The miasma theory is an obsolete medical theory that held diseases—such as cholera, chlamydia, or the Black Death—were caused by a miasma, a noxious form of "bad air" known as night air. The theory held that the origin of epidemics was due to a miasma, emanating from rotting organic matter. Though miasma theory is associated with the spread of disease, some academics in the early nineteenth century suggested that the theory extended to other conditions as well, e.g. one could become obese by inhaling the odor of food. The miasma theory was accepted from ancient times in China; the theory was given up by scientists and physicians after 1880, replaced by the germ theory of disease: specific germs, not miasma, caused specific diseases. However, cultural beliefs about getting rid of odor made the clean-up of waste a high priority for cities; the word miasma comes from ancient Greek and means "pollution". The idea gave rise to the name malaria through medieval Italian. Miasma was considered to be a poisonous vapor or mist filled with particles from decomposed matter that caused illnesses.
The miasmatic position was that diseases were the product of environmental factors such as contaminated water, foul air, poor hygienic conditions. Such infection was not passed between individuals but would affect individuals within the locale that gave rise to such vapors, it was identifiable by its foul smell. It was initially believed that miasmas were propagated through worms from ulcers within those affected by a plague. In India, there was a miasma theory and the Indians take credit for being the first to put this miasma theory into clinical practice; the Indians invented paan, a gambir paste, believed to help prevent miasma. This gambir tree is found in Sri Lanka. In the 1st century BC, the Roman architectural writer Vitruvius described the potential effects of miasma from fetid swamplands when visiting a city: For when the morning breezes blow toward the town at sunrise, if they bring with them mist from marshes and, mingled with the mist, the poisonous breath of creatures of the marshes to be wafted into the bodies of the inhabitants, they will make the site unhealthy.
The miasmatic theory of disease remained popular in the Middle Ages and a sense of effluvia contributed to Robert Boyle's Suspicions about the Hidden Realities of the Air. In the 1850s, miasma was used to explain the spread of cholera in London and in Paris justifying Haussmann's renovation of the French capital; the disease was said to be preventable by scouring of the body and items. Dr. William Farr, the assistant commissioner for the 1851 London census, was an important supporter of the miasma theory, he believed that cholera was transmitted by air, that there was a deadly concentration of miasmata near the River Thames' banks. Such a belief was in part accepted because of the general lack of air quality in urbanized areas; the wide acceptance of miasma theory during the cholera outbreaks overshadowed the correct theory brought forth by John Snow that cholera was spread through water. This slowed the response to the major outbreaks in the Soho district of other areas; the Crimean War nurse Florence Nightingale was a proponent of the theory and worked to make hospitals sanitary and fresh-smelling.
It was stated in'Notes on Nursing for the Labouring Classes' that Nightingale would "keep the air breathes as pure as the external air. Fear of miasma registered in many early nineteenth century warnings concerning what was termed “unhealthy fog”; the presence of fog indicated the presence of miasma. The miasmas behaved like mist, blown with air currents, wafted by winds, it did not travel on air, it changed the air through which it propagated. The atmosphere was infected by miasma. Many believed miasma was magical, was able to change the properties of the air and atmosphere completely. In China, miasma is an old concept of illness, used extensively by ancient Chinese local chronicles and works of literature. Miasma has different names in Chinese culture. Most of the explanations of miasma refer to it as a kind of poison gas; the ancient Chinese thought. The miasma was thought to be caused by the heat and the dead air in the Southern Chinese mountains, they thought that insects’ waste polluted the air, the fog, the water, the virgin forest harbored a great environment for miasma to occur.
In descriptions by ancient travelers, soldiers, or local officials of the phenomenon of miasma, haze, gas, or poison geological gassing were always mentioned. The miasma was thought to have caused a lot of diseases such as the cold, heat strokes, malaria, or dysentery. In the medical history of China, malaria had been referred to by different names in different dynasty periods. Poisoning and psittacosis were called miasma in ancient China because they did not understand the cause of disease. In the Sui dynasty, doctor Tsao Yuan-fung mentioned miasma in his book On Syndromes, he thought. However, in his opinion, miasma was different from dysentery. In his book, he discussed dysentery in another chapter, malaria in a single chapter, he claimed that miasma caused various diseases, so he suggested that one should find ap
Spontaneous generation refers to an obsolete body of thought on the ordinary formation of living organisms without descent from similar organisms. The theory of spontaneous generation held that living creatures could arise from nonliving matter and that such processes were commonplace and regular. For instance, it was hypothesized that certain forms such as fleas could arise from inanimate matter such as dust, or that maggots could arise from dead flesh. A variant idea was that of equivocal generation, in which species such as tapeworms arose from unrelated living organisms, now understood to be their hosts; the idea of univocal generation, by contrast, refers to exclusive reproduction from genetically related parent of the same species. The doctrine of spontaneous generation was coherently synthesized by Aristotle, who compiled and expanded the work of earlier natural philosophers and the various ancient explanations for the appearance of organisms, was taken as scientific fact for two millennia.
