August 20, 2013
The saying goes that one person’s waste is another’s treasure. For those scientists who study urine the saying is quite literal–pee is a treasure-trove of scientific potential. It can now be used as a source of electric power. Urine-eating bacteria can create a strong enough current to power a cell phone. Medicines derived from urine can help treat infertility and fight symptoms of menopause. Stem cells harvested from urine have been reprogrammed into neurons and even used to grow human teeth.
For modern scientists, the golden liquid can be, well, liquid gold. But a quick look back in history shows that urine has always been important to scientific and industrial advancement, so much so that the ancient Romans not only sold pee collected from public urinals, but those who traded in urine had to pay a tax. So what about pee did preindustrial humans find so valuable? Here are a few examples:
Urine-soaked leather makes it soft: Prior to the ability to synthesize chemicals in the lab, urine was a quick and rich source of urea, a nitrogen-based organic compound. When stored for long periods of time, urea decays into ammonia. Ammonia in water acts as a caustic but weak base. Its high pH breaks down organic material, making urine the perfect substance for ancients to use in softening and tanning animal hides. Soaking animal skins in urine also made it easier for leather workers to remove hair and bits of flesh from the skin.
The cleansing power of pee: If you’ve investigated the ingredients in your household cleaners, you may have noticed a prevalent ingredient: ammonia. As a base, ammonia is a useful cleanser because dirt and grease–which are slightly acidic–get neutralized by the ammonia. Even though early Europeans knew about soap, many launderers preferred to use urine for its ammonia to get tough stains out of cloth. In fact, in ancient Rome, vessels for collecting urine were commonplace on streets–passers-by would relieve themselves into them and when the vats were full their contents were taken to a fullonica (a laundry), diluted with water and poured over dirty clothes. A worker would stand in the tub of urine and stomp on the clothes, similar to modern washing machine’s agitator.
Even after making soap became more prevalent, urine–known as chamber lye for the chamber pots it was collected in–was often used as a soaking treatment for tough stains.
Urine not only made your whites cleaner, but your colors brighter: Natural dyes from seeds, leaves, flowers, lichens, roots, bark and berries can leach out of a cloth if it or the dyebath aren’t treated with mordant, which helps to bind the dye to the cloth. It works like this: molecules of dye called chromophores get wrapped inside a more complex molecule or a group of molecules; this shell housing the dye then binds to the cloth. The central nugget of dye is then visible but is protected from bleeding away by the molecules surrounding it. Stale urine–or more precisely the ammonia in it–is a good mordant. Molecules of ammonia can form a web around chromophores, helping to develop the color of dyes as well as to bind it to cloth.
Specific chamberpots dedicated to urine helped families collect their pee for use as mordants. Urine was so important to the textile industry of 16th century England that casks of it–an estimated amount equivalent to the urine stream of 1000 people for an entire year–were shipped from across the country to Yorkshire, where it was mixed with alum to form an even stronger mordant than urine alone.
Pee makes things go boom: Had enough with cleansing, tanning, and dyeing? Then why not use your pee to make gunpowder! Gunpowder recipes call for charcoal and sulfur in small quantities, both of which for aren’t too hard to find. But the main ingredient–potassium nitrate, also called saltpeter–was only synthesized on a large-scale in the early 20th century. Prior to that, makers of gunpowder took advantage of the nitrogen naturally found in pee to make the key ingredient for ballistic firepower.
As detailed in the manual Instructions for the Manufacture of Saltpetre, written by physician and geologist Joseph LeConte in 1862, a person hoping to make gunpowder quickly would need “a good supply of thoroughly rotted manure of the richest kind” which is then mixed with ash, leaves and straw in a pit. “The heap is watered every week with the richest kinds of liquid manure, such as urine, dung-water, water of privies, cess-pools, drains, &c. The quantity of liquid should be such as to keep the heap always moist, but not wet,” he wrote. The mixture is stirred every week, and after a several months no more pee is added. Then “As the heap ripens, the nitre is brought to the surface by evaporation, and appears as a whitish efflorescence, detectible by the taste.”
Different regions of the world had their own recipes for gunpowder, but the scientific principle at work is the same: Ammonia from stagnant pee reacts with oxygen to form nitrates. These nitrates–negatively charged nitrogen-bearing ions–then search for positively charged metal ions in the pee-poo-ash slurry to bind with. Thanks to the ash, potassium ions are in abundance, and voila! After a little filtering, you’ve made potassium nitrate.
