During the 1480s Leonardo had begun to develop a treatise on painting, which was to cover the theoretical knowledge on the appearance of the natural world that a painter should master. Over time this led Leonardo into separate fields of scientific investigation – anatomy, light, the movement of water, the structure of plants and so on. These reached their climax between 1506 and 1512, when Leonardo was in his fifties.

Leonardo aimed to publish several of these investigations as illustrated books, but he was never satisfied with partial knowledge, and could not bring any of his researches to a conclusion. At Leonardo’s death his scientific work remained among his private papers. His researches were barely known beyond his immediate circle, and not properly published until the years around 1900.