Natural History (Pliny)

Naturalis Historia, 1669 edition, title page. The title at the top reads: "Volume I of the Natural History of Gaius Plinius Secundus."

The Natural History (Latin: Naturalis Historia) is an encyclopedia published circa AD 77–79 by Pliny the Elder. It is one of the largest single works to have survived from the Roman Empire to the modern day and purports to cover the entire field of ancient knowledge, based on the best authorities available to Pliny. He claims to be the only Roman ever to have undertaken such a work and prays for the blessing of the universal mother:^[1]

Hail to thee, Nature, thou parent of all things! and do thou deign to show thy favour unto me, who, alone of all the citizens of Rome, have, in thy every department, thus made known thy praise.

The work became a model for all later encyclopedias in terms of the breadth of subject matter examined, the need to reference original authors, and a comprehensive index list of the contents. The work is dedicated to the emperor Titus, son of Pliny's close friend, the emperor Vespasian, in the first year of Titus's reign. It is the only work by Pliny to have survived and the last that he published, lacking a final revision at his sudden and unexpected death in the AD 79 eruption of Vesuvius.

Table of contents

The Natural History consists of 37 books. Pliny devised his own table of contents. The table below is a summary based on modern names for topics.

I	Preface and tables of contents, lists of authorities
II	Mathematical and physical description of the world
III–VI	Geography and ethnography
VII	Anthropology and human physiology
VIII–XI	Zoology
XII–XXVII	Botany, including agriculture, horticulture and pharmacology
XXVIII–XXXII	Pharmacology
XXXIII–XXXVII	Mining and mineralogy, especially in its application to life and art, including: gold casting in silver[2] statuary in bronze[3] painting[4] modelling [5] sculpture in marble[6] precious stones and gems[7]

Production

Purpose

The scheme of his great work was vast and comprehensive, being nothing short of an encyclopedia of learning and of art so far as they are connected with nature or draw their materials from nature. He admits that

My subject is a barren one – the world of nature, or in other words life; and that subject in its least elevated department, and employing either rustic terms or foreign, nay barbarian words that actually have to be introduced with an apology. Moreover, the path is not a beaten highway of authorship, nor one in which the mind is eager to range: there is not one of us who has made the same venture, nor yet one Roman who has tackled single-handed all departments of the subject.

He admits the problems of writing such a work:

It is a difficult task to give novelty to what is old, authority to what is new, brilliance to the common-place, light to the obscure, attraction to the stale, credibility to the doubtful, but nature to all things and all her properties to nature.

Sources

For this work, he studied the original authorities on each subject and was most assiduous in making excerpts from their pages. His indices auctorum are, in some cases, the authorities he had actually consulted (though they are not exhaustive); in other cases, they represent the principal writers on the subject, whose names are borrowed second-hand for his immediate authorities. He frankly acknowledges his obligations to all his predecessors in a phrase that deserves to be proverbial,^[8]

plenum ingenni pudoris fateri per quos profeceris.
to own up to those who were the means of one's own achievements

Any criticism of his faults of omission is disarmed by the candour of the confession in his preface:

nec dubitamus multa esse quae et nos praeterierint; homines enim sumus et occupati officiis.
Nor do we doubt that many things have escaped us also; for we are but human, and beset with duties

In the preface, the author claims to have stated 20,000 facts gathered from some 2,000 books and from 100 select authors. The extant lists of his authorities amount to many more than 400, including 146 of Roman and 327 of Greek and other sources of information. The lists, as a general rule, follow the order of the subject matter of each book. This has been clearly shown in Heinrich Brunn's Disputatio (Bonn, 1856).

A statue of Octavian, c. 30 BC

Bust of Agrippa, Louvre

One of Pliny's authorities is Varro. In the geographical books, Varro is supplemented by the topographical commentaries of Agrippa, which were completed by the emperor Augustus; for his zoology, he relies largely on Aristotle and on Juba, the scholarly Mauretanian king, studiorum claritate memorabilior quam regno (v. 16). Juba is one of his principal guides in botany; Theophrastus is also named in his Indices, and since Theophrastus's botanical work survives, it is possible to see the extent to which Pliny uses him, translating (and occasionally mistranslating) Theophrastus's difficult Greek into Latin. Another work by Theophrastus, On Stones was a useful source of information on ores and minerals. He made use of all of the Greek histories available at the time, such as those of Herodotus and Thucydides, as well as the famous Bibliotheca historica of Diodorus Siculus.

