Medicinal clay
Encyclopedia
The use of medicinal clay in folk medicine
goes back to prehistoric times. The indigenous peoples around the world still use clay
widely, which is related to geophagy
. The first recorded use of medicinal clay goes back to ancient Mesopotamia
. A wide variety of clays is being used for medicinal purposes - primarily for external applications, such as the clay baths in health spas (mud therapy), but also internally. Among the clays most commonly used for medicinal purposes are kaolin and the smectite clays such as bentonite
, montmorillonite
, and Fuller's earth
.
There are considerable problems with the exact nomenclature of various clays. No clay deposit is exactly the same and, typically, mineral clays are mixed in various proportions.
The overwhelming majority of clay mined commercially is for industrial uses, such as construction and oil drilling. Thus, the precise classification and chemical composition of these clays are somewhat secondary to their intended use. For practical purposes, the terms "bentonite
clay", "montmorillonite
clay", and "Fuller's earth
" are basically interchangeable.
On the other hand, the clays that are typically used for medicinal purposes have usually been discovered either based on local folklore, or by simple trial-and-error after investigations by various healing enthusiasts. And so, their discoverers may have been either not too concerned about these clays' precise scientific classification and chemical properties, or perhaps not necessarily adequately equipped to conduct such studies. Their primary, and often only, concern was the efficacy of any particular clay for some specific medical condition or conditions.
"Sodium bentonite / Calcium bentonite
" are the most commonly used medicinal clays today (Sodium bentonite for external use, Calcium bentonite for internal use), although there is no precise definition of what this term means. In fact, typically, "bentonite" refers to a wide spectrum of clays with a wide array of properties (such as a variety of colours). In alternative medicine
, often this is used as more or less a catch-all term for medicinal clays. Another such term is "montmorillonite", which is often interchangeable with "bentonite". Bentonite is included in the United States Pharmacopeia
, and the USP-grade bentonite is widely used in various pharmaceutical and cosmetic preparations as a compounding and suspending agent. It is not entirely clear where the source of USP-grade bentonite is located; it may be a mixture of various bentonites.
Galen
, the famous Greek philosopher and physician, was the first to record the use of clay by sick or injured animals back in the second century AD. This type of geophagy
has been documented in "many species of mammals, birds, reptiles, butterflies and isopods, especially among herbivores."
In particular, in Peru, Amazonian rainforest parrots of some 21 species gather at certain sites on cliff faces where bare soil is exposed, and eat the clayish soil. The soil they seek is highly specific, since they focus on a rather narrow band of exposed soil. What they seek is mostly clay that is less than 0.2 millimetre in particle diameter.
"The oldest evidence of geophagy practiced by humans comes from the prehistoric site at Kalambo Falls
on the border between Zambia
and Tanzania
(Root-Bernstein & Root-Bernstein, 2000)." Here, a calcium-rich white clay was found alongside the bones of Homo habilis
(the immediate predecessor of Homo sapiens).
(since the clay is consumed internally).
The Ebers Papyrus
of about 1550 BC (but containing the tradition going back many centuries earlier) is an important medical text from ancient Egypt. It describes the use of ochre
for a wide variety of complaints, including for intestinal problems, as well as for various eye complaints.
. Its use continued until the 19th century, as it was still listed in an important pharmacopoeia in 1848 (the deposits may have been exhausted by then).
As Pliny
reports about the Lemnian Earth,
Lemnian clay was shaped into tablets, or little cakes, and then distinctive seals were stamped into them, giving rise to its name terra sigillata
- Latin for 'sealed earth'. Dioscorides also commented upon the use of terra sigillata.
Another physician famous in antiquity, Galen
, recorded numerous cases of the internal and external uses of this clay in his treatise on clay therapy.
Clay was prescribed by the Roman obstetrician, gynecologist, and pediatrician Soranus of Ephesus, who practiced medicine around 100-140 AD.
All the above seem to have been bentonitic clays.
(980-1037 CE), the 'Prince of Doctors', wrote about clay therapy in his numerous treatises.
Ibn al-Baitar (1197–1248), a Muslim scholar born at Malaga, Spain, and author of a famous work on pharmacology, discusses eight kinds of medicinal earth. The eight kinds are
(1517‑1564) was interested in investigating the mystery of the Lemnian clay. In 1543, he visited Constantinople where, after making enquiries, he encountered 18 types of different products marketed as Lemnian Earth (he was concerned about possible counterfeits). He then made a special journey to Lemnos, where he continued his investigation, and tried to find the source of the clay. He discovered that it was extracted only once a year (on the 6th of August) under the supervision of Christian monks and Turkish officials.
Modern investigation has shown that this was a clay similar to the modern 'bentonite'.
Too much processing, likewise, may reduce the clay's therapeutic potential. In particular, Mascolo et al. studied 'pharmaceutical grade clay' versus 'the natural and the commercial herbalist clay', and found an appreciable depletion of trace elements in the pharmaceutical grade clay.
The use of medicinal clay in folk medicine
goes back to prehistoric times. The indigenous peoples around the world still use clay
widely, which is related to geophagy
. The first recorded use of medicinal clay goes back to ancient Mesopotamia
. A wide variety of clays is being used for medicinal purposes - primarily for external applications, such as the clay baths in health spas (mud therapy), but also internally. Among the clays most commonly used for medicinal purposes are kaolin and the smectite clays such as bentonite
, montmorillonite
, and Fuller's earth
.
There are considerable problems with the exact nomenclature of various clays. No clay deposit is exactly the same and, typically, mineral clays are mixed in various proportions.
The overwhelming majority of clay mined commercially is for industrial uses, such as construction and oil drilling. Thus, the precise classification and chemical composition of these clays are somewhat secondary to their intended use. For practical purposes, the terms "bentonite
clay", "montmorillonite
clay", and "Fuller's earth
" are basically interchangeable.
On the other hand, the clays that are typically used for medicinal purposes have usually been discovered either based on local folklore, or by simple trial-and-error after investigations by various healing enthusiasts. And so, their discoverers may have been either not too concerned about these clays' precise scientific classification and chemical properties, or perhaps not necessarily adequately equipped to conduct such studies. Their primary, and often only, concern was the efficacy of any particular clay for some specific medical condition or conditions.
"Sodium bentonite / Calcium bentonite
" are the most commonly used medicinal clays today (Sodium bentonite for external use, Calcium bentonite for internal use), although there is no precise definition of what this term means. In fact, typically, "bentonite" refers to a wide spectrum of clays with a wide array of properties (such as a variety of colours). In alternative medicine
, often this is used as more or less a catch-all term for medicinal clays. Another such term is "montmorillonite", which is often interchangeable with "bentonite". Bentonite is included in the United States Pharmacopeia
, and the USP-grade bentonite is widely used in various pharmaceutical and cosmetic preparations as a compounding and suspending agent. It is not entirely clear where the source of USP-grade bentonite is located; it may be a mixture of various bentonites.
Galen
, the famous Greek philosopher and physician, was the first to record the use of clay by sick or injured animals back in the second century AD. This type of geophagy
has been documented in "many species of mammals, birds, reptiles, butterflies and isopods, especially among herbivores."Jared M. Diamond, "Evolutionary biology: Dirty eating for healthy living". Nature 400, 120-121 (1999)
In particular, in Peru, Amazonian rainforest parrots of some 21 species gather at certain sites on cliff faces where bare soil is exposed, and eat the clayish soil. The soil they seek is highly specific, since they focus on a rather narrow band of exposed soil. What they seek is mostly clay that is less than 0.2 millimetre in particle diameter.
"The oldest evidence of geophagy practiced by humans comes from the prehistoric site at Kalambo Falls
on the border between Zambia
and Tanzania
(Root-Bernstein & Root-Bernstein, 2000)." Here, a calcium-rich white clay was found alongside the bones of Homo habilis
(the immediate predecessor of Homo sapiens).
