Dr. W. H. Eccles on Coherers 

 Fijr. 4. 



.„ 10' 4 Ampere 



879 



Point Positive 

 Point Negative 



Volt 



0-2 0-4 



Iron-Mercury Detector. — Steady-Current Curves. 

 Additional Experiments. 

 A coherer was made by heating a polished iron plate in air 

 till rings of colour round the small heated area indicated that 

 the plate was covered with a thin film of oxide. The end of 

 a clean piece of iron wire was so held as to press on the plate 

 at any desired place with a constant force. The plate was 

 made one terminal of the coherer and the wire the other 

 terminal, and this coherer was examined in precisely the 



Iron Point on Oxidized Iron Plate (light blue film). 

 Applied voltage, 0'32. 



same way as the others. A typical series of measurements is 

 set forth in figs. 5 and 6. The curve connecting the energy 



