From the Anesthesiology Department of the Hospital for the Women of Maryland, Baltimore, Md.

Xylocaine is the registered trade mark for lidocaine, manufactured by Astra Pharmaceutical Products, Inc., Worcester, Mass. The material used in this study was Xylocaine Hydrochloride 5% with glucose 7.5%, specific gravity 1.03, and was supplied by the Astra Pharmaceutical Products, Inc. Nupercaine is the registered trade mark for dibucaine, manufactured by the Ciba Pharmaceutical Products, Inc., Summit, N. J. The material used in this study was Nupercaine Hydrochloride, issued in 2-cc. ampules, each ampule containing Nupercaine Hydrochloride 5 mg. and glucose 100 mg.

^*Director, Bureau of Biostatistics, Baltimore City Health Department.

The authors wish to express their appreciation to the obstetric resident staff and to the nursing staff for their willing and necessary help in carrying out this study. They are also grateful to the members of the obstetric visiting staff for their interest and cooperation.