6o8 



NA TURE 



[May 13, 1922 



for I will not " — this Draconian severity being pressed 

 for because " the penalty was not really so heavy as 

 it seemed, for as I privately knew the man had just 

 kept his term " ! 



The index should be read ; it is an epitome of the 

 book. 



Our Bookshelf. 



Der Torf. Von Prof. Dr. H. Puchner. (Enke's 

 Bibliothek fiir Chemie und Technik unter Beriick- 

 sichtigung der Volkswirtschaft : Band I.) Pp. 

 xvi + 355. (Stuttgart: Ferdinand Enke, 1920.) 40 

 marks. 



Peat is always an attractive subject for the investigator, 

 and particularly for the inventor, as it seems to promise 

 so much in return for so little effort. It lies on the 

 surface and needs no expensive mining operations ; it 

 is often on the top of a hill and can be run down to the 

 consumer by gravitation, and it is capable of yielding 

 fuel, ammonia, and various oils by distillation or heating 

 processes, for which it can itself provide the necessary 

 energy. 



The book under notice gives a useful summary of the 

 properties of peat, especially of those studied by the 

 German workers, and it will prove useful to prospective 

 investigators who wish to know something of the 

 nature of the material they have to handle. The great 

 difficulty up to the present has been the drying : in its 

 natural state peat may contain 90 per cent, or more of 

 water, and this has to be reduced considerably before 

 economic utilisation is possible. So far no method that 

 is generally satisfactory seems to have been evolved. 

 The author helps by giving an account of the methods 

 adopted in Carinthia, Oldenburg, and elsewhere, as 

 well as a list of methods proposed or used in factories 

 where peat is converted into saleable products. The 

 number of methods of utilisation suggested or actually 

 tried is considerable. During the war attempts were 

 made in Germany and Sweden to use it for firing railway 

 engines, but it was found necessary to fill not only the 

 tenders but also one or two waggons with fuel if any 

 length of journey was contemplated. Much more 

 successful are the efforts to convert peat into power gas, 

 and one feels on looking through the book that the 

 problem of utilisation of peat must surely be near its 

 solution. It would certainly add to the resources of 

 the world if satisfactory methods could be worked out. 



The Homogeneous Electro-Thermic Effect. {Including 

 the Thomson Effect as a Special Case) By Carl 

 Benedicks. (Ingeniors Vetenskaps Akademiens : 

 Handlingar Nr. 5, 192 1.) Pp. 117. (Stockholm : 

 A.-B. Svenska Teknologforeningens Forlag; London: 

 Chapman and Hall, Ltd., 1921.) 155. net. 



The Swedish Academy is issuing in English a series 

 of memoirs on scientific subjects in order to make the 

 work of Swedish men of science more widely known, 

 and the volume under notice is the fifth to be issued. 

 It deals with the transport of heat along a conductor 

 through which an electric current is passing, and the 

 author concludes from his measurements that there is, 



NO. 2741, VOL. 109] 



in addition to the Kelvin effect, a further flow of heat 

 with or against the electric current even when the con- 

 ductor is homogeneous and originally at a uniform 

 temperature. His measurements are in general made 

 on long cylinders, the centre of each being turned down 

 to a narrow neck. The electric current through the 

 neck causes a transport of heat to one or other side of 

 the neck, and the difference of temperature of the two 

 sides is measured by thermo-junctions. This differ- 

 ence does not vary with the magnitude of the electric 

 current according to the same law as the Kelvin effect, 

 nor is it always of the same sign as the latter. The 

 author proposes to call this new effect " the homo- 

 geneous electro-thermic effect." 



The Wisdotn of the Beasts. By C. A. Strong. Pp. 

 x + 76. (London: Constable and Co., Ltd., 1921.) 

 5s. net. 



This is not a zoological treatise on animal instincts and 

 the like, but a series of philosophical fables of excellent 

 humour — indeed the prefatory quotation from the 

 Prologue to Phaedrus' Book I. makes us shrewdly 

 suspect the author of exquisite satire directed at 

 relativity and other scientific concepts. The fable of 

 " The Bird and the Fish " will cause amusement to the 

 disciples of Einstein : — a young bird, inexperienced in 

 the phenomenon of moving air and in its effects, is set 

 thinking by the fact that on a certain day it took less 

 time than usual to fly from the church steeple to the 

 stream, and more than usual to make the return flight : 

 after much cogitation it satisfies its philosophic soul 

 thus : — " Ah ! I have it at last ; what has changed is 

 not the field, but the clock. By flying away from a 

 clock you alter its time-keeping so that it loses, and by 

 flying towards it you alter its time-keeping so that it 

 gains. The time-keeping of clocks is not a fixed and 

 unalterable thing, but depends on whether you move 

 or stand still." And such is the style of the majority 

 of these fables. 



Analyses and Energy Values of Foods. By Dr. R. H. A. 

 Plimmer. Pp. 255. (London : H.M.S.O., 1921.) 

 6s. net. 



This work, which was carried out for the War Ofl!ice 

 authorities, contains the most comprehensive series of 

 food analyses performed in the British Isles. As the 

 author points out, they are best regarded not as a 

 replica of but as a supplement to the very complete 

 set of data by Atwater and Bryant, U.S. Department 

 of Agriculture. In some cases the number of analyses 

 is not great, but since the results are from foods as 

 actually supplied in Great Britain, they carry more 

 weight in this country than more numerous figures 

 published for other countries. The tables are very 

 carefully arranged, so that the composition of the entire 

 food; or any part of it, may be seen at a glance. There 

 is also an excellent summary of analyses in a form suit- 

 able for calculation. Information is given regarding 

 the methods employed, and a short appendix tabulates 

 the common food stuffs which do, and also those which 

 do not contain accessory food factors or vitamins. 

 The volume undoubtedly represents a valuable and 

 distinct advance in knowledge. 



