Discovered Thallium and invented the Crookes tube
The Crookes Tube
William Crookes invented the Crookes tube around 1869. The invention of the Crookes tube helped William in many other experiments which later helped the discernment of x-rays.
In 1861 Crookes discovered the element of Thallium. William Crookes had some sulfuric acid that was given from a friend. He removed all the selenium and observed it with a spectroscope. William noticed a yellow green light that was unusual to everyone. He named this element Thallium after the Greek word Green twig.
CATHODE RAYS, CROOKES TUBES AND THE DISCOVERY OF THE ELECTRON