SPECTROSCOPY IN INDUSTRY 



By Geobge R. Harrison, Ph. D. 

 Massachusetts Institute of Technology, Cambridge, Mass. 



[With 4 plates] 



The spectroscope, long recognized as one of the most powerful 

 tools of scientific investigation, has been used during the past 40 

 years to obtain information which has revolutionized physics, chem- 

 istry, and astronomy, and greatly affected biology, metallurgy, and 

 medicine. Since many modern industries rest on scientific discoveries 

 in these fields, it would be surprising if the spectroscope were not 

 found useful in connection with technological processes. So rapidly, 

 in fact, are spectroscopic methods now being adopted by industrial 

 laboratories, that most manufacturers of spectroscopic equipment 

 are having difficulty in keeping up with orders for their instruments, 

 and some are even beginning to worry about the availability of such 

 raw materials as crystal quartz, needed for prisms and other optical 

 parts. Spectroscopic methods have been found particularly valuable 

 in the metals industries, in those industries which involve the can- 

 ning and packaging of foods, and in all other industries which use 

 materials whose purity must be carefully determined and controlled. 



The spectroscope has served the physicist and the astronomer as a 

 telescope, a microscope, a speedometer, a thermometer, a tape meas- 

 ure, and a clock, in addition to its more usual functions ; and in each 

 role it has exceeded in range and power the more common forms of 

 these devices. Today in industry its greatest usefulness is found in 

 applications which supplement chemical wet methods of qualitative 

 and quantitative analysis, and with its aid our ability to detect and 

 measure small quantities of material has been extended very greatly. 



As has often been pointed out, a teaspoonful of salt cannot hide 

 from a spectroscope in a swimming pool full of water. Though 

 far less gold than would repay concentration is found in sea water, 

 the spectroscope has no difficulty in detecting the small amount which 



1 Presented at a meeting of The Franklin Institute held Thursday, February 3, 1938. 

 Reprinted by permission from the Journal of the Franlclin Institute, vol. 226, No. 1, 

 July 1938. 



203 



