502 



NATURE 



[December 29, 1921 



thirds of the cost," and the range is, at the same 

 time, available for cooking. "Gas has its advan- 

 tages when small quantities of hot water are 

 generated where and when required." "By far 

 the greater part of the waste of fuel used for a 

 hot-water supply is due to loss of heat from un- 

 coated pipes and tanks. Four-fifths of the fuel 

 used may be saved by the use of good non-con- 

 ductors." " The cost of continuous warming by 

 coal as against gas fires is about one-third or 

 one-quarter, but gas is far the more convenient 

 and economical when a living-room is only occa- 

 sionally used and required to be ready for occupa- 

 tion in a short time "; moreover, the use of gas 

 fires or other smokeless fuel conserves coal and 

 cleans the skies. In the matter of lighting, Mr. 

 Barker points out the economy of using for pas- 

 sages or as a night-light a lamp of higher voltage 

 than that in the mains. " The use of a 200 volt 

 lamp on a 50 volt circuit would give a night-light 

 probably at about one-twentieth the cost of a 

 paraffin-wax night-light." 



Such quotations suffice to show the practical 

 suggestions put in simple and clear language, of 

 which the book is full. In dealing with Acntila- 

 tion and heating in connection with comfort and 

 health — that is, with physiological principles — the 

 author evokes, as so many do, some mysterious 

 influence in addition to the physical qualities of 

 the air. Without adducing a particle of evidence, 

 he writes of " something probably in the nature 

 of ionisation or deionisation or variation of poten- 

 tial." He considers the view that sensations of 

 stuffiness are dependent on temperature and 

 humidity (movement must be added) as "totally 

 inadequate." Well, let him compare the physical 

 conditions of Montana out of doors with those in 

 the room in London best ventilated and warmed 

 by his own methods. . L. H. 



Metallurgical Principles and Processes. 



(1) The Physical Chemistry oj the Metals. By 

 Prof. R. Schenck. Translated and annotated 

 by R, S. Dean. Pp. viii + 239. (New York: 

 J. Wiley and Sons, Inc. ; London : Chapman 

 and Hall, Ltd., 1920. J 22s. 6d. net. 



(2) Electric Furnaces in the Iron and Steel In- 

 dustry. By W. Rodenhauser, J. Schoenawa, 

 and C. H. Vom Baur. Translated from the 

 original by the latter, and now completely re- 

 written. Third edition, revised. Pp. xxi-t-460. 

 (New York : J. Wiley and Sons, Inc. ; Lon- 

 don : Chapman and Hall, Ltd., 1920.) 245. net. 



(1) T)ROF. SCHENCK'S course of lectures, 

 X delivered to an audience of technical 

 men at Aachen, was first published in 1909, and 

 at once proved of great service to teachers of 

 metallurgy and to students desirous of acquiring 

 NO. 2722, VOL. 108] 



an insight into the scientific principles underlying 

 metallurgical processes. At the same time, it 

 directed the attention of physical chemists to the 

 large mass of intrinsically interesting material for 

 the study of chemical reactions and equilibria 

 which is available from metallurgical sources. 

 The subjects of the lectures were : — The proper- 

 ties of metals ; metallic solutions and alloys ; car- 

 bides, oxides, sulphides, and mattes ; the pro- 

 cesses of oxidation and reduction ; blast-furnace 

 reactions ; and the reactions of sulphides. Of 

 these the subject of the constitution and structure 

 of alloys has been treated by many writers, and 

 text-books of metallography are numerous, but 

 the kindred studies of mattes and slags, and of 

 roasting and smelting reactions, have received far 

 less attention. There is, therefore, room for such 

 a work, and a translation is to be welcomed. 



In view of the time that has elapsed since the 

 delivery of the original lectures, however, it would 

 have been advisable to subject the text to 

 thorough revision, as many advances have been 

 made in the meantime. A few later data have 

 been incorporated, but the alterations are trivial. 

 The most interesting sections are those concerned 

 with mattes and similar mixtures and with the 

 blast-furnace reactions. These sections will re- 

 pay study by physical chemists as well as by 

 metallurgists on account of the interest presented 

 by the equilibria involved. It is difficult to obtain 

 absolutely satisfactory data, as the reactions are 

 often slow, especially when solid phases are con- 

 cerned, and some of the investigations in this field 

 have had to be repeated with additional precau- 

 tions. The value of the work to the metallurgist 

 would have been increased by the inclusion of a 

 section dealing with silicates, on account of the M 

 importance of the slag in most smelting processes. ■ 

 l^he presence of a liquid mixture of silicates, in 

 which metallic oxides can dissolve, is an essential 

 condition of many operations, both in the ferrous 

 and the non-ferrous industries, and the changes 

 of the slag in an open-hearth steel furnace during 

 the W'orking of the charge, or the relations 

 between the compositions of the slag and the 

 matte in copper smelting, for instance, furnish 

 examples of equilibria which are as interesting 

 theoretically as they are important in practice. 



The translation is unfortunately marred by many 

 inaccuracies. Apart from the very numerous and; 

 irritating misspellings of proper names the sense' 

 of the original is often missed, especially in the 

 section dealing with the electron theory of metals. 

 A revision of this section has been designedly 

 excluded on the ground that the subject deserves 

 a separate treatise, but it would have been well to 

 omit the subject altogether or to revise it in the 