Working method

The following is a description of his methods of work on the natural history by his nephew, Pliny the Younger:

Does it surprise you that a busy man found time to finish so many volumes, many of which deal with such minute details? You will wonder the more when I tell you that he for many years pleaded in the law courts, that he died in his fifty-seventh year, and that in the interval his time was taken up and his studies were hindered by the important offices he held and the duties arising out of his friendship with the Emperors. But he possessed a keen intellect; he had a marvellous capacity for work, and his powers of application were enormous. He used to begin to study at night on the Festival of Vulcan, not for luck but from his love of study, long before dawn; in winter he would commence at the seventh hour or at the eighth at the very latest, and often at the sixth. He could sleep at call, and it would come upon him and leave him in the middle of his work. Before daybreak he would go to Vespasian-- for he too was a night-worker—and then set about his official duties. On his return home he would again give to study any time that he had free. Often in summer after taking a meal, which with him, as in the old days, was always a simple and light one, he would lie in the sun if he had any time to spare, and a book would be read aloud, from which he would take notes and extracts. For he never read without taking extracts, and used to say that there never was a book so bad that it was not good in some passage or another. After his sun bath he usually bathed in cold water, then he took a snack and a brief nap, and subsequently, as though another day had begun, he would study till dinner-time. After dinner a book would be read aloud, and he would take notes in a cursory way. I remember that one of his friends, when the reader pronounced a word wrongly, checked him and made him read it again, and my uncle said to him, "Did you not catch the meaning?" When his friend said "yes," he remarked, "Why then did you make him turn back? We have lost more than ten lines through your interruption." So jealous was he of every moment lost.

Style

Ancient bust of Seneca

His style betrays the influence of Seneca^{[citation needed]}. It aims less at clearness and vividness than at epigrammatic point. It abounds not only in antitheses, but also in questions and exclamations, tropes and metaphors, and other mannerisms of the Silver Age. The rhythmical and artistic form of the sentence is sacrificed to a passion for emphasis that delights in deferring the point to the close of the period^{[citation needed]}. The structure of the sentence is also apt to be loose and straggling. There is an excessive use of the ablative absolute, and ablative phrases are often appended in a kind of vague "apposition" to express the author's own opinion of an immediately previous statement, e.g.,^[9]

dixit (Apelles) … uno se praestare, quod manum de tabula sciret tollere, memorabili praecepto nocere saepe nimiam diligentiam.

Publications

First publication

Common Dolphin

Pliny apparently published the first ten books himself in 77 and was engaged on revising and enlarging the rest during the two remaining years of his life. The work was probably published with little, if any, revision by the author's nephew Pliny the Younger, who, when telling the story of a tame dolphin and describing the floating islands of the Vadimonian Lake, thirty years later,^[10] has apparently forgotten that both are to be found in his uncle's work.^[11] He describes the Naturalis historia as a Naturae historia and characterizes it as a "work that is learned and full of matter, and as varied as nature herself."^[12]

The probable absence of the author's final revision may partly account for many repetitions, for some contradictions, for mistakes in passages borrowed from Greek authors, and for the insertion of marginal additions at wrong places in the text. Alternatively (or in addition), the work has been transcribed many times, and the chances of poor copying can only have increased as copies multiplied.

Manuscripts

Pliny's Natural History, mid-12th century manuscript, Abbaye of Saint-Vincent, Le Mans, France

About the middle of the 3rd century, an abstract of the geographical portions of Pliny's work was produced by Solinus; and early in the 4th century, the medical passages were collected in the Medicina Plinii. Early in the 8th century, we find Bede in possession of an excellent manuscript of parts of the work. Bede used the work in his own book "De Rerum Natura", especially the sections on meteorology and gems. However, he updated and corrected Pliny on the tides.