Though challenged in the 17th and 18th centuries by the experiments of Francesco Redi and Lazzaro Spallanzani, spontaneous generation was not disproved until the work of Louis Pasteur and John Tyndall in the mid-19th century. Rejection of spontaneous generation is no longer controversial among biologists. By the middle of the 19th century, experiments of Louis Pasteur and others refuted the traditional theory of spontaneous generation and supported biogenesis. Spontaneous generation refers both to the supposed processes by which different types of life might emerge from specific sources other than seeds, eggs, or parents, to theoretical principles presented in support of any such phenomena. Crucial to this doctrine are the ideas that life comes from non-life and that no causal agent, such as a parent, is needed; the hypothetical processes by which life emerges from nonliving matter on a time scale of minutes, weeks, or years are sometimes referred to as abiogenesis. Such ideas have no operative principles in common with the modern hypothesis of abiogenesis, which asserts that life emerged in the early ages of the planet, over a time span of at least millions of years, subsequently diversified, that there is no evidence of any subsequent repetition of the event.
The term equivocal generation, sometimes known as heterogenesis or xenogenesis, describes the supposed process by which one form of life arises from a different, unrelated form, such as tapeworms from the bodies of their hosts. In the years following Louis Pasteur's 1859 experiment, the term "spontaneous generation" fell out of favor. Experimentalists used a variety of terms for the study of the origin of life from nonliving materials. Heterogenesis was applied to the generation of living things from once-living organic matter, Henry Charlton Bastian proposed the term archebiosis for life originating from inorganic materials. Disliking the randomness and unpredictability implied by the term "'spontaneous' generation," in 1870 Bastian coined the term biogenesis to refer to the formation of life from nonliving matter. Soon thereafter, English biologist Thomas Henry Huxley proposed the term abiogenesis to refer to this same process and adopted biogenesis for the process by which life arises from existing life.
Active in the 6th and 5th centuries BCE, early Greek philosophers, called physiologoi in antiquity, attempted to give natural explanations of phenomena, ascribed to the agency of the gods. The physiologoi sought the material principle or arche of things, emphasizing the rational unity of the external world and rejecting theological or mythological explanations. Anaximander, who believed that all things arose from the elemental nature of the universe, the apeiron or the "unbounded" or "infinite," was the first western thinker to propose that life developed spontaneously from nonliving matter; the primal chaos of the apeiron, eternally in motion, served as a substratum in which elemental opposites generated and shaped the many and varied things in the world. According to Hippolytus of Rome in the third century CE, Anaximander claimed that fish or fish-like creatures were first formed in the "wet" when acted on by the heat of the sun and that these aquatic creatures gave rise to human beings.
Censorinus, writing in the 3rd century, reports: Anaximander of Miletus considered that from warmed up water and earth emerged either fish or fishlike animals. Inside these animals, men took. Anaximenes, a pupil of Anaximander, thought that air was the element that imparted life and endowed creatures with motion and thought, he proposed that plants and animals, including human beings, arose from a primordial terrestrial slime, a mixture of earth and water, combined with the sun's heat. Anaxagoras, believed that life emerged from a terrestrial slime. However, he held that the seeds of plants existed in the air from the beginning, those of animals in the aether. Xenophanes traced the origin of man back to the transitional period between the fluid stage of the earth and the formation of land, under the influence of the sun. In what has been seen as a prefiguration of a concept of natural selection, Empedocles accepted the spontaneous generation of life but held that different forms, made up of differing combinations of parts, spontaneously arose as though by
Steven Paul Novella is an American clinical neurologist and assistant professor at Yale University School of Medicine. Novella is best known for his involvement in the skeptical movement. Novella's academic specialization is in neurology, including more amyotrophic lateral sclerosis, myasthenia gravis and neuromuscular disorders and the treatment of hyperactive neurological disorders. Novella received his medical degree from Georgetown University School of Medicine in 1991, did a year of residency in internal medicine at Georgetown University Hospital/Washington Hospital Center, completed his residency in neurology at Yale–New Haven Hospital in 1995, was board certified in neurology in 1998. Growing up, Novella did not always want to be a physician. In an interview for the Books and Ideas podcast he said, I think I entertained various career ideas; when I was growing up I thought about being a lawyer for a while and by the time I went to college, I knew I wanted to go into a science background and I did premed in undergraduate school.
