When we were very young, a standard method of poisoning a witch grandmother was to feed her ground glass. Scepticism followed years of fruitless exploration of news and medical reports for examples of deaths from this cause. Two pertinent items of recent research bring the problem back.
A year ago Reimann et al1 reported an unusual case in which finely powdered tricalcium phosphate had been inhaled and ingested inadvertently for three years. The quantity of this compound (a common ingredient of dentifrices) which had been absorbed was large. Crystals were identified in the intestinal mucosa, but it was not certain whether they were absorbed through the intestinal epithelium or transported from the lungs. To find out, the authors experimented with rats, feeding them large amounts of this substance, powdered sand, and a barium sulfate preparation used for radiography.
Microscopic particles of all three substances were present six to eight
GROUND GLASS FOR GRANDMOTHERS. JAMA. 1965;194(12):1318-1319. doi:10.1001/jama.1965.03090250052020