JnLY 24, 19141 



SCIENCE 



139 



new research. Through most of the book this 

 is very well done, but the causes of climatic 

 change through geologic time do not find ade- 

 quate treatment. There is, for instance, a 

 rather extensive presentation and commenda- 

 tion of the several hypotheses of a wandering 

 pole, but almost no discussion of the influence 

 of changing atmospheric composition and none 

 of such factors as a possible reversal of the 

 oceanic circulation or possible changes in solar 

 radiation. The absence of a dynamic proof of 

 polar wandering adequate to account for cli- 

 matic change makes it seem to the reviewer 

 the least supported of all the climatic hy- 

 potheses. 



To sum up this volume in a sentence — it is 

 in the broad and admirable treatment of the 

 present processes of sedimentation and in the 

 interpretations which they give to the older 

 sedimentary rocks that the book wiU. be found 

 to have its unique value. 



Joseph Barrell 



Some Fundamental Problems in Ohemistry. 



By E. A. Letts. New York, D. Van Nos- 



trand Co. 1914. 15 X 22 cm. Pp. v -f 235. 



Price $2.50. 



In the preface the author says that one of 

 his " chief ideas was to contrast certain ancient 

 views, such as those of atoms and a primordial 

 element or primordial elements in the shai)e of 

 air, earth, fire, and water, together with the 

 possibility of transformations of these latter 

 into each other, with the modern conception of 

 electrons and the discovery of changes, such 

 as those which the radioactive elements experi- 

 ence, which amount in fact to a change of one 

 so-called chemical element into others. . . ." 

 It is perhaps a question whether many readers 

 wiU agree with the author that these two 

 modern discoveries prove that even in science 

 history may repeat itself; but fortunately one 

 may like the book without accepting the 

 author's thesis. 



•The book consists of four chapters on the 

 older chemistry and seven on the newer chem- 

 istry. Under older chemistry the subheads 

 are: ancient theories regarding the nature of 

 matter and more recent theories as to the 



nature of energy; the atomic theory and 

 atomic weights; the periodic law. There is 

 nothing especially interesting or novel about 

 this portion of the book and it might well have 

 been omitted, thus giving the author an 

 opportunity to amplify the portion on the 

 newer chemistry, which is very interesting. 



The newer chemistry, as understood by the 

 author, deals with the effects of electrical dis- 

 charges on gases in high vacua, radioactivity, 

 Lockyer's theory of inorganic evolution, and 

 Arrhenius's views on the birth and death of 

 worlds. This part is admirable though dis- 

 tinctly not critical. The author apparently 

 accepts, without much reservation, all the 

 transmutations which Eamsay has described. 



With Pliicker tubes as a starting-point the 

 author discusses the production of cathode 

 rays when the degree of exhaustion is in- 

 creased, and the properties of these rays. 

 From cathode rays he passes to canal rays and 

 thence to Eontgen rays. After that come Bee- 

 querel rays and then the discovery of radium 

 by the Curies. The properties of the a, /?, and 

 y rays are discussed and then the decomposi- 

 tion products of radium. The facts in regard 

 to the production of helium are followed by an 

 account of Eamsay's experiments on the 

 alleged formation of lithium, carbon and neon. 

 The author does not point out, as he well 

 might have done, that it would be in the in- 

 terest of science for Ramsay either to accept 

 Mme. Curie's work on lithium or to repeat it 

 and show wherein the discrepancy occurs. 

 The present state of things is distinctly not 

 creditable, and Eamsay's unwillingness to 

 meet the situation raised by Mme. Curie's 

 work on the alleged production of lithium has 

 caused Ramsay's work on the alleged produc- 

 tion of carbon and neon to be received with 

 much suspicion. The last chapter on radio- 

 activity deals with J. J. Thomson's discussion 

 of the periodic law on the basis of the electron 

 theory. 



The chapter on inorganic evolution may be 

 summed up as follows: In the very hottest 

 stars we find hydrogen, helium, asterium and 

 doubtless other gases still unknown. At the 

 next (lower) temperatures, we find these gases 



