The other day I was poking around online reading about rocks and dinosaurs when I should have been working, and I discovered that what I knew as the Cretaceous–Tertiary (KT) boundary is also called the Cretaceous–Paleogene (KP) boundary. (K is used instead of C to make it easier to pronounce.) You may be familiar with this boundary as marking the extinction of the dinosaurs roughly 65 million years ago. Well, one thing led to another, and I learned some interesting things about the names of recent geologic periods and epochs.

Geologists originally categorized Earth’s crustal rocks from oldest to most recent as Primary, Secondary, Tertiary, and Quaternary. Because each type was associated with a particular period in Earth’s history, you could also talk about, for example, the Tertiary period. However, most of these geological time periods have since been placed into a larger framework, broken down into finer-grained subdivisions, and given generally more informative names.

As part of this process, the Tertiary (66 million to 2.6 million years ago) and the Quaternary (2.6 million years ago to the present day) were once assigned to the Cenozoic era. (Eras are longer than periods but shorter than eons.) However, as scientists learned more about the fossils of the Cenozoic, it began to make more sense to split the Tertiary itself into two periods, the Paleogene and the Neogene, on the basis of the fossils found in rocks of each period. These names were proposed in Europe and adopted only slowly by North American geologists.

The Paleogene is the older of the two periods; the name comes roughly from the Greek phrase ancient-born. However, it’s part of the Cenozoic era, which translates more or less as recent life. (The Cenozoic is preceded by the Mesozoic and Paleozoic: middle life and ancient life, respectively.) Ceno- comes from the Greek word kainos, meaning new or recent, and we also see this root in the -cene ending in the sequence of epochs running from the Paleocene to the Holocene.

Wait, Paleocene? Wouldn’t that mean something like ancient recent? Indeed it would. Not only is the Paleogene (ancient-born) part of the Cenozoic (recent life), but the Paleocene epoch could be translated as something like the ancient recent epoch.

It actually makes perfect sense. Compared to the Paleozoic, which stretches from 541 million years ago to 252 million years ago, the Cenozoic is recent indeed. However, the Cenozoic itself contains older and more recent epochs. Imagine that you trade in your old car for a new one frequently; you may find yourself explaining to a confused friend that the Toyota was your old new car, and your new new car is a Honda. It’s something like that with the -cene epochs, all more recent than what came before but needing to be subdivided somehow according to their relative ages.

From oldest to most recent, these epochs  are the Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, and Holocene. The names Paleocene and Holocene make nice bookends: the ancient recent epoch and the entirely recent epoch (holo- comes from the Greek word for whole, which we also see in holographic and holistic). The epochs in between make sense, although evidently not if you know much about Greek grammar.

Eo- comes from eos, the Greek word for dawn, and is used to describe the earliest appearance of something, in this case modern fossils. Oligo-, mio-, plio-, and pleisto- are based on Greek words ranging in meaning from few to most, and they refer to increasing numbers of modern fossils, or increasing degree of recentness. H.W. Fowler, in his Dictionary of Modern English Usage, took a very dim view of these coinages, or, as he called them, “regrettable barbarisms.” His entry for Miocene described the word as

A typical example of the monstrosities with which scientific men in want of a label for something, and indifferent to all beyond their own province, defile the language. The elements of the word are Greek, but not the way they are put together, nor the meaning demanded of the compound.

If this seems harsh, keep in mind that in the 19th century when these names were coined, every educated person was expected to have learned Greek. Fowler made this point not because he thought the words could be changed; he knew they were too well-established for that. His hope was that scientists “may some day wake up to their duties to the language—duties much less simple than they are apt to suppose.” I’m guessing that he would also find the recent coinage Anthropocene similarly wanting or perhaps even worse. However, he is not here to comment, and my more recent edition of Fowler’s Modern English Usage, edited by R. W. Burchfield, is far more temperate, noting that “the time has come for the hatchet to be buried. A simple irreg. suffices” to characterize these words.

The geologic time scale is a fascinating thing full of evocative names. We’ll come back to it again, I’m sure.

