November 3, 1923] 



NA TURE 



647 



Thomdike's pages material throwing light on their 

 own special- studies. Medieval students may indeed 

 be congratulated on the appearance of a work which 

 will lighten their labours and illumine their path. Nor 

 is it only the specialist to whom it will appeal. Many 

 are puzzled by the extravagant claims sometimes made 

 to-day for the " Middle Ages." An attempt to pene- 

 trate the mass of medieval literature will probably 

 produce a strong reaction from an\ >iu h conceptions, 

 but the ordinary reader is liable to retire vanquished 

 before he has covered a tithe of the material or gained 

 any broad \ie\v of its course. Such readers will lie 

 grateful tq hnd in these volumes a thoroughly reiulahle 

 presentation of medieval thought, while 'e\ery page 

 provides e\ idence of the sources where each statement 

 may be verified. The admirably full and well-arranged 

 indices are a very welcome element. Prof. Thorndike's 

 work undoubtedly takes rank as an important con- 

 tribution to the history of civilisation. 



Dorothea Waley Singer. 



Chemical Works of Reference. 



(i) A Comprehensive Treatise on Inorganic and 

 Tlwrnu-firal Chemistry. By Dr. J. W. Mellor. Vol. 3 : 

 ( hi., Ca, Sr, Ba. Pp. x-f927. (London: 



Longmans, Green and Co., 1923.) f^;\s. net. 



(2) A Dictionary of Applied Cheniisiry. By Sir 

 Edward Thorpe. Vol. 4 : L-Oxydisilin. Revised 

 ami eiilar-eil editiui-i. Pp. \iii f 740. (London: 

 i,(iiiL;iii:i!' . ( li'f 1 ;i ;in(! ("o.. ii)22.) ')0>v. net. 



(3) Text r C/iniiistry. Edited by 

 T^ ' .hMi mend. Vol. 9, I'art i: Cobalt. 



.! the l-'Jcnients of the Platniiini droap. \)\ 

 J. Newioii l''riend. ((lrirrHr> S^ii n.t iiic Text-books.) 

 Second edition, revised. Pp. xxv -rjO;. (London: 

 ( . (irithn and Co., Ltd., 1922.) i8,v. net. 



(i) 'T^IIE third volume ol Dr. Mrl|Mi\ uieat tivatiM 

 X deals with the tun iiiad--, iupprr, sil\tr. 

 L'ltld, and < .ilrium. ^trMiitinni, iMrinin. I'l ,1 w . m k :<\ 

 > iv(\vv 111 u'liirh the cji-nifn; 



ol less 1: a text l)n(,k, 1' 



adopted ' ■il.iin di.ad-. 



■I, the anthdi- 



i ":ii I'.iii and 



iili ir ' .ilrjiiiii 



th. 



,hl. 



iMiliil ill 

 aiT 



tha^ 

 the 

 sepa 



interpolation of copper, silver, and gold between the 

 alkalies and the alkaline earths is, of course, a con- 

 cession to the law of octaves as expressed in Mendeleeff 's 

 series of thirteen short periods. 



In addition to the disadvantage of separating the 

 alkalies and the alkaline earths, the arrangement 

 suffers from the drawback that copper, silver and 

 gold may be regarded as forming a first stage in the 

 winding up of the anomalies of the metals of the 

 transition series. They therefore exhibit, in an 

 attenuated form, the influence of the phenomena of 

 co-ordination, which dominates so fully the chemical 

 properties of the elements which immediately precede 

 them in the periodic classification. It is therefore a 

 real disadvantage that the wide range of amines and 

 of double salts which are formed by these metals are 

 described at a stage when the theory of co-ordination 

 has not yet been discussed. 



In his preface the author states tiiat he has been 

 much pleased with the general reception which the first 

 two volumes have received. The reviewer can confirm 

 from his own experience the value of the author's 

 treatise, even at the present stage, when scarcely half of 

 the work is available for reference, and is confident that 

 the treatise when complete will be of very great service 

 to all serious students of inorganic chemistry. 



(2) The fourth volume of the new edition of the 

 " Dictionary of Applied Chemistry " covers the section 

 from L to 0, with the exception that the articles on 

 oxygen, ozone, etc., are held over for a later volume. 

 In the section now published there has been a con- 

 siderable expansion, from 600 to 740 pages. While 

 most of the princii)al articles in the xolume have con- 

 tributed somethiiiL; to this increase of length, the most 

 notable changes an to in found in the series of articles 

 under the headin;^ ■ Nitrogen." The article on 

 nitrogen itself do(> not appear to have been altered 

 \ ( r\ Ld'taiK ; luit in wriliii- the >cciion on the manu- 

 lacturc ol nitric a.cid. Prof. Ilart has secured the 



Ji.ii.MiMi iMii III Pr. F. C. Zeisberg, of Du I'ont de 



d Coinpanx. and a > oinpletilv new Miies 



'ha-raius is gixcn li' ilhi-.trate niodci-n pr,icti(c in 



:'■ manufacture oi tln> ,e id. In addition to this, the 

 earlier article on the ntili>at ion ol ,itnio>pliiTic nitr. ^ucn 

 ' ' an aniclr o| iuail\- three times 



- R . I'artniL'lt 'ii. in w hn h a nuich 



fuller aecoi; 1 oi the \an<iii. pi : the 



fixation ot inio'.^n .ind "I the method^ u-iu i^i tlie 

 oxidation ot anininiua to ml m ac id. 



( ;, The e. mImI edition o| 1 M". Imk lid"- ' 



!(-;'■■ '■, 111 let < omnielit , Mill e \ er\ llttlt ;i.-;i 



h,: de 111 the hook , a j u 1 1 lioin the ailihtinii of 



.->onie noie.s on the deieetioii and otiniation o| the 

 ]>latiniiin nulals. It is, huwt\ er, notew oi t h\ that tlic 



NO. 2818, VOL. F 1 2 J 



