June 28, 1900] 



NATURE 



195 



adopted, and information is here given for that purpose. 

 The Bessemerising of copper mattes is briefly described. 

 Silver-copper smelting and refining is limited in its 

 application to ores comparatively free from sulphur, 

 arsenic, and lead, and therefore but little used. The 

 plant employed is specified and illustrated by diagrams 

 and tables. The book concludes with a short account 

 of the various wet methods used for argentiferous slimes. 

 The author's attempt to cover the ground embraced by 

 such a wide subject within a moderate compass will, with 

 the aid of tables and summaries, prove most valuable 

 both to practical men and to students. 



OUR BOOK SHELF. 

 The History of Lnttguage. By Henry Sweet, M..'\. 



Pp. xi + 148. (London : J. M. Dent and Co., 1900.) 

 There are few living scholars who are so well qualified 

 as Dr. Sweet to write a thoroughly comprehensive intro- 

 duction to the science of language. He is, as is well 

 known, one of the foremost European authorities on 

 phonetics ; but at the same time he is a profound and 

 original thinker on those psychological aspects of lin- 

 guistic science in which few phoneticians take any 

 interest. And while possessing a competent knowledge 

 of Indogermanic comparative philology in its latest 

 developments, he is preserved from the narrowness of 

 view of the mere Indogennanist by having made a prac- 

 tical study of Arabic, Finnish and Chinese. Notwith- 

 standing its small size, this " priiner" is a very remark- 

 able book. In completeness of outline, it is superior to 

 any elementary manual of the subject known to us ; and 

 it is no mere arid skeleton, but contains a good deal of 

 novel and interesting illustration of the principles ex- 

 pounded. Perhaps it is not quite so easy to master as 

 a " primer" is usually expected to be. Although strictly 

 elementary, in the sense that it assumes no previous 

 philological knowledge on the reader's part, it does 

 undoubtedly demand considerable power of close atten- 

 tion and some trainmg in habits of scientific thought. 

 It will therefore probably be less acceptable to absolute 

 beginners than to those who have already some general 

 knowledge of the subject and desire to render their con- 

 ceptions of it more systematic and precise. Even by 

 advanced philological scholars it may be studied with 

 interest and profit. 



The contents of the book may be said to consist of 

 three portions : an exposition of the general principles 

 affecting the development of language, an outline of the 

 history of the Aryan family of languages, and a state- 

 ment of the author's views as to the exterior affinities of 

 Aryan and the locality in which it was developed. Per- 

 haps the third part is somewhat out of place in an ele- 

 mentary book, but it is at any rate interesting. Dr. 

 Sweet's hypothesis is that primitive Aryan arose in 

 Scandinavia out of a mixture of the language of Ugrian 

 conquerors with that of the aboriginal population among 

 whom they were absorbed. This is not now such a 

 startling heresy as it would have been a few years ago, 

 though it is not likely at present to find a ready welcome 

 from Indogermanists. The apparent affinities between 

 Aryan and Ugrian certainly seem too striking to be due 

 to mere coincidence, but it is a long step from this admis- 

 sion to the acceptance of the definite theory here pro- 

 pounded. The writers who have hitherto advocated 

 somewhat similar views have always discredited their 

 case by their ignorance of philology and their lack of 

 scientific caution. It is to be hoped that Dr. Sweet will 

 give to the world a full exposition of the grounds on 

 which his conclusions are based. Whether he succeeds 



NO. 1600, VOL. 62] 



in the establishment of his particular thesis or not, he 

 can hardly fail to make a valuable contribution towards 

 the ultimate solution of the question. 



Micro-organisms and Fermentation. By Alfred Jorgensen. 



Pp. xiii-l-318. (London: Macmillan and Co., Ltd., 



1900.) 

 The study of the biology of fermentation has made 

 considerable progress in recent years. The knowledge 

 that has been gained of the nature and mode of action 

 of the living agents in question is mainly due to the 

 efforts of foreign observers. Through the investigations 

 of Pasteur, and most notably of Hansen, the subject 

 became a recognised branch of methodical and practical 

 inquiry. To be in a position to employ the essential and 

 to exclude the deleterious agents in a fermentative pro- 

 cess is to substitute scientific for haphazard methods. 

 This, briefly put, is the aim of technical mycology, and 

 the gain to a given industry is considerable, as e.g. in 

 brewing and distilling operations. Of the books dealing 

 with micro-organisms and fermentation. Dr. Jorgensen's 

 has long occupied a leading position, and hardly requires 

 an introduction to the specialist. The new edition just 

 issued has been completely revised, and the English 

 translation has been well done by Dr. A. K. Miller and 

 Mr. A. E. Lennholm. Dr. Jorgensen's reputation as a 

 teacher and investigator, as well as his intimate associa- 

 tion with Hansen, place this work above the ordinary 

 run of text-books. The first chapters deal with the 

 methods of microscopical and physiological examination 

 of micro-organisms, and the methods for obtaining and 

 utilising pure cultures of the useful races of sac- 

 charomyces are described. The examination of water 

 and air is next dealt with— a subject of importance on 

 account of the injurious organisms that may exist in the 

 air and water of a brewery. The chapter on bacteria is 

 somewhat incomplete. The technical mycologist has 

 commenced to study the bacteria more closely, and a 

 fuller account of this branch of the subject will be found 

 in Lafar's book. An interesting account is given of the 

 alcohol-forming bacteria, and of certain symbiotic fer- 

 ments, e.g. Kephir and the ginger-beer plant. The 

 moulds of importance in technical work are fully dealt 

 with. 



Of recent work, Buchner's "Zymase" is shortly 

 alluded to ; but more mention might have been made of 

 Calmette's investigations at Lille and S^clin upon the 

 symbiotic action of moulds and yeasts in the alcoholic 

 fermentation. The account of the alcoholic ferments in 

 Chapter v. is naturally the main and distinctive feature 

 of this work, and it will be particularly valuable to the 

 English reader on account of the lucid description it con- 

 tains of Hansen's investigations upon yeasts. The 

 I various species of bottom and top fermentation yeasts of 

 ' interest to the brewing chemist are fully dealt with. 

 The final chapter is devoted to the application of the 

 results of scientific research in practice. The value of 

 the book is added to by a number of illustrations and a 

 very full bibliography. As an introduction to the 

 morphology and biology of the alcoholic ferments, Dr. 

 Jorgensen's work leaves little to be desired, and consti- 

 tutes a valuable complement to the text-books which 

 deal mainly with the chemical side of the subject. 



.\. M. 



Photography in Colours. By R. C. Bayley. Pp. 74. 



(London : Iliffe, Sons and Sturmey, Ltd., 1900.) 

 This little book is practically a reprint of a series of 

 articles by the author which have already appeared in 

 a photographic periodical, but the subsequent revisions 

 and convenience of reference occasioned by their collec- 

 tion under one cover should render them more service- 

 able. The general principle has been to avoid techni- 

 calities and purely executive details, aiming rather to 



