CONTENTS. 



PAGE 



I. Researches in Telephony. By A. Graham Bell ... 1 

 II. ScheeWs Green : Its Composition as usunlbj prepared, and 

 Some Experiments upon Arsenite of Copper. By S. P. 

 Sharples, S. B 11 



III. Contributions from the Chemical Laboratory of Harvard 



College : — 



1. On the Ethers of Uric Acid. By H. B. Hill . . 26 



2. On Some of the Salts of Methyluric Acid, Q H^ (CH^) 



N^O^. By Oscar R. Jackson 36 



IV. Contributions from the Physical Laboratory of the Massa- 



chusetts Institute of Technology : — 



11. On the Effect of Temperature on the Viscosity of Air. 



By Silas W. Holman 41 



V. Contributions to the Botany of North America. By Asa 



Gray 51 



VI. Contributions from the Laboratory of S. P. Sharpies : — 



Schweinfurt Green : Some Experiments on the Action of 

 Arsenic Trioxide on Copper Acetate, with the View 

 of Investigating the Composition of the above Com- 

 pound. By E. R. Hills 85 



VII. Milk Analyses. By S. P. Sharples 98 



VIII. On a New Mode of Manipulating Hydric Sulphide. By 



JOSIAH P. CoOKE, Jr 113 



IX. On the Process of Reverse Filtering and its Application to Large 



Masses of Material. By Josiah P. Cooke, Jr. . . . 124 

 X. Contributions from the Physical Laboratory of Harvard 

 College : — 



12. On Vortex Rings in Liquids. By Johx Trow- 



bridge 131 



XL Contributions from the Physical Laboratory of Harvard 

 College : — 



14. On a New Method of Comparing the Electro-motive 



Forces of Two Batteries and Measuring their Inter- 

 nal Resistance. By B. O. Peirce, Jr. . . . 137 



15. On a New Method of Measuring the Resistance of a 



Galvanic Battery. By B. O. Peirce, Jr. . . 140 



