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Über dieses Buch

Originally published in French, this updated and expanded English translation offers a definitive treatment on clays and effects on human health including the long history of clays used as pharmaceutical and therapeutic agents, the origins of clays, their structural properties and modes of action.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Background

Abstract
There is a long history of using clay to treat human health, physical balance, and psychophysiological balance. The literature is full of empirical examples of clay uses, supported by traditional methods often perpetuated in the form of legends related to recovery. Numerous cultural or worship practices have supported these uses, with or without solid justification, but always for reasons close to vital concerns. In popular tradition it is the earth (in English), the terre (in French), that has a powerful part in supporting life. It is the task of modern scientists to distinguish among the many uses of clays, those that are truly explainable and those that are less logical or even doubtful. It is the job of scientists to integrate tradition into science.
Michel Rautureau, Celso de Sousa Figueiredo Gomes, Nicole Liewig, Mehrnaz Katouzian-Safadi

Chapter 2. Clay and Clay Mineral Definition

Abstract
Any science, scientific field, or scientific domain requires a well-established and defined object of study as well as appropriate methodologies to develop knowledge about that object. However, over time the definition or concept of the object of study can undergo modifications and adaptations due to scientific advances, both in theoretical and experimental terms.
Clay science is multidisciplinary with the object of study both clay and clay minerals. It receives important contributions from other sciences or disciplines, such as mineralogy, crystallography, chemistry, geochemistry, sedimentology, geology, pedology, agronomy, soil mechanics, colloid chemistry, materials science, biology and biotechnology, medicine and public health, pharmacy, geoengineering, and environmental engineering. As in other sciences the object or objects of study referred to require a definition that would deserve general acceptance by all those interested in it, both theoretically and practically, despite the historical evolution of the concepts. Different from other sciences, the enormous diversity of the natural material denominated clay, in geological, compositional (physical, chemical, and physicochemical), and technological terms, as well as the enormous diversity of clay fields of interest and applications, may justify the lack of consensus on clay and clay mineral definition that is shown in this chapter.
Michel Rautureau, Celso de Sousa Figueiredo Gomes, Nicole Liewig, Mehrnaz Katouzian-Safadi

Chapter 3. Historical Aspects of a Natural Pharmacopeia: Clay in the Corpus of The Medieval Pharmacopeia Written in Arabic

Abstract
This chapter opens with an historical presentation of some translations of Ancient Greek medical texts. They reached us partly thanks to translations into Arabic carried out during the Middle Ages. These texts were progressively enriched and thereafter evolved autonomously. Stories of conquests and religions, both ancient and medieval, are superimposed on the evolution of this knowledge, without being the exclusive causes. Therapies based on clay and its various daily uses are described in the corpus of profane texts of pharmacy, pharmacopeia, medicine, and rules for healthy living. In this chapter these points, disclosed in chronological order and by topics, are dealt with, concentrated only on some fundamental studies in medicine and pharmacy.
Michel Rautureau, Celso de Sousa Figueiredo Gomes, Nicole Liewig, Mehrnaz Katouzian-Safadi

Chapter 4. Description of Clay Materials

Abstract
Clay origin and nomenclature and clay modes and conditions of formation are discussed in this chapter. Also the typology of clay deposits and the quality of clay, in terms of purity, required for clay uses in the field of human health are dealt with as well. In addition to the almost general beneficial effects of clay and clay minerals it is acknowledged that some clay minerals could have real or potentially harmful effects on the respiratory system if inhaled, due to the fibrous character of their particle shapes. The study of clay and clay minerals' quality requires a thorough knowledge of both principles and analytical methods (chemical, thermal, textural, microscopic, diffractometric, and spectrometric) used in mineralogy in order to identify and characterize the crystallochemical specificities of clay minerals, the crystallochemical formula of those natural clay mineral species utilized in the field of health exhibited in the present chapter. Clay exploitation also takes into account clay utilizations in various domains such as pedologic, crafts, and industrial and chemical, all depending upon clay mineral crystallochemistry.
Michel Rautureau, Celso de Sousa Figueiredo Gomes, Nicole Liewig, Mehrnaz Katouzian-Safadi

Chapter 5. Clay Reactivity Depending Upon the Crystallochemical Properties of Clay Minerals

Abstract
The crystallochemical models of clay mineral structures are described in this chapter because clay properties and inherent reactivity depend entirely on the specificities of those structures. Clay reactivity is strongly conditioned by the surface properties of clay mineral particles that are basically dependent on the particle global electric charge and its spatial distribution pattern, different from basal surfaces to edge surfaces. Particle electric charge results mainly from atomic substitutions that occur in both the octahedral and tetrahedral layers. In clay minerals bearing interlayer spaces chemical reactivity also possibly occurs on internal surfaces.
The reactivity of the clay–water system is quite common in natural clays. It is often used in mud therapy and peloid therapy in the form of paste for topical therapeutic and cosmetic applications, and it is also studied as well as the clay–water system that in the form of dispersion (“argillic water”) is used for internal therapeutic purposes. Clay’s ionic exchange capacity and color, two important properties whenever clay is used in the field of health, are also discussed.
Michel Rautureau, Celso de Sousa Figueiredo Gomes, Nicole Liewig, Mehrnaz Katouzian-Safadi

