Paul G. Ellis (Letters, 17 March) wrongly surmises that I do not know the difference between slaked lime and quicklime. The statement that supplies to the Lódz ghetto administration by Alfred Toepfer's company included the substance used, among other things, to cover cadavers derives from the Toepfer Foundation's own website and from the 2000 official history. Toepfer's entire trading with the SS war criminals who ran the Lódz ghetto was inherently sinister since the ghetto was a significant part of the Nazi policy of Vernichtung durch Arbeit (death through work).
Michael Pinto-Duschinsky, Oxford