Keith Houston | The Book: A Cover-to-Cover Exploration of the Most Powerful Object of Our Time | W. W. Norton & Company | August 2016 | 18 minutes (4,720 words)

Below is an excerpt from The Book, by Keith Houston. This story is recommended by Longreads contributing editor Dana Snitzky.

* * *

Never get involved in a land war in Asia.

To an ancient Egyptian of the third century BCE, the rolls of papyrus on which the country recorded its history, art, and daily business would have been of all-consuming importance. Scrolls made from papyrus were the medium for hundreds of thousands of books lodged at Alexandria’s wondrous library, and blank papyrus sheets were one of the chief exports to Egypt’s friends, allies, and trading partners across the Mediterranean. But papyrus’s 3,000-year monopoly was about to come under threat. Invented by Egypt’s upstart Hellenic neighbors and made from animal hides at great cost in sweat and blood, parchment was smooth, springy, and resilient where papyrus was rough, brittle, and prone to fraying. Its rise at papyrus’s expense, however, had little to do with the ergonomics of its use or the economics of its manufacture and everything to do with ambitious pharaohs who ignored the cardinal rule of military leadership: never get involved in a land war in Asia.

*

The Pergamenes’ book-collecting mania was so notorious that citizens of the nearby town of Scepsis, having inherited Aristotle’s library…, took the extraordinary step of burying it.

The invention of parchment is traditionally ascribed to King Eumenes II of Pergamon, ruler from 197 to 159 BCE of a Greek city-state located in what is now northwestern Turkey. Pergamon comprised only the city itself and a few local towns when Eumenes was crowned as king, but at his death thirty-eight years later it had been transformed into a political, martial, and cultural powerhouse. Chief among his achievements was the founding of a great library to rival that of Alexandria, and Eumenes’s institution boasted some 200,000 volumes at its peak. The Pergamenes’ book-collecting mania was so notorious that citizens of the nearby town of Scepsis, having inherited Aristotle’s library from one of the late philosopher’s students, took the extraordinary step of burying its literary treasure to stop it falling into the hands of their acquisitive neighbors. Nor did Eumenes stop at books: in a bid to assemble a staﬀ worthy of his new library he approached Aristophanes, the chief librarian at Alexandria, to oﬀer him a job. The Egyptian king Ptolemy clapped the librarian in irons to ensure his continued loyalty.

The contemporary story of the invention of parchment in Pergamon, as related by Pliny in his compendious but erratic Natural History, is a simple one. Writing in the first century CE, Pliny says that King Ptolemy of Egypt—the same Ptolemy, presumably, whom Eumenes had goaded with his importunate headhunting—was so incensed by the rise of Pergamon’s library that he banned exports of the papyrus on which it depended. Eumenes responded to the embargo by directing his subjects to find an alternative writing surface; thus, parchment was invented, and Eumenes got the credit.

Pliny’s geopolitical parable is not exactly bursting with detail. Dating his story is diﬃcult: exactly which Ptolemy it was (and there were many) who forbade the export of papyrus is not clear, nor was it specified whether it was Eumenes II or his namesake who had invented parchment. And if Pliny’s knowledge of royal family trees was shaky, his grasp of history was worse. Writing some five centuries earlier, the Greek writer Herodotus, dubbed the “Father of History” and who would have been required reading for any later scholar, had described how Greeks of the Ionian tribe wrote their books on animal skins when papyrus was scarce. But to hear Pliny tell it, parchment was the spontaneous product of a bibliographic spat—Eumenes’s retort to Ptolemy’s library envy—that had taken place in more recent, civilized times. Parchment’s origins were a good deal more ancient, and its road to prominence much bloodier, than Pliny knew.

As Herodotus had noted back in the fifth century BCE, people of the ancient world had been writing on animal skins long before the tussle between Eumenes and Ptolemy, but the practice was older still. Egyptian texts dated to between 2550 and 2450 BCE mention the use of leather as a writing surface, and the Cairo Museum possesses a fragment of a leather document written shortly after that. A millennium later, the Egyptian “Book of the Dead,” a collection of incantations entombed with the dead to help them navigate the afterlife, was commonly written on durable animal skins instead of papyrus. The Sumerians were no strangers to the use of animal skins either; a cuneiform tablet dated to 800 BCE describes how pelts were steeped in baths of flour, beer, and “first quality” wine before being pressed with alum (a mineral salt that causes animal tissues to contract), oak galls (nutlike tree growths caused by burrowing wasp larvae), and “the best fat of a pure ox.” A later account of the preparation of goatskin, found in Carchemish in the kingdom of the Hittites (now on the border between Turkey and Syria), is less insistent on fine ingredients. In this recipe, skins were to be soaked in goat’s milk and flour, rubbed with oil and cow fat, and finally treated with alum soaked in grape juice and oak galls.