Urine gives you a whiter smile: Urine was a key ingredient in many early medicines and folk remedies of dubious effectiveness. But one use–and those who’ve tried it say it works–is as a type of mouthwash. While “urine-soaked grin” isn’t the insult of choice these days, a verse by Roman poet Catullus reads:
Egnatius, because he has snow-white teeth, smiles all the time. If you’re a defendant in court, when the counsel draws tears, he smiles: if you’re in grief at the pyre of pious sons, the lone lorn mother weeping, he smiles. Whatever it is, wherever it is, whatever he’s doing, he smiles: he’s got a disease, neither polite, I would say, nor charming. So a reminder to you, from me, good Egnatius. If you were a Sabine or Tiburtine or a fat Umbrian, or plump Etruscan, or dark toothy Lanuvian, or from north of the Po, and I’ll mention my own Veronese too, or whoever else clean their teeth religiously, I’d still not want you to smile all the time: there’s nothing more foolish than foolishly smiling. Now you’re Spanish: in the country of Spain what each man pisses, he’s used to brushing his teeth and red gums with, every morning, so the fact that your teeth are so polished just shows you’re the more full of piss.
The poem not only reveals that Catullus wasn’t a fan of Egnatius, but that Romans used urine to clean and whiten their teeth, transforming morning breath into a different smell entirely. The active ingredient? You guessed it: ammonia, which lifted stains away.
But perhaps one of the most critical uses of urine in history was its role in making the above home remedies obsolete. Urea, the nitrogen bearing compound in urine, was the first organic substance created from inorganic starting materials. In 1828, German chemist Friedrich Wöhler mixed silver cyanate with ammonium chloride and obtained a white crystalline material that his tests proved was identical to urea. His finding disproved a hypothesis of many leading scientists and thinkers of the time, which held that living organisms were made up of substances entirely different than inanimate objects like rocks or glass. In a note to a colleague, Wöhler wrote, “I can no longer, so to speak, hold my chemical water and must tell you that I can make urea without needing a kidney, whether of man or dog; the ammonium salt of cyanic acid is urea.”
Wöhler’s discovery showed that not only could organic chemicals be transformed and produced in the lab, but that humans were part of nature, rather than separate from it. In doing so, he began the field of organic chemistry. Organic chemistry has given us modern medicines, materials such as plastic and nylon, compounds including synthetic ammonia and potassium nitrate…and, of course, a way to clean our clothes or fire a gun without using our own (or someone else’s) pee.
April 8, 2013
If you suffered from a medical ailment in the year 1900, your treatment options were varied: You could take everything from Dr. Tutt’s Liver Pills to Hollister’s Golden Nugget Tablets, Dr. Sawen’s Magic Nerving Pills or Dr. Comfort’s Candy-Covered Cathartic Compound.
Of course, their titles notwithstanding, the creators of these pills weren’t always doctors, and the medicines certainly hadn’t gone through the controlled randomized trials we have today to ensure safety—they could contain ingredients that were ineffective, or worse, toxic. In many cases, their proprietors might not have known what they were even putting in these so-called “snake oil” medicines (a term that likely stemmed from the sale of actual snake oil to supposedly treat joint pain).
But now, at least, we do. Mark Benvenuto, a chemist at University of Detroit Mercy, recently led a research group that chemically analyzed several dozen patent medicines dating to the late 1800s and early 1900s from the Henry Ford Museum‘s collections. Their findings, which they presented yesterday at the annual meeting of the American Chemical Society in Atlanta, were that many of the pills, powders and ointments tested had beneficial ingredients like calcium and zinc—but that others had toxins such as lead, mercury and arsenic.
“Back in the day, this was a very trial-and-error kind of field,” Benvenuto said in an interview. “The stuff that we think of as dangerous now, though it was dangerous, was as cutting-edge as they had at the time.”
The researchers figured out what was in the historical medicines via a pair of methods. For the solid pills and powders, they used X-ray fluorescence, in which a substance is bombarded with X-rays and the particles emitted as a result indicate the material’s composition. For the liquid ointments, they used nuclear magnetic resonance testing, which relies on the electromagnetic emissions of a material’s nuclei when placed in a magnetic field.
