It will not be possible to review in detail the lines of work sketched above. An outline of the synthetic work on systems of the mineral oxides and a paragraph on the volcano researches will perhaps suffice to indicate the general plan and purpose of the laboratory’s work. It should be added that the results of many of the researches of the laboratory, detailed below, have been published in the pages of the Journal (see =21=, 89, 1906, and later volumes). _Mineral Researches._—The mineral studies include: I. _One-component systems_: silica, with its numerous polymorphic forms and their relations to temperature and the conditions of rock formation; alumina; magnesia; and lime. II. _Two-component systems_: silica-alumina, including sillimanite and related minerals; silica-magnesia, including the tetramorphic metasilicate MgSiO_{3}; silica-lime, including wollastonite; the alkali silicates, particularly with reference to their equilibria with carbon dioxide and with water; ferric oxide-lime; alumina-lime; alumina-magnesia, including spinel; and hematite-magnetite, a solid-solution series of an unusual type. III. _Three-component systems_: silica-alumina-magnesia, completed but not yet published; silica-alumina-lime, complete, including the compounds that enter into the composition of portland cement; silica-magnesia-lime, completed but not yet published, including, however, published work on the diopside-forsterite-silica system, and on the CaSiO_{3}-MgSiO_{3} series; and alumina-magnesia-lime. IV. _Four components_: SiO_{2}-Al_{2}O_{3}-MgO-CaO: the incomplete system anorthite-forsterite-silica; SiO_{2}-Al_{2}O_{3}-CaO-Na_{2}O: the series of lime-soda feldspars (albite-anorthite), and the series nephelite (carnegieite)-anorthite; SiO_{2}-Al_{2}O_{3}-Na_{2}O-K_{2}O: the sodium-potassium nephelites. V. _Five components_: SiO_{2}-Al_{2}O_{3}-MgO-CaO-Na_{2}O: the ternary system diopside-anorthite-albite (haplo-basaltic and haplo-dioritic magmas). Fairly complete studies have also been made of the mineral sulphides of iron, copper, zinc, cadmium, and mercury, and the conditions controlling the secondary enrichment of copper sulphide ores are now being investigated. In connection with the sulphide investigations, the hydrated oxides of iron have been studied chemically and microscopically and the results will soon be ready for publication. Throughout the work the mere accumulation of bodies of facts has been held to be secondary in importance to the development of new methods of attack and the evaluation of new general principles, and the specific problems studied have been selected from this point of view.