838 



SCIENCE. 



[N. S. Vol. VIII. No. 206. 



chloride solutions are oily to the touch and 

 serve to make cotton thread pliable. 



The reviewer does not wish to give the idea 

 that this work is chiefly technical ; it is not ; it 

 is a scientific text-book of the highest rank ; 

 but the author notices briefly many important 

 modern uses of common substances which are 

 not known to the average teacher of chemistry, 

 but should be known to the average advanced 

 student. We find descriptions and drawings of 

 apparatus for making argon, helium, liquid air 

 (Linde), liquid oxygen (both Pictet and Cail- 

 letet) and fluorine (Moissan). Each chapter 

 has an appendix on ' Technique and Experi- 

 ments,' in which the best laboratory and lec- 

 ture-room experiments are described with 

 drawings ; the author's previous books on inor- 

 ganic and organic preparations are guarantee 

 that this part of the work is excellent. 



One feature in the book calls for adverse 

 criticism. No mention is made of relations be- 

 tween the atomic weights and properties of ele- 

 ments till the close of the book, where one page 

 is given to relations like those existing between 

 the atomic weights of the halogens, and two 

 pages to the periodic system. No mention is 

 made of the periodic law as a generally recog- 

 nized law. The author says : " Mendelejeffhas 

 definitely stated that the properties of the ele- 

 ments are periodic functions of their atomic 

 weights ;" and this is the only reference. to such 

 a law. This seems to the reviewer a serious 

 blemish in a book otherwise so excellent. It 

 may be that the author feels towards the periodic 

 law as the Irishman felt towards government, 

 but at least a fuller discussion of the subject is 

 desirable. Surely the recognition given of late 

 years to the ' family' relations of the elements, 

 and the use of the periodic system throughout 

 text-books, have been a great help to students. 

 One misses this in the author's treatment of 

 the halogens, for example ; yet the single hal- 

 ogens and their compounds ai'e so well discussed, 

 and the chapter on iodine is such a master- 

 piece, full of information, some of which will be 

 new to most college professors, that it becomes 

 hard to criticise anything so good. 



This work is an excellent text-book for ad- 

 vanced college students ; it is an excellent book 

 of reference for the lecturer and high-school 



teacher, and it should be carefully read by col- 

 lege professors. E. R. 



Lecture Notes on the Theory of Electrical Measure- 

 ments. By William A. Anthony. New 

 York, John Wiley & Sons. Pp. 90. 

 This little volume is designed to furnish the 

 student with the broad outlines of the subject 

 treated, and to thus assist him in getting jjos- 

 session of the subject as more elaborately pre- 

 sented in a series of lectures. The funda- 

 mental equations upon which electrical measure- 

 ments are based are given, and the physical 

 conditions to which they apply are stated with 

 clearness. The book opens with a short chapter 

 on C.G.S. units. Then follow chapters on the 

 magnetic field, current, potential and electro- 

 motive force and resistance, with a statement 

 of Ohm's law. The international electrical 

 units are then treated. The general plan of 

 measuring resistance, current and potential is 

 explained, the instruments used being repre- 

 sented in diagram. The second branch of the 

 subject closes with a treatment of the methods 

 of calibrating amperemeters, voltmeters, re- 

 sistance sets and bridge wires. The remaining 

 portion of the work, comprising sixteen pages, 

 is devoted to the effects of the current in heat- 

 ing, glow and arc lighting, electrolysis and 

 electro-magnetic induction. The electro-mag- 

 netic circuit is also discussed. The book is 

 provided with an index and table of contents. 



F. E. N. 



The Mechanical Composition of Wind Deposits. 

 By JoHAN August IJdden. (Augustana Li- 

 brary Publications, No. 1.) Rock Island, 

 Illinois. 1898. Large 8vo. Pp. 69. 

 Professor Udden has for some years been 

 engaged in researches concerning the mechan- 

 ical composition of the loess skirting Mississippi 

 River, and has been led to a comparative study 

 of the composition of other deposits, especially 

 of eolic origin, and also to a highly-refined in- 

 vestigation of atmospheric dust ; and his prin- 

 cipal results, with many of the details, are in- 

 corporated in this memoir. For convenience, 

 he classifies wind-deposits in eleven grades, 

 from coarse gravel (8-4 millimeters in diameter) 

 to very fine dust (xj8~2d 5 niil'i°i6ters in diam- 

 eter), and the examination was so conducted as 



