The Six million jew BullShit holohoax from the year 1900 and onward.
The history of large gas chambers (more than 200 cubic meters in volume) goes back to at least the early 1920′s when tunnels were used by the British to fumigate railroad trains in Russia and Poland when the British had a military presence there during the chaotic post World War I period.
The standard procedure then was to fumigate an entire railroad train at one time within a sealed tunnel with hydrocyanic acid (also referred to simply as cyanide or cyanide gas). Zyklon-B had not yet been invented and so the cyanide had to be introduced into the tunnels either from gas-filled tanks or else generated within the tunnels by the dropping of cyanide salt into barrels filled with sulfuric acid (the so-called “barrel method”).
The British experience with typhus in Poland and Russia during that period was described many years later in the Proceedings of the Royal Society of Medicine as follows:1