Learn more:

• Geologic time scale from the University of California Museum of Paleontology
• Geologic time scale article from Wikipedia (more detail on the history)
• Article on the Anthropocene from Space.com

This is one of my very favorite times of year; on sunny days, the low-angle sunlight makes the colorful leaves on the trees glow. “Season of mists and mellow fruitfulness,” Keats wrote in his poem “To Autumn,” but it’s also the season of some interesting chemistry. To celebrate the brilliant hues of Northern Hemisphere autumn, today we’ll look at the names of the chemicals that give the leaves their color.

The green in leaves in the spring and summer comes from chlorophyll, the chemical that makes photosynthesis possible. The word chlorophyll was coined in the early 19th century. It has two Greek roots. Khloros means pale green, and phyllon means leaf. (That one also appears in phyllosilicate, which describes clay minerals with thin sheets, or leaves, of silica; it also appears in phyllo dough.)

Leaves also contain carotenoids during much of their lifetimes. These pigments provide yellow, red, and orange colors in the plant world. For example, in about six months we’ll be seeing the cheery yellow of a carotenoid in daffodils. As some fruits mature, we see the chlorophyll slowly disappear as the green fruit ripens to yellow, orange, or red. You may have heard of lycopenes or β-carotene, which are considered micronutrients in foods. (I talked about lycopenes and their unlikely etymological connection to wolves in an earlier post.) The words carotene and carotenoid come from carote, the Latin word for that iconic orange vegetable, the carrot.

Something similar to the ripening of fruit happens in leaves in the fall: as trees prepare for winter and shut down photosynthesis in their leaves, the chlorophyll fades away and the carotenoids that they contain become more obvious. In addition, some fruits and many trees also begin to produce another pigment, anthocyanin, in response to the shorter days of fall. It also contributes to the colors of the fall foliage as the chlorophyll disappears. Anthocyanin, like chlorophyll, comes from two Greek roots: anthos, for flower, and kuanos, for blue.

So now you know what sets the woods and tree-lined streets ablaze: the chlorophyll is disappearing, and the carotenoids and anthocyanin are shining forth. It goes by fast; enjoy!

Learn more:

• Fall colors page and an overview of the science behind fall colors from the US Forest Service
• Chemistry of Fall Colors from scifun.org (more detail on the chemistry)
• Centripetal Fall Colors from Earth Science Picture of the Day (why some trees change color from the top down)
• Carotenoids page at the Linus Pauling Institute’s Micronutrient Center
• In October 1862, the Atlantic published Henry David Thoreau’s essay Autumnal Tints, in which Thoreau presents his careful observations as a naturalist and builds thoughtful analogies to human life and death. It’s a beautiful autumn read.

The word muscle comes from the Latin musculus, which means little mouse. But why? It’s because the rippling movement of certain muscles under the skin was thought to resemble the movement of a mouse. My mental image—and it is not a pleasant one—is of a mouse running or moving underneath a thin rug or blanket. Although it’s an unnerving image, I can see the connection.

The Greek word mŷs can also mean either mouse or muscle; this word gives us the prefix myo-, as in myalgia (muscle pain) or myocardial infarction (damage to or death of the muscular tissue of the heart due to lack of oxygen).

While we’re looking at the human body, we can examine another unexpected connection, this one between the skeleton and arteriosclerosis, or hardening of the arteries. Skeleton is ultimately derived from the Greek verb skellein, to dry up, via skeletos (dried up) and skeletos soma (dried-up body).

Skellein is related to skleros, meaning hard, a natural enough association with dried things. This made its way into Latin and then English as sclero, which is combined with other roots to form words. It appears in the the word scleroderma, for example, the name of a skin condition, often painful, in which the skin becomes hardened. And arteriosclerosis is any thickening and hardening of the arteries.

So there you have it: muscles like mice and a skeleton consisting of what’s left after everything else has dried up and blown away.

Learn more:

• Check out the skeletal system and muscular system (with all of their fascinating names) at InnerBody.com.

Sometimes I worry that I’ll describe the origin of a word incorrectly because I get my Greek and Latin roots confused. At this distance, it’s easy to see all the Greek and Roman words and deities as a combined source rather than remembering that Greek and Latin are two distinct languages representing different cultures and different times. And, in fairness to 21st century humans trying to keep things straight, Latin borrowed from Greek, and the sciences have sometimes taken words from both languages to describe the same thing.

