An improved osmotic balance

The construction and operation of the osmotic balance has been described. Because of the damping effect of the cell immersed in the solvent the sensitivity of the balance is diminished. This can be avoided if a suitable weight is placed above the central knife‐edge of the beam of the balance. A way to calculate the dimensions of a cell which gives the lowest possible temperature sensibility has been discussed. The disadvantage of a thick cell wall with respect to reference point adjustments has been pointed out. The measurements made with the balance have shown that osmotic pressures of the magnitude 0.011 ± 0.001 g./cm.2 can be measured. An example of the use of the balance has been given for three samples of nitrocellulose.