He may be one of the fifteenth centuryâ€™s best known scientists and empiricists, but Leonardo has become synymous with mystery and obscurantism.
The smoke which blurs the features of his most famous painting, also coils around the edges of these burnt-brown anatomy drawings and the plans he made elsewhere for real world inventions.
So today it could be his legacy is most present in antiquated pen and ink studies like this, and in the backward-facing handwriting that accompanies them.
Itâ€™s not that we learned so much from his observations and blueprints. Leonardo is said to have kept his findings to himself. His machines were too fantastical for his era.
But filmmakers and game designers make heavy working use of the aesthetic of his private, ochre drawings and script. Skulls like these crop up all the time in movies and intro sequences.
It hardly need be mentioned that the secretive mood evoked by the old masterâ€™s researches also inspired one of the 21st centuryâ€˜s best selling books.
In fact, the closer Leonardo came to understanding humanity and improving our lot, the further we now plunge him into the realms of the arcane and the hidden.
In our times of mapped DNA, our love of these smoky studies could be a nostalgia trip. I hope one day they can revisit our own scientific reports with as much delight.
This work can be seen in Leonardo Da Vinci: Painter at the Court of Milan, The National Gallery, London. The show runs until 5 February 2012 see gallery website for more details.