The findings, Benvenuto says, will provide extra context for visitors to the Ford Museum, helping them better understand this era of medical quackery. “You can look at Dr. J.J. Gallop’s Vegetable Family Pills and find out what’s supposed to be in them from the box, and what they cost from some old newspaper that’s archived, but you can’t tell what’s really in them without testing,” he said.
Though some medicines intentionally misled customers about their contents and made outlandish claims, the presence of mercury in, say, Dr. F. G. Johnson’s French Female Pills doesn’t necessarily indicate that Mr. Johnson was a quack, Benvenuto said. Mercury was long used as the primary treatment for syphilis, as it kills the spirochete bacteria that cause the disease, though it can also harm the patient. (Lewis and Clark, among others, used mercury to treat the sexually-transmitted infection, and archaeologists have even pinpointed some of the camping spots of their Corps of Discovery Expedition by finding traces of mercury in the soil.)
In an era before rigorously controlled trials, putting a what was commonly believed to be a safe cure into a medicine and simply selling it to people was considered normal practice, and may have indeed led to progress in medicine. “Nowadays, we start by seeing if a drug can kill certain kinds of cells, then we’ll try it in mice, then dogs, then humans,” Benvenuto said. “Obviously, we have a better system now, but I think this type of medicine was the first step in the road to where we are now. Compared to folk cures, it was a first step at being logical.”
March 20, 2013
B.F Skinner, a leading 20th century psychologist who hypothesized that behavior was caused only by external factors, not by thoughts or emotions, was a controversial figure in a field that tends to attract controversial figures. In a realm of science that has given us Sigmund Freud, Carl Jung and Jean Piaget, Skinner stands out by sheer quirkiness. After all, he is the scientist who trained rats to pull levers and push buttons and taught pigeons to read and play ping-pong.
Besides Freud, Skinner is arguably the most famous psychologist of the 20th century. Today, his work is basic study in introductory psychology classes across the country. But what drives a man to teach his children’s cats to play piano and instruct his beagle on how to play hide and seek? Last year, Norwegian researchers dove into his past to figure it out. The team combed through biographies, archival material and interviews with those who knew him, then tested Skinner on a common personality scale.
They found Skinner, who would be 109 years old today, was highly conscientious, extroverted and somewhat neurotic—a trait shared by as many as 45 percent of leading scientists. The analysis revealed him to be a tireless worker, one who introduced a new approach to behavioral science by building on the theories of Ivan Pavlov and John Watson.
Skinner wasn’t interested in understanding the human mind and its mental processes—his field of study, known as behaviorism, was primarily concerned with observable actions and how they arose from environmental factors. He believed that our actions are shaped by our experience of reward and punishment, an approach that he called operant conditioning. The term “operant” refers to an animal or person “operating” on their environment to affect change while learning a new behavior.
Operant conditioning breaks down a task into increments. If you want to teach a pigeon to turn in a circle to the left, you give it a reward for any small movement it makes in that direction. Soon, the pigeon catches onto this and makes larger movements to the left, which garner more rewards, until the bird completes the full circle. Skinner believed that this type of learning even relates to language and the way we learn to speak. Children are rewarded, through their parents’ verbal encouragement and affection, for making a sound that resembles a certain word until they can actually say that word.
Skinner’s approach introduced a new term into the literature: reinforcement. Behavior that is reinforced, like a mother excitedly drawing out the sounds of “mama” as a baby coos, tends to be repeated, and behavior that’s not reinforced tends to weaken and die out. “Positive” refers to the practice of encouraging a behavior by adding to it, such as rewarding a dog with a treat, and “negative” refers to encouraging a behavior by taking something away. For example, when a driver absentmindedly continues to sit in front of a green light, the driver waiting behind them honks his car horn. The first person is reinforced for moving when the honking stops. The phenomenon of reinforcement extends beyond babies and pigeons: we’re rewarded for going to work each day with a paycheck every two weeks, and likely wouldn’t step inside the office once they were taken away.
