May 23, 19(12.] 



SCIENCE. 



817 



ists, of theoretical views then under discus- 

 sion, of their plans for travel and for 

 lecturing, of their publications in periodicals, 

 separates of which they forward to each other, 

 as well as of purely personal and domestic 

 matters, and but rarely of political questions. 

 All the letters are given in full for reasons 

 named by Dr. Kahlbaum in the preface. 



About the year 1860 Schonbein wrote to 

 Liebig of finding antozone in fluorite froia 

 Wolsendorf, and the Munich chemist re- 

 plied that he had taken much pains to secure 

 more of the mineral, but in vain; 'all the gold 

 in the world' would not buy it, for no more 

 could be found. In 1863 Liebig had the sad 

 news to communicate of domestic affliction in 

 the loss of a daughter, Frau Carriere. In this 

 intimate way the friends exchanged words 

 of sympathy, their hopes and fears, successes 

 and discouragements, as well as their likes 

 and dislikes. 



The bibliographical and biographical notes 

 added by the editor increase greatly the value 

 of the interesting volume, which closes with 

 a letter from Liebig to Schonbein's widow, 

 dated September 8, 1868; in this he refers to 

 his forty-six years of acquaintance with his 

 Swiss friend whom he first met in student 

 days at Erlangen. 



Henry Careington Bolton. 



Handhooh for the Electrical Laboratory and 

 Testing Room. By Dr. J. A. Fleming. Vol. 

 I., Equipment, Resistance, Current, Poten- 

 tial, Power. London, The Electrician 

 Printing and Publishing Company; New 

 York, D. Van Nostrand Co. 8vo. Pp. 

 538. $5.00. 



Notwithstanding the shower of electrical 

 books that has poured from the press for the 

 past few years, comparatively few text-books 

 have appeared which are well adapted for use 

 in the American colleges of engineering. 

 There has particularly existed a deficiency in 

 the list of books available for the purposes of 

 individual instruction and reference in the 

 electrical laboratories. And a new book de- 

 signed for this special purpose must be re- 

 ceived with interest. 



The widely and favorably known name of 



the author of the book before us adds to the 

 interest in this volume, and an examination 

 of the book shows that such an interest is 

 justified. The volume (which the author 

 proposes to supplement by a later one) con- 

 tains five chapters, respectively setting forth 

 the author's view of a proper laboratory 

 equipment (190 pages), the measurement 

 of electrical resistance (148 pages), the- 

 measurement of electrical current (82 pages),, 

 the measurement of electromotive force 

 (48 pages) and the measurement of elec- 

 tric power (63 pages). It is proposed to com- 

 plete the work — as announced in the preface — 

 by a second volume devoted to the measure- 

 ments of capacity, inductance, electric quan- 

 tity, the magnetic testing of iron, photometry 

 and the testing of electric lamps, the testing of 

 electric batteries, electric meters, dynamos, 

 motors and transformers. It is thus apparent 

 that the book now in hand intentionally deals 

 solely and somewhat abstractly with the meas- 

 urement of the several fundamental electrical 

 quantities which enter into various engineer- 

 ing tests, but a consideration of these tests 

 is postponed until the later volume. We are 

 therefore perhaps justified in assuming that 

 this volume is intended for preliminary in- 

 struction in the laboratory where electrical 

 engineering tests and measurements are ac- 

 tually executed in full. This assumption 

 places a book of this character in its most 

 favorable relation towards the instruc- 

 tion in American engineering colleges, and 

 we will consider it from this point of view. 

 No adequate book occupies this place, and a 

 suitable one would be joyfully hailed by all 

 teachers whose fortunes require them to direct 

 college laboratories devoted to electrical engi- 

 neering. 



For text-book purposes, this volume, however, 

 does riot favorably appeal. More than thirty- 

 five per cent, of the text is contained in the 

 first chapter, which deals with the arrange- 

 ment of electrical testing laboratories and the 

 equipment which the author believes is desir- 

 able to have laid down therein. This is an 

 interesting portion of the book, and contains 

 much valuable suggestive matter. It may be 

 read with profit by any teacher of electrical 