Both recipes describe more or less the same process. First, soaking a pelt in a frothing, enzyme-rich bath of fermenting liquor softens it up, loosens its hairs, and, by means of rising bubbles of carbon dioxide, cleans it. Once the hair has been pushed oﬀ by hand or scraped oﬀ with a knife, the skin is treated with astringent tannic acids (such as those in alum and oak galls) to “tan” the skin, tightening it up and increasing its durability. The skins of a huge variety of animals were processed according to this basic recipe, and exotic beasts such as lions, leopards, hippos, and hyenas posthumously rubbed shoulders in the tannery with domesticated species such as cattle, sheep, pigs, and donkeys.

The result of all this soaking, scraping, and tanning, however, was not parchment but leather. Tough, flexible, and water resistant, leather was a surprisingly accommodating writing surface, capable of being worked to any desired smoothness and absorbing ink well, but it lacked the rigidity, delicacy, and portability that made papyrus an ideal vehicle for writing. And though the Pergamenes were not the first people to write on leather, they may have discovered the one thing that transforms soft, pliable hide into taut, smooth parchment.

* * *

The name of this conflict, the so-called Sixth Syrian War, hardly resounds through history.

Pergamon’s invention might never have left the land of its birth were it not for the war that convulsed Egypt at the midpoint of Eumenes’s reign. In 173 BCE, Rome was growing apprehensive about a “cloud in the east”—the predatory Greek king Antiochus IV, head of the Seleucid dynasty, uncle of Egypt’s Ptolemy VI Philometor, and ruler of a swath of the ancient world that stretched from the Aegean Sea in the west to the Gulf of Oman in the east. Worried that Antiochus planned to annex his nephew’s kingdom, Rome sent a delegation to Philometor at Alexandria under cover of paying tribute to the young king. The envoys’ real mission was to monitor the increasingly febrile atmosphere in the region.

It was not long before the situation deteriorated. Philometor, who had ruled with his mother until her death in 176 BCE (his name meant “he who loves his mother”), had fallen under the influence of ambitious advisers and in 170 BCE, still only a teenager, he was persuaded to invade a disputed part of the Seleucid Empire known as Coele-Syria.

The invasion was a disaster.

Forewarned, Antiochus defeated the invading Egyptian army and promptly counterattacked. Within a year he had occupied Egypt and coerced Ptolemy into declaring Antiochus as his “protector,” reducing the pharaoh to little more than a puppet king. Only Alexandria eluded Antiochus’s grasp: besieged and running out of food, its citizens nevertheless proclaimed Philometor’s younger brother—Ptolemy VIII Euergetes,* or “benefactor”—to be Egypt’s rightful ruler. With control of Egypt’s monarch snatched away, the frustrated Antiochus released Philometor and withdrew, calculating that an Egypt divided between two feuding kings would be easier to subdue.

The Ptolemies did not oblige. Philometor and Euergetes reconciled to face their uncle together. Exasperated, in 168 BCE Antiochus invaded a second time, sweeping aside the remnants of Egyptian opposition as he marched directly to Alexandria. He was drawn up short four miles from the city by a group of men led by a Roman senator: this was Gaius Popilius Laenas, a notoriously short-tempered troubleshooter dispatched by the Senate in response to the Ptolemies’ pleas for help. As the invading general approached the Roman deputation with his arm outstretched in greeting, Popilius pressed into Antiochus’s hand a tablet bearing the Senate’s ultimatum: leave Egypt or suﬀer the consequences. Before the stunned Antiochus could reply, Popilius drew a circle in the sand around him with his staﬀ and, essentially, dared the conqueror to cross the line. “Before you step out of that circle,” Popilius said, “give me a reply to lay before the senate.”

