"A German Jewish scientist, his invention with his brother-in-law Carl Bosch of the Haber-Bosch process, to make ammonia fertiliser, enriched the whole world. Estimates of the number of people who are alive today on account of his invention are in the hundreds of millions, and even in the billions. What a great benevolence to mankind, you might say, what a saviour of lives! But the same man was also responsible for the invention of chemical warfare. He not only invented chlorine gas but perso...