bearing the title given in the head lines, have been placed in the hands of the writer, who has read them with the greatest pleasure. The first volume contains a brief sketch of the Sheffield Laboratory, including a list of the publications (131) of the present officials of the department and their colaborers, followed by a series of papers in detail relating to general inorganic chemistry. Although the writer had studied these investigations as they appeared in print in the various journals, he can truthfully say that from the moment his attention was again attracted to the first lines of the first article which read "in the course of some experiments with caesium compounds, bromine was added to a concentrated solution of caesium chloride with an astonishing result," his interest in the remarkable results obtained in the preparation and study of double halides, by Professor Wells and his associates, was revived; indeed, this interest became so great that he read on and on, through one paper after the other, unconscious of his surroundings and the flight of time until the final paragraph was reached, when the book was closed with the conviction that it was overflowing with facts, bristling with suggestions, and deserving of the most careful study by all chemists, but especially those who fail to realize the immense work remaining to be done in the inorganic field. Five hundred double halides have been studied, more than a third of which have been made in the Yale laboratory. It is not very surprising then to read in the final chapter, "that the valency of a negative halide has no influence upon the types of double salts that it forms; ' that "molecules of alkaline halides possess nearly the same combining power as negative halides; that double halides probably increase in ease of formation and variety from the iodides to the fluorides," and then "some indications of regularity have been observed in connection with these researches, but it must be admitted that the results have been negative as far as throwing light upon the structure of this class of compounds is concerned." While the prevailing thought in Volume I is "double halogen salts," we meet in the companion volume anilides, formyl derivatives, amidines, imido esters, thiazoles, urea amidines, acyclic benzoyl pseudoureas and thiosemicarbazidic esters-all attesting, by the skilful way in which they have been prepared and studied, the keen originating power, and the untiring energy and zeal of their various authors. Just a bit of the "double halide" spirit has found its way into several of these organic papers, for upon P. 34 will be noticed (C,H,NO.NH.CO.CH1),HBr.Br., (C,H,NO,.NH.CO.CH,),HBr. Br,, etc., which are perfectly analogous to the perhalides CsBr. Br,, CsI.I,, and NH Br. Br. This slight digression into the field that received such ample consideration in the first volume is most pardonable, nay, it is desirable and should be pursued farther whenever it is at all possible. Much more might be said, but as the character of the volumes is now in a measure indicated, the writer would conclude with the recommendation that the reader of these lines should study the papers for himself, feeling assured that when he has done so, he will concur with the writer in the opinion that these researches not only reflect great credit upon their authors and the university in which they were planned, but that they will be real incentives to the great body of young, enthusiastic chemists to go forward and do likewise. EDGAR F. SMITH. THE JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. WILLIAM A. NOYES, Editor, EDWARD HART, W. F. HILLE- Contributions to the Chemistry of the Rare Earths of the Yttrium Group. I. By L. M. Dennis and Benton Dales.......... Electrolytic Deposition of Lead from a Phosphoric Acid Solution. By Liquid Mixtures of Minimum Boiling-Point. By Clifford D. Holley.. 448 The Volumetric Estimation of Alumina, and Free and Combined Sul- Burette Arrangement. By E. M. Johnson.. A Generator for Hydrogen Sulphide. By J. N. Swan The Determination of Copper by Aluminum Foil. By Geo. E. Perkins Supplementary Note to a "Gravimetric Method for the Estimation of Hydrogen Dioxide." By George E. Hosch..... New Books: Elementary Electricity and Magnetism; Enzymes and Their Application; Reprints of Science Classics No. 1, Studien zur Kentniss der Abhängigkeit der Viscosität der flüssigen Körper von der Temperature und von ihrer chemischen Constitution; The Ex- perimental Study of Gases; The Manufacture of Paint; Leçons sur Îa Theorie des Gaz; The Manufacture of Mineral and Lake Pig- ments; The Elements of Physical Chemistry; Drying Oils, Boiled Entered at the Post-office, Easton, Pa., as Second-class Matter Everything intended for insertion in the Journal should be addressed to the Editor, William A. Noyes, Terre Haute, Ind. Orders for back numbers of the Journal should be addressed to the Librarian, É. G. Love, 108 West 55th Street, New York City. Changes of address should be sent to the Secretary, A. C. Hale, 352 A Hancock Street, President: Ira Remsen, Johns Hopkins University, Baltimore, Md. Librarian: E. G. Love, 108 W. 55th St., New York City. Committee on Papers and Publications: William A. Noyes, Editor; Edward Hart, W. F Hillebrand, J. H. Long, Wm. McMurtrie, Arthur A. Noyes, Edgar F. Smith, H. N Stokes, H. P. Talbot, H. W. Wiley. Committee on Membership: Wm. McMurtrie; C. L. Reese; E. G. Love. Finance Committee: J. H. Wainwright; Durand Woodman; C. F. McKenna. Directors. Members ex-officio: Ira Remsen, Pres.; Albert C. Hale, Sec.; Albert P. Hallock, PAPERS ACCEPTED FOR PUBLICATION. Lecture Experiments, Illustrating Catalytic Action. By Arthur A. Noyes and G. V. Sammet. New Apparatus in Water Analysis. By George E. Thomas and Clarence A. Hall. An Electrolytic Study of Pyroracemic Acid. By George W. Rockwell. The Ammonium Tungstates. By Thomas M. Taylor. A New Method for the Approximate Determination of Uric Acid in Urine. By Julius Rudisc! and Leopold Boroschek. A New Qualitative Test for Cobalt. By J. L. Danziger. Ammonium Vanadicophosphotungstates. By Edgar F. Smith and Franz F. Exner. A Note on the Volumetric Determination of Copper. By S. W. Parr. Lead Sulphocyanate. By R. D. Hall. The Interaction of Sulphuretted Hydrogen and Arsenic Acid. By L. W. McCay. Copyright, 1902, by William A. Noyes, Chairman of the Committee on Papers and Publications of the CONTRIBUTIONS TO THE CHEMISTRY OF THE RARE EARTHS OF THE YTTRIUM GROUP. THE BY L. M. DENNIS AND BENTON DALES. Received January 30, 1902. HISTORICAL. I. HE first of the rare earths was discovered by Gadolin,' in 1794, in a heavy black mineral which had been found at Ytterby some six years before by Arrhenius. Three years later the earth was named yttria by Ekeberg, and the mineral "yttriastone." The latter is the gadolinite of the present day mineralogists. Ekeberg found yttria in a new mineral in which he had. discovered tantalum and which he called yttrotantalite. The earth was further studied by Berzelius* and by Berlin, both of whom considered it homogeneous. 5 Scheerer observed that when yttria was heated strongly in an open vessel it took on a yellow color, which it lost on heating in the presence of reducing gases, and that it remained colorless if cooled quickly, whereas it became colored again if heated in contact with air. He thought this phenomenon due to the presence 1 Sv. Vet. Akad. Handl., p. 137 (1794); Crell's Ann., (1796) I, 313. 2 Crell's Ann., 2, 63 (1799). 3 Sv. Vet. Akad. Handl., p. 68 (1802); Ann. de. Chim., 43, 278. * Schw. J., 16, 404. Sv. Vet. Akad. Handl., pp. 209, 212 (1835); Ann. Chem. (Liebig), 28, 222. Pogg. Ann., 56, 482. |