The main workroom in Justus von Liebig's laboratory in Giessen, Germany, 1842. Liebig (1803-1873) was a German chemist and professor who devised the method of using a laboratory to teach his students, an innovation that remains central to modern instruction. In this drawing, professors and students alike wear hats to keep the ashes from charcoal burners out of their hair. The arrangement of the lab and its equipment soon became standard for chemistry teaching labs: workbenches with cupboards, shelves, water supply and sink; and, at the back, air shafts for dealing with noxious gases. On the tables are such items as beakers, flasks, evaporation basins, bell jars and mortars, all still familiar to chemistry students today.