In the 9th century, Alcuin sends to Charlemagne for a copy of the earlier books;^[13] and Dicuil gathers extracts from the pages of Pliny for his own Mensura orbis terrae (ca. 825).

Pliny's work was held in high esteem in the Middle Ages. The number of extant manuscripts is about 200; but the best of the more ancient manuscripts, that at Bamberg, contains only books xxxii–xxxvii. Robert of Cricklade, prior of St. Frideswide's Priory at Oxford, dedicated to Henry II a Defloratio consisting of nine books of selections taken from one of the manuscripts of this class, which has been recently recognized as sometimes supplying us with the only evidence for the true text. Among the later manuscripts, the codex Vesontinus, formerly at Besançon (11th century), has been divided into three portions, now in Rome, Paris, and Leiden respectively, while there is also a transcript of the whole of this manuscript at Leiden.

Despite, or perhaps because of, the multiplicity of texts in circulation, many were in a poor state. Thus, when Petrarch bought a copy in Mantua in 1350, he wrote:

What would Cicero, or Livy, or the other great men of the past, Pliny above all, think if they could return to life and read their own works?

He answered his own rhetorical question that they would scarcely recognise them, owing to corruptions and errors that had over the years built up in the texts, an inevitable result of multiple hand copying. Petrarch went on to correct some of the most barbarous texts, but translation was difficult owing to the way Pliny, for example, introduced non-Latin words or described techniques long since lost or forgotten.

Printed copies

One of the earliest illustrated copies of the Natural History

The work was one of the first classical manuscripts to be printed, at Venice in 1469 by Johann and Wendelin of Speyer, but the text was, in the words of J. F. Healy, "distinctly imperfect". The next important edition is Philemon Holland's much improved translation of 1601, and further versions multiplied as Pliny's reputation grew during the Renaissance. It inspired many scholars to look again at the achievements of the classical world and the ways nature could be studied. It helped revive interest in minerals and mining, for example, and Pliny is much quoted by Georg Agricola in his magnum opus De Re Metallica.

Sir Thomas Browne expressed a wholesome skepticism about Pliny's dependability in his Pseudodoxia Epidemica (1646):^[14]

"Now what is very strange, there is scarce a popular error passant in our days, which is not either directly expressed, or diductively contained in this Work; which being in the hands of most men, hath proved a powerful occasion of their propagation. Wherein notwithstanding the credulity of the Reader is more condemnable then the curiosity of the Author: for commonly he nameth the Authors from whom he received those accounts, and writes but as he reads, as in his Preface to Vespasian he acknowledgeth."

Highlights

The work divides neatly into the organic world of plants and animals and the realm of inorganic matter, although there are frequent digressions in each section. He is especially interested in not just describing the occurrence of plants and animals, but also their exploitation (or abuse) by man, especially Romans. The description of metals and minerals is particularly detailed and valuable for the history of science as being the most extensive compilation still available from the ancient world.

Anthropology

He wrote that a menstruating woman who uncovers her body can scare away hailstorms, whirlwinds and lightning. Anything she touches turns sour including wine and meat. Seeds turn sterile, and plants wither. If she strips naked and walks around the field, caterpillars, worms and beetles fall off the ears of corn. Even when not menstruating, she can lull a storm out at sea by stripping.^[15]

Botany

Papyrus plants at Syracuse, Sicily

Spiny dye-murex used to make purple in Pliny's day

A black pearl and a shell of the black-lipped pearl oyster

A special interest attaches to his account of the manufacture of papyrus and the various grades of papyrus available to Romans. Different types of trees and the properties of the wood from them receives a vigorous treatment. He describes the olive tree in some detail, praising its virtues as one might expect. Botany is well discussed by Pliny, using Theophrastus as one of his sources.

Rosa Gallica

One of his favourite topics is spices, such as pepper, ginger and cane sugar. The latter, rather surprisingly, is used only as a medicine. He mentions several different varieties of pepper, complaining of their cost, comparable with that of gold and silver. Pliny is critical of luxury, but yet spends much time describing rare and expensive products popular with the rich and famous of Rome and is particularly scathing about perfumes:

Perfumes are the most pointless of luxuries, for pearls and jewels are at least passed on the one's heirs, and clothes last for a time, but perfumes lose their fragrance and perish as soon as they are used.