Mulling Popilius’s demand, and aware of the might of the state on whose behalf it had been issued, Antiochus eventually oﬀered the meek reply, “I will do what the senate thinks right.” Popilius accepted his hand in friendship. The Seleucid king withdrew his forces from Egypt, the Ptolemies were restored to power, and the crisis was averted.

The name of this conflict, the so-called Sixth Syrian War, hardly resounds through history. The Ptolemies and Seleucids had been quarreling over Coele-Syria for a hundred years, and after five earlier conflicts fought by the same dynasties over the same parcel of land, a sixth must have paled into irrelevance. If Antiochus’s invasion is mentioned at all outside of academic circles, it is usually because of Popilius’s brazen treatment of the invader: according to the author William Safire, the circle that Popilius drew in the desert outside Alexandria has a decent claim to being the origin of the phrase “a line in the sand.” (Its main competitor is the story of William B. Travis, lieutenant colonel at the Alamo, who drew a line in the sand with his sabre and said to his men, “Those prepared to die for freedom’s cause, come across to me.”)

For ancient scribes and scholars, however, the Sixth Syrian War was a watershed. Egypt’s economy was wrecked, with papyrus exports driven down and eventually halted altogether, and the literate societies of the ancient world suﬀered accordingly. Unexpectedly, though, Pergamon’s Eumenes II, he of the renowned library, seemed to have the papyrus shortage solved almost before it arose.

In 168 and 167 BCE, as the war in Egypt came to a close, Eumenes’s brother Attalus was in Rome on diplomatic business. Among the Pergamene delegation was Crates of Mallus, chief scholar at Pergamon’s library, who craved the same approval that the Romans accorded to Aristarchus, his rival at the Library of Alexandria. (Aristarchus had succeeded Aristophanes, the jailbird librarian.) Unfortunately, Crates’s visit did not begin well: he fell into an open sewer on the city’s Palatine Hill and broke his leg in the process. The librarian made the most of his forced convalescence by delivering lectures to rapt Roman audiences, sparking a renewed interest in grammar and literary criticism as he did so. Though the content of his talks has been lost, the medium on which they were written has not: Crates’s books were made of parchment, in the Pergamene fashion, and a Rome starved of papyrus was eager to learn more about this promising replacement. Ever ready to curry favor with his hosts, Crates ordered a shipment to be brought to Rome, and so parchment began its relentless spread across the ancient world.

* * *

A skin split into two layers yields kelaf (flesh side) and duxustus (hair side) parchment, which are suitable for tefillin and mezuzah respectively.

What, then, elevated the membrana, or “skin,” with which Crates dazzled Rome above the leather used in centuries past? Today, parchment is often described as untanned leather, but this manages to be an oversimplification and an oxymoron at the same time. An untanned skin is rawhide, not leather; not to mention early parchment often was tanned to some degree by the vegetable acids in its preparation baths. But to quibble over this definition misses the point. The innovation that distinguished parchment from leather was not chemical, but mechanical.

Having soaked and unhaired a skin, the Pergamenes discovered that by stretching it on a frame and allowing it to dry before cutting it down, the skin could be made to maintain its tautness and resilience. In mammals the dermis, the middle layer of skin from which leather and parchment are made, is composed of a network of minute collagen fibers. As an unhaired skin soaks in its preparation vat, these fibers absorb and become saturated with the bath’s liquid, and this, in turn, mingles with the skin’s own secretions to suﬀuse it with a sticky, adhesive fluid. Stretching the skin causes some of its fibers to break while others are pulled tight, aligning with the plane of the skin, and as the realigned fibers dry out they cause the skin to set in place. (Tanning, by contrast, chemically bonds the collagen fibers together, actively preventing the skin from stretching. The Pergamenes are thought to have modified the ingredients of their preparation baths to minimize this eﬀect.)

The result of this combined stretching and drying process is a taut, flexible material. Whereas leather is soft and limp, a sheet of parchment flexed gently across its surface readily springs back to its original shape and will hold a crease if folded more firmly. More opaque than papyrus, and without the fibrous ridges that made it diﬃcult to write on both sides of a sheet, parchment’s physical qualities, the Pergamenes found, made it an almost perfect substrate for writing. Moreover, parchment was stronger than papyrus: a skin gashed by a careless tanner’s knife could be safely sewn up, while loose leafs of parchment could be pierced with an awl and tied together without danger of tearing—a property that would be instrumental in shaping the book as we know it.