(since the clay is consumed internally).
The Ebers Papyrus
of about 1550 BC (but containing the tradition going back many centuries earlier) is an important medical text from ancient Egypt. It describes the use of ochre
for a wide variety of complaints, including for intestinal problems,PAPYRUS EBERS, 1937 translation. as well as for various eye complaints.Recipes for Treating the Eyes: Papyrus Ebers
. Its use continued until the 19th century, as it was still listed in an important pharmacopoeia in 1848 (the deposits may have been exhausted by then).
As Pliny
reports about the Lemnian Earth,Cited in Thompson CJS. The mystery and art of the apothecary, by C.J.S. thompson. London: John Lane; 1929. p. 44.
Lemnian clay was shaped into tablets, or little cakes, and then distinctive seals were stamped into them, giving rise to its name terra sigillata
- Latin for 'sealed earth'. Dioscorides also commented upon the use of terra sigillata.
Another physician famous in antiquity, Galen
, recorded numerous cases of the internal and external uses of this clay in his treatise on clay therapy.
Clay was prescribed by the Roman obstetrician, gynecologist, and pediatrician Soranus of Ephesus, who practiced medicine around 100-140 AD.Soranus' gynecology, Owsei Temkin (tr.), JHU Press, 1991 (reprint). pp. 239-240. ISBN 0-8018-4320-0
All the above seem to have been bentonitic clays.
(980-1037 CE), the 'Prince of Doctors', wrote about clay therapy in his numerous treatises.
Ibn al-Baitar (1197–1248), a Muslim scholar born at Malaga, Spain, and author of a famous work on pharmacology, discusses eight kinds of medicinal earth.L. Leclerc, "Traite des simples", II, 1881, pp. 421-427; for a general appreciation of this work see Baron Carra de Vaux, "Les penseurs de lslam", II, 1921, pp. 289-296 (original note in Laufer) The eight kinds are
(1517‑1564) was interested in investigating the mystery of the Lemnian clay. In 1543, he visited Constantinople where, after making enquiries, he encountered 18 types of different products marketed as Lemnian Earth (he was concerned about possible counterfeits). He then made a special journey to Lemnos, where he continued his investigation, and tried to find the source of the clay. He discovered that it was extracted only once a year (on the 6th of August) under the supervision of Christian monks and Turkish officials.
Modern investigation has shown that this was a clay similar to the modern 'bentonite'.
from CDC.gov website Callahan GN. Eating dirt. Emerg Infect Dis [serial online] 2003 Aug. (accessed 16 June 2009)
Too much processing, likewise, may reduce the clay's therapeutic potential. In particular, Mascolo et al. studied 'pharmaceutical grade clay' versus 'the natural and the commercial herbalist clay', and found an appreciable depletion of trace elements in the pharmaceutical grade clay.
The use of medicinal clay in folk medicine
goes back to prehistoric times. The indigenous peoples around the world still use clay
widely, which is related to geophagy
. The first recorded use of medicinal clay goes back to ancient Mesopotamia
. A wide variety of clays is being used for medicinal purposes - primarily for external applications, such as the clay baths in health spas (mud therapy), but also internally. Among the clays most commonly used for medicinal purposes are kaolin and the smectite clays such as bentonite
, montmorillonite
, and Fuller's earth
.
There are considerable problems with the exact nomenclature of various clays. No clay deposit is exactly the same and, typically, mineral clays are mixed in various proportions.
The overwhelming majority of clay mined commercially is for industrial uses, such as construction and oil drilling. Thus, the precise classification and chemical composition of these clays are somewhat secondary to their intended use. For practical purposes, the terms "bentonite
clay", "montmorillonite
clay", and "Fuller's earth
" are basically interchangeable.
On the other hand, the clays that are typically used for medicinal purposes have usually been discovered either based on local folklore, or by simple trial-and-error after investigations by various healing enthusiasts. And so, their discoverers may have been either not too concerned about these clays' precise scientific classification and chemical properties, or perhaps not necessarily adequately equipped to conduct such studies. Their primary, and often only, concern was the efficacy of any particular clay for some specific medical condition or conditions.
"Sodium bentonite / Calcium bentonite
" are the most commonly used medicinal clays today (Sodium bentonite for external use, Calcium bentonite for internal use), although there is no precise definition of what this term means. In fact, typically, "bentonite" refers to a wide spectrum of clays with a wide array of properties (such as a variety of colours). In alternative medicine
, often this is used as more or less a catch-all term for medicinal clays. Another such term is "montmorillonite", which is often interchangeable with "bentonite". Bentonite is included in the United States Pharmacopeia
, and the USP-grade bentonite is widely used in various pharmaceutical and cosmetic preparations as a compounding and suspending agent. It is not entirely clear where the source of USP-grade bentonite is located; it may be a mixture of various bentonites.
Galen
, the famous Greek philosopher and physician, was the first to record the use of clay by sick or injured animals back in the second century AD. This type of geophagy
has been documented in "many species of mammals, birds, reptiles, butterflies and isopods, especially among herbivores."Jared M. Diamond, "Evolutionary biology: Dirty eating for healthy living". Nature 400, 120-121 (1999)
In particular, in Peru, Amazonian rainforest parrots of some 21 species gather at certain sites on cliff faces where bare soil is exposed, and eat the clayish soil. The soil they seek is highly specific, since they focus on a rather narrow band of exposed soil. What they seek is mostly clay that is less than 0.2 millimetre in particle diameter.
"The oldest evidence of geophagy practiced by humans comes from the prehistoric site at Kalambo Falls
on the border between Zambia
and Tanzania
(Root-Bernstein & Root-Bernstein, 2000)." Here, a calcium-rich white clay was found alongside the bones of Homo habilis
(the immediate predecessor of Homo sapiens).
(since the clay is consumed internally).
The Ebers Papyrus
of about 1550 BC (but containing the tradition going back many centuries earlier) is an important medical text from ancient Egypt. It describes the use of ochre
for a wide variety of complaints, including for intestinal problems,PAPYRUS EBERS, 1937 translation. as well as for various eye complaints.Recipes for Treating the Eyes: Papyrus Ebers
. Its use continued until the 19th century, as it was still listed in an important pharmacopoeia in 1848 (the deposits may have been exhausted by then).
As Pliny
reports about the Lemnian Earth,Cited in Thompson CJS. The mystery and art of the apothecary, by C.J.S. thompson. London: John Lane; 1929. p. 44.
Lemnian clay was shaped into tablets, or little cakes, and then distinctive seals were stamped into them, giving rise to its name terra sigillata
- Latin for 'sealed earth'. Dioscorides also commented upon the use of terra sigillata.
Another physician famous in antiquity, Galen
, recorded numerous cases of the internal and external uses of this clay in his treatise on clay therapy.
Clay was prescribed by the Roman obstetrician, gynecologist, and pediatrician Soranus of Ephesus, who practiced medicine around 100-140 AD.Soranus' gynecology, Owsei Temkin (tr.), JHU Press, 1991 (reprint). pp. 239-240. ISBN 0-8018-4320-0
All the above seem to have been bentonitic clays.
(980-1037 CE), the 'Prince of Doctors', wrote about clay therapy in his numerous treatises.
Ibn al-Baitar (1197–1248), a Muslim scholar born at Malaga, Spain, and author of a famous work on pharmacology, discusses eight kinds of medicinal earth.L. Leclerc, "Traite des simples", II, 1881, pp. 421-427; for a general appreciation of this work see Baron Carra de Vaux, "Les penseurs de lslam", II, 1921, pp. 289-296 (original note in Laufer) The eight kinds are
(1517‑1564) was interested in investigating the mystery of the Lemnian clay. In 1543, he visited Constantinople where, after making enquiries, he encountered 18 types of different products marketed as Lemnian Earth (he was concerned about possible counterfeits). He then made a special journey to Lemnos, where he continued his investigation, and tried to find the source of the clay. He discovered that it was extracted only once a year (on the 6th of August) under the supervision of Christian monks and Turkish officials.