He does give a summary of their ingredients, such as attar of roses, which he says is the most widely used base. Other substances added are myrrh, cinnamon, and balsam gum, to mention but a few.

Zoology

A mosquito and a fly in a Baltic amber necklace

In zoology, he mentions the different kinds of purple dye, especially the murex snail, which was the highly prized source of Tyrian purple. He describes the elephant and hippopotamus in detail, as well as the value and origin of the pearl and the invention of fish farming and oyster farming. Aquaria were popular pastimes of the rich, and Pliny provides several amusing anecdotes of the problems of owners becoming too closely attached to their fishes.

Honey bee on tufted vetch

The discussion of the origin of amber is especially incisive, and he correctly identifies the source as being the fossilised resin of pine trees. One piece of evidence is that some samples exhibit encapsulated insects, a feature that is readily explained if the original material is a viscous resin. He refers to the way in which it will exert a charge when rubbed, a property well known to Theophrastus. Pliny devotes considerable space to bees, which he admires for their industry and organisation, and of course their honey. Pliny relies on many previous authors and describes the use of smoke by beekeepers at the hive to collect the honeycombs. He also discusses the queen bee and her crucial role in the swarm.

His description of the song of the nightingale is an elaborate example of his occasional felicity of phrase.

Metallurgy

Gold nuggets

Gold pounded into a paper-thin sheet of metal leaf

Agrippina and Claudius on gold aureus

Pliny has an extensive discussion of metals including gold, silver, copper, mercury, lead, tin and iron, as well as their many alloys such as electrum, bronze, pewter, and steel. He devotes much space to a long discussion about the greed for gold, such as the absurdity of using the metal for coins in the early Republic. He gives several examples of the way rulers proclaimed their prowess by exhibiting gold loot from their campaigns, such as that by Claudius after conquering Britain, as well as relating the stories of Midas and Croesus. He then proceeds to discuss why the metal is unique in its malleability and ductility being far greater than any other metal. The examples given are its capability of being beaten into fine foil with just one ounce, producing 750 leaves four inches square. Fine gold wire can be woven into cloth, although imperial clothes usually combined it with natural fibres like wool. He once saw Agrippina the Younger, wife of Claudius, at a public show on the Fucine Lake involving a naval battle, wearing a military cloak made of gold.

Given gold's value and importance to the Romans, its occurrence and extraction receives a long section of text and starts with a rejection of the ideas initiated by Herodotus of Indian gold obtained by ants or dug up by griffins in Scythia. The section is discussed in more detail below.

Goddess Minerva on a Roman silver plate, 1st century BCE

Silver comes next in Pliny's pantheon of greed. It does not occur in native form and has to be mined, usually occurring with lead ores. Spain produced the most silver in his time, many of the mines having been started by Hannibal. One of the largest had galleries running for between one and two miles into the mountain, "water-men" (which he calls "aquatini") draining the mine, and they

stood night and day in shifts measured by lamps, bailing out water and making a stream.

Pliny is probably referring to the reverse overshot water-wheels operated by treadmill and found in Roman mines in the 1920s as discussed below. Britain, he says, is very rich in lead, which is found on the surface at many places, and thus very easy to extract; production was so high that a law was passed attempting to restrict mining.

Roman coins were struck, not cast, so these coin moulds were created for forgery

Another of Pliny's obsessions is with fraud and forgery, and in particular coin counterfeiting by mixing copper with silver, or even admixture with iron. Tests had been developed for counterfeit coins and proved very popular with the victims, mostly ordinary people. In the same section, he deals with the liquid metal mercury, which is also found in silver mines. He correctly says it is toxic, and amalgamates with gold, so is used for refining and extraction of that metal. He says mercury is used for gilding copper. Antimony is found in silver mines and is used as an eyebrow cosmetic.

