Its effects and even its mechanism were quite discernible to the naked eye, as the cure progressed, as when the crisis reached its highest intensity, patients floated to the top of the water in their bath, so much had the internal heat rarefied the air and the liquid in their bodies; but if they remained too long in the water, 'three, four or even six hours per day', then relaxation followed, water progressively impregnated the membranes and fibres, the body grew heavier and naturally sank down to the bottom of the water.