1. Based on a lecture delivered to the Physical Society of Sheffield, on October 28, 1924.
2. Works, vol. 1, p. 410. Brit. Ass. Rep., 1881.
3. Dupre's well-known equation. Equation 3 has been obtained by Edser, and a similar equation is obtainable from Laplace's theory, considering the attractions between particles of liquid and solid, and liquid and liquid.
4. Phil. Mag. 46, p. 244 (1923).
5. Phys. Review, 13, p. 273 (1921).