Tough as it is, parchment is not indestructible. Unlike leather, parchment “breathes,” absorbing or releasing moisture to match its environment, and overly damp or dry conditions can eventually damage parchment or its contents. Ink and illustrations may flake oﬀ a damp sheet of parchment; it may “cockle,” or wrinkle, and lose its stiﬀness; and it becomes prey to bacteria and mold that can discolor and eventually eat through the parchment entirely. A dry sheet of parchment, on the other hand, will wrinkle, grow brittle, and eventually crack. Fortunately, the temperate climate of Europe, where parchment found greatest use, is relatively benign. Long periods of excessive humidity are rare enough to prevent parchment from becoming too damp, and though parchment can dry out, it requires years in an arid environment—again, a rarity in continental Europe—for it to do so. Parchment is so resistant to dryness, in fact, that it can be heated to 480 degrees Fahrenheit (approximately 250 degrees Celsius) before it begins to shrink and brown. If heated while wet, however, a temperature of only 100 degrees (around 40 Celsius) will shrink a sheet of parchment like a sock left in a hot wash.

In spite of these shortcomings, parchment was an undeniably superior writing material—smooth under a pen’s nib, long-lived, and resistant to rough handling. It was perfectly equipped to replace papyrus, in other words, and that is precisely what it did as it was assimilated in turn by each new culture that took it up. The Jewish people of what became modern-day ancient Israel, for instance, were among the earliest and most enthusiastic adopters of parchment, as the Dead Sea Scrolls attest. Of the hundreds of documents and fragments found in 1946 in caves near the Dead Sea, more than 90 percent are written on parchment; dated to between 200 BCE and 50–70 CE, the scrolls show how rapidly parchment overtook its Egyptian rival. Even so, ancient Jewish law was strict in its treatment of this new writing material. The tanneries that processed skins, and which often used noisome horse dung to unhair pelts, had to be sited out of town and downwind of prevailing northwesterlies, with one rabbi of special olfactory sensitivity declaring a minimum safe distance of fifty cubits, or seventy-five feet, from the town wall. For ritual documents, only the skins of “clean” animals would do: oxen, sheep, goats, and deer were acceptable, but camels, hares, pigs, and “rock badgers,” or hyrax, were not.

Parchment became integral to Jewish tradition. The Mishneh Torah, a fourteen-volume companion to the Torah composed in the twelfth century by Rabbi Moses Maimonides, demands specific forms of parchment for diﬀerent texts. The Torah, Maimonides wrote, is to be written only upon gewil, or whole parchment, and then only on its hair side. A skin split into two layers yields kelaf (flesh side) and duxustus (hair side) parchment, which are suitable for tefillin (scrolls contained in small boxes worn on the head and left arm) and mezuzah (scrolls placed on doorposts) respectively. In the cases of kelaf and duxustus, only the inner surfaces exposed when the parchment is split are suitable for writing. Skins prepared by non-Israelites or Samaritans were prohibited.

Having listed in exhaustive detail the minutiae that governed the ritual use of parchment, Maimonides was considerably more vague as to its manufacture. The few lines the Mishneh Torah devotes to the subject are puzzling, and describe a process that would produce a material more akin to leather than parchment. The crucial stretching process is omitted (though parchment found among the Dead Sea Scrolls does show signs of stretching, rolling, or pressing), and skins are to be finished with “gall-wood or similar materials which contract the pores of the hide,” which sounds suspiciously like tanning.

* * *

Any pontiﬀ would surely have recalled the words of Revelations 2 in which Pergamon is branded a ‘seat of Satan.’

Christianity embraced parchment as eagerly as had its elder sibling, and the spread of the new religion throughout the Western world mirrored the ongoing shift in writing materials. By the fifth century CE, more Christian books were written on parchment than papyrus, and there were more Christian books than any other kind. Oddly enough, the Vatican continued to issue papal edicts, or “bulls,” on papyrus until 1022, during the papacy of Benedict VIII. Catholic conservatism may be to blame, but then any pontiﬀ would surely have recalled the words of Revelations 2 in which Pergamon is branded a “seat of Satan.” Perhaps Benedict VIII was the first pope who could suppress a reflexive shiver when setting quill to the pergamena charta, or “Pergamene paper,” that had long been used for more mundane Christian manuscripts.