Today, the spotlight has shifted from such behavior analysis to cognitive theories, but some of Skinner’s contributions continue to hold water, from teaching dogs to roll over to convincing kids to clean their rooms. Here are a few:
1. The Skinner box. To show how reinforcement works in a controlled environment, Skinner placed a hungry rat into a box that contained a lever. As the rat scurried around inside the box, it would accidentally press the lever, causing a food pellet to drop into the box. After several such runs, the rat quickly learned that upon entering the box, running straight toward the lever and pressing down meant receiving a tasty snack. The rat learned how to use a lever to its benefit in an unpleasant situation too: in another box that administered small electric shocks, pressing the lever caused the unpleasant zapping to stop.
2. Project Pigeon. During World War II, the military invested Skinner’s project to train pigeons to guide missiles through the skies. The psychologist used a device that emitted a clicking noise to train pigeons to peck at a small, moving point underneath a glass screen. Skinner posited that the birds, situated in front of a screen inside of a missile, would see enemy torpedoes as specks on the glass, and rapidly begin pecking at it. Their movements would then be used to steer the missile toward the enemy: Pecks at the center of the screen would direct the rocket to fly straight, while off-center pecks would cause it to tilt and change course. Skinner managed to teach one bird to peck at a spot more than 10,000 times in 45 minutes, but the prospect of pigeon-guided missiles, along with adequate funding, eventually lost luster.
3. The Air-Crib. Skinner tried to mechanize childcare through the use of this “baby box,” which maintained the temperature of a child’s environment. Humorously known as an “heir conditioner,” the crib was completely humidity- and temperate-controlled, a feature Skinner believed would keep his second daughter from getting cold at night and crying. A fan pushed air from the outside through a linen-like surface, adjusting the temperature throughout the night. The air-crib failed commercially, and although his daughter only slept inside at night, many of Skinner’s critics believed it was a cruel and experimental way to raise a child.
4. The teaching box. Skinner believed using his teaching machine to break down material bit by bit, offering rewards along the way for correct responses, could serve almost like a private tutor for students. Material was presented in sequence, and the machine provided hints and suggestions until students verbally explained a response to a problem (Skinner didn’t believe in multiple choice answers). The device wouldn’t allow students to move on in a lesson until they understood the material, and when students got any part of it right, the machine would spit out positive feedback until they reached the solution. The teaching box didn’t stick in a school setting, but many computer-based self-instruction programs today use the same idea.
5. The Verbal Summator. An auditory version of the Rorschach inkblot test, this tool allowed participants to project subconscious thoughts through sound. Skinner quickly abandoned this endeavor as personality assessment didn’t interest him, but the technology spawned several other types of auditory perception tests.
January 7, 2013
Around 120 B.C.E., the Relitto del Pozzino, a Roman shipping vessel, sank off the coast of Tuscany. More than two millennia later, in the 1980s and 90s, a team sent by the Archeological Superintendency of Tuscany began to excavate the ruins, hauling up planks of rotting wood.
“It wasn’t an easy task. The wreck is covered by marine plants and their roots. This makes it hard to excavate it,” underwater archaeologist Enrico Ciabatti told Discovery News in 2010. “But our efforts paid off, since we discovered a unique, heterogeneous cargo.”
That cargo, it turned out, included ceramic vessels made to carry wine, glass cups from the Palestine area and lamps from Asia minor. But in 2004, the archaeologists discovered it also included something even more interesting: the remains of 2,000-year-old medicine chest.
Although the chest itself—which had presumably belonged to a Roman doctor—was apparently destroyed, researchers found a surgery hook, a mortar, 136 wooden drug vials and several cylindrical tin vessels (called pyxides) all clustered together on the ocean floor. When they x-rayed the pyxides, they saw that one of them had a number of layered objects inside: five circular, relatively flat grey medicinal tablets. Because the vessels had been sealed, the pills had been kept completely dry over the years, providing a tantalizing opportunity for us to find out what exactly the ancient Romans used as medicine.
Now, as revealed today in a paper in the Proceedings of the National Academy of Sciences, a team of Italian chemists has conducted a thorough chemical analysis of the tablets for the first time. Their conclusion? The pills contain a number of zinc compounds, as well as iron oxide, starch, beeswax, pine resin and other plant-derived materials. One of the pills seems to have the impression of a piece of fabric on one side, indicating it may have once been wrapped in fabric in order to prevent crumbling.
Based on their shape and composition, the researchers venture that the tablets may have served as some sort of eye medicine or eyewash. The Latin name for eyewash (collyrium), in fact, comes from the Greek word κoλλυρα, which means “small round loaves.”