Chapter 6. General Information on Clay Applications for Health and Well-Being

Abstract
This chapter reports on the ordinary clay applications in the field of health: first, the function of the nature of the pathologies to be treated, second, the function of the clay potentialities to treat certain pathologies, and third, the function of the principal reactivity domains pertaining to clay and living organisms.
Adsorption and absorption are the clay properties that most justify both the ingestion of clay (in powders or water dispersion) to treat internal health disorders of the gastrointestinal tract promoting the neutralization of stomach acidity or the fixation and posterior elimination of toxins or other toxic compounds or even the supplementation of deficient bioessential chemical elements (e.g., Fe, Zn, Ca, Mg) and the cutaneous applications of clay for skin care purposes. Heat capacity is another property related to clay pastes when, for example, mud packs are used topically to treat some skeletal–muscular rheumatic pathologies and skin inflammatory disorders (e.g., psoriasis). Clay reactivity and the specificities of the distinctive modes of application and action that can occur in clay–human body interaction, emphasizing various effects, such as the barrier effect, the fixation and transfer of essential or toxic chemical elements, as well as heat transfer are dealt with as well.
Michel Rautureau, Celso de Sousa Figueiredo Gomes, Nicole Liewig, Mehrnaz Katouzian-Safadi

Chapter 7. Therapies Based on Clay

Abstract
The therapies based on clay dealt with in this chapter are classified in two main groups, physical therapies and chemical therapies, involving either physical or chemical exchanges between the clay- bearing material and the human body, respectively. Physical therapies involve energy exchanges that can be induced during a massage by employing mechanical pressure on the previously heated (maximum at 45–50°C) clay pack, and from the pressure and heat being applied; the beneficial effects of improvement of muscular tone and blood circulation through abrasive and gumming action may occur. Chemical therapies involve chemical exchanges that could be promoted and developed by the applied pressure and heat. Beneficial effects could result from the chemical exchanges of the transdermal absorption of eventual bioessential elements and compounds existing in the liquid phase.
Historically the use of clays made it possible to develop empirical processes with real effectiveness, which justified the transfer of knowledge from generation to generation. Little by little these applications proved to be in relation to scientifically explained properties. Whenever possible we present these relations by specifying that the scientific projections can constantly justify an evolution of these models and consequently modify, make more accurate, or refute these explanations.
The two large fields of action we have just quoted above bring into play either the environmental relations (soft mechanical action, heat transfer) or the specific qualities of the clay particles (exchanges of water, chemical effects). Another type of action, more indirect but considerable, is the impact on the microorganisms. Clay can isolate them from the medium that contains them, coat them or destabilize them and neutralize their effects. It can also intervene by fixing toxins produced by these microorganisms and in this way suppress their effects.
Michel Rautureau, Celso de Sousa Figueiredo Gomes, Nicole Liewig, Mehrnaz Katouzian-Safadi

Chapter 8. Principal Modes of Clay Use

Abstract
There is a long tradition of the use of clay for therapeutic purposes. The so-called healing or curative clay can be used either for internal or external applications. The so-called edible clay is a type of healing clay used for internal applications, ingested in the form of clay/potable water dispersions (argillic water), bits/pieces of natural clay, or even manufactured cookies or wafers consisting of a clay–animal fat blend and slowly chewed.
For external or topical therapeutic applications clay is used in the form of a clay–water paste called either mud (equivalent to natural peloid), or just peloid or peloid s.s. (strictu senso) that corresponds to maturated and manipulated mud or natural peloid, called mud therapy and peloid therapy, respectively. Mud therapy and peloid therapy have been successfully used as treatments for various inflammatory disorders including rheumatic diseases and chronic inflammatory skin disorders such as psoriasis or atopic dermatitis. The mechanisms of action of mud and peloid packs for healing and skin care have been and still are the object of study by physicians specialized in medical hydrology, the mechanisms being attributed to a combination of thermal and physicochemical effects.
We have approached above the large domains of clay application (skin and intestinal mucous) and the excluded domains of clay application (respiratory tracts, visual and auditory systems, internal actions within the organs). Also, the clay mineral properties that come into play in varied types of application have been mentioned. Now, without entering into the specifically medical field, which is too complex and outside our descriptive framework, we deal with applications that we wish to preserve.
Michel Rautureau, Celso de Sousa Figueiredo Gomes, Nicole Liewig, Mehrnaz Katouzian-Safadi

Chapter 9. Provisioning, Recycling, and Trade of Clay

Abstract
Natural clay to be used in the field of health and well-being, whether used as it occurs at its natural site, or after extraction from the deposit, is submitted to a refining processing in order to concentrate the finest grain fraction (enriched in clay minerals sometimes associated with organic compounds and finely grained carbonates, potentially the most interesting components in therapeutic or cosmetic terms). In the first situation clay in the form of paste (after being mixed with mineral water, e.g., seawater) is used at its natural site or at a nearby site as mud in mud therapy treatments, or as small pieces chewed and ingested, or even ingested after being dispersed preferentially in potable water providing argillic water. Processed clay is available on the market in two main states: powders (used in pharmaceutical formulations) and paste (used in peloids to be applied, for instance, at spa resorts after undergoing more or less complex manipulation and maturation), and in both states a microbiological check-up is necessary to assure sanitary safety. This sanitary safety is also required when recycling previously used clay paste.
Michel Rautureau, Celso de Sousa Figueiredo Gomes, Nicole Liewig, Mehrnaz Katouzian-Safadi

Backmatter

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