Research Tools: Timeline of Anatomy and Printing

Herophilus teaches anatomy in Alexandria, Egypt. While teaching, he performs dissections of human bodies. He is considered by many to be the founder of modern human anatomy. None of his original texts survive to modern times, but his work is heavily drawn on by later authors including Greek physician and philosopher Galen.

Galen, a prolific researcher, author, and a practicing physician in Rome, produces works on human anatomy ca 150. These are derived from his dissections of apes, monkeys, cows, dog, as well as his experience treating injuries. Roman law restricts human dissection. Later, knowledge of Greek anatomical treatises is lost to Western Europeans in the Early Middle Ages, but is retained in Byzantium and the Islamic world where scholars translate Greek anatomical treatises into Arabic.

Galen’s anatomical treatises, along with others, are translated from Arabic into Latin. Later translations are made from the Greek originals.

The first European Medical School is founded at Salerno, Italy, where human bodies are publicly dissected. In 1316, Mondino de’Liuzzi stages public dissections in Bologna, Italy, and produces his major work Anatomia Corporis Humani, considered the first modern dissection manual, which will remain in widespread use through the 16th century.

To make a woodcut, an engraver starts by drawing an image, usually a tracing of a pencil drawing, onto the side grain of a wood plank. Areas not printed are cut away well below the surface with a knife or gouge, leaving the flat surface to be inked.

In the 1400s, paper becomes available in Western Europe. Soon thereafter, the earliest known European woodcut print is done on paper in 1423. Once moveable type is invented in the 1450s, the printing process is forever changed. Woodcuts can be put into type blocks along with moveable type, so that the image and type can be printed together in one run through the press. The Gutenberg Bible is printed in 1455.

In copperplate engraving, an engraver copies a drawing onto the surface of a copper plate. Areas that will be white when printed are cut away below the surface with a sharp tool, leaving the flat surface to be inked. Copperplate engravings allow for finer lines and more detail than woodcuts, but the printing of the image requires more pressure than type or woodcuts (leaving a characteristic line of indentation around the image). Because of this difference in pressure, if moveable type on the page is desired then the page has to be run through the press twice, once for the image and once for the type.

The world’s first permanent anatomical theater opens at the University of Padua, Italy, demonstrating the importance of dissection and anatomical studies to medical education.

The first illustrated printed medical book is published in Venice by Johannes de Ketham, Fasciculus Medicinae, which translates to “little bundle of medicine”. The first edition included six illustrations.

Leonardo da Vinci though an artist not a physician, occasionally performs dissections as part of his wide-ranging research. Based on this work he generates ink drawings with annotations of muscles and nerves. While dissection is not illegal or prohibited by the church in this time, it is not universally accepted as appropriate behavior by his patrons in Rome.

Andreas Vesalius publishes the first profusely illustrated printed anatomy, De Humani Corporis Fabrica. After performing his own dissections, Vesalius refutes some previously accepted anatomical and physiological tenets established by Galen.

In etching, a plate is covered with a thin, acid-impervious coating. Lines are drawn through the coating with a stylus, exposing the metal of the plate. An application of acid then eats into the exposed areas. The longer the plate is exposed to acid, the deeper the bite and stronger the line. An etching usually has a free and spontaneous appearance, with great delicacy of line, but can also mimic the formality of engraving.

Unlike other engraving techniques, mezzotint proceeds from dark to light. A metal plate is totally abraded with a tool called a rocker. If inked and printed at this point, it produces an even, rich black. The design consists of areas of tone rather than lines, and is produced by smoothing areas of the plate with a scraper or a burnishing tool. The more scraping or burnishing, the lighter the area. The resultant illustrations have effects of light and shadow. By printing multiple color layers, different shades can be combined to produce rich hues that look much like oil painting.

Anatomists Jan Schwammerdam, Frederik Ruysch and others create anatomical specimens and museums. Govard Bidloo starts an artistic movement toward greater anatomical realism. The first art academies are founded and anatomy is a key part of the curriculum.

Anatomy ascends to a prominent position in the medical curriculum. Anatomists begin to dissect systematically and produce anatomical atlases profusely illustrated in changing styles based on their dissections.

Jacob Christoff Le Blon is widely recognized as the first to create trichromatic mezzotint prints utilizing layers of yellow, red, and blue. This method was popular for anatomical figures and historical subjects. His student Gautier d’Agoty perfected a method of printing colored layers of mezzotint and produced dramatic anatomical prints with this method.

In wood engraving, an engraver draws an image on polished blocks of dense end-grain wood (usually boxwood). Tools similar to metal engraving are used to produce non-printing lines. The uncut surface takes the ink and prints onto paper. The block can be inserted into a frame along with moveable type, and the entire page can be printed in one run through the press. The process allows for more detail than the older woodcut technique.

In lithography, a design is drawn or painted on a polished or grainy flat surface of a stone with a greasy crayon or ink. This image is chemically fixed on the stone with a weak solution of acid and gum arabic. The stone is flooded with water, which is absorbed everywhere except where repelled by the greasy ink. Oil-based printer’s ink is then rolled on the stone, which is repelled in turn by the water-soaked areas and accepted only by the drawn design. A piece of paper is laid on the stone and run through the press with light pressure. The design may be divided among several stones, properly registered, to produce a lithograph in more than one color through multiple printings on the same page.

Photography is a process invented in the 1830s and ‘40s in which an image is produced on a chemically sensitized surface by the action of light. Unlike previous processes of anatomical representation, the image created is a "copy" of the subject, produced by technology, not recreated by the hand of an artist.

The X ray is a form of radiation produced by accelerating a flow of electrons through a vacuum tube. In 1895 Wilhelm Roentgen performed experiments showing that radiation emitted by this process could pass through flesh and other low-density substances that are opaque to ordinary light, but not bone. Roentgen discovered that X rays could produce viewable images of the interior of the body on a photographic plate or on a screen with a fluorescent coating ("fluoroscope").