February io, 192 i] 



NATURE 



755 



subject^is laid indiscriminately before the 

 reader. 



Having said this much, and being forewarned 

 as to these limitations, it is indisputable that the 

 book has many good i>oints, chief of which is that 

 it will be of considerable use to mineralogists, and 

 especially to those of a petrological bent ; for 

 chemical crystallography is largely ignored, except 

 as it concerns naturally occurring crystallised sub- 

 stances. Next must come the valuable fact that 

 the book is not only written under the influence of 

 the knowledge acquired during the last seven years 

 by means of X-ray analysis, but also inspired by the 

 presence in the same university of the discoverer 

 of this remarkable method of probing crystal 

 structure. It is also noticeable that certain sec- 

 tions of the book are specially good, chiefly from 

 their novel mode of presentation and illustration. 

 The four pages of drawings of crystals showing 

 their optical properties are of a very original char- 

 acter, and if one were not reminded so forcibly 

 of the wall diagram by their grouping in such 

 closely compacted numbers, the effect would have 

 been more pleasing and the result more striking. 



Doubtless the main use for the book will be as 

 an aid to the author's own students, in affording 

 an authentic account of their professor's lectures. 

 The book covers an immense amount of ground, 

 but is, in the main, elementary and superficial, 

 b<,-sides being crudely and cheaply illustrated. It 

 is largely redeemed, however, by the many refer- 

 ences to X-ray results and by its occasional 

 bursts of originality. A. E. H. T. 



Our Bookshelf. 



Penrose's Annual. Vol. xxiii. of The Process Year 

 Book and Review of the Graphic Arts, 1921. 

 Edited by William Gamble. Pp. xii-(- 88-1- plates. 

 (London : Percy Lund, Humphries, and Co., 

 Ltd.; Bradford: The Country Press, 1921-) 

 Price los. bd. net. 

 This is the second issue after the war, and there 

 is evidence that the editor has now been able to 

 resume the high level of quality that he had 

 attained before the publication of these instructive 

 annuals was interrupted by the exigencies of mili- 

 tary service. The volume may not be quite so 

 thick as, but it seems to us superior to, last year's 

 in many ways, especially in the quality and variety 

 of its specimens of reproduction. The editor, in 

 his summing up of the year's progress, finds no 

 striking new departure to record, though there 

 is much evidence of progress in many directions. 

 The activity during the year has been rather in 

 laying foundations that may well be expected to 

 lead to future advances than in the realisation of 

 improvements. Rotary photogravure holds its 

 own, and is doubtless firmly established, as in 

 NO. 2676, VOL. 106] 



the Times Weekly Edition Illustrated Supplement, 

 but it appears that the production of the cylinders 

 cannot be ensured within the short time necessary 

 to enable a daily newspaper to be produced entirely 

 by this process. The shortage of skilled labour 

 in the process trade is becoming acute. 



Among the several interesting and useful 

 articles is a contribution from Prof. Namias, who 

 finds that bichromated papers (as carbon tissue) 

 may be impregnated with the chromate, and vet 

 remain stable for a very considerable time, if not 

 indefinitely, by using a neutral chromate with a 

 small quantity of an alkali, preferably caustic 

 potash. Such paper does not spontaneously de- 

 teriorate. To prepare it for use, the sheets may 

 be hung in a box in which is a small dish contain- 

 ing acetic acid for about half an hour. Obviously 

 other methods of acidification may be adopted. 

 Dr. Reginald S. Clay suggests a method of photo- 

 graphy in colour by means of a series of inter- 

 ference units (Newton's rings). 



The New Hasell Annual and Almanack for the 

 Year 192 1. By Dr. T. A. Ingram. Thirty- 

 sixth year of issue. Pp. lvi-t-823. (London: 

 Henry Frowde, Hodder and Stoughton, 192 1.) 

 Price 7s. 6d. net. 

 We are always glad to see this useful annual, 

 which is invaluable for reference in many matters. 

 The volume gives the " most recent and authorita- 

 tive information concerning the British Empire, 

 the nations of the world, and all the important 

 topics of the day." It contains among other 

 details, including interesting astronomical and 

 meteorological data, a useful list of all the scien- 

 tific and other societies in the I'nited Kingdom, 

 and the names of the holders of the various Nobel 

 prizes from the date of their foundation. There 

 are also many valuable articles dealing with such 

 diverse subjects as the statistics of education in 

 the British Isles and the present state of aviation. 

 A wide field is surveyed, and the positions of all 

 the outstanding points are recorded. 



Das Schmereproblem. By Prof. A. Goldscheider. 



Pp. iv-(-9i. (Berlin: Julius Springer, 1920.) 



Price 10 marks. 

 In this little monograph Prof. Goldscheider, whose 

 earlier researches into cutaneous sense physiology 

 are well known, criticises the evidence relied upon 

 by v. Frey to establish the specificity of the peri- 

 pheral basis of cutaneous pain. The following 

 sentence expresses sufficiently the author's point 

 of view : " The sensation of pain, therefore, owes 

 its existence to a heightening of irritability pro- 

 duced by the stimulus ; unlike other sensations, it 

 is not the simple expression of an excitation due to 

 a peripheral stimulus, but presupposes an in- 

 creased tonus of the sensory nerve-cell in com- 

 parison with the physiological condition " (p. 89). 



Many of Prof. Goldscheider 's criticisms are in- 

 teresting, but the value of his book as a coiitribu- 

 tion to psycho-physiology is greatly diminished by 

 his failure to take account of the recent researches 

 of Dr. Henry Hciid and the latter's colleagues. 



