The values of the skin impedance decreased strongly immediately after bathing and then increased and reached the maximum values about one-two hours after bathing at Tamagawa Hot-Spring.
If the bathing was continued daily during about 2 weeks, the values of the skin impedance before bathing and one-two hours after bathing both decreased gradually day by day.
In the case of fresh water bathing, the values of the skin impedance decreased remarkably immediately after bathing in the same way as bathing at Tamagawa Hot-Spring and then increased quickly and reached the maximum 30 minutes or one hour after bathing.
If the bathing was continued daily during about 2 weeks, the values of the skin impedance before bathing decreased only slightly, but the values of the skin impedance later than 30 minutes-one hour after bathing showed a stronger increase over the values before bathing. In case of continuous bathing in a simple Hot-Spring, the values of the skin impedance before bathing showed no change every day, but the value later than one-two hours after bathing showed only a slight increase i. e. lower than the values before bathing.
From these findings it is surmised that the decrease of the skin impedance immediately after bathing at Tamagawa Hot-Spring is caused by sweat excretion, and the decrease of that before and one-two hours after bathing, if bathing is continued daily at the same spring, is due to the cell infiltration at cutis and- corium and to the protoplasm activation of living body caused by stimulation of the denaturalized tissue substances produced by bathing dermatitis.
The increasing values of the skin impedance 30 minutes-one hour after bathing in spite of almost no change before bathing every day in case of the continuous bathing method of fresh water is considered to be due to the contraction of capillary blood vessels or phenomenon of feeling chilly after a bath. The slight increase of the values of the skin impedance after 30 minutes-one hour after bathing in case of using the continuous bathing method of simple hot spring may be caused by continuance of dilatation of capillary blood vessels.
The values of the skin impedance through contacting the electrode at skin surface was increased by injection of adrenalin and atropine, and decreased by injection of pilocarpine and ergotamine, but the values of the skin impedance through the mucous membrane of eyes i. e. through the electrode which was inserted into the physiological NaCl solution filled in the under water glasses contacted to both eyes showed almost no change owing to injection of all above mentioned drugs.
From these findings it is considered that the skin impedance consists in the skin surface, and the decrease of its values is related to incline of the parasympatic nerve function and to the sympatic nerve function.
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