In a post last week about chemical elements named for places, I mentioned the name tellurium, which comes from the Latin goddess of the Earth, Tellus. Actually, the Romans used two terms to refer to Earth: Tellus and Terra, or Terra Mater (mother Earth). The latter name may be an outright borrowing of the Greek religious concept of mother Earth, Gaea (or Gaia, or Ge Mater).

Both the Greek and the Roman names for mother Earth come down to us in science, in part because eventually Latin borrowed the prefix geo from Greek. Ge Mater is obviously the inspiration of geology, geography, geodesy, geometry, and geode. Terra Mater is where we get terrestrial (and terrain, and terrarium).

There’s a similar split in the names for things associated with the moon. The Greek goddess of the moon, Selene, gave her name to the element selenium and to the study of the moon, selenology. However, the term lunar, derived from the name of the Roman moon goddess Luna, is much more prominent, and selenology is generally called lunar science. Mars and Martian come from the Roman god, but we also use areology, from the Greek god Ares, to describe the study of the…errr..geology of Mars.

I suspect I’m not the first one to be confused; selenium was named after the moon analogously to tellurium after Earth, but selenium is from the Greek deity and tellurium is from the Roman deity. Furthermore, the term aurora borealis gets aurora from the Roman goddess of the dawn (for its beautiful colors) and borealis from the Greek god of the north wind, Boreas.

I’ll try hard to keep my roots straight, but I can’t feel too bad about seeing Greek and Latin as, if not a single source, at least two deeply interconnected sources.

This is the third and final post in a series on some of the most glorious plant families of the summer garden and orchard. Part 1 covered cucurbits, and part 2 discussed nightshades. Today the drupes of the Prunus family have their turn.

The genus Prunus includes plums, apricots, cherries, and peaches, among other stone fruits. This type of fruit, a fleshy mass surrounding a large pit, is called a drupe. Drupe comes from the Greek word for olive, a fine representative of the type.

The plums we eat are generally Prunus domestica. The Greeks called them prounon, and the Romans called them prunus. The Latin name worked its way into Germanic languages with an R instead of an L, giving us the word plums, at least when they’re fresh. The dried ones are prunes, although I understand that this word has become so firmly associated with constipation and old age that the prune-sellers are pushing the term “dried plums.” Plums gave their name to the entire Prunus genus.

The Romans called peaches malum Persicum, for Persian apple; the scientific name retains the Persian attribution: Prunus persica, or Persian plum. Although the Romans obviously thought that the peach came from Persia, its genes tell a different story: it probably came from China before making its way to Persia and thence to the Romans and eventually the rest of us. Time changed the shortened Latin name persica to pessica and then to pesca; at that point (medieval Latin), it made its way into French as peche, and then into English as peach.

The peach shares a subgenus, Amygdalus, with the almond. (If you look inside a peach pit, you’ll see a little kernel that bears more than a passing resemblance to an almond. This kernel contains a compound that can decompose into hydrogen cyanide. Opinions differ on how dangerous these things are to consume, but I’m going to play it safe and advise you not to eat them, feed them to the dog, or otherwise oversee their ingestion.) I mention the Amygdalus subgenus so that I can also mention that the amygdala in your brain got its name because it’s almond-shaped.

Apricots are currently Prunus armenaica (which translates as Armenian plum), but their first official botanical name was Mala armenaica (another apple!). Again, though, they actually originated in China. The English name comes from the Latin word praecoquis by a very circuitous route. The Latin word means “early ripening”; apricots were originally thought to be a type of peach that ripened earlier than the peaches people already knew about. From Latin, the word traveled into Greek, where it sprouted a variant plural form, berikókkia. Arabic borrowed that word as barqūq, and that’s the name that southwestern Europe got hold of during the period of Muslim rule in the Iberian peninsula. The word entered English as abrecock, probably from a Spanish variant on the Arabic term. French picked it up, probably from the same source, as abricot, and that spelling likely influenced the shift in the English word to its present form in the late 16th century. Whew!