So by I had decided that that’s what I wanted to do. So I would say in my late teens is when I decided to go into medicine. Novella is a proponent of scientific skepticism, which he defines as:... one who prefers beliefs and conclusions that are reliable and valid to ones that are comforting or convenient, therefore rigorously and applies the methods of science and reason to all empirical claims their own. A skeptic provisionally proportions acceptance of any claim to valid logic and a fair and thorough assessment of available evidence, studies the pitfalls of human reason and the mechanisms of deception so as to avoid being deceived by others or themselves. Skepticism values method over any particular conclusion. In response to an editorial in The New York Times in which Paul Davies concluded "until science comes up with a testable theory of the laws of the universe, its claim to be free of faith is manifestly bogus," Novella said, It's not true because science is not dependent upon faith in a naturalistic world.
It just follows the methods as if it is naturalistic... it is not a system of beliefs. People ask me and they will ask you as skeptics what do you believe? Well, it's not about belief. Do you believe in ESP? It doesn't matter if I believe in ESP; the only thing that matters is what is the evidence for ESP?... It's important I think to present skepticism as a method of inquiry not a set of conclusions, not a set of beliefs. In 1996 Novella, his brother Bob, Perry DeAngelis founded The Connecticut Skeptical Society; as Evan Bernstein tells it, "One night sometime in late 1995, Perry was over Steve's condo, casually flipping through a copy of SI. He was reading through the list of local groups, commented to Steve:'There's no local skeptics group in Connecticut. We should start one.'"The group joined with the Skeptical Inquirers of New England and the New Hampshire Skeptical Resource to form the New England Skeptical Society. Novella serves as president of the NESS. In the early days of the New England Skeptical Society, Novella participated in investigations of various paranormal claims.
Sometimes these were part of the screening process for the One Million Dollar Paranormal Challenge offered by the James Randi Educational Foundation. Novella investigated such claims as Ouija boards, the ability to control the flipping of a coin, a mind reader who got zero out of 20 correct, many dowsers. Novella and the NESS examined some phenomena described by people who were not competing for the One Million Dollar prize, such as haunted houses, the ability to communicate with the dead, recording the voices of ghosts, known as electronic voice phenomenon, or EVP. In May 2005, Novella started The Skeptics' Guide to the Universe podcast with his friends Perry DeAngelis and Evan Bernstein, his brothers Bob and Jay. DeAngelis remained with the show until his death in August, 2007. In July 2006, Rebecca Watson joined the podcast as a regular, staying through December, 2014. Cara Santa Maria joined the cast in July, 2015. Novella both hosts the show and does the editing and post-production. In an interview for the Books and Ideas podcast he said, I am responsible for the content and prepping it and I do all the post production which I know, as you know is a lot of work.
So you know, it's a good 20, 30 hours a week that I put into putting out this podcast, it is like having a second job. And, you know, it’s a labor of love; when asked about the purpose of the podcast Novella said, We deal with controversial topics or topics on the fringe of science, although sometimes we do just straight up interesting science news stories, whatever captures our interest. But we deal with the paranormal or conspiracy theories, or health fraud, consumer protection type of issues, and our goal is to give our listeners the tools to look at science in the news, science in society and have some way of navigating through all of the claims and all of the hype and have the tools to figure things out for themselves more than anything else. In 2007, Novella started a blog, Neurologica, "your daily fix of neuroscience and critical thinking", for which he writes three articles per week on a wide range of subjects related to science or skepticism, he is the executive editor of the blog Science-Based Medicine for which he is a regular contributor, he is
Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. A few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, are present in most of its habitats. Bacteria inhabit soil, acidic hot springs, radioactive waste, the deep portions of Earth's crust. Bacteria live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, only about half of the bacterial phyla have species that can be grown in the laboratory; the study of bacteria is known as a branch of microbiology. There are 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water. There are 5×1030 bacteria on Earth, forming a biomass which exceeds that of all plants and animals. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere.
