Final answer:
In 1922, arsenic, mercury, and mustard gas were three materials that caused deaths due to poisoning, through contaminated water, industrial exposure, and chemical warfare respectively.
Step-by-step explanation:
Three materials discussed in the The Poisoner's Handbook that caused death by poisoning in 1922 are arsenic, mercury, and mustard gas. Arsenic poisoning could occur through contaminated drinking water and was notorious for causing death over centuries. Mercury, with its detrimental effects on the central nervous system, could cause death through exposure from industrial processes or contaminated water. Mustard gas, used as a chemical weapon during World War I, resulted in numerous fatalities from its delayed but severe blistering effects on the lungs and skin.