THE introduction of the osmotic and electrolytic dissociation theories of solutions initiated, as is well known, a new era in the development of chemistry, and the new direction which was there-by given to the interpretation of chemical processes taking place in aqueous solution soon made itself powerfully felt also in the various branches of biological science and in the study of colloids. The influence of different salts on colloidal matter and on the living cells of plants and animals became the subject of extensive and intensive investigation, and it was found that many of the observed phenomena could best be interpreted as due to the specific action of ions.
Hydrogen Ions: their Determination and Importance in Pure and Industrial Chemistry.
By Dr. Hubert T. S. Britton. (Monographs on Applied Chemistry, Vol. 3.) Pp. xiv + 515. (London: Chapman and Hall, Ltd., 1929.) 25s. net.