Abstract
Using the Byreck method, both the height reached by the water (h) in the dishcloth above the water level in the reservoir and the mass increase (w) were simultaneously measured, and the results were as follows. The relationship between h and the given time (t) could not be explained by the Washburn-equation in the experiment time range. However, it could be expressed by the following equation proposed by Gillespie in consideration of the distribution of the water : dh/dt=A/h+B, where A and B were the constant. Also, the maximum height of rise could be predicted by this equation. The quotient (w/h) increased rapidly in the early stages of water uptake, and it almost reached an equilibrium value after several minutes. Because the value varied according to the sample, the evaluation of water absorbency only by the height of rise (Byreck method) is doubtful.