Modern investigation has shown that this was a clay similar to the modern 'bentonite'.
from CDC.gov website Callahan GN. Eating dirt. Emerg Infect Dis [serial online] 2003 Aug. (accessed 16 June 2009)
Too much processing, likewise, may reduce the clay's therapeutic potential. In particular, Mascolo et al. studied 'pharmaceutical grade clay' versus 'the natural and the commercial herbalist clay', and found an appreciable depletion of trace elements in the pharmaceutical grade clay."The pharmaceutical clay shows an appreciable depletion of elements as Zn, V, Ga, Cr, Cd, Fe, Mo, Ni, Cu, Sb, S and Rb. Instead, the natural clay is characterised by high quantities of U, V, Cd, Mo, Tl, Ag, Ni, Cu, Sb, As, S, Se and Br, likely because of sulphide occurrence." -- Nicola Mascolo, Vito Summa, F. Tateo, Characterization of toxic elements in clays for human healing use. Applied Clay Science, Volume 15, Issues 5-6, 1999
Folk medicine
-Description:Refers to healing practices and ideas of body physiology and health preservation known to a limited segment of the population in a culture, transmitted informally as general knowledge, and practiced or applied by anyone in the culture having prior experience.All cultures and societies...
goes back to prehistoric times. The indigenous peoples around the world still use clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...
widely, which is related to geophagy
Geophagy
Geophagy is the practice of eating earthy or soil-like substances such as clay, and chalk. It exists in animals in the wild and also in humans, most often in rural or preindustrial societies among children and pregnant women...
. The first recorded use of medicinal clay goes back to ancient Mesopotamia
Mesopotamia
Mesopotamia is a toponym for the area of the Tigris–Euphrates river system, largely corresponding to modern-day Iraq, northeastern Syria, southeastern Turkey and southwestern Iran.Widely considered to be the cradle of civilization, Bronze Age Mesopotamia included Sumer and the...
. A wide variety of clays is being used for medicinal purposes - primarily for external applications, such as the clay baths in health spas (mud therapy), but also internally. Among the clays most commonly used for medicinal purposes are kaolin and the smectite clays such as bentonite
Bentonite
Bentonite is an absorbent aluminium phyllosilicate, essentially impure clay consisting mostly of montmorillonite. There are different types of bentonite, each named after the respective dominant element, such as potassium , sodium , calcium , and aluminum . Experts debate a number of nomenclatorial...
, montmorillonite
Montmorillonite
Montmorillonite is a very soft phyllosilicate group of minerals that typically form in microscopic crystals, forming a clay. It is named after Montmorillon in France. Montmorillonite, a member of the smectite family, is a 2:1 clay, meaning that it has 2 tetrahedral sheets sandwiching a central...
, and Fuller's earth
Fuller's earth
Fuller's earth is any non-plastic clay or claylike earthy material used to decolorize, filter, and purify animal, mineral, and vegetable oils and greases.-Occurrence and composition:...
.
Questions of nomenclature
The overwhelming majority of clay mined commercially is for industrial uses, such as construction and oil drilling. Thus, the precise classification and chemical composition of these clays are somewhat secondary to their intended use. For practical purposes, the terms "bentonite
Bentonite
Bentonite is an absorbent aluminium phyllosilicate, essentially impure clay consisting mostly of montmorillonite. There are different types of bentonite, each named after the respective dominant element, such as potassium , sodium , calcium , and aluminum . Experts debate a number of nomenclatorial...
clay", "montmorillonite
Montmorillonite
Montmorillonite is a very soft phyllosilicate group of minerals that typically form in microscopic crystals, forming a clay. It is named after Montmorillon in France. Montmorillonite, a member of the smectite family, is a 2:1 clay, meaning that it has 2 tetrahedral sheets sandwiching a central...
clay", and "Fuller's earth
Fuller's earth
Fuller's earth is any non-plastic clay or claylike earthy material used to decolorize, filter, and purify animal, mineral, and vegetable oils and greases.-Occurrence and composition:...
" are basically interchangeable.
On the other hand, the clays that are typically used for medicinal purposes have usually been discovered either based on local folklore, or by simple trial-and-error after investigations by various healing enthusiasts. And so, their discoverers may have been either not too concerned about these clays' precise scientific classification and chemical properties, or perhaps not necessarily adequately equipped to conduct such studies. Their primary, and often only, concern was the efficacy of any particular clay for some specific medical condition or conditions.
"Sodium bentonite / Calcium bentonite
Bentonite
Bentonite is an absorbent aluminium phyllosilicate, essentially impure clay consisting mostly of montmorillonite. There are different types of bentonite, each named after the respective dominant element, such as potassium , sodium , calcium , and aluminum . Experts debate a number of nomenclatorial...
" are the most commonly used medicinal clays today (Sodium bentonite for external use, Calcium bentonite for internal use), although there is no precise definition of what this term means. In fact, typically, "bentonite" refers to a wide spectrum of clays with a wide array of properties (such as a variety of colours). In alternative medicine
Alternative medicine
Alternative medicine is any healing practice, "that does not fall within the realm of conventional medicine." It is based on historical or cultural traditions, rather than on scientific evidence....
, often this is used as more or less a catch-all term for medicinal clays. Another such term is "montmorillonite", which is often interchangeable with "bentonite". Bentonite is included in the United States Pharmacopeia
United States Pharmacopeia
The United States Pharmacopeia is the official pharmacopeia of the United States, published dually with the National Formulary as the USP-NF. The United States Pharmacopeial Convention is the nonprofit organization that owns the trademark and copyright to the USP-NF and publishes it every year...
, and the USP-grade bentonite is widely used in various pharmaceutical and cosmetic preparations as a compounding and suspending agent. It is not entirely clear where the source of USP-grade bentonite is located; it may be a mixture of various bentonites.
Animal geophagy
A relevant subject is how the animals - both in the wild and domesticated - seek out and consume different types of earth in general, and clay in particular (of course clay is pretty well omnipresent in various types of soil).Galen
Galen
Aelius Galenus or Claudius Galenus , better known as Galen of Pergamon , was a prominent Roman physician, surgeon and philosopher...
, the famous Greek philosopher and physician, was the first to record the use of clay by sick or injured animals back in the second century AD. This type of geophagy
Geophagy
Geophagy is the practice of eating earthy or soil-like substances such as clay, and chalk. It exists in animals in the wild and also in humans, most often in rural or preindustrial societies among children and pregnant women...
has been documented in "many species of mammals, birds, reptiles, butterflies and isopods, especially among herbivores."
In particular, in Peru, Amazonian rainforest parrots of some 21 species gather at certain sites on cliff faces where bare soil is exposed, and eat the clayish soil. The soil they seek is highly specific, since they focus on a rather narrow band of exposed soil. What they seek is mostly clay that is less than 0.2 millimetre in particle diameter.
Historical use
There is a large amount of anthropological and historical literature describing the medicinal use of clay around the world from the earliest times.Human prehistory
Some scholars believe that prehistoric ancestors such as Homo erectus and Homo neanderthalensis used ochres to cure wounds as well as paint caves. Ochres are a mixture of clay and iron hydroxides."The oldest evidence of geophagy practiced by humans comes from the prehistoric site at Kalambo Falls
Kalambo Falls
Kalambo Falls on the Kalambo River is a 772ft single drop waterfall on the border of Zambia and Tanzania at the southeast end of Lake Tanganyika. The falls are some of the tallest uninterrupted falls in Africa...
on the border between Zambia
Zambia
Zambia , officially the Republic of Zambia, is a landlocked country in Southern Africa. The neighbouring countries are the Democratic Republic of the Congo to the north, Tanzania to the north-east, Malawi to the east, Mozambique, Zimbabwe, Botswana and Namibia to the south, and Angola to the west....
and Tanzania
Tanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...
