Description
Autograph Letter Signed, to Mr. Suffolk, thanking him for his valuable suggestion, agreeing to grind some slides and “to mount some of the spectera. It seems to me that this method will answer perfectly”. 1 page 4 x 7 inches, engraved heading, in good condition, one minor repair. Grand Hotel Eastbourne, 26 September 1899. Sir William Crookes, F.R.S. (1832-1919), physicist, inventor and chemist, discovered thalium (1861). In 1875 he invented the radiometer. Crookes’s name is preserved in his vacuum tubes. He did not invent the vacuum tube with a cathode and anode to produce an electric current, but his Crookes tubes were superior. With them he discovered the basic properties of the electric discharge, or cathode ray, from which J.J. Thomson was to discover the electron, confirming Crookes’s own views on the nature of cathode rays.