664 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1913. 



which may in the future be presented in a similar Avay to this or 

 other institutions of learning and to return to these institutions for 

 use in scientific research the entire profits arising from such business. 

 As the methods and aims of this new movement have already been 

 elsewhere fully treated,^ they may here be passed over, but on account 

 of both the intrinsic scientific interest and the Institution's asso- 

 ciations with it, the subject of electrical precipitation of suspended 

 particles will be presented in some detail chiefly by compilation from 

 articles which have appeared in various scientific journals - amplified 

 somewhat from unpublished notes on the work, furnished for the 

 purpose by members of the technical staffs, at present busied with 

 these developments. 



HISTORY OF ELECTRICAI. PRECIPITATION. 



The removal of suspended particles from gases by the aid of elec- 

 tric discharges is by no means a new idea. As early as 1824 we 

 find it suggested by Hohlfeld^ as a means of suppressing ordinary 

 smoke, and again a quarter of a century later by Guitard.* These 

 suggestions, which do not seem to have stimulated any practical 

 study of the question, were soon entirely forgotten and only brought 

 to light again by Sir Oliver Lodge ^ many years after he himself had 

 independently rediscovered the same phenomena and brought them 

 to public attention in a lecture before the Liverpool section of the 

 Society of Chemical Industry, November 3, 1886.*^ The first recorded 

 attempt to apply these principles commercially appears to have been 

 made at the Dee Bank Lead Works. The general principle of elec- 

 trical precipitation of suspended matter was at this time patented 



1 Report of the Secretary of the Smithsonian Institution for the year ending June 30, 

 1912, pp. 3-5. Also " The Research Corporation, an Experiment in Public Administra- 

 tion of Patent Rights," F. G. Cottrell ; Report of the Eighth International Congress of 

 Applied Chemistry, vol. 24, pp. 59-69, September, 1912. Also reprinted Journal of In- 

 dustrial and Engineering Chemistry, vol. 4, pp. 864-867, December, 1912. 



2 " The Electrical Precipitation of Suspended Particles," by F. G. Cottrell, Journ. Ind. 

 and Eng. Chem., vol. 3, 542-550, August, 1911. " Electrical Fume Precipitation," by F. G. 

 Cottrell, Trans. Amer. Inst. Min. Eng., vol. 43, pp. 512-520, 755-762 (New York meeting. 

 February, 1912). "The Control of Dust in Portland Cement Manufacture by the Cottrell 

 Precipitation Processes," by Walter A. Schmidt ; reprint Eighth Inter. Congress Applied 

 Chem., vol. 5, pp. 117-124, 1912 : also reprinted from Journal Industrial and Engineering 

 Chemistry, vol. 4, pp. 719-723, October, 1912. " Electrical Precipitation of Suspended 

 Particles," by Linn Bradley, Trans. Amer. Electrochemical Soc, vol. 22, pp. 489-497, 1912. 

 " Electrical Precipitation of Cement Dust," Philip S. Taylor, Journ. Electr. Power and 

 Gas, Mar. 14, 1914. 



3 " Das Nicderschlagen des Rauchs durch Electricitat Hohlfeld," Kastner Archiv. Naturl., 

 vol. 2, pp. 205-206 (1824). 



* C. F. Guitard, Mechanics Magazine, Nov., 1850. 



■^Historical Note on "Dust Electrification and Heat," O. J. Lodge, Nature, vol. 71. 

 p. 582 (1905). 



« " The Electrical Disposition of Dust and Smoke with Special Reference to the Col- 

 lection of Metallic Fumes and to a Possible Purification of tlie Atmosphere," Journ. Soc. 

 Chem. Ind., vol. 5, pp. 572-576 (1886), with appended bibliography. 