Cherry has a much simpler story: from Greek kerasós to Latin ceresia or cerasia and on into Old French as emcherise (and thence to today’s French word for this fruit, cerise). The English word lost the s at the end because it was misconstrued as indicating the plural. Something similar happened to pease, which was originally a collective (non-count) noun, like interference, that could be used as a singular noun if you needed to refer to a single pea. However, because people took it for a plural word, the singular word pea was formed from it. Anyway, the cherries we eat are generally either Prunus avium (the sweet kind) or Prunus cerasus (the sour kind). Prunus avium can be translated as bird cherry, which will make a lot of sense to anyone who has had to share a cherry tree with the birds.

One last note, and a brief foray into another genus. The genus Prunus is in the family Rosaceae, which contains not just roses but apples and pears, and also the genus Rubus, which contains raspberries and blackberries. This is one of my very favorite groups of summer fruits. Not only are raspberries among the most luscious and luxurious of summer edibles, they’re representatives of a type of fruit with a cool name: drupelets. They’re called that because they consist of many small drupes.

It’s a little late for any of these drupes at the Farmer’s Market in my part of the country; I saw peaches and plums and even raspberries a couple of weeks ago, but they’re probably about finished. If you’re lucky enough that these summer yummies are still around, enjoy them in all their fresh local splendor.

Learn more:

•  Determined gardeners might like to see the list of all the plants in the genus Prunus at Dave’s Garden.
• If you are hoping to find your own local cucurbits, nightshades, and drupes, you might be interested in Local Harvest, which will help you find Farmer’s Markets, CSAs, and more in your area.

A surprising number of chemical elements are named for places. (Well, it surprised me, anyway.)

Many of the elements that have been identified since the late 18th century are named for their places of discovery. Would you have guessed that more of these elements are named for Scandinavia or Scandinavian cities than for any other geographical location? One town, Ytterby, accounts for no fewer than four of the names: erbium, terbium, ytterbium, and yttrium. There is also hafnium (from Hafnia, the Latin name for Copenhagen), holmium (from Holmia, or Stockholm), scandium (from Scandia, or Scandinavia), and thulium (from another ancient name for Scandinavia, or the far north: Thule).

Here are the other “modern” elements named for places:

• The continent of Europe has its namesake, Europium.
• Francium and gallium (from the Latin Gallia) are named for France, although the latter may also a pun on the middle name of its discoverer, Paul-Émile Lecoq de Boisbaudran; le coq, French for rooster, is gallus (chicken) in Latin. Lutetium comes from Lutetia, the Latin name for what would become Paris.
• Germanium, of course, is named for Germany, and Hassium comes from the Latin name for Hesse in Germany. Rhenium is named for a river, the Rhine (Rhenus in Latin), and Darmstadtium is named for the city of its discovery, Darmstadt.
• Polonium is named for Poland, the homeland of its discoverer, Marie Curie.
• Strontium is named for the small town of Strontian, Scotland, where the first specimen known to contain it was found in a lead mine.
• Ruthenium comes from the Latin name for Russia, Ruthenia. Dubnium is named for the Russian research institute where it was discovered.
• Four elements are named for locales in the US. The series of names Berkelium, Californium, and Americium reads like a peculiar rendering of an address. Berkelium is joined by Livermorium, named only last year for the Lawrence Livermore National Laboratory in California.

A couple of the element names have a longer history:

• Copper takes its name from Cyprus (Kupros to the Greeks), which was a huge source of copper in ancient times. (It’s possible, however, that the island took its name from the metal.) The Latin Cyprium aes (metal from Cyprus) was shortened to cuprum (which accounts for the Cu on the periodic table).
• As I noted in an earlier post, The Magnetes legacy, magnesium and manganese both take their names from an area in ancient Greece called Magnesia.

This may seem a bit of a stretch, but astronomical objects can be considered places too. (Just ask any astronaut who’s been to the moon.) The following elements are named for places in the solar system:

• Helium was first identified from its lines in the solar spectrum, and its name comes from the Greek name for the sun, helios.
• Tellurium comes from the Latin tellus, or Earth. Selenium resembles tellurium and is named, by analogy, for the moon, although selene is the Greek word for the moon, not the Latin word.
• Cerium and palladium are named for the first and second asteroids ever discovered, Ceres and Pallas, which were each discovered a couple of years before their respective elements.
• Uranium, neptunium, and plutonium are named for the planets Uranus and Neptune and the dwarf planet Pluto. The celestial objects in turn take their names from the Greek god of the sky, the Roman god of the sea, and the Greek god of the underworld. (Mercury the planet and Mercury the element were both named for the Roman god Mercury, so Mercury the element is not named for the planet.)

