Organization:
In this publication measurements of interfacial angles of crystals are used to classify and identify chemical substances.
T. V. Barker, who developed the classification-angle system, was about to begin the systematic compilation of the index when he died in 1931.
The compilation work was undertaken by a number of interested crystallographers in the Department of Mineralogy of the University Museum at Oxford.
Since 1948 the working headquarters has been the Department of Geology and Mineralogy.
Numerous cooperating individuals in Great Britain, Holland, the United States, and Belgium have contributed editorially or by making calculations.
Great interest and practical help have been given by the Barker Index Committee.
Financial and material help have come from academic, governmental, and industrial organizations in England and Holland.
Editors for Volumes 1, and 2, were M. W. Porter and the late R. C. Spiller, both of Oxford University.
A third volume remains to be published.
Substances:
Volume 1, deals with 2991 compounds belonging to the tetragonal, hexagonal and trigonal, and orthorhombic systems;
and Volume 2,, with about 3500 monoclinic substances.
Volume 3,, in preparation, will treat the anorthic compounds described in Groth's Chemische Krystallographie.
Properties:
The Barker system is based on the use of the smallest number of interfacial angles necessary for indexing purposes.
Other morphological, physical, and optical property values are also given.
Sources of data:
The index is essentially a new treatment of previously compiled morphological data.
Most of the data used are from Groth's Chemische Krystallographie.
Criticality:
Every calculation has been made independently by two workers and checked by one of the editors.
Use of nomenclature, symbols, units, physical constants:
Accepted crystallographic symbolism has been used;
other symbols related to the index necessarily have been introduced.
Currency:
This publication covers the old literature (Groth);
there is no mechanism for keeping the volumes up to date.
Format:
The publication form is that of clothbound books.
The data are presented in lists and tables.
Part 1 in both volumes is labeled "Introduction And Tables".
The tables include those for the classification angles, refractive indices, and melting points of the various types of crystals.
Part 2 of Volume 1, and Parts 2 and 3 of Volume 2, contain the crystal descriptions.
These are grouped into sections according to the crystal system, and within each section compounds are arranged in the same order as in Groth's Chemische Krystallographie.
An alphabetical list of chemical and mineralogical names with reference numbers enables one to find a particular crystal description.
References to the data sources are given in the crystal descriptions.
Publication and distribution:
The Barker index is published for the Barker Index Committee by W. Heffer & Sons, Ltd., 4 Petty Cury, Cambridge, England.
Volume 1, containing Parts 1 and 2 was published in 1951;
Volume 2,, in three parts, in 1956.
The two volumes are available from the publisher for $16.80 and $28.00, respectively.

2-2.

Crystal data

organization:
The present edition of crystal data was written by J.D.H. Donnay, the Johns Hopkins University, Baltimore, Md. (Part 2) ) and Werner Nowacki, University of Berne, Switzerland (Part 1) ) with the collaboration of Gabrielle Donnay, U. S. Geological Survey, Washington, D. C.
Many collaborators in the United States and Switzerland helped in collecting and assembling data, in making calculations, and in editing.
Support came from academic and industrial groups in these two countries.
The Geological Society of America gave a grant-in-aid to complete the work and bore the expenses of publication.
Preparation of a second edition is in progress under the sponsorship of the Crystal Data Committee of the American Crystallographic Association.
Coeditors are J.D.H. Donnay, G. E. Cox of Leeds University, and Olga Kennard of the National Council for Medical Research, London.
Financial grants have been received from the National Science Foundation and the (British) Institute of Physics for the compilation work and the publication costs.
The continuity of the project is suggested by plans for an eventual third edition.
Substances:
Elements, alloys, inorganic and organic compounds.
(Metal data will not be included in the second edition, since these have been collected independently by W. B. Pearson, National Research Council, Ottawa, and published as A handbook of lattice spacings and structures of metals and alloys by Pergamon Press.
) properties:
Crystallographic data resulting mainly from X-ray and electron diffraction measurements are presented.
Cell dimensions, number of formula units per cell, space group, and specific gravity are given for all substances.
For some substances, auxiliary properties such as the melting point are given.
Sources of data:
Part 1, of the present edition covers the literature to mid-1948;
Part 2,, up to the end of 1951.
Much of the material comes directly from secondary sources such as Strukturbericht.
Criticality:
The vast number of compounds to be covered, the limited resources to do the job, and the immediate need for this type of compilation precluded a thorough evaluation of all available data in the present edition.
Future editions may be more critical.
Use of nomenclature, symbols, units, physical constants:
Since Parts 1, and 2, were prepared independently, the abbreviation schemes and the chemical symbols used differ in the two parts.
The second edition should have greater uniformity.
Currency:
A second edition is in preparation, and there are long range plans for a third.
Format:
Data in the present edition are presented in tables and lists.
Part 1, deals with the classification of crystalline substances by space groups and is not a numerical data compilation.
The compounds are divided according to composition into seven categories.
Part 2, contains determinative tables for the identification of crystalline substances.
These are arranged according to crystal system.
There are formula and name indexes covering both parts.
References for Part 1, are given at the end and for Part 2, in the tables.
Publication and distribution:
The present edition of crystal data (Af), published in 1954 as Memoir 60 of the Geological Society of America, is now out of print.
The manuscript of the second edition will probably be ready by the end of 1960.

2-3.

