The Golgi apparatus was observed in 1897 by Italian cytologist Camillo Golgi. In Golgi’s early studies of nervous tissue, he established a staining technique that he referred to as reazione nera, meaning “black reaction”; today it is known as the Golgi stain. In this technique, nervous tissue is fixed with potassium dichromate and then suffused with silver nitrate. While examining neurons that he stained by using his black reaction, Golgi identified an “internal reticular apparatus.” This structure became known as the Golgi apparatus, though some scientists questioned whether the structure was real and attributed the find to free-floating particles of Golgi’s metal stain. In the 1950s, however, when the electron microscope came into use, the existence of the Golgi apparatus was confirmed.