And finally, how about a place named for an element? Argentina got its name from the Latin word for silver, argentum.

Learn more:

• Timeline of element discovery from ThoughtCo.com
• History of chemical elements from the National Nuclear Data Center

Welcome to part 2 in a series of posts about the late summer garden harvest. (Part 1, on the cucurbits, is here; part 3, on the drupes, is here.) Today we’re going to look at the Solanaceae, or nightshades.

Solanaceae is a large family that includes edible species such as tomatoes, peppers, eggplant, and potatoes, along with a great many other things (petunias, the hallucinogenic datura, and the poisonous deadly nightshade, for example). The origin of the name Solanaceae is unclear, but it may rest on an association of certain plants in the family with either the sun or with a soothing effect produced by ingesting them.

Sweet peppers, chili peppers, and tomatoes are New World plants. Those lovely things on the left are red peppers, fine specimens of the species Capsicum annuum, which is the most common of the cultivated Capsicum species.

Columbus brought back some variety of Capsicum annuum to Europe, and it was given the common name pepper because it was spicy, like the unrelated black pepper that Europeans were already familiar with, although it packed more of a punch. It’s not clear where the genus name Capsicum came from, although it may be derived from the Latin capsa, or box, presumably for the blocky hollow shape of many varieties. Capsaicin, the name of the compound that gives chili peppers their heat, is derived from capsicum.

The tomato, quintessential summer harvest and beloved of gardeners today, was once considered poisonous in Europe and North America. Columbus introduced it to Europe after his first voyage to the New World (it probably first appeared in Peru or Mexico). The plant’s resemblance to deadly nightshade made it an object of suspicion, although it also made it possible for Linnaeus to correctly classify it as belonging to the same family, the Solanaceae.

An early common name in Europe was the German wolfpirisch, or wolf peach. The peach part was for its physical appearance, and the wolf part comes from a belief that the tomato, like nightshade, could be used to conjure werewolves. (Definitely an unsavory plant, then, in this early view.)

The scientific name is Solanum lycopersicum, and the species name lycopersicum is essentially the Latin version of wolf peach. As we saw in an earlier post, lyco comes from the Greek word for wolf; malum persicum, or Persian apple, is what the Romans called peaches. (We’ll learn more about peaches later in the week when we talk about the drupes in the genus Prunus.) The wolfish connection lingers, linguistically anyway, in the name lycopene, which refers to an antioxidant compound found in tomatoes (and also red peppers, incidentally). The English common name, tomato, comes from the Nahuatl word tomatl.

Other early common names indicate more favorable views of the tomato. The Italian pomodoro, or golden apple,  suggests the relative speed with which Italian cooks (and eaters) adopted the tomato, first as decoration for the table and then as edible and even tasty. The French pomme d’amour or love-apple reflects the belief that it was an aphrodisiac.

In England and North America, it took longer to persuade people that tomatoes were harmless. I’ve read of people growing what they called love-apples as ornamental potted plants in 1850s America, believing they were poisonous to eat but appealing to the eye. There are competing stories for what finally moved tomatoes from poisonous to palatable in the public mind in the US, and the truth is shrouded in mystery. Suffice it to say that when Campbell’s condensed tomato soup was introduced in 1897, the tomato was in the kitchen, and the garden, to stay.

We’ll look at one more nightshade, this one from India rather than the Americas. The eggplant probably reached Europe some time in the early  Middle Ages. The English common name is traced back to yellow or white varieties grown in the 17th century that looked something like goose eggs or hen’s eggs. The scientific name, Solanum melongena, has a more complicated history. Byzantine Greek borrowed and adapted the Arabic name, which in turn came from a Dravidian word. The Greek version, melitzána, then made it into medieval Latin, there to be picked up by botanists when it came time to assign an official name. Another Arabic word eventually morphed into the French aubergine and similar words in other languages.

Later in the week, we’ll close this series with part 3, which will look at the drupes of the genus Prunus.

Learn more:

• This Smithsonian.com blog post explains why tomatoes were once fearful objects.
• The Nibble has a chili glossary.
• Vegetarians in Paradise has a history of the eggplant.

