viii MINUTES. [April 24, 



" The Chemical Work of the U. S. Geological Survey," by Frank 

 Wigglesworth Clarke, of Washington. 



" Recent Work on the Physics of the Ether," by Paul R. Heyl, 

 of Philadelphia. (Introduced by Prof. Harry F. Keller.) 



" Effect of Bleaching Powder Upon Bacterial Life in Water," 

 by Prof. William Pitt Mason, M.D., of Troy, N. Y. Discussed by 

 Prof. Kraemer and Dr. W. J. Holland. 



" The Detonation of Gun Cotton," by Prof. Charles E. Munroe, 

 of Washington. 



On motion it was ordered that a telegram conveying the Society's 

 good wishes and great regret at his absence from the meeting be 

 sent to Prof. Simon Newcomb. To this telegram a reply was re- 

 ceived from Prof. Newcomb thanking the Society for its kind greet- 

 ings which he highly appreciated. 



Afternoon Session — 2.30 o'clock. 

 William B. Scott, LL.D., Vice-President, in the Chair. 



" South American Fossil Cetacea," by Dr. Frederick W. True, 

 of Washington. Discussed by Prof. W. B. Scott. 



" The Destruction of the Fresh Water Fauna of Western Penn- 

 sylvania," by Dr. Arnold E. Ortman, of Pittsburgh. 



" The Stratigraphic Position of the Oolitic Iron-Ore at Blooms- 

 burg, Pa.," by Gilbert van Ingen, of Princeton. (Introduced by 

 Prof. W. B. Scott.) 



Albert A. Michelson, LL.D., Vice-President, in the Chair. 



" Machines and Engineering in the Renaissance and in Classical 

 Antiquity," by Prof. Christian Hiilsen, of Rome Italy. (Intro- 

 duced by Dr. W. W. Keen.) 



" On the Extent and Number of the Indo-European Peoples," 

 by Prof. Maurice Bloomfield, of Baltimore. 



"A Mechanical Device for the Tabulation of the Sums of 

 Numerous Variable Functions," by Prof. Ernest W. Brown, of 

 New Haven. 



" The Burning Bush and the Origin of Judaism," by Prof. Paul 

 Haupt, of Baltimore. 



