Cyclopropane, also known as trimethylene, was first synthesized by August Von Freund in 1882 in Austria. It was later introduced as a surgical anesthetic in the early 1930s. A colorless gas that induces anesthesia rather quickly, cyclopropane is often recycled and recirculated through the patient during an operation due to its high cost. Cyclopropane is no longer a heavily used anesthetic.