Given that the Mars rover Curiosity is in the news (it did not find methane in the planet’s atmosphere, contrary to earlier reports), this seems like a good time to pass along something I learned this week about the geological periods on Mars.

Mars is currently not a very happening place, geologically speaking—at least in terms of big events like volcanic eruptions and such. Its geological history is divided into three major periods, the latest of which has lasted for three billion years and counting. (The Earth has four periods, most of which are subdivided fairly finely.) Each period is named for a place on the Martian surface where features typical of that time period appear. The interesting thing to me, as a word geek, is that an alternative naming system has been proposed based on the geochemical events that were going on during each period. First, the current names:

Noachian: This period is named for Noachis Terra, a plain in the southern hemisphere that  features some of the oldest landscapes on Mars, including large eroded craters. There may have been water: drainage networks formed by flowing water, and possibly even bodies of surface water. There were definitely impacts. This period lasted until about 3.7 billion years ago.

Hesperian: Hesperia Planum, also in the southern hemisphere, is a large lava plain. In Greek and Roman times, Hesperia was used to refer to the western regions. (For the Greeks, this was Italy; for the Romans, it was Spain.) Hesperus was the name given to Venus when it was visible in the evening, and the Hesperides were the nymphs who lived in a beautiful garden at the far western edge of the world. During the period named for this landform, there were lava flows and there was massive flooding that created outflow channels. It lasted until about three billion years ago (give or take; the boundary is fuzzy).

Amazonian: Amazonis Planitia, named after the mythical women warriors the Amazons, is a relatively young, smooth plain in the northern hemisphere, west of Olympus Mons. This period covers the last three billion years; there were lava flows (but not recently), glacial and other ice-related activity, and a whole lot of surface weathering.

The new names are:

Phyllocian: This runs through the early  Noachian, about four billion years ago, and is named for the clay (phyllosilicate) minerals that formed during this period. The phyllo in phyllosilicate is the same root as in phyllo dough, and it goes back to a Greek word for leaf. Phyllosilicate minerals consist of parallel sheets, or leaves, of silicate tetrahedra.

Theiikian: During this period, volcanoes provided sulfur dioxide, which combined with water to form sulfuric acid, ultimately leading to the formation of silicate minerals. Thion, the Classical Greek word for sulfur, was adapted for the name of this period, which lasted until about three and a half billion years ago.

Siderikan: Think rust. After the volcanoes went quiet and liquid water all but disappeared, the rocks on the surface sat and oxidized, as they do to this day. This period is named for the iron oxides that give Mars its orange-red color. In Classical Greek, the word for iron is sidéros.

So there you have it. Enjoy your weekend, and if you get the chance, look for Hesperus, aka Venus, in the west just after sunset.

Learn more:

• News article from Nature on the latest Curiosity results, and the abstract of the paper in Science describing the results
• Although Mars was long thought to lack plate tectonics, there is now some evidence for a rudimentary plate tectonics system.

My last post was about the link between the words melancholy and choler, which are based on the Greek word for bile. Melancholy and choler were associated with black bile and yellow bile, respectively, which were two of the four humors in a system of ancient and medieval medicine. The humors were different fluids in the human body, and diseases were believed to arise from imbalances among them.

The English word humor in this sense came from French, which got it from Latin, specifically umor, or body fluid, which is related to the verb umere, or to be moist. The word humor in this sense is related to humid, which also has to do with dampness or moisture. Although the concept of four humors is a thing of the past, we still talk about the vitreous humor (literally glassy fluid), the gel-like substance that fills the eyeball between the lens and the retina.

The system of four humors was embedded in a complex web of associations. Each humor had its season and its organ in the body, and was thought to have attributes described by various permutations of the characteristics hot, cold, wet, and dry. For example, yellow bile, or choler, was thought to be hot, dry, and associated with summer and the spleen. (I haven’t been able to find out what it means for a fluid to be dry; perhaps this is some sort of figurative use, as in dry wine, but I don’t know.)

This system was intended to provide guidelines for treating illness. It was eventually extended to personality types, or temperaments. Each temperament was seen as a particular blending of the four humors; the word comes from the Latin temperare, meaning to mix. Galen, who devised this system, identified nine temperaments; the four that are the most familiar today are the ones that he called choleric, melancholic, sanguine, and phlegmatic, each associated with one of the humors.

