An Index of Mineral Species and Varities Arranged Chemically, with

479
Notes and N e w s
Announcements and other items of crystallograph~ interest will be published under this heading at the discretion of the
Editorial Board. Copy should be sent direct to the British Co-editor (R. C. Evans, Crystallographic Laboratory,
Gavendish Laboratory, Cambridge, England).
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n o t later t h a n 31 D e c e m b e r 1951.
International Union of C r y s t a l l o g r a p h y
The Second General Assembly a n d I n t e r n a t i o n a l Congrass of t h e U n i o n was held in Stockholm from 27 J u n e
to 3 J u l y 1951 a n d was followed by Symposia on
A d v a n c e d Techniques in Structure D e t e r m i n a t i o n a n d
on Electron Diffraction in Liquids a n d Gases held on
4 a n d 5 J u l y 1951. A brief account of t h e proceedings
a t these meetings will be published later, b u t detailed
abstracts of t h e 230 papers read at t h e Congress a n d
Symposia m a y be o b t a i n e d from t h e Secretary of th~
Local C o m m i t t e e (F. E. W i c k m a n , S t o c k h o l m 50,
Sweden), price 7 Swedish kronor, post free.
B o o k Reviews
Works intended for notice in this column should be sent direct to the Editor (P. P. Ewald, Polytechnic Institute of Brooklyn,
99 Livingston Street, Brooklyn 2, N . Y . , U.S.A.). A s far as practicable books will be reviewed in a country different
from that of publication.
An Index of Mineral Species and Varieties Arranged C h e m i c a l l y , w i t h an Alphabetical I n d e x
o f accepted Mineral Names and S y n o n y m s .
B y M. H . HEY. Pp. x x + 609. L o n d o n : p r i n t e d b y
o r d e r of t h e T r u s t e e s o f t h e B r i t i s h M u s e u m . 1950.
Price 30s.
This useful and c o n v e n i e n t work of reference comprises
two m a i n parts: a catalogue of minerals arranged according
to their qualitative chemical composition, a n d an alphabetical hst of about 12,000 mineral names. For each of
the names in the latter List a reference is given to s t a n d a r d
text-books or to periodicals where a s u m m a r y description
can be found. The status of the n a m e as a species, variety
or s y n o n y m also is indicated, a n d a finding-number is
cited to the chemical catalogue. The chemical catalogue
is essentially a d e t e r m i n a t i v e scheme based on qualitative
analysis. The classification e m p l o y e d is based primarily
on a separation into anions a n d t h e n into metals arranged
in the order of the periodic table. The silicates, comprising a b o u t one-third of all entries, are arranged differently. These are broken down into four special groups:
silicates w i t h other anions, silicates n o t containing
a l u m i n u m , silicates containing a l u m i n u m a n d no other
metal, a n d silicates containing a l u m i n u m a n d other
metals. The m a i n categories of classification a n d t h e
individual substances e n t e r e d therein are n u m b e r e d .
Anorthite, CaA12SiO . thus has t h e finding-number
16.9.2 [section 16 (silicates containing a l u m i n u m a n d
other metals), subsection 9 (ahtminosilicates of calcium),
e n t r y 2 following gehlenite, Ca2A19SiOT, 16.9.1]. Crossreferences are given w h e n e v e r t h e y are of value, as in t h e
case of minerals containing two or more different anions.
The general handling of t h e chemical formulation is
accurate and critical, a n d attests to t h e author's wide
knowledge of mineral chemistry. A m o n g the very few
errors of fact n o t e d m a y be m e n t i o n e d t h e listing of
uraeonite as a species instead of as a s y n o n y m of uranopilite, a n d the classification of m e t a - a u t u n i t e a n d metatorbernite as varieties of a u t u n i t e a n d torbernite, respectively. The structure s t u d y of B e i n t e m a (1938) has shown
t h a t the m e t a phases are distinct hydrates, a n d at least
m e t a - t o r b e r n i t e occurs as a species in nature.
Virtually all k n o w n mineral names are included in the
chemical catalogue, w h e t h e r good, bad or indifferent. The
general status of the n a m e is indicated b y t y p e size or
t e x t u a l c o m m e n t , a n d a concise, d o c u m e n t e d discussion
is frequently given of substances whose relations are
problematic. A n u m b e r of n a m e d artificial c o m p o u n d s
are included. I t seems u n f o r t u n a t e t h a t Dr H e y has
rejected Schaller's scheme of adjectival modifiers to
describe compositional variation in minerals. The syst e m a t i z a t i o n of n o m e n c l a t u r e in this way is a n a t u r a l
expression of t h e m o d e r n concept of minerals as phases
t h a t v a r y serially in composition between natural limits.
I t would seem advisable to follow the trend t o w a r d fewer
a n d more meaningful names, rather t h a n to preserve t h e
chaotic n o m e n c l a t u r e t h a t has s t e m m e d largely from the
older notion of species as constituting phases of essentially
fixed composition.
