THE

AMERICAN

JOURNAL OF SCIENCE.

EDITOR: EDWARD S. DANA.

ASSOCIATE EDITORS

PROFESSORS WILLIAM M. DAVIS AND REGINALD A. DALY,
OF CAMBRIDGE,

PROFESSORS HORACE L. WELLS, CHARLES SCHUCHERT,
HERBERT E. GREGORY, WESLEY R. COE AND
FREDERICK E. BEACH, of New Haven,

PROFESSOR EDWARD W. BERRY, OF BALTIMORE,
DRS. FREDERICK L. RANSOME AND WILLIAM BOWIE,
OF WASHINGTON.

FIFTH SERIES

VOL. IV-[WHOLE NUMBER CCIV].

WITH PLATE ONE

NEW HAVEN, CONNECTICUT.

1922.

Reprinted with the permission of The American Journal of Science

JOHNSON REPRINT CORPORATION
111 Fifth Avenue
New York 3, New York

Johnson Reprint Company Limited
Berkeley Square House

London, W. 1.

First reprinting, 1963, Johnson Reprint Corporation

Number 19.

ART. I. The Melting of Potash Feldspar; by G. W. MOREY

and N. L. BowEN,

ART. II. Triassic Reptilian Order Thecodontia, by F.

VON HUENE,

..

ART. III.—A Discussion of Triple Salts; by H. L. WELLS,

ART. IV. Horned Eocene Ungulates; by E. L. TROXELL,

ART. V. The Genus Hyrachyus and its Subgroups; by E.

L. TROXELL (with Plate I),

ART. VI-A New Occurrence of Ilsemannite; by C. W. Cook,

ART. VII. On the Zonal Division and Correlation of the

Silurian of Bohemia; by J. PERNER, with the collaboration

of O. KODYM,

SCIENTIFIC INTELLIGENCE.

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Chemistry and Physics.-A New Process for the Industrial Production of Barium

Hydroxide for Treatment of Molasses in Sugar Refining, DEGUIDE and BODE:

Advanced Course of Instruction in Chemical Principles, A. A. NOYES and

M. S. SHERRILL, 73.-Determination of Sulphur in Iron and Steel, H. B.

PULSIFER: Organic Chemistry, V. v. RICHTER, 74.-Friction and Lubri-

cation, HARDY and DOUBLEDAY, 75.-Power Alcohol, G. W. MONIER-

WILLIAMS, 76.-The Journal of Scientific Instruments: La Théorie Ein-

steinienne de la Gravitation, 77.

Geology and Mineralogy.-Gravity Anomalies and their Geological Interpre-

tation, 78.-Publications of the United States Geological Survey, G. O.

SMITH, 79.-Die Eruptivgesteine des Kristianiagebietes IV; Das Fengebiet

in Telemark, Norwegen, W. C. BRÖGGER, 80.- Mineral Resources of the

Philippine Islands for 1919 and 1920, 82. - A List of new Crystal Forms

of Minerals: Handbook and Descriptive Catalogue of Gems and Precious

Stones in the U. S. National Museum, G. P. MERRILL, etc.: Virginia Geo-

logical Survey, T. L. WATSON: The Topographic and Geological Survey

of Pennsylvania, G. A. ASHLEY: Geology of Drumheller Coal Field, Alberta,

J. A. ALLAN, 83.-Potash in a new area of Texas, 84.

Natural History.-Arctic Alcyonaria and Actinaria, A. E. VERRILL: Genetics,

An Introduction to the Study of Heredity, H. E. WALTER, 84.-—A Natur-

alist in the Great Lakes Region, E. R. DOWNING: La Constitution des

plantes vasculaires révélée par leur Ontogénie, G. CHAUVEAUD, 85.-The

Vegetation of New Zealand, L. COCAYNE: Les Mouvements des Végétaux,

R. DUTROCHET: Die Pflanzenwelt Afrikas, insbesondere seiner tropischen

Gebiete, A. ENGLER, 86-Précis de Physiologie Végétale, L. MAQUENNE:

The North American Slime-moulds, T. H. MACBRIDE, 87.-Soil Conditions

and Plant Growth, E. J. RUSSELL: A Handbook of the British Lichens,

A. L. SMITH, 88.

Miscellaneous Scientific Intelligence.-The Outline of Science, J. A. THOMPSON,

88.-Publications of the Smithsonian Institution, C. D. WALCOTT, 89.-

Banking, Principles and Practice, R. B. WESTERFIELD: Civic Science in

the Home. G. W. HUNTER and W. G. WHITMAN, 90.-Memoirs of the

Queensland Museum: United States Life Tables, J. W. GLOVER, 91.—Public

Opinion, W. LIPPMANN, 92.-Publications of the Carnegie Foundation for

the Advancement of Teaching, 93.-American Association for the Advance-

ment of Science: Observatory Publications, 94.

Obituary.-G. SIMONDS: A. BACOT: L. A. RANVIER: H. M. HowE, 94.