September 29, 1923] 



NATURE 



463 



metallurgy of which is described in this volume is alu- 

 minium^ presumably on account of its use in air-craft, 

 but it is not the only metal used, and it may be 

 questioned whether it was worth while introducing 

 Lit. The metallurgy of aluminium is adequately 

 lescribed in a number of text-books. Similarly, it is 

 lot clear why the electrolytic refining of copper has 

 jeen singled out for treatment. A general article on 

 the principles of electrolytic refining giving illustra- 

 ftions from various metals, would have been more 

 useful. 

 Mr. Francis FitzGerald has compressed a remarkable 

 lount of information into his article on electric 

 imaces. It gives exactly the kind of treatment of 

 the subject that is required in a volume of this kind. 

 Mr. Coad-Pryor has written two articles, both of them 

 ^very good. That on " Furnaces for Laboratory Use " 

 of moderate length, while the one on " Refractories " 

 of considerable dimensions. They are packed full 

 )f information and the treatment is admirable. Of 

 very solid merit also are the two articles by Dr. Hanson, 

 )ne on iron carbon alloys, the other on the defects and 

 lilures of metals. The former, however, is rather 

 jrfunctory in its reference to cast-iron. It deals with 

 >ure iron carbon alloys, and has only a very slight 

 j'eference to commercial cast-irons containing silicon, 

 langanese, phosphorus, and sulphur. The article on 

 le defects and failures of metals is most valuable. It 

 represents what may be called National Physical 

 iboratory experience at its best. The author, how- 

 ever, is incorrect in attributing the growth of cast-iron 

 )n repeated heatings to the pressure caused by the 

 formation of oxides of iron. The main cause, at any 

 ite, is the volume increase caused by the separation 

 >f silica. The statement on page 372 that " a ' crystal- 

 le ' fracture (one containing bright facets along which 

 ipture of the crystals has occurred — not an inter- 

 crystalline fracture) indicates by the size of the facets, 

 the general size of the crystal structure of the material," 

 scarcely correct in this unqualified form, seeing how 

 reatly the fracture may be made to vary according to 

 the method of producing it. 

 Dr. Rosenhain contributes seven articles, and these 

 )nstitute between one-third and one-quarter of the 

 itire metallographical section. He deals with (i) 

 some special alloys, (2) aluminium alloys, (3) the 

 licroscopic examination of metals, (4) the relations 

 >f strain and structure in metals, (5) the thermal and 

 lechanical treatment of metals, (6) the thermal study 

 )f metals, and (7) the microstructure of metals and 

 illoys. The most considerable of these is the article 

 )n the relations of strain and structure and the con- 

 ception of amorphous metal. The subject is handled 

 rith the author's well-known ability. It is well to 



NO. 2813, VOL. 112] 



remember, however, that the conception of amorphous 

 metal is not by any means generally accepted to-day 

 among metallographers, and it may be doubted whether 

 anything is gained by such a sentence as appears on 

 page 397 — " At the present moment indeed, even those 

 who, on certain grounds, vehemently oppose this 

 theory have no alternative to offer which can afford 

 any satisfactory explanation of the great group of 

 facts which this theory so readily co-ordinates." In 

 the section headed " Tempering and Quenching " 

 (page 411), Dr. Rosenhain attributes the hardening of 

 a carbon steel by quenching to " the development of 

 a very large number of minute crystallites of both a 

 iron and cementite," and the existence of an " envelope 

 of amorphous iron which is so highly viscous as to be, 

 in effect, an intensely hard solid." As to this, there is 

 no evidence of the formation of cementite in a properly 

 quenched steel. More causes operate in the hardening 

 of steel by quenching in water than are indicated in 

 this article. 



Sir George Beilby's striking work on metal aggregates 

 receives attention in two articles written by Mr. W. D. 

 Haigh on the aggregation of solids and the flow of 

 solids. There is a long and very useful article by 

 Dr. W. H. Hatfield on " Special Steels," which, with 

 the valuable article by Sir Robert Hadfield on " Man- 

 ganese Steels," does something to bring the " works " 

 atmosphere of applied science into this section of the 

 dictionary. The volume closes with a detailed index 

 of the subjects dealt with in aeronautics and metallurgy, 

 and finally with a general index of the principal articles 

 in the five volumes. H. C. H. Carpenter. 



Tubicolous Worms. 



(i) A Monograph oj the British Marine Annelids. Vol. 

 4, Part I : Polycha;ta — Hermellidse to Sabellidse. 

 Pp. vii -I- 250 -f- plates 11 2-1 27. 50^. net. (2) Vol. 

 4, Part 2 : Polychseta — Sabellidse to Serpulidae ; with 

 Additions to the British Marine Polychreta during 

 the Publication of the Monograph. Pp. xii-l-251- 

 539 + plates 115 -117 and 128-138. (Published for 

 the Ray Society). By Prof. W. C. Mcintosh. 

 (London : Dulau and Co., Ltd., 1922-23.) 505. net. 



THE volumes under notice constitute the last two 

 parts of " A Monograph of the British Marine 

 Annelids." The Council of the Ray Society in the 

 preface to the final volume, issued with the last part, 

 " believe that they are interpreting the feelings of the 

 members of the Society in offering to their President 

 congratulations on the completion of this monograph, 

 of which the first part was published no less than half 

 a centurj^ ago." This is an expression in which all 

 zoologists would wish to join, and rejoice that Prof. 



