952 



NATURE 



LDi:<_imber 29, 1923 



1 111 h a well-known icxt-lwok, would 



id .j.ti.in of a uniforni ti-chniquc. 



il bacteria, 

 (I,, orL'anisrns 



,1,,. 11 :> : .i\ I- Iwen 



giviu u- i .lu.ni 



bacteria an 



connexion i"ui ■ ■!■ .m 



rapidly iIkiulm! "t l'." i' n.i .imi .1. hm- 



amoelK* " ■'' 'li<- iMrtt-na mn^t he 



Considi . ''iiplcx i)()|)ul.iliuii u\ thf 



soil. '■ ' ■ "KNTON. 



If/M/' r.xiDnlmilum H , '. /; w; . Compiled 



m/ W//;< hi^/'tiliir. 



. , ; :n, I'lrcboiS, lluistuij^ 



!'!^/',-,in)- iiiitl Shotfirer. By Prof. 

 j. I. i.f.iMi. r.iii I. I'p. viii f-258. Part 2. Pp. 

 vi + 259-5.i'>- l''iit ,v i'])- vi + 547-872. (New 

 York and London ; M( (".raw -Hill Book Co. Inc., 

 1923-) 3piiris.T,--^.<Hl. 

 Thk object of ilic woik under notice is, as stated In the 

 author in his jm la( r. that of " enabling candidates to 

 |)a^^ sui ( csstul cxaniinations for positions of responsi- 

 bility in ( (lal mining," and it consists of a set of answers 

 to no Uss than 2975 questions, set in examinations in 

 the various coal-mining states of the United States of 

 America and in ( anada lur \ariiius -rades of colliery 

 olhcials. Opinions will ( crlainly (lifter as to whether 

 lliis is the best wa\ ol (lualitying a man for the duties 

 that he will ha\e to perform after he has passed such 

 examinaiion ; it may readily be granted that a man, 

 gifted with an exceptional memory, might get off by 

 rote the whole of the answers to the questions given in 

 these three \ dluincs and would thus with ordinary luck 

 pass successlulh any of the examinations referred to, 

 but it is also ww certain that this fact would not 

 qualify him to hold a position as a responsible under- 

 ground ofli( ial. I'he educational value of such a book 

 is therefore very tjuestionable. At the same time the 

 work has been well done. Prof. Beard has Ixcn the 

 Principal of the School of Mines, International Corre- 

 spondence Schools, Scranton, Pa., Secretary to the 

 State Board of Mining Examiners. Iowa, and has held 

 many other positions that qualily him thoroughly for 

 the work that he has undertaken, and his book may be 

 used with e\ery confidence in its accuracy. It must, 

 however, be borne in mind that coal mining methods, 

 legislation, and nomenclature are so different in the 

 United States from what they are in Great Britain that 

 many of the answers given would prove seriously mis- 

 leading to British candidates for similar positions in 

 the latter country. 



The Properties of Matter. By Prof. Basil C. McEwen. 



Pp. vi-t-3i6. (London : Longmans, Green and Co., 



1923.) 10^. 6d. net. 

 As a text-book, this work differs from its predecessors 

 in the order of treatment of the subjects. Commencing 

 with the First Law of Thermodynamics and the more 

 general Principle of the Conservation of Energy, a 

 logical sequence leads to the study of the kinetic theory 

 of matter, which is most easily treated in connexion 

 with the gaseous state. The continuity of the gaseous 

 and liquid states supplies the natural transition to a 

 detailed study of liquids, and solids are dealt with last 



NO. 2826, VOL. 1 12] 



of all. The reviewer can recommend this ord< 

 his own experience in lerHirini.' to university «' 

 and is of theopi 

 fH)ok reaches a 1 

 of the latter halt are n 

 I ii iiiti r on < aj)illarity sc 

 Mot luiitain many 



, ,,. iii-;ti!i' ' i-" ' .. t vi....n 



enerL'\ i> i 



Is \C1 \' sill U i , .U H I 



new tdition is (all' 



then include an account 01 me ( r\ sialline structure of 



solids as revealed bv X-rav analysis. H. S. A, 



references to modem work. 



^i.rf;,, i. tension and <'<ri ,. 

 i'he chapter 01 

 '•• ' xpandcd wu.ii 1 

 the author will 



Mai I oil I 



\W Dr. 



•U 1- 



l'".\i k\- [)ractitioner ol nicaieuie li ircjuentls : 



to n ronimend a climate suitable for convales* 



for a chronic disease ; few doctors can acfjuirc from 



experience the geographical and metenroloiriral know- 



leclLie to enable tl ■ 



to this iinporlani 



H.iwkins ])ni\ides a \olume on the subject, i' 



his own expen 



numerous mi 



arrangement o 



indications fol 



and climate oi 



.1 til 



information derive;. .._ 

 ;)ul)lications. The main 

 I . -. i^ ,, geographical, therr>'>'"» 

 iwiiiL'^ the descriptions of the 

 \arious districts and towns, i nere 

 also a separate ehapter on therapeutics of the English 

 climate, in which the classification is based on n 

 In one appendix the health resorts are t.i 

 according to seasonal suitability, and in the other the 

 waters of the various Spas are described. 

 . In spite of the complexity of the subject, information 

 with regard to locality or disease can readily be found, 

 and reference is facilitated by the inclusion of a lar^e 

 number of meteorological (harts and the addition of a 

 well-preparnl indt \. I'he hook will be of considerable 

 value to plnsii ians and others interested in medical 

 climatology. 



The Elniicnls of Co-ordinate Geometry. By S. L. Loney. 



Part 2 : Tnlinear Co-ordinates, etc. Pp. viii-t-22S. 



(London : Macmillan and Co.. Ltd., 1923.") 6s. 

 This part of Prof. Loney 's " Co-ordinate Geometr\ '" 

 contains, in order, chapters on cross-ratio geometr\ . 

 trilinear and areal co-ordinates, tangential equations, 

 reciprocation, projection, and invariants of conies. 

 Methods of teaching geometry have advanced consider- 

 ably in the last twenty years, and the arrangement 

 adopted by Prof. Lom'\- would scarcely be accepted as 

 the natural one now. I rilinear and areal co-ordinates 

 are here introduced from the purely metrical point of 

 view. Now it would be more customary* to read the 

 chapters on projection and reciprocation first and then 

 to treat trilinears and areals as particular cases of 

 homogeneous co-ordinates. 



Coming from an experienced teacher of mathematics, 

 the book -ixes all necessary assistance to a student 

 reading its subject-matter for the f"irst tiuK- in the order 

 treated. Abundant examples are given, but those on 

 homogeneous co-ordinates include a greater proportion 

 of metrical questions than a present-day teacher would 

 endorse {e.g. pp. 85-87, Nos. i, 2, 6. 7. i^'. 17. 20. 22, 

 23, 24). 



