MARY PREVITEâS SPEECH AT THE SIXTIETH ANNIVERSARY CELEBRATION OF THE LIBERATION OF THE WEIHSIEN CONCENTRATION CAMP. August 17, 2005 Weifang, Shandong Province, China. Honorable Mayor Zhang Xinqi, honorable friends of Weifang, you have earned our deepest gratitude by inviting us here to celebrate this Day of Liberation.
TIL that in 1669, Hennig Brand discovered phosphorus by boiling down urine and heating the residue to very high temperatures. He was trying to make gold though, and he hoped that the yellow color of urine meant there was gold in it. (chemicool.com) submitted 4 years ago by virnovus 8. 89 comments; share; save
X-ray machine. The first X-ray device was discovered accidentally by the German scientist Wilhelm Roentgen (1845-1923) in 1895. He found that a cathode-ray tube emitted invisible rays that could penetrate paper and wood. The rays caused a screen of fluorescent material several yards away to glow.homas Alva Edison invented an X-ray fluoroscope in 1896. American physiologist Walter Cannon used Edison's device to observe the movement of barium sulfate through the digestive system of animals and, eventually, humans.