498 SCIENCE PROGRESS 



Monographs on Industrial Chemistry. Edited by Sir E. Thorpe. (London : 

 Longmans, Green & Co., 1918.) 



(1) Colour in Relation to Chemical Constitution. By E. R. Watson, M.A., 

 D.Sc. [Pp. xii + 197, with 4 coloured plates and 65 figures of absorption 

 curves, spectra, etc.] (Price 12s. 6d. net.) 



If a perusal of Prof. Watson's work leaves one with a somewhat confused 

 feeling— like the Scotchman who, having been presented with a dictionary, 

 remarked later that he found it to contain " a deal of interesting reading, but a 

 wee bit disconnected ! "—the fault is not necessarily the author's, as the whole 

 subject is so complex and chaotic that little more can be done by a conscientious 

 writer than to state shortly what is known on the matter, and the special theories 

 of various experimenters. This Prof. Watson has done with considerable skill, 

 and the very large number of absorption curves given offer at least an indication 

 of the results obtained. Hitherto there has been no work on this important 

 subject in the English language, and even in German the latest book— Ley's 

 Beziehimgen zwischen Farbe und Konstitution — only brings one up to 191 1. It is 

 hardly possible in a review to deal in detail with so abstruse a subject as the 

 connection between colour and constitution, but it will suffice to note that suc- 

 cessive chapters deal with the Early History of the subject, the Quinonoid Theory, 

 Absorption Spectra and Methods for their Measurement, Spectra of Typical 

 Organic Substances and Dyes, Relationships between Constitution and Depth of 

 Colour, Theories on the Nature of the Vibrations causing Absorption Bands and 

 Colour, Infra-red Absorption Spectra of Organic Substances, Fluorescence, 

 Colour and Spectra of Inorganic Compounds, and, lastly, a Bibliography dealing 

 with the literature of the subject. 



Prof. Watson, on p. 29, quite rightly emphasises the importance of the 

 spectrophotometer as a means of estimating colour— further developments may 

 certainly be looked for in this direction. The diagram on p. 35, however, and the 

 statement on p. 36 that " this family of curves is a set of parallel straight lines," 

 are a little difficult to comprehend, as, according to this, the solution should 

 continue to absorb light even at infinite dilutions. 



Prof. Watson's work should prove of service to those who are investigating 

 this fascinating borderland where chemistry, physics— and commerce — meet 

 together. 



(2) Coal and its Scientific Uses. By William A. Bone, D.Sc, Ph.D., F.R.S., 

 Professor of Chemical Technology in the Imperial College of Science and 

 Technology, Chairman of the British Fuel Economy Committee (191 5-17). 

 [Pp. xv + 491, with numerous illustrations, diagrams, and tables.] (Price 

 21s. net.) 



More than usual interest attaches at the present moment to Prof. Bone's masterly 

 treatise on Coal and its uses, owing to the strange turn of events which has landed 

 us this winter in the midst of a coal shortage. But even without this pressing 

 reminder of the importance of the subject the book would stand out as a really 

 valuable contribution to scientific literature. 



Hitherto there has really been no satisfactory treatise dealing with Coal right 

 from its very origin to the ultimate uses to which it is put both as a domestic and 

 industrial fuel and also as a chemical raw material. 



Although the author has written a real scientific book which is likely to become 

 a standard work on the subject, he has, nevertheless, managed to infuse a certain 



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