(Root-Bernstein & Root-Bernstein, 2000)." Here, a calcium-rich white clay was found alongside the bones of Homo habilis
Homo habilis
Homo habilis is a species of the genus Homo, which lived from approximately at the beginning of the Pleistocene period. The discovery and description of this species is credited to both Mary and Louis Leakey, who found fossils in Tanzania, East Africa, between 1962 and 1964. Homo habilis Homo...
(the immediate predecessor of Homo sapiens).
Use by aboriginal peoples
Clay is used widely by indigenous peoples around the world, and is related to geophagyGeophagy
Geophagy is the practice of eating earthy or soil-like substances such as clay, and chalk. It exists in animals in the wild and also in humans, most often in rural or preindustrial societies among children and pregnant women...
(since the clay is consumed internally).
Ancient Egypt and Mesopotamia
The first recorded use of medicinal clay is on Mesopotamian clay tablets around 2500 B.C. Also, ancient Egyptians used clay. The Pharaohs’ physicians used the material as anti-inflammatory agents and antiseptics. It was also an ingredient used for making mummies. It is also reported that Cleopatra used clays to preserve her complexion.The Ebers Papyrus
Ebers papyrus
The Ebers Papyrus, also known as Papyrus Ebers, is an Egyptian medical papyrus dating to circa 1550 BC. Among the oldest and most important medical papyri of ancient Egypt, it was purchased at Luxor, in the winter of 1873–74 by Georg Ebers...
of about 1550 BC (but containing the tradition going back many centuries earlier) is an important medical text from ancient Egypt. It describes the use of ochre
Ochre
Ochre is the term for both a golden-yellow or light yellow brown color and for a form of earth pigment which produces the color. The pigment can also be used to create a reddish tint known as "red ochre". The more rarely used terms "purple ochre" and "brown ochre" also exist for variant hues...
for a wide variety of complaints, including for intestinal problems, as well as for various eye complaints.
Lemnian clay
This was a clay used in Classical Antiquity. It was mined on the island of LemnosLemnos
Lemnos is an island of Greece in the northern part of the Aegean Sea. Administratively the island forms a separate municipality within the Lemnos peripheral unit, which is part of the North Aegean Periphery. The principal town of the island and seat of the municipality is Myrina...
. Its use continued until the 19th century, as it was still listed in an important pharmacopoeia in 1848 (the deposits may have been exhausted by then).
As Pliny
Pliny the Younger
Gaius Plinius Caecilius Secundus, born Gaius Caecilius or Gaius Caecilius Cilo , better known as Pliny the Younger, was a lawyer, author, and magistrate of Ancient Rome. Pliny's uncle, Pliny the Elder, helped raise and educate him...
reports about the Lemnian Earth,
"...if rubbed under the eyes, it moderates pain and watering from the same, and prevents the flow from the lachrymal ducts. In cases of haemorrhage it should be administered with vinegar. It is used against complaints of the spleen and kidneys, copious menstruation, also against poisons, and wounds caused by serpents."
Lemnian clay was shaped into tablets, or little cakes, and then distinctive seals were stamped into them, giving rise to its name terra sigillata
Terra sigillata
Terra sigillata is a term with at least three distinct meanings: as a description of medieval medicinal earth; in archaeology, as a general term for some of the fine red Ancient Roman pottery with glossy surface slips made in specific areas of the Roman Empire; and more recently, as a description...
- Latin for 'sealed earth'. Dioscorides also commented upon the use of terra sigillata.
Another physician famous in antiquity, Galen
Galen
Aelius Galenus or Claudius Galenus , better known as Galen of Pergamon , was a prominent Roman physician, surgeon and philosopher...
, recorded numerous cases of the internal and external uses of this clay in his treatise on clay therapy.
"Galen... used as one of his means for curing injuries, festering wounds, and inflammations terra sigillata, a medicinal red clay compressed into round cakes and stamped with the image of the goddess Diana. This clay, which came from the island of Lemnos, was known throughout the classical world."
Clay was prescribed by the Roman obstetrician, gynecologist, and pediatrician Soranus of Ephesus, who practiced medicine around 100-140 AD.
Other clays used in classical times
The other types of clay that were famous in antiquity were as follows.- Terra chia, Terra cymolia (Cimolean earth): these were both white earths and considered of great value.
- Samian earth: Pliny in c. 50 AD (Nat. Hist.) details two distinct varieties, colyrium - an eye salve, and aster, which was used as a soap as well as in medicines.
- Terra sigillata strigoniensis (Strigian earth, derived from SilesiaSilesiaSilesia is a historical region of Central Europe located mostly in Poland, with smaller parts also in the Czech Republic, and Germany.Silesia is rich in mineral and natural resources, and includes several important industrial areas. Silesia's largest city and historical capital is Wrocław...
) - this clay, yellow in colour, appears to have been famous later in medieval times.
All the above seem to have been bentonitic clays.
- The earth which did not stain the hands was known as rubrica.
Medieval times
In medieval Persia, AvicennaAvicenna
Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā , commonly known as Ibn Sīnā or by his Latinized name Avicenna, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived...
(980-1037 CE), the 'Prince of Doctors', wrote about clay therapy in his numerous treatises.
Ibn al-Baitar (1197–1248), a Muslim scholar born at Malaga, Spain, and author of a famous work on pharmacology, discusses eight kinds of medicinal earth. The eight kinds are
- the terra sigillata,
- Egyptian earth,
- Samian earth,
- earth of Chios,
- Cimolean earth or pure clay (cimolite), soft earth, called al-hurr, green in color like verdigris, is smoked together with almond bark to serve as food when it will turn red and assume a good flavor; it is but rarely eaten without being smoked - also called 'Argentiera',
- earth of vines called ampelitis (Pliny XXXV, 56) or pharmakitis from Seleucia in Syria,
- Armenian earth (also known as the Armenian boleArmenian boleArmenian bole, also known as bolus armenus or bole armoniac, is an earthy clay, usually red, native to Armenia. It is red due to the presence of iron oxide; the clay also contains hydrous silicates of aluminum and possibly magnesium.-Uses:...
), salutary in cases of bubonic plague, being administered both externally and internally, - earth of Nishapur.
Renaissance period, and up to the present
A French naturalist Pierre BelonPierre Belon
Pierre Belon was a French naturalist. He is sometimes known as Pierre Belon du Mans, or, in Latin translations of his works, as Petrus Bellonius Cenomanus.Belon was born in 1517 at Soulletiere near Cérans-Foulletourte...
(1517‑1564) was interested in investigating the mystery of the Lemnian clay. In 1543, he visited Constantinople where, after making enquiries, he encountered 18 types of different products marketed as Lemnian Earth (he was concerned about possible counterfeits). He then made a special journey to Lemnos, where he continued his investigation, and tried to find the source of the clay. He discovered that it was extracted only once a year (on the 6th of August) under the supervision of Christian monks and Turkish officials.
Modern investigation has shown that this was a clay similar to the modern 'bentonite'.
Preparation of clay
Clay gathered from its original source deposit is refined and processed in various ways by manufacturers. This can include heating or baking the clay, since the raw clay tends to contain a variety of micro-organismsToo much processing, likewise, may reduce the clay's therapeutic potential. In particular, Mascolo et al. studied 'pharmaceutical grade clay' versus 'the natural and the commercial herbalist clay', and found an appreciable depletion of trace elements in the pharmaceutical grade clay.
