548 



SOIENOE. 



[N. S. Vol. IX. No. 224. 



Periods,' 'Pliocene Beds,' 'Pleistocene Accu- 

 mulations,' ' The Steppe Period,' etc. 



The abysmal origin of the black shales of the 

 Ordovician, with graptolites, is defended on the 

 following grounds : The persistence of lith- 

 ological characters over wide areas ; their re- 

 placement by much greater thickness of normal 

 sediments along ancient coast lines ; the fre- 

 quent occurrence together of blind trilobites 

 and those with abnormally large eyes, and the 

 interstratification of the black shales with 

 radiolarian cherts similar to the modern 

 abysmal radiolarian oozes. 



The glacial origin of the boulder beds of the 

 Talchin stage of the Indian series, proposed by 

 W. T. Blanford, is accepted ; and confirmatory 

 evidence is cited in the cases of the similar signs 

 of glaciation in beds of a corresponding age in 

 Australia, South Africa and southern Brazil. 



As a digest of the general facts of British 

 geology in its special nomeclature the book will 

 be of value to those who have not access to the 

 fuller treatises. 



Henry S. Williams. 



The Examination of Water {Chemical -and Bac- 

 teriological). By William P. Mason. New 

 York, John Wiley & Sons. 1899. Pp. 135. 

 The progress that has been made during the 

 last decade in methods of sanitary "water analy- 

 sis, and especially in the interpretation of 

 the results of such analysis, amply justifies 

 an attempt at the marshalling of the new 

 data and the revaluation of the old. To both 

 students and practical workers the need of 

 a really modern treatise in the English lan- 

 guage has become imperative, and Professor 

 Mason's little book will, on this ground, be cor- 

 dially received. It will be a fact regretted by 

 many, however, that the present work is so 

 limited in scope. While the author correctly 

 insists upon the paramount importance of a 

 complete knowledge of the source of a sample 

 of water and of the conditions under which the 

 sample is collected, and rightly emphasizes 

 the futility of ' standards ' of purity, he has 

 evidently not intended to include in this book 

 any discussion of some of the other and most 

 vital problems of water analysis. 



The various methods for the determination of 



chlorine, nitrites, nitrates, free ammonia, albu- 

 minoid ammonia, etc., and the other significant 

 chemical tests are described in the second chap- 

 ter, and the author's selection of recommended 

 methods will, on the whole, meet with gen- 

 eral approval. The useful ' normal chlorine ' 

 maps, prepared respectively by the Massachu- 

 setts and Connecticut State Boards of Health, 

 are reproduced and the hope is expressed that 

 the task of the water- analyst will, in the future- 

 be made still easier through the preparation of 

 similar charts by other Commonwealths. 



Some analysts will consider that more stress 

 might have been profitably laid upon the Heh- 

 ner method for the determination of ' perma, 

 nent hardness,' especially in view of the fact 

 that this method has been found greatly su- 

 perior to the ' soap test ' in dealing with the 

 waters in some parts of the United States. In 

 this chapter, too, it will occasion some surprise 

 to find no reference whatever to the Kjeldahl 

 niethod for determining organic nitrogen. 



In the chapter upon bacteriological exami- 

 nation the author seems to be treading on 

 less familiar ground than in the preceding sec- 

 tion. In his description of the method of prep- 

 aration of sugar bouillon the importance of the 

 preliminary removal of muscle-sugar is over- 

 looked, as is the fact that the indol test may 

 be vitiated by the presence of muscle-sugar in 

 the broth. Bliquel's method of examination 

 and his theory of ' auto-infection ' of waters are 

 given a much more important place than would 

 be accorded them by most bacteriologists. The 

 author's statement on p. 117 that ' great cold is 

 not fatal to germ-life ' certainly needs some 

 revision. Edwin O. Jordan. 



A Monograph of the North American Potentilleae. 

 Bj' Per Axel Rydberg. Memiors from the 

 Department of Botany of Columbia Univer- 

 sity. Volume II. Issued November 25, 1898. 

 4to. Pp. 223. 112 plates. 

 Some years ago Dr. Per Axel Rydberg, a 

 Scandinavian botanist educated in America, 

 became interested in the group of the Rose 

 Family which contains the Cinquefoils, and 

 which have been known as the Potentilleae. 

 Finding in the great collections of Columbia 

 University (now transferred to the New York 



