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All normal compounds of beryllium which are soluble in water are strongly acid in reaction to litmus, dissolve notable quantities of their own hydroxide which increases in amount with the concentration of the solution, set free carbon dioxide from carbonates and attack certain metals. In short, they act in many respects like the acids themselves would act from which they are derived. In spite of these facts they show less hydrolysis, and consequent smaller concentration of hydrogen ions, at least in the case of the chloride, nitrate and sulphate, (iveys, 1899; 10 and Brunner, 1900; 1) when treated by the well-known method of sugar inversion, than the corresponding salts of iron and aluminum. By the same method of determination, the hydrogen ions are thrown back into the undissociated condition when but a small fraction of the beryllium hydroxide has been dissolved which the normal salt is capable of holding in solution, (Parsons, 1904; 10). The reasons for these phenomena are not at present understood. The sulphate has been recently studied with a view to a solution of this problem, (1907; 10) and it has been shown that the addition of beryllium hydroxide to a solution of the sulphate, raises the freezing point and diminishes the conductivity; that no beryllium enters into the formation of a complex anion and that while the hydroxide can be partially removed by dialysis if dialyzed into pure water, there is little evidence of a colloid being present. It has been suggested that we may have here a new instance of solution, wherein the solid, when once dissolved, acts as a true solvent for its own oxide or hydroxide, and there are some analogies which point strongly to this view, (1907; n).