Attempts to print in colour were made prior to the eighteenth century, with varying degrees of success. The first medical book to contain a coloured illustration was Gasparo Aselli's De lactibus, sive Lactis venis (Milan, 1627), which includes a chiaroscuro woodcut in black, red, and two shades of brown. It was not until the publication of Sir Isaac Newton's Opticks in 1704, that the development of colour printing began to make significant progress. Newton's treatise provided a sound scientific foundation for colour theory, and it was not long before experimentation in colour printing was attempted. On the Continent the leading experimenter in colour printing was Jacques-Christophe Le Blon (1667-1741), who developed a three-colour method for printing illustrations. By using plates inked in the primary colours of yellow, blue, and red, Le Blon found they could be combined in various ways to produce any desired hue. Each plate was prepared using a mezzotint technique, which provided gradations of shading. Le Blon had acquired a privilege to publish a book of anatomical illustrations, but he died before the project could begin. One of Le Blon's pupils was Gautier d'Agoty, who appropriated his master's method, adding a fourth plate in black, which provided additional shades of grey and black. He also adopted Le Blon's ambitious plan to publish colour-printed anatomical plates with descriptive text. In 1745 eight plates of the muscles of the face, neck, head, tongue, and larynx were issued. A further twelve plates of muscles of the pharynx, torso, legs, and arms were published in 1746. The specimens for the illustrations were prepared by G.J. Duverney, lecturer in anatomy at the Jardin du Roi. The two sets of plates were combined, and issued as Myologie complete in 1746. In the dedication and 'advertisement' to this work Gautier d'Agoty claimed the invention of four-colour printing as his own, for which he obtained a copyright.