The use of medicinal clay in folk medicine
Folk medicine
-Description:Refers to healing practices and ideas of body physiology and health preservation known to a limited segment of the population in a culture, transmitted informally as general knowledge, and practiced or applied by anyone in the culture having prior experience.All cultures and societies...
goes back to prehistoric times. The indigenous peoples around the world still use clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...
widely, which is related to geophagy
Geophagy
Geophagy is the practice of eating earthy or soil-like substances such as clay, and chalk. It exists in animals in the wild and also in humans, most often in rural or preindustrial societies among children and pregnant women...
. The first recorded use of medicinal clay goes back to ancient Mesopotamia
Mesopotamia
Mesopotamia is a toponym for the area of the Tigris–Euphrates river system, largely corresponding to modern-day Iraq, northeastern Syria, southeastern Turkey and southwestern Iran.Widely considered to be the cradle of civilization, Bronze Age Mesopotamia included Sumer and the...
. A wide variety of clays is being used for medicinal purposes - primarily for external applications, such as the clay baths in health spas (mud therapy), but also internally. Among the clays most commonly used for medicinal purposes are kaolin and the smectite clays such as bentonite
Bentonite
Bentonite is an absorbent aluminium phyllosilicate, essentially impure clay consisting mostly of montmorillonite. There are different types of bentonite, each named after the respective dominant element, such as potassium , sodium , calcium , and aluminum . Experts debate a number of nomenclatorial...
, montmorillonite
Montmorillonite
Montmorillonite is a very soft phyllosilicate group of minerals that typically form in microscopic crystals, forming a clay. It is named after Montmorillon in France. Montmorillonite, a member of the smectite family, is a 2:1 clay, meaning that it has 2 tetrahedral sheets sandwiching a central...
, and Fuller's earth
Fuller's earth
Fuller's earth is any non-plastic clay or claylike earthy material used to decolorize, filter, and purify animal, mineral, and vegetable oils and greases.-Occurrence and composition:...
.
Questions of nomenclature
The overwhelming majority of clay mined commercially is for industrial uses, such as construction and oil drilling. Thus, the precise classification and chemical composition of these clays are somewhat secondary to their intended use. For practical purposes, the terms "bentonite
Bentonite
Bentonite is an absorbent aluminium phyllosilicate, essentially impure clay consisting mostly of montmorillonite. There are different types of bentonite, each named after the respective dominant element, such as potassium , sodium , calcium , and aluminum . Experts debate a number of nomenclatorial...
clay", "montmorillonite
Montmorillonite
Montmorillonite is a very soft phyllosilicate group of minerals that typically form in microscopic crystals, forming a clay. It is named after Montmorillon in France. Montmorillonite, a member of the smectite family, is a 2:1 clay, meaning that it has 2 tetrahedral sheets sandwiching a central...
clay", and "Fuller's earth
Fuller's earth
Fuller's earth is any non-plastic clay or claylike earthy material used to decolorize, filter, and purify animal, mineral, and vegetable oils and greases.-Occurrence and composition:...
" are basically interchangeable.
On the other hand, the clays that are typically used for medicinal purposes have usually been discovered either based on local folklore, or by simple trial-and-error after investigations by various healing enthusiasts. And so, their discoverers may have been either not too concerned about these clays' precise scientific classification and chemical properties, or perhaps not necessarily adequately equipped to conduct such studies. Their primary, and often only, concern was the efficacy of any particular clay for some specific medical condition or conditions.
"Sodium bentonite / Calcium bentonite
Bentonite
Bentonite is an absorbent aluminium phyllosilicate, essentially impure clay consisting mostly of montmorillonite. There are different types of bentonite, each named after the respective dominant element, such as potassium , sodium , calcium , and aluminum . Experts debate a number of nomenclatorial...
" are the most commonly used medicinal clays today (Sodium bentonite for external use, Calcium bentonite for internal use), although there is no precise definition of what this term means. In fact, typically, "bentonite" refers to a wide spectrum of clays with a wide array of properties (such as a variety of colours). In alternative medicine
Alternative medicine
Alternative medicine is any healing practice, "that does not fall within the realm of conventional medicine." It is based on historical or cultural traditions, rather than on scientific evidence....
, often this is used as more or less a catch-all term for medicinal clays. Another such term is "montmorillonite", which is often interchangeable with "bentonite". Bentonite is included in the United States Pharmacopeia
United States Pharmacopeia
The United States Pharmacopeia is the official pharmacopeia of the United States, published dually with the National Formulary as the USP-NF. The United States Pharmacopeial Convention is the nonprofit organization that owns the trademark and copyright to the USP-NF and publishes it every year...
, and the USP-grade bentonite is widely used in various pharmaceutical and cosmetic preparations as a compounding and suspending agent. It is not entirely clear where the source of USP-grade bentonite is located; it may be a mixture of various bentonites.
Animal geophagy
A relevant subject is how the animals - both in the wild and domesticated - seek out and consume different types of earth in general, and clay in particular (of course clay is pretty well omnipresent in various types of soil).Galen
Galen
Aelius Galenus or Claudius Galenus , better known as Galen of Pergamon , was a prominent Roman physician, surgeon and philosopher...
, the famous Greek philosopher and physician, was the first to record the use of clay by sick or injured animals back in the second century AD. This type of geophagy
Geophagy
Geophagy is the practice of eating earthy or soil-like substances such as clay, and chalk. It exists in animals in the wild and also in humans, most often in rural or preindustrial societies among children and pregnant women...
has been documented in "many species of mammals, birds, reptiles, butterflies and isopods, especially among herbivores."Jared M. Diamond, "Evolutionary biology: Dirty eating for healthy living". Nature 400, 120-121 (1999)
In particular, in Peru, Amazonian rainforest parrots of some 21 species gather at certain sites on cliff faces where bare soil is exposed, and eat the clayish soil. The soil they seek is highly specific, since they focus on a rather narrow band of exposed soil. What they seek is mostly clay that is less than 0.2 millimetre in particle diameter.
Historical use
There is a large amount of anthropological and historical literature describing the medicinal use of clay around the world from the earliest times.Human prehistory
Some scholars believe that prehistoric ancestors such as Homo erectus and Homo neanderthalensis used ochres to cure wounds as well as paint caves. Ochres are a mixture of clay and iron hydroxides."The oldest evidence of geophagy practiced by humans comes from the prehistoric site at Kalambo Falls
Kalambo Falls
Kalambo Falls on the Kalambo River is a 772ft single drop waterfall on the border of Zambia and Tanzania at the southeast end of Lake Tanganyika. The falls are some of the tallest uninterrupted falls in Africa...
on the border between Zambia
Zambia
Zambia , officially the Republic of Zambia, is a landlocked country in Southern Africa. The neighbouring countries are the Democratic Republic of the Congo to the north, Tanzania to the north-east, Malawi to the east, Mozambique, Zimbabwe, Botswana and Namibia to the south, and Angola to the west....
and Tanzania
Tanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...
(Root-Bernstein & Root-Bernstein, 2000)." Here, a calcium-rich white clay was found alongside the bones of Homo habilis
Homo habilis
Homo habilis is a species of the genus Homo, which lived from approximately at the beginning of the Pleistocene period. The discovery and description of this species is credited to both Mary and Louis Leakey, who found fossils in Tanzania, East Africa, between 1962 and 1964. Homo habilis Homo...
(the immediate predecessor of Homo sapiens).
Use by aboriginal peoples
Clay is used widely by indigenous peoples around the world, and is related to geophagyGeophagy
Geophagy is the practice of eating earthy or soil-like substances such as clay, and chalk. It exists in animals in the wild and also in humans, most often in rural or preindustrial societies among children and pregnant women...
(since the clay is consumed internally).
