RESUMEN
The effect of the granules composed of Natril siccatus and herbal extracts in hydrotherapy was studied by recording skin surface temperature, deep body temperature from the intact skin, pletysmography, impedance pletysmography, blood pressure and subjective evaluation. These were measured before taking the testee into the Hubbart tank containing 0.0085% of herb granules at 40°C for 10 minutes, soon after taking a bath and at proper period until 2 hours.<br>The control study was done in simple water-bath in the same method. 30 testee were used for the test.<br>Results were as follows:<br>1. Skin surface temperature of H. G. group showed significant higher at the distal area of the extremities compaired with the control group.<br>2. Deep body temperature of H. G. group showed significant higher at right heel (10mm depth from the skin), palm (5mm) and calf (30mm) against the control.<br>3. The wave height of pletysmography of the index and the first toe of H. G. group was higher than the control at 100 minutes later.<br>4. IPG of H. G. group showed significant difference in upper and lower extremities against the control.<br>5. The change of the blood pressure showed no difference between two groups.<br>6. The subjective evaluation was scored and the t-test showed significant difference against the control, especially the difference was the most marked in utility feeling, and the effect of keeping warmth was in significant difference.<br>We may conclude that the H. G. in hydrotherapy has a sweet smell, make fell at home, keep warmth and play a role to promote blood circulation.