Note 19 — Chapter XVII · BORON, ALUMINIUM, AND THE ANALOGOUS METALS OF THE THIRD GROUP
George Kamensky translation
The effects of purely mechanical subdivision on the solubility of alumina are evident from the fact that native anhydrous alumina, when converted into an exceedingly fine powder by means of levigation, dissolves in a mixture of strong sulphuric acid and a small quantity of water, especially when heated in a closed tube at 200°, or when fused with acid sulphate of potassium (see Chapter XIII., Note 9).