6 COMPRESSED GASES-NAMELY, OXYGEN, NITROGEN, HYDROGEN, HELIUM, CARBON DIOXIDE, NITROUS OXIDE, AIR, COMBINATIONS OF OXYGEN AND CARBON DIOXIDE, ACETYLENE, CYCLOPROPANE, ETHYLENE, PROPANE, COMBINATIONS OF HYDROGEN WITH MIXTURES OF HYDROCARBONS PRODUCED BY DEEP CRACKING OF LIGHT PETROLEUM OILS, AND VARIOUS OTHER COMBINATIONS OF THE FOREGOING GASES