June 28, 1907] 



SCIENCE 



999 



the skies clear, the stroll through the park 

 to the golf ehib was greatly enjoyed by the 

 members, many of whom visited the Phipps 

 Conservatory on their way. 



In connection with the postprandial ex- 

 ercises resoliitions of thanks to the officers 

 and trustees of the Carnegie Institute and 

 the various generous citizens of Pittsburg 

 who had provided for the comfort of the 

 association were passed, and the association 

 finally adjourned to meet in Chicago on 

 May 5 as the guests of the Art Institute 

 of Chicago, the Field Museum of Natural 

 History and the Chicago Academy of Sci- 

 ences, which united in tendering a joint 

 invitation to the association to hold its next 

 meeting in Chicago. 



A committee on the publication of the 

 'Proceedings' of the meeting, consisting of 

 Dr. W. J. Holland, Dr. George A. Dorsey 

 and Professor P. M. Eea, was appointed. 

 A full account of the meeting, together 

 with the papers read will be issued. 



The meeting is declared by all who were 

 present to have been most enjoyable, and 

 the American Association of Museums is 

 tindoubtedly firmly established as one of 

 the national societies which is destined in 

 coming years to exert a very beneficial in- 

 fluence upon the wide field of activities 

 which is represented by the museums of 

 art and of science in America. 



SCIENTIFIC BOOKS 

 Clays; Their Occurrence, Properties, and 

 Uses, with especial reference to those of the 

 United States. By Heineich Eies, Ph.D., 

 Assistant Professor of Economic Geology in 

 Cornell University. Pages xvi and 490. 

 ZsTew York : John Wiley & Sons ; London : 

 Chapman & Hall, Limited. 1906. 

 This comprehensive and well-balanced trea- 

 tise on clays devotes the first five chapters, 

 2Y6 pages, to the origin, the chemical and 

 physical properties and kinds of clays, and to 

 the methods of mining and manufacture. 



Chapters VI. and VII., 183 pages, describe the 

 distribution of clays in the United States. 

 The last chapter, of seven pages, is devoted to 

 an account of the fullers' earth, including its 

 properties, methods of mining and uses, and 

 distribution in the United States. 



In the special state descriptions the subject 

 matter is set forth in the order of the geo- 

 logical formations as permitting the greatest 

 uniformity of treatment, and as involving the 

 least amount of repetition. In those states 

 with which the present reviewer is most famil- 

 iar, the descriptions are adequate and well 

 presented, though necessarily in a concise 

 manner. 



For this part of the work the author is 

 peculiarly well prepared from first-hand ac- 

 quaintance, since he has personally examined 

 and written reports on the clays for the 

 geological surveys of a number of states, as 

 well as for the United States Geological 

 Survey. In these reports will naturally be 

 found much of the matter of a general nature 

 of the present treatise, since a general dis- 

 cussion of the origin, properties, and varieties 

 of clays would be an appropriate and desirable 

 introduction to the detailed description of 

 their occurrences in the state reports, yet it 

 must not be inferred that the general or intro- 

 ductory part of the volume before us is a 

 mere compilation and repetition of the ma- 

 terial already published in the several state 

 reports by the author. As a matter of fact 

 there is much in the introductory chapters 

 and in the illustrations that has not ap- 

 peared in any of these reports. 



The clay resources of the different states are 

 not equally well known, hence some inequality 

 in the state descriptions, through no fault, 

 however, of the author, because some of the 

 important clay states, like Illinois for in- 

 stance, have very little literature bearing on 

 their clays. 



In discussing the origin of clays the author 

 emphasizes the facts that in the decomposition 

 of feldspar, CO, is not an essential factor, 

 since the mineral is decomposed by water 

 alone; and that other feldspars besides ortbo- 

 clase yield kaolinite. He also opposes the 

 recently advanced view of Eosler that the 



