November 21, 19 12] 



NATURE 



11^ 



which are social, not individual. Combined with 

 these comes the growth of totemism and the re- 

 cognition of emotions which we class indiscrimin- 

 ately as religious. 



The first part of the work is devoted to an 

 account of the customs in Melanesia, contributed 

 by Mr. R. W. Williamson. Needless to say, this 

 instalment is illustrated by a fine series of 

 photogfraphs. 



The work, as a whole, if it does not make all its 

 readers anthropologists, is admirably designed to 

 excite popular interest in a most fascinating 

 science. 

 Griindriss der Biochemie fiir Siudierende und 



Aerzte. By Prof. Carl Oppenheimer. Pp. 



vii + 399. (Leipzig: Georg Tliieme, 1912.) 



Price 9 marks. 

 The title of Prof. Oppenheimer's book is some- 

 what misleading. One expects to learn something 

 fundamental about the chemistry of living 

 organisms, but the subject matter is mainly con- 

 cerned with the chemistry of mammalian func- 

 tions. 



The book is divided into two sections. The first 

 consists of a description of chemical substances. 

 As such it comprises a synopsis of organic 

 chemistry with references to the biological source 

 and significance of the substances described. The 

 second section contains a brief outline of the 

 chemical processes concerned in mammalian 

 physiology. 



The scope of this book indicates that it is in- 

 tended for medical students preparing for their 

 examination in physiology. The compressed de- 

 scriptions render the reading dull, and at the 

 same time the amount of information is not suffi- 

 cient to make the book useful for reference pur- 

 poses. Bearing these points in mind there is no 

 doubt that the author has accomplished his pur- 

 pose. There is a clear, short statement concerning 

 the chemical properties of the different compounds 

 found in the body, a description of enzyme action, 

 and an outline of the chemical processes concerned 

 in the activity of the body. A knowledge of the 

 facts described would enable a student to pass 

 any ordinary examination in physiological 

 chemistry. H. E. R. 



Le spends of our Little Brothers : Fairy Lore of 



Bird and Beast. By Lilian Gask. Pp. 268. 



(London: G. Harrap and Co., n.d.) Price 



35. 6d. net. 



These stories, retold from the folk-lore of many 



lands, will inspire sympathetic interest in animal 



life in the young readers for whom they are 



written. From every point of view they are far 



better than the grotesque tales often supposed to 



be suitable for children. They tell of self-sacrifice, 



right relations of man to the creatures around him, 



the blessing of pit)', the wrong of wanton killing, 



the suffering caused by thoughtlessness, the origin 



of the totem as the bond of union between men, 



and many like matters. We have read the stories 



with interest, and congratulate the author upon 



her rendering of them. .\s a gift-book the 



collection merits wide distribution. 



XO. 2247, VOL. 90] 



LETTERS TO THE EDITOR. 

 [The Editor does not hold himself responsible for 

 opinions expressed by his correspondents. Neither 

 can he undertake to return, or to correspond with 

 the writers of, rejected manuscripts intended for 

 this or any other part of Nature. No notice is 

 taken of anonymous communications.] 



The Investigation of Flint. 



The remarkable body which we know as "flint" 

 was, in the early history of mankind in this part of 

 the world, as important, relatively to the general 

 conditions of life, as the metal " iron " is at the pre- 

 sent day. In order to interpret correctly the signifi- 

 cance of fractured flints — whether as due to man's 

 agency or to other causes — and also in order to infer 

 from the glaze, polish, colour, opacity, or other 

 features of a humanly worked flint what are the 

 geological and other physical conditions to which it 

 has been subjected, very definite and accurate know- 

 ledge of flint, only to be arrived at by careful quanti- 

 tative investigation, such as the skilled physicist and 

 chemist can bring to bear, is necessary. Yet the 

 entire scientific world is in a remarkable state of 

 ignorance with regard to flint. 



Flint has been neglected by the geologist, minera- 

 logist, chemist, and physicist for reasons which are 

 not very obvious. At the present moment there is 

 great need for a thorough study of flint, a study 

 which no one man can undertake and carry through. 

 At the same time, it is possible for an individual to 

 indicate what are the lines of investigation which 

 seem to be those which should be followed, and I 

 venture to make the attempt. 



(i) First, as to the history and nature of "flint." 

 By the word "flint" we understand the black-looking 

 siliceous nodules which occur in the upper chalk of 

 this country, and have been broken up and variously 

 altered and re-deposited in the Tertiary and Quater- 

 nary strata. Any investigation of " flint " as thus 

 understood must include an inquiry into the history 

 and nature of "chert," and of those flint-like con- 

 cretions which occur in both Tertiary and Mesozoic 

 strata. The history and the structure of agate must 

 also be compared with those of flint, since geodes of 

 agate are not only also composed of silex, but have 

 many properties in common with flints. 



It will be further necessary to distinguish and 

 account for the varieties of flint which are known to 

 occur in the chalk. Thus we have in the chalk of 

 the south of England not only nodular flints disposed 

 in distinct beds or horizons of stratification, but we 

 have also tabular flint formed in fissures which 

 traverse obliquely or vertically many feet of thickness 

 of chalk strata. We have also local varieties of 

 chalk-flints, some darker and greener when thin 

 splinters are examined, others yellower, and others 

 of a bluish tendency. Others, again, are somewhat 

 o^rcv and opaque. Some Lincolnshire flint appears 

 to differ in this way from Brandon flint. Such differ- 

 ences are also to be observed in the flints of different 

 horizons in one and the same chalk-pit. 



Some observers call those flints which, after frac- 

 ture, tend to develop a bluish glaze " chalcedonic " ; 

 but there are nodules which superficially look like 

 "flints" to be found in association with ordinary black 

 flints in the chalk of the south of Enafland, which 

 arc apparently true chalcedony throughout, nearly 

 transparent and colourless, with a bluish cloud in 

 the depths. These almost invariably are oblong 

 nodules embedding a sponge, and form beautiful 

 objects when cut and polished. Often they contain 

 (even when in the chalk) small quantities of iron, 

 which produce in the transparent chalcedonic sub- 

 stance striking patches of red and brown colour. 



