Jagadish Bose's Mercury coherer , which had the additional property of being self restoring, was "adopted" by Marconi for his radio receiver. Jagadish Bose had no interest in commercialising or patenting his design. It's history is somewhat of a sore point. Most Bengali's believe J.C. Bose was ripped off and not given due credit.

"Sir J C Bose's Diode Detector Received Marconi's First Transatlantic Wireless Signal of December 1901 (The “Italian Navy Coherer” Scandal Revisited)" https://www.tandfonline.com/doi/abs/10.1080/02564602.1998.11...

Non paywalled link https://www.cse.iitm.ac.in/~murthy/sirjcbose.pdf

https://en.wikipedia.org/wiki/Jagadish_Chandra_Bose

Anyhow, rather than grains and gravels of metal that had to be physically separated by tapping, the oil-film-over-mercury would reset on its own due to surface tension when the EM stimulation ceased. This allowed for higher "Baud".