Salt may be made from human excrements, burnt and calcined, made
into lees and dried slowly at a fire, and all the excrements produce
salt in a similar way and these salts when distilled, are very
strong.

[Footnote: VASARI repeatedly states, in the fourth chapter of his
_Introduzione della Scultura_, that in preparing to cast bronze
statues horse-dung was frequently used by sculptors. If,
notwithstanding this, it remains doubtful whether I am justified in
having introduced here this text of but little interest, no such
doubt can be attached to the sketch which accompanies it.]