Fluorescent lamp began with the Geissler tube continued as even better vacuums were produced. The most famous was the evacuated tube used for scientific research by William Crookes. That tube was evacuated by the highly effective mercury vacuum pump created by Hermann Sprengel. Research conducted by Crookes and others ultimately led to the discovery of the electron in 1897 by J. J. Thomson and X-rays in 1895 by Wilhelm Roentgen. But the Crookes tube, as it came to be known, produced little light because the vacuum in it was too good and thus lacked the trace amounts of gas that are needed
Carl August Wilhelm Berends junger Ärzte am Krankenbett" (Education of Young Physicians at the Bedside), in which he described his experiences at the Thielschen Krankenhaus in Frankfurt. Shortly after his death in 1826, his one-time student, Karl Sundelin, published Berends' lectures on practical medical science (""Vorlesungen über die praktische Arzneiwissenschaft""). Carl August Wilhelm Berends Carl August Wilhelm Berends (April 19, 1759 – December 1, 1826) was a German physician born in Anklam, Pomerania. He studied medicine at Viadrina University in Frankfurt an der Oder, where in 1788 he became a professor of medicine. In 1811 he moved to the University of Breslau, being due