Codex @codex  0

A chronic disease in which an immune response triggered by gluten damages the small intestine. The modern definition must not simply be read back into the coeliac affection of Aretaeus. ^[ref]

These names refer to several unrelated chemical classes: blood and bile pigments, a photosynthetic pigment family, an amino sulfonic acid, a disputed historical faecal extract, and storage polysaccharides or proteins. Similar colour or a historical name does not establish chemical identity.

Haematocrystallin denotes the crystallizable colouring substance of red blood, now identified with hemoglobin. It combines a globin protein with iron-containing haem groups. Within intact red cells it reversibly binds oxygen; oxygenated and deoxygenated forms have different absorption spectra. Crystals obtained from blood differ with species and preparation. This is not the same thing as a crystal formed from an old tissue haemorrhage. The word does not mean that all circulating blood normally consists of free pigment crystals.^[ref]

Haematoidin is the yellow-orange to reddish pigment characteristically encountered in old extravasated blood, sometimes as rhomboidal crystals or radiating clusters. It is associated with bilirubin and lacks the iron retained in haemosiderin. The historical inference that any reddish blood-derived crystal must be the same substance as haematocrystallin is therefore wrong. In a tissue preparation the local matrix and other constituents can complicate an exact chemical identification from appearance alone.^[ref]

Haematin is a dark iron-containing derivative of haem, obtained when the globin association and the iron's chemical environment are altered. In modern chemical usage, hematin is the ferric hydroxide form of the haem pigment; hemin is the corresponding chloride form. Historical preparations and terminology were less consistently separated. Neither should be equated with iron-free bilirubin, and a haem-derived crystal test is not the crystallization of intact hemoglobin.^[ref][ref]

Chlorophyll is the green pigment system of photosynthetic organisms, present in organized pigment-protein assemblies in chloroplasts in green plants. Modern chemistry distinguishes several chlorophylls: chlorophyll a, for example, has a magnesium-containing tetrapyrrolic ring system and a hydrophobic side chain. It absorbs light used in photosynthetic energy conversion. Extraction into alcohol can reveal the green pigment, but a leaf extract is a mixture rather than a chemically pure universal chlorophyll. Its green colour must not be attributed to iron in the same way as haem.^[ref]

Biliverdin is a green, open-chain tetrapyrrolic pigment. In modern haem catabolism, ring cleavage by haem oxygenase releases iron and forms biliverdin; reduction then produces bilirubin. The pigments contribute to changing colours of some resolving haemorrhages and to bile-pigment chemistry. This sequence concerns degradation of the haem group, not conversion of the entire globin protein directly into one green molecule.^[ref]

Taurin, now taurine, is a colourless crystalline amino sulfonic acid with the structure ${\mathrm{H}}_2\mathrm{NC}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_3\mathrm{H}$. It contains sulfur and nitrogen and can form conjugates with bile acids, including taurocholic acid. It is not itself a green bile pigment, an ordinary carboxylic amino acid, or a standard amino acid directly inserted into proteins by translation. The chemical classification and formula distinguish it from neighbouring names in the list.^[ref]

Excretin was the name William Marcet gave to a crystalline material extracted from human faeces. His contemporary account describes treatment with hot alcohol, removal of material with lime, extraction with ether, and formation of silky needle-like crystals; the material was insoluble in water, soluble in ether and hot alcohol, and melted in the low-to-mid 90s Celsius. His 1859 account reports carbon, hydrogen, oxygen and sulfur and gives an equivalent-weight formula based on an assumed sulfur content. These are historical analytical claims, not a modern authenticated molecular specification. Later work questioned the purity and chemical individuality of excretin, so that old name alone does not establish a definite modern structure.^[ref][ref]

Glycogen is an animal glucose-storage polysaccharide, particularly important in the liver and skeletal muscles. Its highly branched chains contain alpha-(1→4) links with alpha-(1→6) branch points. Preparations form opalescent dispersions and commonly show a reddish-brown iodine reaction rather than the intense blue associated with long amylose chains. Hydrolysis yields glucose. Liver glycogen can support the regulation of circulating glucose, whereas muscle glycogen mainly supports local muscle metabolism; a modern account must distinguish those physiological destinations.^[ref]

Gluten is the cohesive protein-rich material left when wheat dough is washed to remove much of its starch. It is not a single small molecule: modern analysis distinguishes gliadin and glutenin families whose associations contribute extensibility and elasticity. It is poorly soluble in water as a dough network, contains nitrogen, and on full hydrolysis supplies amino acids. Its nutritive role is that of a plant protein mixture, not a nitrogen-free carbohydrate.^[ref]

Legumin is a seed storage globulin associated particularly with peas and related legumes. A classical preparation extracts protein into suitable dilute salt solution and precipitates it under changed conditions. Modern legumins are 11S globulin assemblies, often hexamers formed from processed subunits. They are nitrogen-containing proteins, chemically distinct from starch despite occurring beside it in a seed. The older name vegetable casein indicates an analogy of precipitation or nutritive role; it does not establish identity with milk casein.^[ref]

Translation. The stomach, the internal organ responsible for digestion, performs digestion poorly whenever diarrhoea takes hold of a person; and the diarrhoea consists of liquid, undigested food. Unless this happens from a temporary cause for only one or two days, the whole person becomes weak through wasting of the body, and the coeliac affection of Aretaeus becomes a chronic disease, through weakness of the digestive heat and chilling of the stomach. Then the food is indeed broken down under the action of heat, but the heat does not digest it completely or turn it into an appropriate nutritive fluid: it leaves it half-finished (the printed word is incomplete), through failure of the completing power. The food, abandoned by the process, changes for the worse in colour, smell and consistency. Its colour is white and lacking bile; its smell is foul and dung-like; and it is liquid and without cohesion because the process has failed, retaining only the beginning of digestion as its one good quality. Hence there is gaseous, continual, foul-smelling belching in the stomach.

Text and medical meaning. The scan ends PDF volume p. 101 with λείπε- and begins p. 102 with ἀδρανείῃ. The translation marks this defective word rather than silently pretending that the missing ending is visible. The corresponding edited Greek has λείπει, “leaves”, which supplies the sense used here. The Oxford extract also separates the conditional clause from the following sentence more abruptly than that edition; the translation carries its evident qualification forward. ^[ref]

Aretaeus of Cappadocia uses κοιλίη for the stomach or digestive belly and σκῆνος, literally a tent or dwelling, for the body. ἀτροφίη indicates wasting or failure of nourishment; it need not denote the modern histological concept of atrophy. “Appropriate nutritive fluid” renders χυμὸν οἰκεῖον: the product that the author thinks suitable for bodily nourishment, rather than a modern chemical identification. The pale, foul, loose output is an observed feature; the explanation by weak digestive heat is the author's theory. It is not a modern account of digestion. ^[ref]

The historical coeliac affection of Aretaeus cannot establish a modern diagnosis of coeliac disease. Modern coeliac disease involves an immune response to gluten that damages the small intestine; the ancient symptom description alone cannot identify that mechanism. The diagnosis should therefore not be read back into the passage as certain. ^[ref]