Sanguine comes from the Latin word for blood, sanguis, because the sanguine temperament was believed to result from an excess of blood. A sanguine person is an upbeat happy sort. We still use this word to mean optimistic or cheerful, although we no longer think it has anything to do with a healthy ruddy complexion. You also see this Latin root in sanguinary, which means involving bloodshed or bloodthirsty. I was puzzled by the similarity between these words until I learned how they’re connected.

Phlegm is pretty much the phlegm we know, the only one of the humors to have made it down to today under the same name. Oddly enough, phlegm was thought to be cold and moist and associated with winter, but the Greek root from which it originally sprang, phlégma, has to do with inflammation and heat, which I suppose makes sense in the context of upper respiratory illnesses in which fever and phlegm coincide. The phlegmatic temperament was believed to be calm, even stolid or sluggish. The word is still used to describe calm, unemotional people.

In fact, although the humoral system of medicine and the concept of four temperaments have long since been overtaken by more sophisticated approaches¹, the names of all four temperaments linger on as adjectives that describe people or attitudes. What is most interesting to me is that although we don’t think of optimism in terms of blood any more, or depression or calmness in terms of black bile or phlegm, the link connecting the bitter fluid bile with irritability or anger remains strong. You can talk about the bilious rant you had to listen to, read a comments thread on some news article and marvel at the bile-filled invective, or vent your spleen. (Just don’t vent it here, please.)

1 Well, more or less. The idea of four temperaments lives on, in mutated form, in some current personality systems, although psychology has pretty much settled on five aspects of personality known as the Big Five personality traits.^↩

Learn more:

• The History of Medicine Division of the National Library of Medicine (part of the NIH) has an overview of ancient Greek medicine (from the gods to Galen, what more could you ask?).
• ThoughtCo.com has a nice Four Humors page.

You don’t see the string chol in too many words except for fairly specialized terms in biochemistry or medicine, so I had to wonder whether there’s some connection between the words choleric, melancholy, and cholesterol. There is, and you can throw the word cholera into the mix too.

Choler entered English around the 14th century as a borrowing from French, which got it from Latin. It meant either bile or a digestive complaint. The latter meaning ultimately came from the Greek word cholericós, or bilious, and in that sense, it’s the ancestor of cholera, which originally probably referred to a serious gastrointestinal disorder in general and not just to what we today identify as cholera.

Bile was once associated with irritability and bad temper. Choler, of course, appears in choleric, which is still used today to describe an individual who is behaving irascibly. It was once considered essentially a personality type or tendency resulting from a preponderance of yellow bile (more on the four humors and their personality types here).

Bile is synthesized in the liver and sent on to the gall bladder and thence to the duodenum (the upper part of the small intestine¹), where it plays an important role in the digestion of fats. Cholesterol is a waxy white crystalline substance that is also made in the liver. It was first found in gallstones (gall is another word for bile), and was originally called cholesterin. The name was derived from two Greek roots, cholé, or bile, and stereós, or solid; the word cholesterol came into use in 1894.

So what about melancholy? It was originally thought of as a morose outlook associated with a preponderance of black bile. Black bile was one of the four humors, or fluids, in ancient and medieval medicine, and was thought to be secreted by the kidneys or spleen. The Greek roots are mélanos, or black, and cholé. Mélanos also contributed to melanin, the name of a black pigment in human hair, skin, and eyes, and melanoma, the name of a dark-colored malignant skin tumor.

Melancholy also entered English around the 14th century via French and, ultimately, Latin. It was originally spelled melancolie or malancolie. The latter spelling arose because of a false association with the French word mal, or sickness (from the Latin malum, meaning misfortune or harm).

So there you have it, a somewhat unlikely set of companion words.

1 The name duodenum is a shorter form of intestinum duodenum digitorum, which describes it as the intestine that is about as long as twelve finger-widths.^↩

Learn more:

• Although cholesterol is demonized today, it actually plays a vital role in your body. This Cholesterol Overview from How Stuff Works gives a fairly balanced picture.
• Many, many words have been written on depression and melancholy. The Ode on Melancholy by John Keats is not a bad place to start.