Optical telescope
The telescope is more a discovery of optical craftsmen than an invention of a scientist. The lens and the properties of refracting and reflecting light had been known since antiquity and theory on how they worked were developed by ancient Greek philosophers, preserved and expanded on in the medieval Islamic world, and had reached a significantly advanced state by the time of the telescope's invention in early modern Europe. But the most significant step cited in the invention of the telescope was the development of lens manufacture for spectacles, first in Venice and Florence in the thirteenth century, and later in the spectacle making centers in both the Netherlands and Germany. It is in the Netherlands in 1608 where the first recorded optical telescopes (refracting telescopes) appeared. The invention is credited to the spectacle makers Hans Lippershey and Zacharias Janssen in Middelburg, and the instrument-maker and optician Jacob Metius of Alkmaar.
History of tracheal intubation
While all these surgical advances were taking place, many important developments were also taking place in the science of optics. Many new optical instruments with medical applications were invented during the 19th century. In 1805, a German army surgeon named Philipp von Bozzini (1773–1809) invented a device he called the "lichtleiter" (or light-guiding instrument). This instrument, the ancestor of the modern endoscope, was used to examine the urethra, the human urinary bladder, rectum, oropharynx and nasopharynx. The instrument consisted of a candle within a metal chimney; a mirror on the inside reflected light from the candle through attachments into the relevant body cavity. The practice of gastric endoscopy in humans was pioneered by United States Army surgeon William Beaumont (1785–1853) in 1822 with the cooperation of his patient Alexis St. Martin (1794–1880), a victim of an accidental gunshot wound to the stomach. In 1853, Antonin Jean Desormeaux (1815–1882) of Paris modified Bozzini's lichtleiter such that a mirror would reflect light from a kerosene lamp through a long metal channel. Referring to this instrument as an "endoscope" (he is credited with coining this term), Desormeaux employed it to examine the urinary bladder. However, like Bozzini's lichtleiter, Desormeaux's endoscope was of limited utility due to its propensity to become very hot during use. In 1868, Adolph Kussmaul (1822–1902) of Germany performed the first esophagogastroduodenoscopy (a diagnostic procedure in which an endoscope is used to visualize the esophagus, stomach and duodenum) on a living human. The subject was a sword-swallower, who swallowed a metal tube with a length of 47 centimeters and a diameter of 13 millimeters. On 2 October 1877, Berlin urologist Maximilian Carl-Friedrich Nitze (1848–1906) and Viennese instrument maker Josef Leiter (1830–1892) introduced the first practical cystourethroscope with an electric light source. The instrument's biggest drawback was the tungsten filament incandescent light bulb (invented by Alexander Lodygin, 1847–1923), which became very hot and required a complicated water cooling system. In 1881, Polish physician Jan Mikulicz-Radecki (1850–1905) created the first rigid gastroscope for practical applications.