THE Anaesthetics Committee, jointly appointed by the Medical Research Council and the Royal Society of Medicinp; is considering the standardization of curare, Inhere are on the market at present two preparations for use in anaesthesia, one amorphous and crystalline, but both depend for their activity on-tubocurarine chloride; the co-existence of reparations of different potency is a source of danger und may result in serious accidents. The amorphous preparation, Intocostrin, has, in fact, about one-quarter the activity of the pure crystalline material. There is also some evidence of wide differences in the reactions of the patient, depending to some extent on the state of health of the individual at the time. The Committee, therefore, considers it advisable, in the present state of knowledge, to base the dose on the individual reaction to an initial small injection rather than on any dose weight ratio. In the average healthy adult this initial dose could be 10–15 mgm. of crystalline d-tubocurarine chloride or 40–60 mgm. of “Intocostrin”. In one otherwise healthy man with a recent perforated gastric ulcer, so little as 5 mgm. of the crystalline material produced adequate muscular relaxation, and 15 mgm. would probably have been a considerable overdose.