Ancient Egypt and Mesopotamia
The first recorded use of medicinal clay is on Mesopotamian clay tablets around 2500 B.C. Also, ancient Egyptians used clay. The Pharaohs’ physicians used the material as anti-inflammatory agents and antiseptics. It was also an ingredient used for making mummies. It is also reported that Cleopatra used clays to preserve her complexion.The Ebers Papyrus
Ebers papyrus
The Ebers Papyrus, also known as Papyrus Ebers, is an Egyptian medical papyrus dating to circa 1550 BC. Among the oldest and most important medical papyri of ancient Egypt, it was purchased at Luxor, in the winter of 1873–74 by Georg Ebers...
of about 1550 BC (but containing the tradition going back many centuries earlier) is an important medical text from ancient Egypt. It describes the use of ochre
Ochre
Ochre is the term for both a golden-yellow or light yellow brown color and for a form of earth pigment which produces the color. The pigment can also be used to create a reddish tint known as "red ochre". The more rarely used terms "purple ochre" and "brown ochre" also exist for variant hues...
for a wide variety of complaints, including for intestinal problems,PAPYRUS EBERS, 1937 translation. as well as for various eye complaints.Recipes for Treating the Eyes: Papyrus Ebers
Lemnian clay
This was a clay used in Classical Antiquity. It was mined on the island of LemnosLemnos
Lemnos is an island of Greece in the northern part of the Aegean Sea. Administratively the island forms a separate municipality within the Lemnos peripheral unit, which is part of the North Aegean Periphery. The principal town of the island and seat of the municipality is Myrina...
. Its use continued until the 19th century, as it was still listed in an important pharmacopoeia in 1848 (the deposits may have been exhausted by then).
As Pliny
Pliny the Younger
Gaius Plinius Caecilius Secundus, born Gaius Caecilius or Gaius Caecilius Cilo , better known as Pliny the Younger, was a lawyer, author, and magistrate of Ancient Rome. Pliny's uncle, Pliny the Elder, helped raise and educate him...
reports about the Lemnian Earth,Cited in Thompson CJS. The mystery and art of the apothecary, by C.J.S. thompson. London: John Lane; 1929. p. 44.
"...if rubbed under the eyes, it moderates pain and watering from the same, and prevents the flow from the lachrymal ducts. In cases of haemorrhage it should be administered with vinegar. It is used against complaints of the spleen and kidneys, copious menstruation, also against poisons, and wounds caused by serpents."
Lemnian clay was shaped into tablets, or little cakes, and then distinctive seals were stamped into them, giving rise to its name terra sigillata
Terra sigillata
Terra sigillata is a term with at least three distinct meanings: as a description of medieval medicinal earth; in archaeology, as a general term for some of the fine red Ancient Roman pottery with glossy surface slips made in specific areas of the Roman Empire; and more recently, as a description...
- Latin for 'sealed earth'. Dioscorides also commented upon the use of terra sigillata.
Another physician famous in antiquity, Galen
Galen
Aelius Galenus or Claudius Galenus , better known as Galen of Pergamon , was a prominent Roman physician, surgeon and philosopher...
, recorded numerous cases of the internal and external uses of this clay in his treatise on clay therapy.
"Galen... used as one of his means for curing injuries, festering wounds, and inflammations terra sigillata, a medicinal red clay compressed into round cakes and stamped with the image of the goddess Diana. This clay, which came from the island of Lemnos, was known throughout the classical world."Dr. H. Van Der Loos, The Miracles of Jesus, Leiden, the Netherlands, Brill, 1965. p. 82.
Clay was prescribed by the Roman obstetrician, gynecologist, and pediatrician Soranus of Ephesus, who practiced medicine around 100-140 AD.Soranus' gynecology, Owsei Temkin (tr.), JHU Press, 1991 (reprint). pp. 239-240. ISBN 0-8018-4320-0
Other clays used in classical times
The other types of clay that were famous in antiquity were as follows.- Terra chia, Terra cymolia (Cimolean earth): these were both white earths and considered of great value.
- Samian earth: Pliny in c. 50 AD (Nat. Hist.) details two distinct varieties, colyrium - an eye salve, and aster, which was used as a soap as well as in medicines.
- Terra sigillata strigoniensis (Strigian earth, derived from SilesiaSilesiaSilesia is a historical region of Central Europe located mostly in Poland, with smaller parts also in the Czech Republic, and Germany.Silesia is rich in mineral and natural resources, and includes several important industrial areas. Silesia's largest city and historical capital is Wrocław...
) - this clay, yellow in colour, appears to have been famous later in medieval times.
All the above seem to have been bentonitic clays.
- The earth which did not stain the hands was known as rubrica.
Medieval times
In medieval Persia, AvicennaAvicenna
Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā , commonly known as Ibn Sīnā or by his Latinized name Avicenna, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived...
(980-1037 CE), the 'Prince of Doctors', wrote about clay therapy in his numerous treatises.
Ibn al-Baitar (1197–1248), a Muslim scholar born at Malaga, Spain, and author of a famous work on pharmacology, discusses eight kinds of medicinal earth.L. Leclerc, "Traite des simples", II, 1881, pp. 421-427; for a general appreciation of this work see Baron Carra de Vaux, "Les penseurs de lslam", II, 1921, pp. 289-296 (original note in Laufer) The eight kinds are
- the terra sigillata,
- Egyptian earth,
- Samian earth,
- earth of Chios,
- Cimolean earth or pure clay (cimolite), soft earth, called al-hurr, green in color like verdigris, is smoked together with almond bark to serve as food when it will turn red and assume a good flavor; it is but rarely eaten without being smoked - also called 'Argentiera',
- earth of vines called ampelitis (Pliny XXXV, 56) or pharmakitis from Seleucia in Syria,
- Armenian earth (also known as the Armenian boleArmenian boleArmenian bole, also known as bolus armenus or bole armoniac, is an earthy clay, usually red, native to Armenia. It is red due to the presence of iron oxide; the clay also contains hydrous silicates of aluminum and possibly magnesium.-Uses:...
), salutary in cases of bubonic plague, being administered both externally and internally, - earth of Nishapur.
Renaissance period, and up to the present
A French naturalist Pierre BelonPierre Belon
Pierre Belon was a French naturalist. He is sometimes known as Pierre Belon du Mans, or, in Latin translations of his works, as Petrus Bellonius Cenomanus.Belon was born in 1517 at Soulletiere near Cérans-Foulletourte...
(1517‑1564) was interested in investigating the mystery of the Lemnian clay. In 1543, he visited Constantinople where, after making enquiries, he encountered 18 types of different products marketed as Lemnian Earth (he was concerned about possible counterfeits). He then made a special journey to Lemnos, where he continued his investigation, and tried to find the source of the clay. He discovered that it was extracted only once a year (on the 6th of August) under the supervision of Christian monks and Turkish officials.
Modern investigation has shown that this was a clay similar to the modern 'bentonite'.
Preparation of clay
Clay gathered from its original source deposit is refined and processed in various ways by manufacturers. This can include heating or baking the clay, since the raw clay tends to contain a variety of micro-organisms"Soil, including kaolinitic and montmorillonitic clays, contains considerable amounts of organic material, including many live microorganisms."from CDC.gov website Callahan GN. Eating dirt. Emerg Infect Dis [serial online] 2003 Aug. (accessed 16 June 2009)
Too much processing, likewise, may reduce the clay's therapeutic potential. In particular, Mascolo et al. studied 'pharmaceutical grade clay' versus 'the natural and the commercial herbalist clay', and found an appreciable depletion of trace elements in the pharmaceutical grade clay.
The use of medicinal clay in folk medicine
Folk medicine
-Description:Refers to healing practices and ideas of body physiology and health preservation known to a limited segment of the population in a culture, transmitted informally as general knowledge, and practiced or applied by anyone in the culture having prior experience.All cultures and societies...
goes back to prehistoric times. The indigenous peoples around the world still use clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...
widely, which is related to geophagy
Geophagy
Geophagy is the practice of eating earthy or soil-like substances such as clay, and chalk. It exists in animals in the wild and also in humans, most often in rural or preindustrial societies among children and pregnant women...
