INDEX. 463 



Electricity — 



Entire quantity of heat produced by the discharge 448 



Ignition and fusion of metallic wires by electrical discharges 449 



Laws of Electrical Ignition - 450 



1. Ignition in proportion to amount of charge 450 



2. Ignition of the wire in proportion to its length 451 



3. Ignition of wires in proportion to their thickness 452 



4. Ignition of wires of difl'erent metals - - 452 



Phenomena following ignition 453 



1. Tearingloose - 453 



2. Breaking into pieces - 453 



3. Fusion - - - 453 



4. Dispersion - - - 454 



Mechanism of fusion - 455 



Changes in the co-efficient of retardation of metals with increasing me- 

 chanical effects - -- 455 



Emory, Major W. H. , Survey of Mexican Boundary Line 48 



Engraving, Bradford's improvement in_ - 31 



Engravings, Proposed catalogue of, and exhibition 45 



Estimates of Keceipts and Expenditures for 1857 — 81 



Exchanges, Account of, during 1856 34 



Exchanges, Statistics of for 1856 - 47 



Executive Committee, Report of -. - - 78 



Expenditures during 1856 - - - 80 



Experiments on Testing Building Material — - 305 



Explorations, Mexican Boundary Line, Major Emory 48 



Llano' Estacado, by Captain Pope 49 



Fort Riley to Bridger's Pass, by Lieutenant Bryan 50 



Missouri and Yellowstone, by Lieutenant Warren — 50 



Upper Missouri, by Dr. Hayden 51 



Washington Territory and California, by Drs. Cooper and Suckley. 51 



Petaulma, California, by E. Samuels 52 



Texas, Kansas, Nebraska, and Utah 52 



Regions east of the Missouri 52 



Other portions of the world 53 



Behring's Straits, by Captain Rogers 63 



La Plata, by Captain Page - 53 



Exploring Expeditions, List of aU that have been made by government 61 



Fishes of the New York Market 253 



Fishes, Tables for Measurements 301 



Fire-proofing of Buildings 147 



Forbes, Professor, Notice of Professor Harvey's Alga;"by 29 



Forest Trees, Report on, by Dr. Asa Gray 32 



Fund, General Statement of Condition of -- - 78 



Gallery of Art, Paintings and Engravings in 44 



Genth, F. A. , Researches on Ammonia Cobalt Bases. - - .- 28 



Geological Report of Trinidad _ - 281 



• Geological Surveys, List of all made byU. S - - 61 



Geology, Account of Professor Hitchock's Papers on 30 



Gibbs Wolcott, Researches on the Ammonia Cobalt Bases 28 



