Some of them have explained this custom to me by stating that this evil spirit wants a light, and that when he gets it he will go away.

They however also take the precaution of moving their position and getting as far as they can into the group of natives who are sleeping round the fire.
If they are obliged to move away from the fire after dark, either to get water or for any other purpose, they carry a light with them and set fire to dry bushes as they go along.
VENERATION FOR CRYSTAL STONES.
The natives of South-western Australia likewise pay a respect, almost amounting to veneration, to shining stones or pieces of crystal, which they call Teyl.

None but their sorcerers or priests are allowed to touch these, and no bribe can induce an unqualified native to lay his hand on them.
The accordance of this word in sound and signification with the Baetyli mentioned in the following extract from Burder's Oriental Customs (volume 1 page 16) is remarkable: And Jacob rose up early in the morning, and took the stone that he had put for his pillow, and set it up for a pillar, and poured oil upon the top of it, and he called the name of that place Bethel.

Genesis 28:18.
From this conduct of Jacob and this Hebrew appellation, the learned Bochart, with great ingenuity and reason, insists that the name and veneration of the sacred stones called Baetyli, so celebrated in all Pagan antiquity, were derived.
These Baetyli were stones of a round form, they were supposed to be animated by means of magical incantations, with a portion of the Deity; they were consulted on occasions of great and pressing emergency as a kind of divine oracle, and were suspended either round the neck or some other part of the body.
...
That this veneration for certain pieces of quartz or crystal is common over a very great portion of the continent is evident from the following extracts from Threlkeld's Vocabulary, page 88: Mur-ra-mai: The name of a round ball, about the size of a cricket-ball, which the Aborigines carry in a small net suspended from their girdles of opossum yarn.

The women are not allowed to see the internal part of the ball; it is used as a talisman against sickness, and it is sent from tribe to tribe for hundreds of miles on the sea-coast, and in the interior; one is now here from Moreton Bay, the interior of which a black showed me privately in my study, betraying considerable anxiety lest any female should see its contents.
After unrolling many yards of woollen cord made from the fur of the opossum, the contents proved to be a quartz-like substance of the size of a pigeon's egg, he allowed me to break it and retain a part.