The nutrient cycle includes the decomposition of dead bodies. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Data reported by researchers in October 2012 and published in March 2013 suggested that bacteria thrive in the Mariana Trench, with a depth of up to 11 kilometres, is the deepest known part of the oceans. Other researchers reported related studies that microbes thrive inside rocks up to 580 metres below the sea floor under 2.6 kilometres of ocean off the coast of the northwestern United States. According to one of the researchers, "You can find microbes everywhere—they're adaptable to conditions, survive wherever they are."The famous notion that bacterial cells in the human body outnumber human cells by a factor of 10:1 has been debunked. There are 39 trillion bacterial cells in the human microbiota as personified by a "reference" 70 kg male 170 cm tall, whereas there are 30 trillion human cells in the body.
This means that although they do have the upper hand in actual numbers, it is only by 30%, not 900%. The largest number exist in the gut flora, a large number on the skin; the vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, though many are beneficial in the gut flora. However several species of bacteria are pathogenic and cause infectious diseases, including cholera, anthrax and bubonic plague; the most common fatal bacterial diseases are respiratory infections, with tuberculosis alone killing about 2 million people per year in sub-Saharan Africa. In developed countries, antibiotics are used to treat bacterial infections and are used in farming, making antibiotic resistance a growing problem. In industry, bacteria are important in sewage treatment and the breakdown of oil spills, the production of cheese and yogurt through fermentation, the recovery of gold, palladium and other metals in the mining sector, as well as in biotechnology, the manufacture of antibiotics and other chemicals.
Once regarded as plants constituting the class Schizomycetes, bacteria are now classified as prokaryotes. Unlike cells of animals and other eukaryotes, bacterial cells do not contain a nucleus and harbour membrane-bound organelles. Although the term bacteria traditionally included all prokaryotes, the scientific classification changed after the discovery in the 1990s that prokaryotes consist of two different groups of organisms that evolved from an ancient common ancestor; these evolutionary domains are called Archaea. The word bacteria is the plural of the New Latin bacterium, the latinisation of the Greek βακτήριον, the diminutive of βακτηρία, meaning "staff, cane", because the first ones to be discovered were rod-shaped; the ancestors of modern bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, about 4 billion years ago. For about 3 billion years, most organisms were microscopic, bacteria and archaea were the dominant forms of life. Although bacterial fossils exist, such as stromatolites, their lack of distinctive morphology prevents them from being used to examine the history of bacterial evolution, or to date the time of origin of a particular bacterial species.
However, gene sequences can be used to reconstruct the bacterial phylogeny, these studies indicate that bacteria diverged first from the archaeal/eukaryotic lineage. The most recent common ancestor of bacteria and archaea was a hyperthermophile that lived about 2.5 billion–3.2 billion years ago. Bacteria were involved in the second great evolutionary divergence, that of the archaea and eukaryotes. Here, eukaryotes resulted from the entering of ancient bacteria into endosymbiotic associations with the ancestors of eukaryotic cells, which were themselves related to the Archaea; this involved the engulfment by proto-eukaryotic cells of alphaproteobacterial symbionts to form either mitochondria or hydrogenosomes, which are still found in all known Eukarya. Some eukaryotes that contained mitochondria engulfed cyanobacteria-like organisms, leading to the formation of chloroplasts in algae and plants; this is known as primary endosymbiosis. Bacteria display a wide diversity of sizes, called morphologies.
Bacterial cells are about one-tenth the size of eukaryotic cells
A fomes or fomite is any inanimate object, that when contaminated with infectious agents, such as bacteria or viruses, can transfer disease to a new host. For humans, skin cells, hair and bedding are common hospital sources of contamination. Fomites are associated with hospital-acquired infections, as they are possible routes to pass pathogens between patients. Stethoscopes and neckties are two such fomites associated with health care providers. Basic hospital equipment, such as IV drip tubes and life support equipment, can be carriers, when the pathogens form biofilms on the surfaces. Careful sterilization of such objects prevents cross-infection. Researchers have discovered that smooth surfaces like door knobs transmit bacteria and viruses better than porous materials like paper money because porous fibrous, materials absorb and trap the contagion, making it harder to contract through simple touch. Fomites include soiled clothes, linens, cups, pencils and surgical dressings; the Italian scholar and physician Girolamo Fracastoro appears to have first used the Latin word fomes, meaning "tinder", in this sense in his essay on contagion, De Contagione et Contagiosis Morbis, published in 1546: "By fomes I mean clothes, wooden objects, things of that sort, which though not themselves corrupted can preserve the original germs of the contagion and infect by means of these".
