Albert Einstein once said, “The only source of knowledge is experience,” but there are many methods of gaining experience, ranging from the legendary school of hard knocks to reading about the world in a well-lit comfy chair.  Experience has to start somewhere, and in the case of human tools, it began in the Olduvai Gorge in southwestern Kenya 2.5 million years ago when one of our ancestors chiseled a rock into a sharp blade.  Archeologists call the quartzite tools found at this site Oldowan, after the gorge, and they greatly enhanced the human condition, according to this month’s Smithsonian Magazine.  Oldowan tools allowed the African Hominins to scavenge meat from carcasses, “some of the earliest evidence of human carnivory,” and to “cut and prepare tubers, which entered their diet in this period,”, and this in turn enabled them to become more settled and less itinerant.

            Humans progressed from there to invent pompom hats (used by the French navy to protect sailor’s heads from low entryways), punts (the dents in wine bottle bottoms that balance them better and allow place for grape sediment to settle), and, from the school of hard knocks, circular dents in plastic milk cartons (that help keep the jug from slitting when banged about).  It was in 1947 that the West Virginian newspaperman and humorist Jim Comstock created the “University of Hard Knocks,” which Wikipedia says is “an honorary society with a mission to recognize people who have made a success of their life without the benefit of higher education.”  It was formally sponsored by Alderson Broaddus College in West Virginia in 1976.  But in a perfect example of function following form, “the society was dissolved in 2014,” thereby becoming a testament to its title and our times.

            Some literal and figurative hard knocks accompany many new endeavors, including  dentistry.  The word “dentist” wasn’t added to English until 1759 after the French “dentiste” that ultimately comes from the Proto-Indo-European root word for tooth, “dent-.”  Before then barbers pulled teeth, as well as shaving faces and drawing blood, but in the 17th century a more refined dental practitioner emerged: “the operator for the teeth,” who was defined as “one skilled in drawing of teeth and making artificial ones.”  A recent online article by Paul Craddock, “Baboon Teeth, Urine Rinses, and More Horrors of Early Dentistry,” brought Charles Allen to my attention.  He wrote the book, “The Operator for Teeth,” in 1685 in which he recommended a blend of powdered-coral, rosewater, and dragon’s blood (red resin from trees in Morocco) for cleaning teeth once a week.  He also described his method for transplanting teeth using dogs, sheep, goats, and, yes, baboons as donors.  Craddock outlined Allen’s transplanting procedure; after completely restraining the patient, “the surgeon would take his knife to the restrained baboon, say, carve out one of its teeth, leaving a bit of its gum still attached. He’d then, as quickly as possible, draw the patient’s rotten tooth and immediately plug the gap with the baboon’s. With time, the baboon’s tooth and gum would knit itself into the patient’s mouth. You could use another human as a donor, Allen advised, but this would be ‘inhumane,’ since the “reparation” of one mouth requires the ‘ruine’ of another.”

            “Dirt Eaters,” an article by Carmena Zimmerman in the “Encyclopedia of North Carolina,” had me wondering about the dental effects of geophagy (or geophagia) which is defined by Merriam-Webster as “the practice of eating earthy substances (such as clay) that in humans is performed especially to augment a scanty or mineral-deficient diet or as part of a cultural tradition.”  People in rural and tribal societies throughout the world practice, geophagy, except in Japan and Korea where it’s not documented, as well as by over 100 primate species.  Technically, geophagy is a form of pica, “an abnormal desire to eat substances (such as chalk or ashes) not normally eaten.”  Pica is derived from the Anglo-Latin term magpie, which was known for its “indiscriminate eating habits.”  Pregnant women in rural settings often resort to eating clay and soil, and Hippocrates, “the father of medicine,” is credited with first identifying geophagia when he wrote around 400 BCE that “if a pregnant woman feels the desire to eat earth or charcoal and then eats them, the child will show signs of these things.”  Another ancient source, a Roman medical textbook, “De Medicina” said, “People whose color is bad when they are not jaundiced are either sufferers from pains in the head or earth eaters.”  Skin color is still used to diagnose geophagia for there are many unwanted side effects, ranging from clogged intestinal tracts to horrible parasites found in earth, but the practice continues, especially where it’s condoned by society, as in Western Africa.   It’s still being studied, but, according to the National Library of Medicine, “even today the reason for geophagia in pregnancy remains elusive.”

            Zimmerman wrote that the practice “was brought to America through the slave trade with Africa and the West Indies. The medical records of colonial and antebellum physicians who treated ailing blacks on plantations indicate that some of their maladies, described as debilitating sluggishness and pale skin coloration, were brought on by habitual and excessive clay eating. The condition was treated as a bad habit that needed to be ended, although some physicians surmised that clay eating was the result of iron deficiency in the body.”  She stated that “Dirt eating was also observed among Indians in the region,” and actually was practiced by many non-Negro peoples.  She added that “the phrase ‘dirt eater’ in North Carolina referred to poor whites who engaged in the practice,” and noted that they were also referred to as “clay eaters” and “sandlappers.”

            Another compulsive eating disorder, and fretful for dentists, is chewing ice, known in medical circles as “pagophagia.”  The Webmd.com article on the subject defined pagophagia as “an intense craving to chew on ice” that’s “often caused by a nutritional deficiency, particularly iron and calcium.  It’s also diagnosed using skin color, along with fatigue, headaches, rapid heartbeat, and other signs.  It’s also damaging to tooth enamel and gums.  So, it was interesting to read “Pellet Ice Is the Good Ice,” a New Yorker article by Helen Rosner, a pagophalic who rhapsodized about her compulsion, at least when it comes to pellet ice, describing it as “cylindrical, with smooth sides and rough ends … Unlike most ice, which is either carved from a larger block or frozen in a mold, it is made from paper-thin flakes of ice that are pressed into a solid mass … and then. pushed through round holes punched in a metal sheet, creating a fragile cylinder that breaks off into pieces … the compression creates flaky layers, which, as in a well-laminated pastry, render the ice pellets lightweight and airy, with crevices and tiny caves into which your drink can penetrate, and a yielding texture perfect to chewing.”

            You’ve now had the experience of reading about it, but if you want to experience perfect ice chewing yourself, it’s hard to find.  Rosner recommends the Opal pellet ice maker (from G.E. for $499), or Sonic Drive-Ins.  When it comes to tasting things – libraries, dirt, or ice – it’s like Julius Caesar wrote, “Experience is the teacher of all things.”