May 6, 1915| 
NATURE 
273 



in Germany, and done well, to attract and to create . 
the impression of progress and thereby to catch the 
market in X-ray apparatus generally. In the end it 
pays and incidentally leads to much interesting work, 
as well as fostering a spirit of enterprise. 
We have received from Kodak, Limited (Wratten 
Division), a copy of the third edition of their booklet 
on photomicrography. As compared with the second 
edition, it is somewhat enlarged, and it comprises 
within its thirty-six pages simple and straightforward 
instructions as to the arrangement of the apparatus, 
undisfigured by diagrams and directions with regard 
to the illuminating system that are too often found 
in the text-books, although they can never be realised. 
We refer to ‘parallel light,” and so on. The price 
of the pamphlet is 3d., and, of course, its strong point 
is the photographic side rather than the microscopical 
side of the art, and especially the use of colour filters. 
The spectrum transmissions of nine filters are given, 
and also the dominant wave-lengths of ten, most of 
the latter being a combination of two. Another table 
gives the absorption bands of the eighteen principal 
stains used in microscopy, with the suitable filters for 
securing maximum contrast in the photograph. Other 
tables give the relative sensitiveness of various 
Wratten plates to different light sources, and exposure 
factors for different focal lengths and apertures of 
objectives, for various magnifications, for different 
light sources, and for fifteen different light filters, in 
connection with the ‘“‘M” plates. The illustrations 
include two excellent reproductions of stained prepara- 
tions, and two little colour filters in a pocket of the 
cover, for viewing them through, serve to demonstrate 
the potency and usefulness of colour filters. 
Tue March number of the Journal of Chemical 
Technology contains a report of a special meeting of 
the London Section of the Institution of Chemical 
Technologists which was held on March 11 to discuss 
“The Future of British Chemical Industry.’ In 
opening the discussion, Colonel C. E. Cassal em- 
phasised the fact that the chemical profession in this 
country stands alone among the professions in that 
it is utterly without organisation, and is split up into 
a number of different camps. At the present time 
there is little sympathy between the college laboratory 
and the technical laboratory; it is on the closer union 
of these that future progress of chemical industry will 
depend. Colonel Cassal, in referring to the ignorance 
of the general public and of State departments as to 
the value of science, illustrated his remarks by a 
reference to the now notorious advertisement of the 
Royal Arsenal, referred to in Nature of April 1 
(p. 119), and to the organisation of “British Dyes, 
Ltd.” Mr. W. J. Dibdin remarked that the chemical 
department of the London County Council, of which 
he was formerly the chief, effected a saving of 
10,000,000l. capital expenditure in the plant necessary 
for dealing with the sewage of London. The general 
trend of the debate was that only by the education of 
the chemist supplemented by the education of the 
employer will it be possible successfully to fight 
Germany in the field of industrial chemistry. 
NO. 2375, VOL. 95| 

‘ 
ALTHOUGH it is perhaps one of the minor chemical 
products, allyl alcohol has been used extensively in 
research, and is by far the most readily accessible of 
the series of unsaturated alcohols. Originally pre- 
pared through the iodide from glycerol, it was a very 
costly product, but came into common use when 
Tollens showed that it could be prepared directly from 
glycerol by heating it with oxalic acid. A greatly 
improved preparation has recently been described by 
Dr. Chattaway in the Journal of the Chemical Society 
(vol. cvii., p. 407). Five hundred grams each of 
glycerol and of anhydrous oxalic acid are heated at 
roo° in a vacuum during four or five hours, whilst 
a certain amount of formic acid is distilled out; the 
product, which contains much dioxalin, is then de- 
composed by heating under ordinary pressure to 
220°-240°, when carbon dioxide is set free and allyl 
alcohol and allyl formate are produced. The oxalic 
acid is decomposed almost completely, leaving a 
residue of glycerol, which can be made up again to 
500 grams, mixed with 500 grams more of oxalic 
acid, and used over again; this can be repeated four 
or five times. The waste of material is therefore very 
small, and the glycerol used up is converted almost 
quantitatively into allyl alcohol, whilst the oxalic acid 
is converted on one hand into carbon dioxide, and on 
the other into formic acid. 
Tue importance, both to the manufacturer and the 
consumer, of having at disposal adequate facilities 
for the scientific investigation and testing of the 
quality of textiles is very great. At the present time 
when immense quantities of such materials are being 
manufactured for military and naval purposes such 
facilities are exceptionally valuable. The Public Tex- 
tile Testing and Conditioning House carried on under 
the auspices of the Corporation of Belfast, and located 
in the Municipal Technical Institute of that city, has 
just issued the fifth edition of its regulations and 
schedule of charges, and this publication indicates 
very strikingly the extent to which textile testing has 
now been elaborated and _ perfected. The Belfast 
testing house is one of the more recently opened, 
having been established in the year 1910 by the cor- 
poration at the direct request of the textile trades of 
Belfast and district. The house is carried on under 
Parliamentary authority, has power to grant certifi- 
cates respecting the articles submitted for examina- 
tion, and certificates so issued are receivable as 
evidence in a court of law. The schedule of charges 
shows that a very wide range of tests are undertaken 
in the testing house. The tests include physical, 
chemical, and microscopical investigations of fibres, 
yarns, cloths, and bleaching and dyeing materials. 
A noteworthy section of the testing scheme is that 
concerned with the determination of the cause of 
defects in cloth, more especially such causes as are 
classed under the technical heading of * tendering.” 
Parr 4 of the Proceedings of the Institution of 
Mechanical Engineers for 1914 has just been issued, 
and contains the recommendations of the refrigeration 
research committee. There are also given charts of 
entropy and total heat for each. of the three sub- 
stances in common use for refrigerating purposes, 
