ferrous sulfate
An astringent salt (FeSO 4 ), usually
obtained in the form of the pale green
efflorescent, crystalline heptahydrate (FeSO
4 .7H 2 O) as a byproduct,
and used extensively in the 19th century in the
production ofSPRINKLED
CALF , MOTTLED
CALF , and TREE
CALF bindings. Unfortunately, its use resulted
in severe deterioration of the leather in most
cases. It was also used in the execution of the JAPAN MARBLE .
It is sometimes used today in dyeing or finishing
with dyewoods to impart a blue-black shade to
leather, in the manufacture of writing inks, and
in engraving and lithography. Also called
"copperas," or "green vitriol." (237 )
![[CoOL]](/icons/sm_cool.gif){kind=icon}