Argon: Air Led over Calcium Carbide and Calcium Chloride at 800 °C (Fischer and Ringe, Thorpe 1912)

Air is nearly 1 % argon. Red-hot calcium carbide with a little calcium chloride swallows both the oxygen and the nitrogen; argon, which combines with nothing, passes straight through. Result: about 11 litres of argon from 7 kg of carbide in two days. It still holds traces of neon, krypton and xenon (0.25 %, mostly neon). Source: Thorpe, Dictionary of Applied Chemistry vol. 1 (1912), p. 291, after Fischer and Ringe (Ber. 41, 2017). Not given: the vessel, the air volume, and how the water and carbon dioxide are taken out. Picture drawn by Youblob.