NATURE 



[May i, 1913 



The lectures begin with nutrition — the talcing in 

 of food, the treatment of this food within the body, 

 its distribution, storage, and transformation, and 

 so on. The respiratory function in plants and 

 animals is then dealt with. Then follow very in- 

 teresting lectures on movement and irritability, 

 and the author is particularly successful in his 

 treatment of the various senses in plants and 

 animals. The general facts and laws of response 

 to various kinds of stimulus are admirably dis- 

 cussed, and the lectures end with an inquiry into 

 the regulation and unification of functions. The 

 reproductive function has been left for separate 

 treatment. 



Prof. Wagner has given us a very thoughtful 

 book, which makes one reflective, and to our mind 

 there is convincingness in its cumulative argument 

 that biology is autonomous, and that it cannot 

 do its own business with the instruments of chem- 

 istry and physics alone. Thus we are led at the 

 end of these lectures to a deliberate, but by no 

 means dogmatic, "Psycho-biology." 



(2) Prof. Jordan has tackled an enormous piece 

 of work — a comparative physiology of the in- 

 vertebrates — and he is to be congratulated on the 

 completion of the first volume, which deals with 

 nutrition. With colossal learning, which must 

 have meant many years of work, he discusses the 

 nutritive function in the various classes. Inci- 

 dentally, he has a good deal to say in regard to 

 habits. The material is very well arranged ; the 

 style is clear ; there are numerous good figures ; 

 and there is an index of about seventy pages. 

 Prof. Jordan has himself made numerous contribu- 

 tions to comparative physiology, and he is at once 

 critical and fair in the way he deals with the huge 

 mass of facts which the active prosecution of a 

 relatively young inquiry has placed at his disposal. 

 After tracing the nutritive functions from class to 

 class, he takes in the concluding chapter an in- 

 teresting general survey of the different kinds of 

 diet, the different ferments, the processes of secre- 

 tion, digestion, and absorption, the rOlc of phago- 

 cytes, and the process of storage. Zoologists and 

 physiologists will be grateful to Prof. Jordan for 

 this valuable book of reference. 



OUR BOOKSHELF. 

 Notes on Sampling and Testing. Second edition : 

 revised and enlarged. Pp. 96 + plates. (Man- 

 chester: Marsden and Co., Ltd., 191^.) Price 

 15. 6d. 

 I 111 lesting-house of the Manchester Chamber of 

 Commerce was established some eighteen years 

 ago for the examination of yarn and cloth as 

 regards proportion of moisture, "strength," and 

 NO. 2270, VOL. 91] 



other physical properties. To these objects have 

 since been added others, including the analysis 

 of sizing materials used on textile fabrics; the 

 testing of wood pulp, oils, metals, fuels, and 

 water; and also investigations respecting the 

 causes of defects in fabrics — for example, mildew, 

 stains, and "tenderness" or deficiency in strength. 

 The handbook contains notes explaining certain 

 of the processes used, the standards adopted, and 

 the reasons for the choice of methods and stand- 

 ards. Examples of calculations are given, and 

 tables of numerical data, with various diagrams 

 and curves, one showing, for instance, the effect 

 of atmospheric moisture on the strength of differ- 

 ent kinds of cloth. Notes on the precautions to 

 be taken in sampling articles for testing are 

 included. 



The services of the testing-house are not re- 

 stricted to the members of the Chamber of Com- 

 merce, but are available to the public generally : 

 and during the last ten years the number of 

 samples submitted annually has more than 

 doubled. One notable function of the establish- 

 ment is to afford help in settlinsr differences be- 

 tween manufacturers or merchants, especially 

 where the experience of the testing-house is of 

 value and analyses are required. 



For those interested in textile industries, to 

 whom it is more particularly addressed, the book- 

 will no doubt prove useful. 



Phvsik der Gestirne. (Bi'icher der Xaturwissen- 

 schaft. Vol. xiii.) By Prof. J. B. Messer- 

 schmitt. Pp. 195 + 13 plates. (Leipzig: 

 Philipp Reclam, jun., n.d.) Price 1 mark. 

 For German readers this small volume affords an 

 interesting and useful summary of the astro- 

 physics of to-day. The introductory chapters 

 deal with spectrum analysis in general, the solar 

 spectrum and the spectroscope; the various con- 

 ditions, e.g., pressure, radial motion and magnetic 

 fields, which modify the radiation are briefly but 

 sufficiently discussed. 



A considerable space is devoted to solar physics ; 

 and, for so small a volume, the general principles 

 are stated very clearly and completely. On de- 

 batable subjects, such as the spectroscopic proof 

 of water-vapour in the Martian atmosphere, Prof. 

 Messerschmitt is commendably reserved, and states 

 the views of both sides with judicial equanimity. 

 More space might usefully have been devoted to 

 the subject of stellar spectra, but the main points 

 are enumerated, and a short, special chapter is 

 devoted to the consideration of stellar tempera- 

 tures. 



Various tables, such as that showing the bright- 

 ness of the sun's surface at different distances 

 from the centre, and another giving the relative 

 brightness of the chief nebula line in various 

 nebula?, afford the student a clear view of many 

 important special problems, while the excellent 

 plates will go far in fixing the general ideas in 

 his mind. 



W. E. R. 





