You will have very large quantities of clothes to disinfect, ten or twenty times as much as the "Textiles Collection," which is only being carried out in order to camouflage the origin of the Jewish, Polish, Czech, and other items of clothing. Your second job is to convert the gas- chambers, which have up to now been operated with exhaust gases from an old Diesel engine, to a more poisonous and quicker means, cyanide. But the Führer and Himmler, who were here on August 15, that is, the day before yesterday, gave orders that I am to accompany all persons who visit the installations.

To Kurt Gerstein, 17 August 1942. Quoted in "Genocide, Critical Issues of the Holocaust" - Page 455 - by Alex Grobman, Daniel Landes, Sybil Milton - History - 1983.