Crystal Structures
organization:
The author of Crystal Structures is Ralph W.G. Wyckoff, University of Arizona, Tucson, Arizona.
The first section of this publication appeared in 1948 and the last supplement in 1960.
Though now complete, the publication is included in this directory because of its importance and because of the long-term nature of its preparation.
Substances:
Elements, inorganic and organic compounds (no alloys).
Properties:
The data presented are derived almost entirely from X-ray diffraction measurements and include atomic coordinates, cell dimensions, and atomic and ionic radii.
Sources of data:
Published literature.
Criticality:
The aim was to state the results of all available determinations of atomic positions in crystals.
Presumably the tabulated data are best available values.
The critical comments in the textual sections of this publication are invaluable.
Use of nomenclature, symbols, units, physical constants:
The terminology used conforms to that of Internationale Tabellen Zur Bestimmung Von Kristallstrukturen.
Currency:
During the years of publication, supplement and replacement sheets were issued periodically.
Coverage of the literature extends through 1954 and includes some 1955 references.
It is to be hoped that some way will be found to keep this important work current.
Format:
The publication form is that of loose-leaf sheets (Af) contained in binders.
The book is divided into chapters and in each chapter the material is grouped into Text, Tables, Illustrations, and Bibliography.
Each group is paginated separately;
numbers sometimes followed by letters are used so that insertions can be made.
Inorganic structures are found in Chapters 2 - 12, organic structures in Chapters 13 - 15.
Within each chapter an effort has been made to group together those crystals with similar structures.
There are three indexes, i.e., an inorganic formula index, a mineralogical name index, and a name index to organic compounds.
Publication and distribution:
Publisher of Crystal Structures is Interscience Publishers, 250 Fifth Avenue, New York 1, N. Y.
The work consists of four sections and 5 supplements.
Price of the complete work including all necessary binders is $148.50.

2-4.

Dana's System Of Mineralogy
organization:
Six editions of James Dwight Dana's System appeared between 1837 and 1892.
In 1915 Edward S. Dana, editor of the sixth edition, asked W. E. Ford of Yale University to prepare a seventh edition of his father's work.
A number of people became involved in the preparation but work was slow until 1937.
In that year a grant was obtained from the Penrose Fund of the Geological Society of America to finance additional full-time workers.
Money was also advanced by the publishers, John Wiley & Sons, Inc.
Volume 1, was completed in 1941 and published in 1944.
The editors of this volume and Volume 2, were the late Charles Palache, Clifford Frondel, and the late Harry Berman, all of Harvard University.
Work on Volume 2, was begun in 1941, interrupted by the war in 1942, and resumed in 1945.
The volume was completed in 1950 and published in 1951.
A supplementary grant from the Geological Society of America helped finance its publication.
Besides the editors there were many contributors in the United States and Great Britain to Volumes 1, and 2.
W. E. Ford, for example, continued to supply data on the occurrence of minerals until his death in 1939.
Volume 3, is nearing completion and there are plans to revise Volume 1.
The project is currently supported by Harvard University.
Substances:
minerals.
Properties:
Crystallographic, physical, optical, and chemical properties.
The crystallographic data given include interaxial angles and unit cell dimensions;
the physical property values include hardness, melting point, and specific gravity.
Sources of data:
Almost entirely original articles in journals;
abstracts and other compilations on rare occasions when original papers are not available.
Criticality:
All information is carefully appraised and uncertain facts are designated by ('?'.
) An authentic diffraction pattern is always obtained and optical properties are frequently checked.
Use of nomenclature, symbols, units, physical constants:
Recommendations of international authorities, such as the International Union of Crystallography, are followed.
There is a complete synonymy at the beginning of each species description.
Currency:
Currency in the usual sense cannot be maintained in an undertaking of this sort.
Format:
The data are presented in text and tables in bound volumes.
Volume 1, of the seventh edition contains an introduction and data for eight classes of minerals;
Volume 2, contains data for forty-two classes.
References are given at the end of each mineral description and a general index is given at the end of each volume.
There will be a comprehensive index in Volume 3, covering all three volumes.
Publication and distribution:
Volume 1 (( Af) of the seventh edition of Dana's System Of Mineralogy was published in 1944 and Volume 2 (( Af) in 1951 by John Wiley & Sons, Inc., New York, N. Y.
(The association of Wiley & Sons with the Dana Mineralogies dates back to 1844 when they published the second edition of the system.
) The two volumes are available from the publisher for $14.00 and $16.00, respectively.

2-5.

The Groth Institute
organization:
"The Groth Institute", which was established in 1958, is a group activity affiliated with the Physics Department of The Pennsylvania State University, University Park, Pa.
Ray Pepinsky is the Director.
The Institute derives its name from Paul Von Groth's Chemische Krystallographie, a five-volume work which appeared between 1906 and 1919.
The resident staff is large and consists of professional assistants, graduate students, abstractors, librarian, technical editor, machine operators, secretarial help, and others.
There are also corresponding members and outside advisory groups.
The Air Force Office of Scientific Research has provided financial assistance in the early stages of the Institute's program.
Substances:
All crystalline substances and other solid-state materials.
Properties:
The aim is to collect a very broad range of physical, chemical, morphological, and structural data for crystals on an encyclopedic scale and to seek all possible useful and revealing correlations of properties with internal structure.
Sources of data:
The first stage of operation has centered on the literature imaging of critical or summarizing tabulations such as the Barker Index.
Coverage of primary literature will follow.
Unpublished data will be available to the Groth institute from cooperating groups and individuals.
Criticality:
Critical evaluation of all data compiled is not a primary aim of this project.
However, the proposed correlation of the many interrelated properties of crystals will reveal discrepancies in the recorded data and suggest areas for reinvestigation.
In addition, the availability of computers will permit recalculation and refinement of much structural information.
Use of nomenclature, symbols, units, physical constants:
For punched-card or tape storage of information all literature values must be conformed to a common language.
In this way a degree of unification of nomenclature, symbols, and units will be realized.