314 Scientific Intelligence. 



should show. On the contrary, the water derived immediately 

 from snow at high altitudes, or from glaciers, contains no hema- 

 tite and is commonly intensely blue. The action of hydrated 

 ferric oxide is different, since its color is yellow, and when present 

 in very small amounts in the water, there is, so to speak, a struggle 

 between it and the organic matter ; if not overcome, the effect is 

 to make the water appear green to the eye. 



14. A Text- Book of General Physics for the use of Colleges 

 and Scientific Schools ; by Charles S. Hastings and Frederick 

 E. Beach; pp. viii, 768. Boston, 1899 (Ginn & Company). — 

 The appearance of a new high grade text-book of physics is an 

 event of much importance to all teachers and students in this 

 department. The authors are to be congratulated upon the 

 admirable manner in which they have treated the entire subject, 

 particularly for their success in adequately presenting so vast a 

 range of topics within the limits of a single moderate-sized 

 volume. The work is characterized by the very careful and 

 thorough treatment of the fundamental conceptions of the sci- 

 ence ; by the well-balanced relation between the different parts, 

 no one portion of the subject being sacrificed to another ; by the 

 clear and precise mathematical development of each successive 

 principle. At many points, moreover, though dealing with topics 

 often treated of, there is much that is fresh and suggestive ; this 

 is particularly true of the chapters on Light. 



The conciseness of expression and the mathematical, though 

 elementary, method of presentation adopted have the advantage 

 of brevity and accuracy, but they may leave much for the 

 teacher to do if his pupils are approaching the subject for the 

 first time. The student, however, who is properly prepared, will 

 find no serious difficulty, and his subsequent work in special 

 advanced fields will be much facilitated by the thorough ground- 

 ing in principles and methods which he has here obtained. 



Too much praise cannot be given to the publishers for the 

 admirable form in which they have placed the work before the 

 public. The page is clear and open, with no confused crowding 

 of mathematical expressions, while the excellence of topography, 

 illustrations and paper leaves nothing to be desired. 



II. Geology and Mineralogy. 



1. New facts regarding Devonian Fishes. Dentition of 

 Devonian Ptyctodontidea ; by C. R. Eastman; Am. Nat., vol. 

 xxxii, pp. 473-488 and 545-560. July and August, 1898. Some 

 new points in Dinichthyid Osteology ; by C. R. Eastman; Am. 

 Nat., vol. xxxii, pp. 747-768. October, 1898.— The first of these 

 papers is the result of study of the rich material from the State 

 Quarry fish-beds discovered by Prof. Calvin in the Devonian of 

 Johnson County, Iowa (see Ann. Rept. Iowa Geol. Survey, vol. 

 vii, 1897) ; private collections made by Mr. E. E. Teller and C. E. 

 Monroe from the Hamilton limestone quarries of Milwaukee, 