The necessarily brief a n d sometimes i n a d e q u a t e indication of the status of the n a m e s included in the chemical
catalogue m a y cause trouble for a non-specialist who,
concerned with a practical problem of identification, m a y
r u n a substance d o w n t h r o u g h t h e classification a n d t h e n
u n k n o w i n g l y be confronted, n o t with an identification,
480
BOOK REVIEWS
b u t w i t h w h a t amounts to a research problem perhaps
involving the re-examination of t y p e material a n d the
resolution of a k n o t t y tangle of nomenclature as well. The
specialist will find the work invaluable for m u c h the same
reason. H e y ' s Index is a boon to the professional mineralogist, a n d is highly recommended to anyone who wishes to
find quickly the chemical composition a n d descriptive
literature of the k n o w n minerals.
CLIFFORD FRONDEL
Mineralogical Laboratory
Harvard University
Uambrldqe, Mass., U.S.A.
Structural Inorganic Chemistry. By A. F. WZLLS.
Pp. xx+727, with 237 figs. Oxford: Clarendon
Press. 2nd ed. 1950. Price 35s.
H a r d l y a n y scientific tool has been of greater importance
for the progress of inorganic chemistry t h a n X - r a y
crystallography. Although this branch of science has now
been practised for nearly forty years, m a n y chemists still
seem to be somewhat bewildered b y its consequences. To
a large e x t e n t this is due to the fact t h a t X - r a y crystallog r a p h y has proved to be a k e y to a formerly practically
u n k n o w n field of chemistry, the solid state, where the
structures are often f u n d a m e n t a l l y different from those of
the finite a t o m groups previously studied in liquids or
gases. I t is, therefore, extremely i m p o r t a n t t h a t textbooks should be written to present the results of X - r a y
crystallography, a n d this in a w a y understandable to the
chemists. One of the causes of the slow adoption of new
structural conceptions is u n d o u b t e d l y the difficulty
generally experienced b y chemists in u n d e r s t a n d i n g the
language of crystallography.
I t was said of the first edition of Dr Wells's book t h a t ,
although its title was Structural Inorganic Chemistry, it
was more a s t u d y of the structure of the solid state. This
criticism was n o t so serious where the descriptive,
systematic p a r t of the book was concerned, because such
a n enormous p a r t of our present knowledge of inorganic
structures is derived from the solid state. On the other
hand, the general p a r t of the book u n d o u b t e d l y confined
the t r e a t m e n t of the subject too m u c h to purely structural
aspects. This limitation has been removed to a great
e x t e n t in the present second edition, where the basis of
the general t r e a t m e n t has been widened considerably. B u t
the difficulty of giving a condensed presentation of some
parts of the basic material is rather obvious. This applies,
for example, to the chapters dealing w i t h the nature of the
chemical bond. The section on X - r a y diffraction, which
has such a direct bearing on crystal-structure determinations, is still t r e a t e d v e r y briefly. The a u t h o r certainly
does n o t underestimate t h e immense value of X - r a y
diffraction methods; r a t h e r he appears to thint: t h a t their
importance necessitates reference to special text-books.
A reviewer cannot help observing t h a t the different
p a r t s of the t e x t are still n o t sufficiently co-ordinated.
This leads, among other things, to unnecessary repetitions,
a n d sometimes obscures i m p o r t a n t general lines. W h y , for
example, does t h e a u t h o r resume the discussion of m a n y
of t h e general characteristics of solid solutions w h e n he
comes to the last chapter of the book (metals a n d alloys)
Most of this discussion is included already in the general
part, a n d some problems, e.g. order-disorder p h e n o m e n a
a n d superlattices, are of such general application t h a t t h e y
should have been considered earlier.
The n a t u r e of t h e metallic bond is n o t t r e a t e d in the
general p a r t of the book b u t is discussed in connexion w i t h
the systematic description of metals a n d alloys. This in
itself is of little importance, b u t it is more serious t h a t the
d e p t h of the t r e a t m e n t does not do justice to the m o d e m
advances in this field, nor to the importance of this t y p e
of chemical bond relative to other types.
I t is quite n a t u r a l t h a t about 70 % of the book (488 out
of the 709 t e x t pages in the second edition) is devoted to
a systematic description of inorganic substances. This
p a r t is certainly suitable for giving a non-erystallographer
a fairly complete knowledge of the structural work
hitherto accomplished. Such a reader will certainly h a v e
no difficulty in following the text, which is also elucidated
b y figures which are generally v e r y clear a n d well drawn.
I n spite of this, however, he will no doubt find t h e
reading r a t h e r d r y ; b u t dryness is probably extremely
difficult to avoid in a presentation of this kind.
The wide field covered b y the book also makes it useful
as a reference work for a person more closely interested in
inorganic structures. This could h a r d l y be said of the first
edition, where all references to the literature were given
in a short list a t the end of the book, a n d w i t h o u t a n y
connexion w i t h the text. I n the new edition the references
are five times as numerous a n d have been inserted in the
text. This means a m a r k e d increase in the usefulness of
the book. I n some instances, however, one still has the
impression t h a t the information concerning relevant
literature is not quite adequate.
G. H ~ o o
Institute of Chemistry
University of Uppsala, Sweden
Books Received
The undermentioned works have been received by the Editors. Mention here does not preclude review at a later date.
Gmelins Handbuch der anorganischen Chemie.
Antimon A 3. Pp. 49, with 6 figs. Weinheim:
Verlag Chemic. 8th ed. 1950. Price DM. 16.50.
Gmelins Handbuch der anorganischen Chemie.
Platin A6. Pp. 35, with 138 figs. Weinheim: Verlag
Chemic. 8th ed. 1951. Price DM. 36.