Like Rabbi Maimonides, medieval Christian writers recorded little interest in how one of the most basic components of their craft was made, and barely a word was written about parchment’s manufacture as it took its place as Europe’s most important writing material. This indiﬀerent silence was finally broken by a single page tucked away at the back of a fourteenth-century reference book. Following the fashion of its time, this untitled volume was made up of choice extracts from many diﬀerent works, bound together at its owner’s instruction. Now owned by the British Library, today the book goes by its catalogue number (Harley MS 3915, to be precise) and is most often cited for containing a sizeable chunk of a reference work called De diversis artibus (The Various Arts), a twelfth-century arts-and-crafts manual attributed to a monk who called himself Theophilus. But though Theophilus holds forth on sundry subjects such as paint mixing, glass blowing, and bookbinding, parchment making is not among them: the page that begins ad faciendas cartas de pellibus caprinis more bononiense (on the Bolognese art of making paper from goatskins) is an unattributed orphan. It is worth quoting in its entirety:

Take goatskins and stand them in water for a day and a night. Take them and wash them until the water runs clear. Take an entirely new bath and place therein old lime and water, mixing well together to form a thick cloudy liquor. Place the skins in this, folding them on the flesh side. Move them with a pole two or three times each day, leaving them for eight days (and twice as long in winter). Next you must withdraw the skins and unhair them. Pour oﬀ the contents of the bath and repeat the process using the same quantities, placing the skins in the lime liquor and moving them once each day over eight days as before. Then take them out and wash them well until the water runs quite clean. Place them in another bath with clean water and leave them for two days. Then take them out, attach the cords and tie them to the circular frame. Dry, then shave them with a sharp knife after which leave for two days out of the sun. Moisten with water and rub the flesh side with powdered pumice. After two days wet it again by sprinkling with a little water and fully clean the flesh side with pumice so as to make it quite wet again. Then tighten up the cords, equalise the tension so that the sheet will become permanent. Once the sheets are dry, nothing further remains to be done.

This is a craft transformed. Gone are the ambiguities of ancient soak-scrape-and-stretch methods, now refined into a rigorous multistep program with detail aplenty. Goatskin is explicitly mentioned, hinting at the fact that goats and sheep were more plentiful than cattle, and easier to raise. The fermenting vegetable and animal matter once used to unhair skins has given way to lime, a potent alkaline mineral that burns unprotected skin, and an additional soaking step has been added so that unhaired skins are thoroughly softened. And lastly, an extra-smooth writing surface is achieved by means of an elaborate series of wetting, drying, shaving, and polishing operations.

The driving force behind these advances was the emergence of parchment making as an industry in its own right. Where once a monastery would have raised its own cattle and made parchment from their skins, by the thirteenth century the needs of bookmaking monks were being met by a new breed of professional parchmenters. As the parchment-making industry matured it acquired the inevitable trade jargon: pelts were tied to drying frames, or “herses,” by wrapping cords around small pebbles called “pippins” pressed into the skin; shaving of the skin was carried out with a curved, moon-shaped knife, or lunellarium, without sharp junctions that might tear the skin; and finished parchment was often “pounced”—polished with powdered pumice, or porous volcanic rock—to improve its color and texture.

Having mastered production of the basic artifact, a skilled parchmenter could branch out into niche varieties and treatments. Parchment was sometimes whitened with liquid chalk in lieu of pouncing, while concoctions made from such things as lime, egg whites, flour, and metal salts were applied to regulate the parchment’s moisture content and so stave oﬀ environmental damage. Transparent parchment, which was variously used for tracing, windowpanes, and even magnifying glasses, was made by treating the skin with substances such as rotten egg whites, gum arabic (an adhesive made from the sap of the acacia tree), or animal glue, and by deliberately under-tightening the skin on its herse. Richly colored purple parchment, so dark that it demanded the use of reflective gold or silver ink, could be made with dye derived from sea snails called murex.

