Wiktionary
n. small fragments of iron, filed from a bar; used to visualize the presence of a magnetic field, and as a food additive
Wikipedia
Iron filings are very small pieces of iron that look like a light powder. They are very often used in science demonstrations to show the direction of a magnetic field. Since iron is a ferromagnetic material, a magnetic field induces each particle to become a tiny bar magnet. The south pole of each particle then attracts the north poles of its neighbors, and this process repeated over a wide area creates chains of filings parallel to the direction of the magnetic field. Iron Filings are used in many places including schools where they test the reaction of the filings to magnets!
Usage examples of "iron filings".
You will also see that random and staggered shelves it has inside, for better distribution of these iron filings.
The material components of this spell are a pinch of saltpeter, a pinch of iron filings, a piece of phosphorous, and a pinch of ashes.
I could smell the woody reek of oak galls brewed with iron filings.
Using an area-effect weapon like the iron filings could be as disruptive to his friends as to the enemy.
One experimenter removed all sand from a tank and substituted iron filings.
The shrimp with which he was experimenting innocently introduced iron filings into the statocyst.
This in turn went to a coherer, which was little more than a glass tube with iron filings in it.
If a signal was picked up, the iron filings slightly welded themselves together and the resistance through them went way down.
My hair lifted in uncombable clots of frizz, like iron filings stirred by a passing magnet.
Abu Hassan had once brought to the Xanga villages a trading product that had stupefied and delighted them: a magnet with a collection of iron filings.
Although they had gone over the plans for the attack countless times before, the maps drew them back, like iron filings to a magnet.
A foolish reason, yet those gates drew him as a lodestone drew iron filings.
Hooke had barricaded himself behind a miniature apothecary shop of bottles, purses, and flasks, and was mixing up his dinner: a compound of mercury, iron filings, flowers of sulfur, purgative waters from diverse springs, many of which were Lethal to Waterfowl.