142 



NATURE 



[October 25, 1917 



by Mr. F. A. Kirkpatrick on the literature of travel 

 we meet a number of scientific names in circum- 

 stances in which physical and biological science 

 find much of their primary impulse for research. 

 Prof. J. W. Adamson contributes a most valuable 

 chapter on the history of education ; and, finally, 

 a chapter on the changes in the language since 

 the time of Shakespeare, by Mr. W. Murison, may 

 be commended to all those who are interested, as 

 all of us ought to be, in the literary exposition of 

 scientific work. 



THE RARER ELEMENTS. 

 Introduction to the Rarer Elements. By Dr. P. E. 

 Browning. Fourth edition, thoroughly revised. 

 Pp. 250. (New York : J. Wiley and Sons, Inc. ; 

 London : Chapman and Hall, Ltd., 1917.) Price 

 75. net. 



WE are pleased to find that in spite of the 

 unrest of the present time it has been pos- 

 sible to publish a fourth edition of the above well- 

 known work. Browning's Introduction to the 

 study of the rarer elements was first published in 

 1903 as a hand-book for the use of students. The 

 work was successful from the first; a second 

 edition appeared in 1908, and a third in 1912. 

 Since then many new facts have been established, 

 and the present issue has been revised and brought 

 up to date, forming a valuable book of reference 

 for practically all that is known about the history, 

 sources, and properties of the rarer elements; 

 numerous reactions are included that will help in 

 the separation and analysis of these little-known 

 bodies. 



The general plan of the work is to give parti- 

 culars of the discovery, occurrence, extraction, and 

 properties of each element, etc., and to conclude 

 with some practical laboratory work ; although the 

 author disclaims any attempt at exhaustive 

 treatment, the student will find much valuable 

 information in its 250 pages. It may be a little 

 startling to the English reader to find in the index 

 to the literature of the subject that, out of twenty- 

 five references quoted, fifteen are American, seven 

 German, two French, and one British ! It is only 

 fair, however, to note that most of the American 

 references are from the Smithsonian Collection 

 of Miscellaneous Papers. 



All the rarer elements, including the rare earths 

 and the rare gases of the atmosphere, are detailed, 

 and a special chapter is devoted to the radio- 

 elements. This latter section, contributed by 

 Prof. B. B. Boltwood, is brief and is con- 

 fined to the well-established data and reactions of 

 these interesting bodies, and their position In the 

 periodic table. The significance of atomic num- 

 bers and the theory of isotopes are also discussed. 



In this chapter a good deal of new matter is 

 introduced ; among other things it is stated that 

 "the chief source of radium has been the minerals 

 containing a higher proportion of uranium, 

 principally carnotite, and the present supply has 

 been largely obtained from the carnotite ores of 

 south-western Colorado." We rather hesitate 

 NO. 2504, VOL. 100] 



to endorse this. Carnotite is a uranium- 

 potassium-vanadate, and authoritative analyses of 

 picked specimens give about 60 per cent, uranium ; 

 but the records of the Bureau of Standards, Wash- 

 ington, show that the commercial ores that are 

 being worked do not contain much more than 2 per 

 cent, uranium. On the other hand, the pitch- 

 blende deposits of St. Joachimsthal give 60 per 

 cent, to 80 per cent. UgOg, and those from Corn- 

 wall and other localities are of the same character. 



In the section devoted to spectroscopic re- 

 actions, a spectrogram is given of certain gallium 

 and iridium products ; this illustration may be of 

 interest from the point of view of pure research, 

 but as a spectrum reproduction it falls very short 

 of what it is possible to do at the present day. 

 The same must be said of the set of six examples 

 of the absorption spectra, of didymiurn, erbium, 

 etc. ; some of these have scales of wave-length 

 that are difficult to read, others are so bad that 

 their value is quite lost, while the erbia series has 

 no scale at all, and in the table of spark spectra 

 of sixteen elements an arbitrary scale is used — 

 this scale could have been given in Angstrom 

 units, which would have added greatly to its 

 value. The list of wave-lengths of the dominant 

 arc and spark lines of the elements is a very good 

 feature and of real value. 



A short chapter is devoted to " some technical 

 applications," and many of the more prominent 

 uses to which the rarer elements have been applied 

 are described. This is an exceedingly important 

 section. When we consider that from this group 

 of bodies, many of which but a few years ago were 

 quite unknown and others simply regarded as 

 chemical and mineral curiosities, have come the 

 incandescent mantle, the metal filament lamp, the 

 pyrophoric alloys, the new steel alloys that are 

 playing such a prominent part in ordnance, naval 

 construction, and engineering, the production of 

 X-rays as in the Coolidge tube, and a host of 

 other minor applications, it must become evi- 

 dent to the most casual observer that the study 

 of these substances gives promise of very sub- 

 stantial reward. 



It does not seem too much to suggest that the 

 application of the rarer elements may, In the 

 near future, rival in value the coal-tar and other 

 industries that are at the moment occupying so- 

 much attention. 



A very Interesting diagram is given showing 

 at a glance the chief associates of the rare 

 elements In natural and commercial products, 

 but for some reason that is not clear the radio- 

 elements have been left out of this scheme. 



We congratulate the author upon the original" 

 form of index that has appeared In the last 

 two editions — a device of very great convenience. 

 Against each element is noted the page where the 

 discovery, extraction, compounds, separation, 

 experimental work, spectrum, and technical 

 application are to be found : this enables one to 

 put one's finger in a moment upon any subject 

 needed and is of the greatest convenience. 



J. H. Gardiner. 



