SCIENCE— ADVERTISEMENTS 



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THALOFIDE CELL" 



A NEW LIGHT REACTIVE RESISTANCE 

 OF GREAT SENSITIVITY 



These new cells will lower their electrical resistance 50 per cent. 



on exposure to .25 of a foot candle when the source used is a 



Tungsten Filament. Special cells are constructed which will do 



this in .06 of a foot candle. 



Their recovery after exposure is extremely rapid as also is 

 their response to the light stimulus which 

 is in marked contrast to the Selenium Cell, 

 especially on exposure to very low light 

 intensities. 



Write for Particulars 



Case Research Laboratory 



AUBURN, NEW YORK 