. The first recorded use of medicinal clay goes back to ancient Mesopotamia
Mesopotamia
Mesopotamia is a toponym for the area of the Tigris–Euphrates river system, largely corresponding to modern-day Iraq, northeastern Syria, southeastern Turkey and southwestern Iran.Widely considered to be the cradle of civilization, Bronze Age Mesopotamia included Sumer and the...
. A wide variety of clays is being used for medicinal purposes - primarily for external applications, such as the clay baths in health spas (mud therapy), but also internally. Among the clays most commonly used for medicinal purposes are kaolin and the smectite clays such as bentonite
Bentonite
Bentonite is an absorbent aluminium phyllosilicate, essentially impure clay consisting mostly of montmorillonite. There are different types of bentonite, each named after the respective dominant element, such as potassium , sodium , calcium , and aluminum . Experts debate a number of nomenclatorial...
, montmorillonite
Montmorillonite
Montmorillonite is a very soft phyllosilicate group of minerals that typically form in microscopic crystals, forming a clay. It is named after Montmorillon in France. Montmorillonite, a member of the smectite family, is a 2:1 clay, meaning that it has 2 tetrahedral sheets sandwiching a central...
, and Fuller's earth
Fuller's earth
Fuller's earth is any non-plastic clay or claylike earthy material used to decolorize, filter, and purify animal, mineral, and vegetable oils and greases.-Occurrence and composition:...
.
Questions of nomenclature
The overwhelming majority of clay mined commercially is for industrial uses, such as construction and oil drilling. Thus, the precise classification and chemical composition of these clays are somewhat secondary to their intended use. For practical purposes, the terms "bentonite
Bentonite
Bentonite is an absorbent aluminium phyllosilicate, essentially impure clay consisting mostly of montmorillonite. There are different types of bentonite, each named after the respective dominant element, such as potassium , sodium , calcium , and aluminum . Experts debate a number of nomenclatorial...
clay", "montmorillonite
Montmorillonite
Montmorillonite is a very soft phyllosilicate group of minerals that typically form in microscopic crystals, forming a clay. It is named after Montmorillon in France. Montmorillonite, a member of the smectite family, is a 2:1 clay, meaning that it has 2 tetrahedral sheets sandwiching a central...
clay", and "Fuller's earth
Fuller's earth
Fuller's earth is any non-plastic clay or claylike earthy material used to decolorize, filter, and purify animal, mineral, and vegetable oils and greases.-Occurrence and composition:...
" are basically interchangeable.
On the other hand, the clays that are typically used for medicinal purposes have usually been discovered either based on local folklore, or by simple trial-and-error after investigations by various healing enthusiasts. And so, their discoverers may have been either not too concerned about these clays' precise scientific classification and chemical properties, or perhaps not necessarily adequately equipped to conduct such studies. Their primary, and often only, concern was the efficacy of any particular clay for some specific medical condition or conditions.
"Sodium bentonite / Calcium bentonite
Bentonite
Bentonite is an absorbent aluminium phyllosilicate, essentially impure clay consisting mostly of montmorillonite. There are different types of bentonite, each named after the respective dominant element, such as potassium , sodium , calcium , and aluminum . Experts debate a number of nomenclatorial...
" are the most commonly used medicinal clays today (Sodium bentonite for external use, Calcium bentonite for internal use), although there is no precise definition of what this term means. In fact, typically, "bentonite" refers to a wide spectrum of clays with a wide array of properties (such as a variety of colours). In alternative medicine
Alternative medicine
Alternative medicine is any healing practice, "that does not fall within the realm of conventional medicine." It is based on historical or cultural traditions, rather than on scientific evidence....
, often this is used as more or less a catch-all term for medicinal clays. Another such term is "montmorillonite", which is often interchangeable with "bentonite". Bentonite is included in the United States Pharmacopeia
United States Pharmacopeia
The United States Pharmacopeia is the official pharmacopeia of the United States, published dually with the National Formulary as the USP-NF. The United States Pharmacopeial Convention is the nonprofit organization that owns the trademark and copyright to the USP-NF and publishes it every year...
, and the USP-grade bentonite is widely used in various pharmaceutical and cosmetic preparations as a compounding and suspending agent. It is not entirely clear where the source of USP-grade bentonite is located; it may be a mixture of various bentonites.
Animal geophagy
A relevant subject is how the animals - both in the wild and domesticated - seek out and consume different types of earth in general, and clay in particular (of course clay is pretty well omnipresent in various types of soil).Galen
Galen
Aelius Galenus or Claudius Galenus , better known as Galen of Pergamon , was a prominent Roman physician, surgeon and philosopher...
, the famous Greek philosopher and physician, was the first to record the use of clay by sick or injured animals back in the second century AD. This type of geophagy
Geophagy
Geophagy is the practice of eating earthy or soil-like substances such as clay, and chalk. It exists in animals in the wild and also in humans, most often in rural or preindustrial societies among children and pregnant women...
has been documented in "many species of mammals, birds, reptiles, butterflies and isopods, especially among herbivores."Jared M. Diamond, "Evolutionary biology: Dirty eating for healthy living". Nature 400, 120-121 (1999)
In particular, in Peru, Amazonian rainforest parrots of some 21 species gather at certain sites on cliff faces where bare soil is exposed, and eat the clayish soil. The soil they seek is highly specific, since they focus on a rather narrow band of exposed soil. What they seek is mostly clay that is less than 0.2 millimetre in particle diameter.
Historical use
There is a large amount of anthropological and historical literature describing the medicinal use of clay around the world from the earliest times.Human prehistory
Some scholars believe that prehistoric ancestors such as Homo erectus and Homo neanderthalensis used ochres to cure wounds as well as paint caves. Ochres are a mixture of clay and iron hydroxides."The oldest evidence of geophagy practiced by humans comes from the prehistoric site at Kalambo Falls
Kalambo Falls
Kalambo Falls on the Kalambo River is a 772ft single drop waterfall on the border of Zambia and Tanzania at the southeast end of Lake Tanganyika. The falls are some of the tallest uninterrupted falls in Africa...
on the border between Zambia
Zambia
Zambia , officially the Republic of Zambia, is a landlocked country in Southern Africa. The neighbouring countries are the Democratic Republic of the Congo to the north, Tanzania to the north-east, Malawi to the east, Mozambique, Zimbabwe, Botswana and Namibia to the south, and Angola to the west....
and Tanzania
Tanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...
(Root-Bernstein & Root-Bernstein, 2000)." Here, a calcium-rich white clay was found alongside the bones of Homo habilis
Homo habilis
Homo habilis is a species of the genus Homo, which lived from approximately at the beginning of the Pleistocene period. The discovery and description of this species is credited to both Mary and Louis Leakey, who found fossils in Tanzania, East Africa, between 1962 and 1964. Homo habilis Homo...
(the immediate predecessor of Homo sapiens).
Use by aboriginal peoples
Clay is used widely by indigenous peoples around the world, and is related to geophagyGeophagy
Geophagy is the practice of eating earthy or soil-like substances such as clay, and chalk. It exists in animals in the wild and also in humans, most often in rural or preindustrial societies among children and pregnant women...
(since the clay is consumed internally).