Cinnabar

The main ore of mercury is cinnabar, long used as a pigment by painters. He says that the colour is similar to that of the cochineal insect. The dust is very toxic, so workers handling the material wear face masks of bladder skin. Copper and bronze are, says Pliny, most famous for their use in statues, of which there were many in Rome. Their most extravagant use was in colossi, gigantic statues as tall as towers, the most famous being the Colossus of Rhodes. He personally saw the massive statue of Nero in Rome, which was later removed after the emperor committed suicide. The face of the statue was modified shortly after Nero's, death during Vespasian's reign, to make it truly a statue of Sol. Hadrian moved it, with the help of the architect Decrianus and 24 elephants, to a position next to the Flavian Amphitheater. This building took the name Colosseum in the Middle Ages, after the statue nearby.

He gives a special place to iron, distinguishing the hardness of steel from what we now call wrought iron, a softer grade with (we know now) a smaller carbon content. He is scathing about the use of iron:

and yet in other places we dig with sheer recklessness when iron is needed – a metal even more welcome than gold amid the bloodshed of war.

Mineralogy

Octahedral shape of diamond

He describes many different minerals and gemstones, building on works by Theophrastus and other authors. The topic concentrates on the most valuable gemstones, because it gives him yet another opportunity to criticize the obsession with luxury products such as engraved gems and hardstone carvings.

Mineral fluorite

He provides a thorough discussion of the properties of fluorspar, noting that it is carved into vases and other decorative objects. It is often banded with purple colours, which is presumably why the Romans regarded it so highly.

He accurately describes the octahedral shape of the diamond and proceeds to mention that diamond dust is used by gem engravers to cut and polish other gems owing to its great hardness. His recognition of the importance of crystal shape is a precursor to modern crystallography, while mention of numerous other minerals presages mineralogy. He also recognises that other minerals have characteristic crystal shapes, but in one example, confuses the crystal habit with the work of lapidaries.

Quartz crystal showing transparency

Rock crystal is valuable for its transparency and hardness, he says, and can be carved into vessels and implements. Pliny relates the story of a woman who owned a ladle made of the mineral, paying the sum of 150,000 sesterces for the item.

Nero deliberately broke two crystal cups when he realised that he was about to be deposed, so denying anyone else of their use.

Pliny returns to the problem of fraud and the detection of false gems using several tests, including the scratch test, where counterfeit gems can be marked by a steel file, and genuine ones not. Perhaps it refers to glass imitations of jewellery gemstones. He refers to using one hard mineral to scratch another, the first allusion to what is now the Mohs hardness scale. Diamond sits at the top of the series because, Pliny says, it will scratch all other minerals.

Agriculture

Roman harvesting machine: overview

Roman harvesting machine: detail

The sixteen overshot wheels at Barbegal are the largest known Roman mill complex.

The methods used to cultivate crops are described extensively by Pliny in Books 18 to 28. He praises Cato the elder and his work De Agri Cultura, which he uses as a primary source. Pliny's work includes discussion of all known cultivated crops and vegetables, as well as herbs and remedies derived from them. It is also a source for some interesting devices and machines used in cultivation and processing the crops. For example, he describes a simple mechanical reaper that cut the ears of wheat and barley without the straw and was pushed by oxen (Book XVIII, chapter 72). This device was forgotten in the Dark Ages, during which period reapers reverted to using scythes and sickles to gather crops. It is depicted on a bas-relief from the later Roman period found at Trier.

Watermills

The same book describes how the grain is ground using pestles powered by water wheels, an important reference to a practice supported by the remains of many Roman water mills found across the Empire. The most impressive extant mills are found at Barbegal in southern France, using water supplied by the aqueduct supplying Arles. The water powered no less than sixteen overshot water wheels arranged in two parallel sets of eight down the hillside. It is thought that the wheels were overshot water wheels with the outflow from the top driving the next one down in the set, and so on to the base of the hill. Vertical water mills were well known to the Romans, being described by Vitruvius in his De Architectura of 25 BC.

Scheme of the water-driven Roman sawmill at Hierapolis, Asia Minor

A sawmill powered by a water wheel is known from another bas-relief from Hierapolis. Rather than using the direct drive from the rotating shaft, the Hierapolis sawmill powered a crankshaft to activate the long saw blades in cutting stone. Part of the apparatus on the sarcophagus shows a gear train, so the speed of cutting could be increased or even controlled by appropriate choice of the gearing. Some partly cut stones have also been found at the site, confirming the method. The same technique could also have been used to cut timber.