English usage of fomes, pronounced, is documented since 1658. The English word fomite, in use since 1859, is a back-formation from the plural fomites; the English-language pronunciation of fomites is, while fomite, is pronounced. Fomites play a conspicuous role in Steven Soderbergh's 2011 film Contagion about a pandemic. Biofilm Focal infection theory Focus of infection Nosocomial infection Vector General characteristics and roles of fomites in viral transmission
Louis Pasteur was a French biologist and chemist renowned for his discoveries of the principles of vaccination, microbial fermentation and pasteurization. He is remembered for his remarkable breakthroughs in the causes and prevention of diseases, his discoveries have saved many lives since, he reduced mortality from puerperal fever, created the first vaccines for rabies and anthrax. His medical discoveries provided direct support for the germ theory of disease and its application in clinical medicine, he is best known to the general public for his invention of the technique of treating milk and wine to stop bacterial contamination, a process now called pasteurization. He is regarded as one of the three main founders of bacteriology, together with Ferdinand Cohn and Robert Koch, is popularly known as the "father of microbiology". Pasteur was responsible for disproving the doctrine of spontaneous generation, he performed experiments. Under the auspices of the French Academy of Sciences, he demonstrated that in sterilized and sealed flasks nothing developed, in sterilized but open flasks microorganisms could grow.
Although Pasteur was not the first to propose the germ theory, his experiments indicated its correctness and convinced most of Europe that it was true. Today, he is regarded as one of the fathers of germ theory. Pasteur made significant discoveries in chemistry, most notably on the molecular basis for the asymmetry of certain crystals and racemization. Early in his career, his investigation of tartaric acid resulted in the first resolution of what is now called optical isomers, his work led the way to the current understanding of a fundamental principle in the structure of organic compounds. He was the director of the Pasteur Institute, established in 1887, until his death, his body was interred in a vault beneath the institute. Although Pasteur made groundbreaking experiments, his reputation became associated with various controversies. Historical reassessment of his notebook revealed. Louis Pasteur was born on December 27, 1822, in Dole, France, to a Catholic family of a poor tanner, he was the third child of Jeanne-Etiennette Roqui.
The family moved to Marnoz in 1826 and to Arbois in 1827. Pasteur entered primary school in 1831, he was an average student in his early years, not academic, as his interests were fishing and sketching. He drew many pastels and portraits of his parents and neighbors. Pasteur attended secondary school at the Collège d'Arbois. In October 1838, he left for Paris to join the Pension Barbet, but became homesick and returned in November. In 1839, he entered the Collège Royal at Besançon to study philosophy and earned his Bachelor of Letters degree in 1840, he was appointed a tutor at the Besançon college while continuing a degree science course with special mathematics. He failed his first examination in 1841, he managed to pass the baccalauréat scientifique degree in 1842 from Dijon but with a mediocre grade in chemistry. In 1842, Pasteur took the entrance test for the École Normale Supérieure, he passed the first set of tests, but because his ranking was low, Pasteur decided not to continue and try again next year.
He went back to the Pension Barbet to prepare for the test. He attended classes at the Lycée Saint-Louis and lectures of Jean-Baptiste Dumas at the Sorbonne. In 1843, he entered the École Normale Supérieure. In 1845 he received the licencié ès sciences degree. In 1846, he was appointed professor of physics at the Collège de Tournon in Ardèche, but the chemist Antoine Jérôme Balard wanted him back at the École Normale Supérieure as a graduate laboratory assistant, he joined Balard and started his research in crystallography and in 1847, he submitted his two theses, one in chemistry and the other in physics. After serving as professor of physics at the Dijon Lycée in 1848, he became professor of chemistry at the University of Strasbourg, where he met and courted Marie Laurent, daughter of the university's rector in 1849, they were married on May 29, 1849, together had five children, only two of whom survived to adulthood. Pasteur was appointed professor of chemistry at the University of Strasbourg in 1848, became the chair of chemistry in 1852.
In 1854, he was named dean of the new faculty of sciences at University of Lille, where he began his studies on fermentation. It was on this occasion that Pasteur uttered his oft-quoted remark: "dans les champs de l'observation, le hasard ne favorise que les esprits préparés". In 1857, he moved to Paris as the director of scientific studies at the École Normale Supérieure where he took control from 1858 to 1867 and introduced a series of reforms to improve the standard of scientific work; the examinations became more rigid, which led to better results, greater competition, increased prestige. Many of his decrees, were rigid and authoritarian, leading to two serious student revolts. During "the bean revolt" he decreed that a mutton stew, which students had refused to eat, would be served and eaten every Monday. On another occasion he threatened to expel any student caught smoking, 73 of the 80 students in the school resigned. In 1863, he was appointed professor of geology and chemistry at the École nationale supérieure des Beaux-Arts, a position he held until his resignation in 1867.