Ancient Egypt and Mesopotamia
The first recorded use of medicinal clay is on Mesopotamian clay tablets around 2500 B.C. Also, ancient Egyptians used clay. The Pharaohs’ physicians used the material as anti-inflammatory agents and antiseptics. It was also an ingredient used for making mummies. It is also reported that Cleopatra used clays to preserve her complexion.The Ebers Papyrus
Ebers papyrus
The Ebers Papyrus, also known as Papyrus Ebers, is an Egyptian medical papyrus dating to circa 1550 BC. Among the oldest and most important medical papyri of ancient Egypt, it was purchased at Luxor, in the winter of 1873–74 by Georg Ebers...
of about 1550 BC (but containing the tradition going back many centuries earlier) is an important medical text from ancient Egypt. It describes the use of ochre
Ochre
Ochre is the term for both a golden-yellow or light yellow brown color and for a form of earth pigment which produces the color. The pigment can also be used to create a reddish tint known as "red ochre". The more rarely used terms "purple ochre" and "brown ochre" also exist for variant hues...
for a wide variety of complaints, including for intestinal problems,PAPYRUS EBERS, 1937 translation. as well as for various eye complaints.Recipes for Treating the Eyes: Papyrus Ebers
Lemnian clay
This was a clay used in Classical Antiquity. It was mined on the island of LemnosLemnos
Lemnos is an island of Greece in the northern part of the Aegean Sea. Administratively the island forms a separate municipality within the Lemnos peripheral unit, which is part of the North Aegean Periphery. The principal town of the island and seat of the municipality is Myrina...
. Its use continued until the 19th century, as it was still listed in an important pharmacopoeia in 1848 (the deposits may have been exhausted by then).
As Pliny
Pliny the Younger
Gaius Plinius Caecilius Secundus, born Gaius Caecilius or Gaius Caecilius Cilo , better known as Pliny the Younger, was a lawyer, author, and magistrate of Ancient Rome. Pliny's uncle, Pliny the Elder, helped raise and educate him...
reports about the Lemnian Earth,Cited in Thompson CJS. The mystery and art of the apothecary, by C.J.S. thompson. London: John Lane; 1929. p. 44.
"...if rubbed under the eyes, it moderates pain and watering from the same, and prevents the flow from the lachrymal ducts. In cases of haemorrhage it should be administered with vinegar. It is used against complaints of the spleen and kidneys, copious menstruation, also against poisons, and wounds caused by serpents."
Lemnian clay was shaped into tablets, or little cakes, and then distinctive seals were stamped into them, giving rise to its name terra sigillata
Terra sigillata
Terra sigillata is a term with at least three distinct meanings: as a description of medieval medicinal earth; in archaeology, as a general term for some of the fine red Ancient Roman pottery with glossy surface slips made in specific areas of the Roman Empire; and more recently, as a description...
- Latin for 'sealed earth'. Dioscorides also commented upon the use of terra sigillata.
Another physician famous in antiquity, Galen
Galen
Aelius Galenus or Claudius Galenus , better known as Galen of Pergamon , was a prominent Roman physician, surgeon and philosopher...
, recorded numerous cases of the internal and external uses of this clay in his treatise on clay therapy.
"Galen... used as one of his means for curing injuries, festering wounds, and inflammations terra sigillata, a medicinal red clay compressed into round cakes and stamped with the image of the goddess Diana. This clay, which came from the island of Lemnos, was known throughout the classical world."Dr. H. Van Der Loos, The Miracles of Jesus, Leiden, the Netherlands, Brill, 1965. p. 82.
Clay was prescribed by the Roman obstetrician, gynecologist, and pediatrician Soranus of Ephesus, who practiced medicine around 100-140 AD.Soranus' gynecology, Owsei Temkin (tr.), JHU Press, 1991 (reprint). pp. 239-240. ISBN 0-8018-4320-0
Other clays used in classical times
The other types of clay that were famous in antiquity were as follows.- Terra chia, Terra cymolia (Cimolean earth): these were both white earths and considered of great value.
- Samian earth: Pliny in c. 50 AD (Nat. Hist.) details two distinct varieties, colyrium - an eye salve, and aster, which was used as a soap as well as in medicines.
- Terra sigillata strigoniensis (Strigian earth, derived from SilesiaSilesiaSilesia is a historical region of Central Europe located mostly in Poland, with smaller parts also in the Czech Republic, and Germany.Silesia is rich in mineral and natural resources, and includes several important industrial areas. Silesia's largest city and historical capital is Wrocław...
) - this clay, yellow in colour, appears to have been famous later in medieval times.
All the above seem to have been bentonitic clays.
- The earth which did not stain the hands was known as rubrica.
Medieval times
In medieval Persia, AvicennaAvicenna
Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā , commonly known as Ibn Sīnā or by his Latinized name Avicenna, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived...
(980-1037 CE), the 'Prince of Doctors', wrote about clay therapy in his numerous treatises.
Ibn al-Baitar (1197–1248), a Muslim scholar born at Malaga, Spain, and author of a famous work on pharmacology, discusses eight kinds of medicinal earth.L. Leclerc, "Traite des simples", II, 1881, pp. 421-427; for a general appreciation of this work see Baron Carra de Vaux, "Les penseurs de lslam", II, 1921, pp. 289-296 (original note in Laufer) The eight kinds are
- the terra sigillata,
- Egyptian earth,
- Samian earth,
- earth of Chios,
- Cimolean earth or pure clay (cimolite), soft earth, called al-hurr, green in color like verdigris, is smoked together with almond bark to serve as food when it will turn red and assume a good flavor; it is but rarely eaten without being smoked - also called 'Argentiera',
- earth of vines called ampelitis (Pliny XXXV, 56) or pharmakitis from Seleucia in Syria,
- Armenian earth (also known as the Armenian boleArmenian boleArmenian bole, also known as bolus armenus or bole armoniac, is an earthy clay, usually red, native to Armenia. It is red due to the presence of iron oxide; the clay also contains hydrous silicates of aluminum and possibly magnesium.-Uses:...
), salutary in cases of bubonic plague, being administered both externally and internally, - earth of Nishapur.
Renaissance period, and up to the present
A French naturalist Pierre BelonPierre Belon
Pierre Belon was a French naturalist. He is sometimes known as Pierre Belon du Mans, or, in Latin translations of his works, as Petrus Bellonius Cenomanus.Belon was born in 1517 at Soulletiere near Cérans-Foulletourte...
(1517‑1564) was interested in investigating the mystery of the Lemnian clay. In 1543, he visited Constantinople where, after making enquiries, he encountered 18 types of different products marketed as Lemnian Earth (he was concerned about possible counterfeits). He then made a special journey to Lemnos, where he continued his investigation, and tried to find the source of the clay. He discovered that it was extracted only once a year (on the 6th of August) under the supervision of Christian monks and Turkish officials.
Modern investigation has shown that this was a clay similar to the modern 'bentonite'.
Preparation of clay
Clay gathered from its original source deposit is refined and processed in various ways by manufacturers. This can include heating or baking the clay, since the raw clay tends to contain a variety of micro-organisms"Soil, including kaolinitic and montmorillonitic clays, contains considerable amounts of organic material, including many live microorganisms."from CDC.gov website Callahan GN. Eating dirt. Emerg Infect Dis [serial online] 2003 Aug. (accessed 16 June 2009)
Too much processing, likewise, may reduce the clay's therapeutic potential. In particular, Mascolo et al. studied 'pharmaceutical grade clay' versus 'the natural and the commercial herbalist clay', and found an appreciable depletion of trace elements in the pharmaceutical grade clay."The pharmaceutical clay shows an appreciable depletion of elements as Zn, V, Ga, Cr, Cd, Fe, Mo, Ni, Cu, Sb, S and Rb. Instead, the natural clay is characterised by high quantities of U, V, Cd, Mo, Tl, Ag, Ni, Cu, Sb, As, S, Se and Br, likely because of sulphide occurrence." -- Nicola Mascolo, Vito Summa, F. Tateo, Characterization of toxic elements in clays for human healing use. Applied Clay Science, Volume 15, Issues 5-6, 1999