went not out, then he would say it had a wonderfull force, and was unquenchable. The Page was contented to have it proved upon him. But soon as they had laid it on him, and did but touch it onely, it took straight of such a flame, and so fired his body, that Alexander himself was in a marvellous perplexity withall. And sure had it not been by good hap, that there were many by, ready with Vessels full of Water to put into the Bath, it had been unpossible to have saved the boy from being burnt to nothing: and yet so he scaped narrowly, and besides was sick long after. Now some apply this Naptha unto the fable of Medea, saying, that therewith she rubbed the Crown and Lawn she gave unto the Daughter of Creon at her marriage, so much spoken of in the Tragedies. For neither the Crown nor the Lawn could catch fire of themselves, neither did the fire light by chance. But by oyling them with this Naphtha she wrought a certain aptness to receive more forcibly the Operation of the fire, which was in place where the Bride sate. for the beams which the first casteth out, have over some bodies no other force, but to heat and lighten them. But such as have an oily dry humour, and thereby a simpathy and proportionable conformity with the nature of fire: it easily enflameth and setteth a fire, by the forcible impression of his beams.