APRIL 4, 1907 | 
NATURE 
BoTanicaL survey work concerned with the mapping of 
the vegetation of a given area according to a plan which 
is the outcome of a method suggested by Prof. C. Flahault, 
of Montpellier, has attracted a small but energetic band 
of workers in the United Kingdom. ‘The latest survey 
prepared by Mr. C. E. Moss, dealing with the distribution 
of vegetation in Somerset, was published in the Geo- 
graphical Journal (October, 1906). In the lowland areas 
Mr. Moss traces the transition from dunes fixed by sea- 
couch grass, Agropyron junceum, and marram-grass, 
Ammophila arundinacea, to dune ponds and dune pastures, 
and so to maritime farmlands. In another sequence of 
associations, the salt marsh, at first settled with Salicornia, 
is converted into land suitable for growing osiers and 
tree willows. 
described for the upland areas, which are as markedly 
characteristic and easily recognised, so that the present 
paper provides an admirable introduction to anyone taking 
up the subject. 
Similarly, typical series of formations are 
Messrs. Cart Zeiss, of Jena, have forwarded a copy 
of their price-list relating to large projection apparatus. 
This list contains a brief reference to everything necessary 
for the projection of microscopic objects, transparencies 
placed horizontally or vertically, and opaque ‘objects. 
Some general information is also given as to selection of 
the optical equipment for special purposes. 
In the Journal of the Royal Microscopical Society, Mr. 
J. W. Gordon describes a top stop for the microscope. 
This is placed in the Ramsden circle of the instrument, 
its effect being to cut off the central part of every beam 
of light. In this way the advantages of a wide aperture 
are preserved, and the definition is improved, as is well 
shown by the photographs illustrating the paper. This 
improvement is attributed to the fact that in an unstopped 
beam the central and marginal parts do not exactly form 
the same image, and the confusion thus caused is obviated 
by the stop. To cut off the marginal rays would be 
merely equivalent to using a narrower aperture. 
RecENT progress in the industry of perfumery and 
essential oils is ably summarised in a report by Messrs. 
A. Haller and H. Gault in the Bulletin de la Société 
d’Encouragement (vol. cix., No. 2). Commercial statistics 
show that as a result of theoretical chemical researches 
there has been equal progress in the manufacture of 
natural essences and in the preparation of artificial per- 
fumes. 
Tue Engineering Standards Committee has issued a 
second report (No. 26; London: Crosby Lockwood and 
Son, price 10s. 6d.) of the locomotive committee on 
standard locomotives for Indian railways. Four additional 
types of locomotive have been included at the request of 
the Indian Railway Board, and at the request of the 
Secretary of State for India the locomotive committee 
has formed itself into a permanent advisory body. 
An address on the duration of the coal reserves of the 
United States, delivered by Mr. Marius R. Campbell to 
the National Geographic Society at Washington, is pub- 
lished in the National Geographic Magazine (vol. xviii., 
No. 2). He enumerates the coal areas of the various 
States, and shows that, while Pennsylvania produces the 
most coal, Montana has the largest coalfields. The total 
amount of coal in the United States, exclusive of Alaska, 
is estimated at 2,200,000 million tons. If the rate of 
NO. 1953, VOL. 75 | 
consumption of 1905 were maintained indefinitely without 
change, this would last for 4ooo years, but if the constantly 
increasing rate which has marked the consumption during 
the past ninety years be maintained, the coal supply will 
practically be exhausted within a hundred years. 
Messrs. F. VigwkG AND Son have just published 
(pp. 417, price 12 marks) a fourth edition, revised and 
enlarged, of Prof. Albert Ladenburg’s well-known 
““Vortrage iiber die Entwicklungsgeschichte der Chemie 
von Lavoisier bis zum Gegenwart,’’ the first edition of 
which appeared so long ago as 1869. The main value of 
the work lies in the careful historical treatment of the 
progress of chemistry up to the time of the introduction 
of the conception of valency. To bring the account up 
to date, however, additional chapters have been written 
for the new edition dealing with recent advances in physical 
chemistry, and including the theories of mass action, 
heterogeneous equilibrium, tautomerism, stereochemistry, 
and solution; a review is also given of recent discoveries 
in organic chemistry. A special feature of this history is 
the very large number of references given to the original 
papers. 
A ruirD edition of Prof. H. Réttger’s ‘* Lehrbuch ‘der 
Nahrungsmittel-Chemie ’’ has just been issued by the 
firm of J. A. Barth, of Leipzig (pp. xiv+go1, price 16 
marks paper covers, 17 marks bound). This work, prob- 
ably for its completeness the most concise treatise on the 
chemistry of foods yet written, has gained in Germany 
a very high reputation, the second edition having been 
exhausted in a little more than three years. To the new 
edition a number of tables and an index of authors’ names 
have been added, and a very complete set of references is 
given to the latest papers-in all departments of the subject. 
Third editions have also been published by F. Tempsky, 
of Vienna, of Franz von Hemmelmayr’s ‘‘ Lehrbuch der 
anorganischen Chemie ’’ and ‘** Lehrbuch der organischen 
Chemie’’ (pp. 237, price 3 krone, and pp. 150, price 2-30 
krone, respectively); these books are designed for use in 
the fifth and sixth classes of the Austrian Realschulen, 
and are of a purely elementary character. 
Since the list of forthcoming scientific books appeared 
in Nature of March 14, Messrs. Swan Sonnenschein and 
Co., Ltd., have announced that they have in preparation :— 
‘“The History and Ethnography of Africa South of the 
Zambezi, from the Settlement of the Portuguese at Sofala 
in September, 1505, to the Conquest of the Cape Colony by 
Great Britain in September, 1795," by G. M. Theal; 
‘Thought and Things: a Study of the Development and 
Meaning of Thought or Genetic Logic,’’ by Prof. J. M. 
Baldwin, 3 vols., vol. ii., ‘‘ Experimental Logic,”’ vol. iii., 
“Real Logic ’’; ‘‘ The History of Philosophy,”” based on 
the work of Dr. J. E. Erdmann, fifth German edition, 
revised by Dr. W. B. Erdmann, edited by W. S. Hough; 
““TLectures in Humanism,” by Prof. J. S. Mackenzie ; 
‘“ Mental Pathology and its Relation to Normal Psycho- 
logy,’ by Prof. Storring, translated by Prof. T. Loveday ; 
“* Physiological Psychology,’’ by Prof. W. Wundt, a trans- 
fation of the fifth and wholly re-written German edition 
oy Prof. E. B. Titchener, vol. ii.; ‘““ The Student’s Text- 
book of Zoology,’’ by A. Sedgwick, F.R.S., vol. iii., com- 
pleting the work; and new editions of ** Elementary Text- 
book of Practical Botany for the Botanical Laboratory 
and Private Student,’’ by Prof. E. Strasburger, English 
edition by Prof. W. Hillhouse; and ‘‘ Handbook of 
Mosses,’’ by J. E. Bagnall. 
