NATURE OF THE ACTION CURRENT IN NITELLA : IV. PRODUCTION OF QUICK ACTION CURRENTS BY EXPOSURE TO NACl.

Treatment of Nitella with NaCl greatly reduces the time required for the action current and produces an action curve with one peak instead of the customary two. The time may be reduced to 0.6 second in place of the usual 15 to 30 seconds. This might be expected if the treatment increased the conductivity of the aqueous part of the protoplasm. The experiments favor this idea although they do not prove its correctness. This effect is prevented by calcium, possibly because calcium inhibits penetration of salts. That penetration is an important factor is indicated by the fact that salts which might be expected to penetrate rapidly have the most effect. Thus NaSCN is more effective than NaCl but Na(2)SO(4) has little or no effect. The action of NH(4)Cl and LiCl is similar to that of NaCl.