vE AND DLUUD IEMFEKATURES The experimental subjects were all normotensive males in the b state drawn from the ward population of the Neurological Institute.N of these patients had subjective,clinical or laboratory evidence of dis of the neuromuscular system of the upper extremities.Experiments v begun between 8:oo-9:oo A.M.and lasted four to six hours.The exp mental period covered May-August 1947.On entering the laboratory fi the wards,subjects stripped immediately and lay on an ordinary hosp Fig.t.Top.26-GAUGE STAINLESS STEEL NEEDLE used for introduction of Y-model therm couple.Needle contains steel wire coated with varnish and baked in place.Loop at end of wi receives lead wire of thermocouple which is knotted in place.This needle is shown in place the forearm in figure sa.Bottom. Brachial artery thermocouple,built in a 24-gauge hypoderm eedle with insulated junction in bevel of needle.Preliminary puncture of artery performed wit togauge needle with to cc.syringe attached;on appearance of arterial blood,syringe is di connected and the 24-gauge needle slipped into the ro-gauge needle,the two bevels lying flusl Between readings of arterial blood temperatures,the inner needle is routinely removed lon enough to show arterial spurting from the ro-gauge needle.No anesthesia used in punctures. bed with a small sheet draped over the hips and with two pillows under heac and shoulders.Air and wall temperatures in the laboratory were identical