Although it remains to be seen just how effective this sort of compound would have been as an actual eye treatment, the rare glimpse into Roman-era medicinal practices is fascinating nonetheless. The vast majority of our knowledge of ancient medicine comes from writings—which may vary in accuracy and lack crucial details—so the presence of actual physical evidence is especially exciting.
December 29, 2012
Today as the year ends, several scientists, innovators and scientific advocates pass into memory. From the inventor of the barcode to the first human to perform an organ transplant, their lives and their work helped to shape our culture, modern way of life and place in human history.
Space Sciences: 2012 saw the passing of a few key figureheads of space exploration, as mentioned in a previous post. In addition, Bernard Lovell, a physicist and astronomer who founded Britain’s Jodrell Bank Observatory of radio telescopes, died August 6. The telescopes he helped build were the first to identify quasars, and one was the only telescope in the western hemisphere capable of tracking Sputnik–the first artificial satellite–after it was launched by the Soviets in 1957. In 1960, his telescope became the first to transmit a command to a deep space probe–Pioneer V–22 million miles away, directing it to separate from its carrier rocket.
Earth and Environmental Sciences: F. Sherwood Rowland, winner of the Nobel prize for chemistry in 1995, died March 10. Sherwood and colleagues warned in a landmark 1974 Nature paper that chlorofluorocarbons–CFCs, a chemical found in refrigerants and aerosol spray cans–were destroying the ozone layer at alarming rates. The ozone layer protects life from the sun’s harmful ultraviolet rays which damage tissues and cause skin cancer in humans; without this layer, life couldn’t exist. His discovery and his efforts to draw public attention to the ozone layer’s destruction helped pave the way for the Montreal Protocol, which in 1987 was adopted by the world community to phase out CFC production.
Barry Commoner, labeled as the “Paul Revere of ecology’ by Time magazine in 1970, passed away September 30. Commoner, a biologist, helped to make saving the planet a political cause by showing that the post-World-War-II technological boom had environmental consequences–he documented the global effects of radioactive fallout and spoke against pollutants released by the petrochemical and nuclear power industries–and he argued that the public had a right to know about the use and extent of industrial pollutants.
Medicine: On July 24, Robert Ledley, a radiologist who invented the CT scanner–technology that produces cross sectional images of the human body–died from Alzheimer’s disease. The technology revolutionized how physicians treat cancer–before this invention, health professionals used exploratory surgery to search for cancerous masses. Joseph E. Murray, the doctor who performed the first successful human organ transplant in 1954 (PDF) when he removed a kidney from one twin and placed it in the other ailing twin, died on June 28. He won the Nobel prize in medicine in 1990. Also dead this year is William House, who invented the cochlear implant–a device that helps restore hearing to the profoundly deaf. He died on December 7.
On Feburary 20, Renalto Pulbecco died; Pulbecco shared the Nobel prize for medicine in 1975 for his work on how certain viruses altered DNA and caused cancer cells to spread at accelerated rates. This finding provided the first concrete evidence that cancer growth is tied to genetic mutations. Another Nobel prize winner to pass away this year was Andrew Huxley, who helped to unravel the mechanism behind how nerve impulses control muscle action. Huxley died on May 30. Joining the list of deceased Nobel laureates is William S. Knowles, who died June 13. Knowles helped devise a mechanism that allowed researchers to separate medicinal compounds from their toxic mirror images (same composition, different chemical orientations); his work won him the Nobel prize in chemistry in 2001.
Technology: Stanford R. Ovchinsky, who died on October 17, invented the rechargeable nickel-metal hydride battery. He also played a role in the development of solar panels, rewritable CDs, and flat panel displays. December 9 saw the death of N. Joseph Woodand, the co-inventor of the barcode now ubiquitous in global commerce. Woodand drew inspiration for the think and thin lines of his product identifiers from Morse code, which he learned as a Boy Scout.
Paleoanthropology: For upwards of 50 years, Phillip Tobias led excavations in South Africa that helped identify extinct species of human ancestors. Tobias, who discovered more than a third of the world’s early hominid fossils, died on June 7. One of his benchmark finds was an extraordinarily complete 2.2-million-year-old fossil skeleton, nicknamed “Little Foot,” uncovered in 1995.
However you celebrate the New Year, may these late greats be in your thoughts!