Procaine hydrochloride is reputed to be a convulsant drug. It is here shown that the drug has a marked anti-convulsive effect (in addition to its antispastic and muscle relaxing actions). This paradox is easily explicable. Dependent on dosage, dilution and rate of administration, exactly opposite effects can be produced in one and the same case. Experience and full conversance with all the possible effects of the drug enable it to be administered for a specific effect . The dose administered in this case is the largest recorded in the time of infusion (4ï¿½5 gm. in 18 minutes and 54.5 gm. in 3.5 days). In addition to relieving practically all forms and severities of pain, intravenous procaine, on account of the diversity of its effects, is a valuable therapeutic agent for a diversity of conditions.