In 1867, he became the chair of or
Alchemy was an ancient branch of natural philosophy, a philosophical and protoscientific tradition practiced throughout Europe and Asia, originating in Greco-Roman Egypt in the first few centuries AD. It aims to purify and perfect certain objects. Common aims were chrysopoeia, the transmutation of "base metals" into "noble metals"; the perfection of the human body and soul was thought to permit or result from the alchemical magnum opus and, in the Hellenistic and Western mystery tradition, the achievement of gnosis. In Europe, the creation of a philosopher's stone was variously connected with all of these projects. In English, the term is limited to descriptions of European alchemy, but similar practices existed in the Far East, the Indian subcontinent, the Muslim world. In Europe, following the 12th-century Renaissance produced by the translation of Medieval Islamic works on science and the rediscovery of Aristotelian philosophy, alchemists played a significant role in early modern science.
Islamic and European alchemists developed a structure of basic laboratory techniques, theory and experimental method, some of which are still in use today. However, they continued antiquity's belief in four elements and guarded their work in secrecy including cyphers and cryptic symbolism, their work was guided by Hermetic principles related to magic and religion. Modern discussions of alchemy are split into an examination of its exoteric practical applications and its esoteric spiritual aspects, despite the arguments of scholars like Holmyard and von Franz that they should be understood as complementary; the former is pursued by historians of the physical sciences who examine the subject in terms of early chemistry and charlatanism, the philosophical and religious contexts in which these events occurred. The latter interests historians of esotericism and some philosophers and spiritualists; the subject has made an ongoing impact on literature and the arts. Despite this split, which von Franz believes has existed since the Western traditions' origin in a mix of Greek philosophy, mixed with Egyptian and Mesopotamian technology, numerous sources have stressed an integration of esoteric and exoteric approaches to alchemy as far back as Pseudo-Democritus's first-century AD On Physical and Mystical Matters.
Although alchemy is popularly associated with magic, historian Lawrence M. Principe writes: Most readers are aware of several common claims about alchemy—for example... that it is akin to magic, or that its practice or now is deceptive. These ideas about alchemy emerged after. While each of them might have limited validity within a narrow context, none of them is an accurate depiction of alchemy in general." The word alchemy comes from Old French alquemie, used in Medieval Latin as alchymia. This name was itself brought from the Arabic word al-kīmiyā' composed of two parts: the Late Greek term khēmeía, khēmía, meaning'to fuse or cast a metal', the Arabic definite article al-, meaning'The'. Together this association can be interpreted as'the process of transmutation by which to fuse or reunite with the divine or original form', its roots can be traced to the Egyptian name kēme, meaning'black earth' which refers to the fertile and auriferous soil of the Nile valley, as opposed to red desert sand.
According to the Egyptologist Wallis Budge, the Arabic word al-kīmiyaʾ means "the Egyptian ", borrowing from the Coptic word for "Egypt", kēme. This Coptic word derives from Demotic kmỉ, itself from ancient Egyptian kmt; the ancient Egyptian word referred to both the country and the colour "black". However, according to Mahn, this theory may be an example of folk etymology. Assuming an Egyptian origin, chemistry is defined as follows: Chemistry, from the ancient Egyptian word "khēmia" meaning transmutation of earth, is the science of matter at the atomic to molecular scale, dealing with collections of atoms, such as molecules and metals. Thus, according to Budge and others, chemistry derives from an Egyptian word khemein or khēmia, "preparation of black powder" derived from the name khem, Egypt. A decree of Diocletian, written about 300 AD in Greek, speaks against "the ancient writings of the Egyptians, which treat of the khēmia transmutation of gold and silver"; the Medieval Latin form was influenced by Greek chymeia meaning'mixture' and referring to pharmaceutical chemistry.
Alchemy is several philosophical traditions spanning three continents. These traditions' general penchant for cryptic and symbolic language makes it hard to trace their mutual influences and "genetic" relationships. One can distinguish at least three major strands, which appear to be independent, at least in their earlier stages: Chinese alchemy, centered in China and its zone of cultural influence. Chinese alchemy was connected to Ta