Caput mortuum
Encyclopedia
Caput Mortuum is a Latin term whose literal meaning is "dead head" or "worthless remains", used in alchemy
and also as the name of a pigment
.
In alchemy, Caput Mortuum (alternately called nigredo) signified a useless substance left over from a chemical operation such as sublimation and the epitome of decline and decay; alchemists represented this residue with a stylized human skull, a literal death's head.
The symbol shown on this page was also used in 18th century chemistry to mean residue, remainder, or residuum. Caput mortuum was also sometimes used to mean crocus metallorum, i.e. brownish-red metallic compounds such as crocus martis (ferrous sulphate), and crocus veneris (copper oxidule).
pigment, used in oil paints
and paper dye
s. It was a very popular colour for painting the robes of religious figures and important personages (e.g. art patrons).
The name for this pigment may have come from the alchemical usage, since iron oxide (rust) is the useless residue of oxidization. It was originally a byproduct of sulfuric acid
manufacture during the 17th & 18th centuries, and was possibly an early form of the copperas process used for the manufacture of Venetian red
and copperas red.
Caput mortuum is also sometimes used as an alternative name for Mummy brown
(alternatively, Egyptian brown), a pigment that was originally made in the 16th and 17th centuries from ground-up mummies, and whose use was discontinued in the 19th century when artists became aware of its ingredients.
Alchemy
Alchemy is an influential philosophical tradition whose early practitioners’ claims to profound powers were known from antiquity. The defining objectives of alchemy are varied; these include the creation of the fabled philosopher's stone possessing powers including the capability of turning base...
and also as the name of a pigment
Pigment
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...
.
Alchemy and chemistry
The symbol shown on this page was also used in 18th century chemistry to mean residue, remainder, or residuum. Caput mortuum was also sometimes used to mean crocus metallorum, i.e. brownish-red metallic compounds such as crocus martis (ferrous sulphate), and crocus veneris (copper oxidule).
Pigment
Caput mortuum (variously spelled caput mortum or caput mortem), also known as Cardinal purple, is the name given to a purple variety of haematite iron oxideIron oxide
Iron oxides are chemical compounds composed of iron and oxygen. All together, there are sixteen known iron oxides and oxyhydroxides.Iron oxides and oxide-hydroxides are widespread in nature, play an important role in many geological and biological processes, and are widely utilized by humans, e.g.,...
pigment, used in oil paints
Oil painting
Oil painting is the process of painting with pigments that are bound with a medium of drying oil—especially in early modern Europe, linseed oil. Often an oil such as linseed was boiled with a resin such as pine resin or even frankincense; these were called 'varnishes' and were prized for their body...
and paper dye
Dye
A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....
s. It was a very popular colour for painting the robes of religious figures and important personages (e.g. art patrons).
The name for this pigment may have come from the alchemical usage, since iron oxide (rust) is the useless residue of oxidization. It was originally a byproduct of sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
manufacture during the 17th & 18th centuries, and was possibly an early form of the copperas process used for the manufacture of Venetian red
Venetian red
Venetian red is a light and warm pigment that is a darker shade of scarlet, derived from nearly pure ferric oxide of the hematite type. Modern versions are frequently made with synthetic red iron oxide.-Venetian red:...
and copperas red.
Caput mortuum is also sometimes used as an alternative name for Mummy brown
Mummy brown
Mummy brown was a rich brown bituminous pigment, intermediate in tint between burnt umber and raw umber, which was one of the favorite colors of the Pre-Raphaelites.-History:...
(alternatively, Egyptian brown), a pigment that was originally made in the 16th and 17th centuries from ground-up mummies, and whose use was discontinued in the 19th century when artists became aware of its ingredients.