639

On chemical materials.

Salt may be made from human excrement burnt and calcined and made into lees, and dried by a slow fire, and all dung in like manner yields salt, and these salts when distilled are very pungent.

Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.

VII * X
Notebooks of Leonoardo da Vinci
VIII: Botany for Painters and Elements of Landscape Painting.
. . .
619,
620,
621,
622,
623,
624,
625,
626,
627
Of preparing the panel.
628
The preparation of oils.
629,
630,
631,
632,
633,
634
On varnishes [or powders].
635,
636,
637
On chemical materials.
638,
639,
640,
641,
642,
643,
644,
645,
646,
647,
648,
649,
650
The relation of art and nature.
651,
652
Painting is superior to poetry.
653,
654
Painting is superior to sculpture.
655,
656
Aphorisms.
657,
658,
659
. . .