---

• n  a colorless flammable gas sometimes used as an inhalation anesthetic

• Their device: a plastic space-chief helmet with a tube to admit oxygen and cyclopropane gas.
• Explosions of anesthetic gases (in this case, a mixture of nitrous oxide, ether and cyclopropane) happen about once in 75,000 operations, and are almost certain to cause serious .
• Anesthesia has progressed from chloroform to cyclopropane and local and spinal anesthesia.