Parchment’s name evolved along with advancements in its manufacture. For hundreds of years the Romans called it membrana, or “skin,” but by the third century a new term had come into vogue, and parchment was referred to as pergamena charta, or “Pergamene paper.” In time, this led to the Old French pergamin, parcemin, and perchemin, and later a whole host of Middle English variants such as parchemeyn, perchmene, parchemynt, and pairchment. The French connection also gave rise to a related term: whereas “parchment” carried connotations of the sheep and goats most commonly farmed in the land of its origin, “vellum,” from the Old French vel, or “calf,” suggested calfskin instead. Calfskin parchment was slightly rougher in texture, making it well suited for painting, and leaves of it were sometimes inserted into sheepskin parchment books where illustrations were required. The distinction between parchment and vellum, however, has always been an uncertain one, and today “vellum” is used to mean any especially fine parchment regardless of the animal from which it was made.

* * *

With its donor animal unsullied by life outside the womb… uterine vellum was prized by the writers of magical charms.

Confronted with an ivory sheet of taut, smooth vellum, it is easy to forget its origins in the flesh. Pens old and new glide eﬀortlessly across it, and parchment invests even a humble rollerball pen with luxury and authority. Whereas an absorbent sheet of paper wicks away ink and blurs lines, the water-based ink found in most modern pens huddles into discrete lines and dots under its own surface tension and dries to a glossy shine atop parchment’s impermeable surface. As a writing material—and in stark contrast to papyrus, at least in its modern form—parchment is hard to beat.

For all its preternatural smoothness and seductive appearance, though, parchment cannot escape its provenance. Whether it was made yesterday or a thousand years ago, a sheet of parchment is the end product of a bloody, protracted, and very physical process that begins with the death of a calf, lamb, or kid, and proceeds thereafter through a series of grimly anatomical steps until parchment emerges at the other end. Like laws and sausages, if you love parchment it is perhaps best not to see it being made.

For the morbidly curious, hints of parchment’s provenance are not diﬃcult to see. Tiny hairs still cling to the surface of many a sheet of parchment, and holding it up to the light reveals the delicate tracery of veins—which, if the animal was not properly bled upon its slaughter, are darker and more obvious. Even the best vellum, meticulously scraped and polished so that hair and flesh sides are nigh indistinguishable, cannot obscure its source material: in an ironic reversal of the shape a skin takes while attached to its erstwhile inhabitant, a sheet of parchment left to its own devices will curl toward its less elastic hair side. More unsettling still than these visible reminders, however, is the means by which a very specific form of parchment, called “virgin” vellum, is produced.

Virgin vellum was parchment of the very highest quality, and parchmenters were willing to go to some lengths to make it. It has long been known that the best parchment comes from the skins of the youngest animals, and there is archaeological evidence—specifically, animal bones excavated in the “heel” of Italy—that the proportion of cattle slaughtered at less than twelve months of age grew steadily in line with parchment production. Not only was the skin less likely to be blemished by insect bites, scars, and the like, but the thinner skins of younger animals were easier to work. It follows that if the best parchment is made from the youngest animals, then vellum made from aborted or stillborn calves and lambs must be best of all. Known less euphemistically as “uterine” or “abortive” vellum, this miraculous material was sought after not only for its qualities as a writing surface but also for its unimpeachable purity, with its donor animal unsullied by life outside the womb. For this reason uterine vellum was prized by the writers of magical charms and grimoires (written with the left, or sinister, hand); ultimately, this association with the occult was so strong that the production of uterine vellum was outlawed in some medieval Italian cities.

*

This, then, is parchment: the pale, virginal product of a bloody manufacturing process; a delicate writing surface that can withstand desert heat and European chill for centuries or even millennia; the medium upon which ancient and medieval writers set down the most important religious, literary, and scientific tracts of their times. Write with a good pen on a piece of parchment and you may wish you never had to go back to paper again.

* * *

*Eagle-eyed readers will have noticed a Ptolemy VII–shaped hole in proceedings. This unhappy scion of the Ptolemaic dynasty is thought to have been Ptolemy Philometor’s son, born long after the war with Antiochus. Ptolemy VII succeeded his father for less than two months before his uncle, Ptolemy Euergetes, had him put to death.↩

* * *

Reprinted from The Book by Keith Houston. Copyright © 2016 by Keith Houston. With permission of the publisher, W.W. Norton & Company, Inc. All rights reserved.