There are later references to floating water mills from Byzantium. The Aqua Traiana fed water mills arranged in a parallel sequence at the Janiculum, under the present American Academy in Rome. The milling complex had a long history and were famously put out of action by the Ostrogoths when they cut the aqueduct in 537 AD during the first siege of Rome. Belisarius restored the supply of grain by using mills floating in the Tiber. The complex of mills bear parallels with a similar complex at Barbegal in southern Gaul and to sawmills on the river Moselle by the poet Ausonius. The use of multiple stacked sequences of reverse overshot water-wheels was widespread in Roman mines.

Art history

The Ludovisi Cnidian Aphrodite, Roman marble copy

Pliny's chapters on ancient art are especially valuable because his work is virtually the only classical source of information on the subject.

In the history of art, the original Greek authorities are Duris of Samos, Xenocrates of Sicyon, and Antigonus of Carystus. The anecdotic element has been ascribed to Duris (xxxiv. 61, Lysippum Sicyonium Duris begat nullius fuisse discipulum etc.); the notices of the successive developments of art and the list of workers in bronze and painters to Xenocrates; and a large amount of miscellaneous information to Antigonus. The last two authorities are named in connection with Parrhasius (xxxv. 68, hanc ei gloriam concessere Antigonus et Xenocrates, qui de pictura scripsere), while Antigonus is named in the indices of xxxiii – xxxiv as a writer on the "toreutic art", or the art of embossing metal, or working it in ornamental relief or intaglio.^{[disambiguation needed ]}

Greek epigrams contribute their share in Pliny's descriptions of pictures and statues. One of the minor authorities for books xxxiv – xxxv is Heliodorus of Athens, the author of a work on the monuments of Athens. In the indices to xxxiii – xxxvi, an important place is assigned to Pasiteles of Naples, the author of a work in five volumes on famous works of art (xxxvi. 40), probably incorporating the substance of the earlier Greek treatises; but Pliny's indebtedness to Pasiteles is denied by Kalkmann, who holds that Pliny used the chronological work of Apollodorus, as well as a current catalogue of artists. Pliny's knowledge of the Greek authorities was probably mainly due to Varro, whom he often quotes (e.g. xxxiv. 56, xxxv. 173, 156, xxxvi. 17, 39, 41). Varro probably dealt with the history of art in connection with architecture, which was included in his Disciplinae.

Laocoon and his sons

For a number of items relating to works of art near the coast of Asia Minor and in the adjacent islands, Pliny was indebted to the general, statesman, orator and historian Gaius Licinius Mucianus, who died before 77. Pliny mentions the works of art collected by Vespasian in the Temple of Peace and in his other galleries (xxxiv. 84), but much of his information about the position of such works in Rome is from books, not personal observation. The main merit of his account of ancient art, the only classical work of its kind, is that it is a compilation ultimately founded on the lost textbooks of Xenocrates and on the biographies of Duris and Antigonus.^{[disambiguation needed ]} In several passages, he gives proof of independent observation (xxxiv. 38, 46, 63, xxxv. 17, 20, 116 seq.). He prefers the marble Laocoön and his Sons in the palace of Titus (now in the Vatican) to all the pictures and bronzes in the world (xxxvi. 37). The statue is attributed by Pliny to three sculptors from the island of Rhodes: Agesander, Athenodoros and Polydorus. It shows the Trojan priest Laocoön and his sons Antiphantes and Thymbraeus being strangled by sea serpents. The priest had tried to expose the Trojan horse by attacking it with a spear, but the gods were displeased and sent a snake to prevent him achieving his task. The statue was probably originally commissioned for the home of a wealthy Roman. It was unearthed in 1506 near the site of the Domus Aurea of the Emperor Nero, in the vineyard of Felice De Fredis; informed of the fact, Pope Julius II, an enthusiastic classicist, acquired it and placed it in the Belvedere Garden at the Vatican, now part of the Vatican Museums. The discovery of the Laocoön made a great impression on Italian sculptors and significantly influenced the course of Italian Renaissance art. Michelangelo is known to have been particularly impressed by the massive scale of the work and its sensuous Hellenistic aesthetic, particularly its depiction of the male figures. The influence of the Laocoön is evidenced in many of Michelangelo's later works, such as the Rebellious Slave and the Dying Slave, created for the tomb of Pope Julius II. The tragic nobility of this statue is one of the themes in Gotthold Lessing's essay on literature and aesthetics, "Laokoön", one of the early classics of art criticism.

