The correspondence of the commander of the camp with the pharmaceutical firm Bayer concerning the sale of 150 prisoners for experimental purposes has been preserved. After an agreement on the price of 170 marks per person (the camp required 200 marks) the deal was concluded. This is evidenced by a letter from Bayer to the commander of the Auschwitz concentration camp, in which it is stated: “We have received 150 prisoners sent by you. Despite the exhaustion, we consider them suitable. We will keep you regularly informed about the progress of the experiments.” In the following letter he reports: “Experiments have been made. There is no one left alive. I will contact you soon about new deliveries.”