An interim report written at the request of the Med. Res. Council. Topics discussed: Physical properties and uses of CCl2: CHCl; Animal experiments; Previous work in human anesthesia; Present investigation[long dash]Trials in 127 cases. Major operations lasting from 7 min. to 3 hrs. 10 min. were performed with this anesthetic; Methods and cost of administration; Stages and signs of anesthesia; Effects on respiratory and cardiovascular systems; Effects on sugar metabolism and blood urea; After-effects. CCl2:CHCl resembles chloroform but is less potent and less toxic. Present knowledge is insufficient to recommend its general use but the drug deserves more thorough investigation. 17 references.