

ervices at the disposal of the home industry in syn- 
hetic dyes. But, largely owing to lack of appreciation 
f the value of scientific knowledge on the part of 
manufacturers, the result in almost all cases was 
¢ ee and disappointment, so that this 
e compelled by force of adverse Deeicciicnnes to 
fer their activities to other branches of chemical 
In 1915, however, the Government became 
ware somewhat tardily of our national deficiencies 
1 Tegard to the manufacture of dyewares, and Dr. 
Cain was appointed a member of the technical com- 
mittee of British Dyes, Limited, afterwards holding 
e position of chief chemist in the newly erected 
Dalton works of this firm. His experiences in these 
vo phases of the English colour trade, extending over 
twenty-five years, are embodied in the manual under 
review. 
It is obvious that in a handbook of some 260 pages 
all the important colouring matters cannot be included, 
and among the notable omissions are such well-known 
‘synthetic dyes as the Hessian purples, formyl violet, 
rhodamine S, the acridine yellows, and the first 
representatives of the anthraquinone vat dyes, namely, 
indanthrene blue and yellow. Nevertheless, a judicious 
and typical selection has been made, and the author 
_ has given full working details wherever he has possessed 
first-hand practical knowledge of the factory operations. 
_ This impress of realism is especially noticeable in 
the informative chapters on azo and triphenylmethane 
dyes ; for in both these branches of colour production 
Dr. Cain ranked as an expert. As, however, this work 
will be read by students, it is perhaps permissible to 
point out that the somewhat unnecessary rubrics at 
the beginnings of the chapters on monoazo and disazo 
_ dyes do not tally with the arrangement adopted in the 
: text. Fast red B contains two naphthalene nuclei, 
although classed as a mixed benzene-naphthalene dye, 
and diamond black F, placed in the purely naph- 
 thalenoid section, contains a benzene nucleus, and 
there are several other similar discrepancies in classifica- 
tion. In a future edition these headings might with 
advantage be omitted. 
In spite of the apathy prevailing before the war in 
this branch of chemical,industry, British chemists had 
developed a sound technique in the manufacture of 
certain standard dyes such as magentas, aniline blues, 
and safranines. The manual contains useful informa- 
tion in regard to these intricate preparations. On the 
theoretical side it will be noticed that the author has 
not adopted the prevailing view that the oxazines, 
thiazines, and azines are ortho-quinonoid derivatives. 
The future may show that this conservatism is well 
grounded. 
NO. 2781, VOL. 111] 
eS Se 
NATURE 












a 
——EE———E—EE—E—E——————— 
_ The two closing sections of the book present a 
marked contrast. The penultimate chapter on anthra- 
quinone and allied colours is, with two exceptions, 
already noted, detailed and comprehensive ; the last 
chapter on indigoid colours is an unfinished fragment 
constituting a sad reminder of the sudden and pre- 
mature close of an active life devoted to the theory 
and practice of colour chemistry. 
' To the student of organic chemistry this work offers 
a concise introduction to the fascinating though 
complex subject of synthetic dyes. To the expert 
colour-maker or user it supplies a full bibliography 
with copious references and an adequate index. Both 
classes of readers will find the book to be an excellent 
supplement to the author’s earlier volume on the 
manufacture of intermediates. Gel M; 

Rea’s “ British Basidiomycetz.” 
British Basidiomycete: A Handbook to the larger 
British Fungi. By Carleton Rea. (Published under 
the auspices of the British Mycological Society.) 
Pp. xii+799. (Cambridge: At the University 
Press, 1922.) 30s. net. 
VERY mycologist will welcome the appearance 
of this volume, which is issued under the 
auspices of the British Mycological Society and repre- 
sents thirty years of careful and continuous field-work 
on the part of its author. The author, whose skill in 
distinguishing our fleshy agarics one from another has 
been freely placed at the disposal of so many students 
of fungi in this country, is to be congratulated heartily 
upon having crowned his life’s labours with the publica- 
tion of a work at once so comprehensive and so valuable 
for reference. 
Massee’s ‘“ British Fungus-Flora ” appeared in the 
years 1892-1895. In the interval some hundreds of 
Basidiomycete, either new or new to Britain, have 
been discovered in this country—many of them by 
Mr. Rea himself—and descriptions of all these species 
are included in the present volume. In accuracy of 
description the book is an immense advance on anything 
previously produced in Britain. 
There are a number of commendable features in the 
(1) Every species is numbered, Rea’s last 
number being 2546; (2) the species actually seen are 
indicated by the letters v.v, (vidi vivum); (3) in the 
description of species the essential characters are placed 
in italics; and (4) the derivation and meaning of the 
name of each genus and species is given, philology thus 
illuminating mycology. 
The classification adopted is based chiefly on the 
well-considered system set forth by Patouillard in his 
GI 
work : 
