CONTRIBUTION TO THE MEASUREMENT OF COLLODID-OSMOTIC PRESSURE BY KROGH AND NAKAZAWA'S METHOD

抄録

1. The colloid-osmotic pressure of horse blood serum was measured by Krogh and Nakazawa's method, using a collodion membrane with a standard membrane potential of 2-5 millivolts. The colloid-osmotic equilibrium between the inner and outer liquids of the osmometer is practically attained after 24 hours.
2. In order to compare the relative colloid-osmotic pressures of several solutions, one is able to compare with fair accuracy the pressures measured at any time after between 3 and 24 hours.
3. The fact that the colloid-osmotic pressure is proportional to the absolute temperature, which was reported by Imai of Pro-fessor Katsu's laboratory, is confirmed.
4. The colloid-osmotic pressure decreases more rapidly than is proportional to the ocncentration. The relationship between the colloid-concentration and the osmotic pressure of colloidal solu-tions is expressed by the general formula
P=aTG/1-lC'
where P is the colloid-osmotic pressure, C the colloid-concentra-tion, T the absolute temperature, and a constant. b is the value which may be considered to be practically a constant, though theoretically it is variable with the change in the non-solvent space of the solution. This general formula includes the equations hitherto put forward by Ostwald, Haller, and Verney. The applicabitity of equation wqs verified by experiments.