Xerography was invented in the late 1930s by an American patent lawyer named Chester Carlson. At first, engineers considered the idea useless and several years passed before the potential of the invention was appreciated by industry. During those years, IBM, Kodak, General Electric and RCA were among the companies that turned Carlson away. The Battelle Memorial Institute, a nonprofit organization, invested in Carlson's research and eventually signed a licensing agreement with a company called Haloid. Battelle and Haloid collaborated in research and demonstrated the technique in 1948. Haloid subsequently became Xerox.
Galen's medical works were regarded as authoritative until well into the Middle Ages. Galen left a physiological model of the human body that became the mainstay of the medieval physician's university anatomy curriculum, but it suffered greatly from stasis and intellectual stagnation because some of Galen's ideas were incorrect; he did not dissect a human body.  Greek and Roman taboos had meant that dissection was usually banned in ancient times, but in Middle Ages it changed: medical teachers and students at Bologna began to open human bodies, and Mondino de Luzzi (ca. 1275–1326) produced the ﬁrst known anatomy textbook based on human dissection.