In the temple near the Flaminian Circus, he admires the Ares and the Aphrodite of Scopas, "which would suffice to give renown to any other spot". He adds:

At Rome indeed the works of art are legion; besides, one effaces another from the memory and, however beautiful they may be, we are distracted by the overpowering claims of duty and business; for to admire art we need leisure and profound stillness (ibid. 26–72).

He discusses the passion among the Roman elite for collecting engraved gems and extravagant hardstone carvings with his usual irony.

Roman mining

Panorama of Las Médulas

Pliny provides lucid descriptions of many areas of Roman technology, some of which have been verified by scholarly research and archaeology. Thus, he gives a clear description of gold mining, which includes large-scale use of water to scour alluvial gold deposits. The description probably refers to mining in Northern Spain, especially at Las Médulas, shown at right, and the remains of water tanks and numerous Roman aqueducts has been verified on the ground at this vast site. Fieldwork in the surrounding area has discovered many more Roman mines where similar techniques were used on a large scale. At another location, Montefurado on the river Sil, the river itself was diverted to expose placer deposits in the bed of the river. It is likely that Pliny saw the operations of gold extraction himself, since the sections in Book xxxiii read like an eye witness report. He was a Procurator in Hispania Tarraconensis in the later years of his life, so would have had access to the many mines of the region.

Drainage wheel from Rio Tinto mines

However, similar remains have been found in Britain, especially at Dolaucothi in west Wales, where excavations in the modern village have confirmed the presence of a fort and settlement, as well as a bathhouse nearby. Field work has also established the extensive use of hydraulic mining to prospect for gold by construction of several aqueducts and many water reservoirs and tanks at the minehead, just as Pliny describes. The water supply was used for hushing the deposits, by releasing a full tank, the water wave scouring the ground below. Alternatively, the aqueduct stream could be simply released onto the deposit, the water wearing it down if of a soft and alluvial nature. Hard rock veins could be worked by fire-setting with the water used to scour away the rock debris. The same water supplies were probably used in a controlled way to drive watermills to crush the ore, and to wash the resultant powder for extraction of the gold dust.

His work supplements the De Architectura of Vitruvius, who describes many devices and engines for construction of buildings and aqueducts, as well as dewatering machines such as reverse overshot water-wheels and the use of the Archimedean screw. They were used in deep mining when shafts penetrated the water table, and examples have been found in many Roman mines when re-entered by modern mining attempts. The system found at the Rio Tinto copper mines in Spain comprised a set of 16 such wheels arranged in pairs in a vertical sequence with a total lift of 96 feet. The wheels were worked as treadmills by workers standing on the tops, and lifting would have needed careful co-ordination to remove the water effectively.

Sequence of wheels found in Rio Tinto mines

Pliny describes methods of underground mining, including the use of fire-setting to attack the gold-bearing rock and so extract the ore. It involved creating a fire against a hard rock working to weaken it sufficiently to be able to remove it effectively, followed by quenching with water or vinegar. The method was fraught with problems, not least of which was the formation of large volumes of toxic gases, so ventilation was essential in the confined galleries. One way of achieving a good flow of air was by means of adits, which would not only drain excess water but also allow air to circulate freely through the mine. Three such adits were driven through barren rock at Dolaucothi direct to the workings. Two remain open to this day, and the method was used widely in later mines in Britain. That it was widespread is attested by Diodorus Siculus describing the gold mines of Ancient Egypt.

In another part of his work, Pliny describes the use of undermining^{[disambiguation needed ]} to gain access to the veins, but it probably refers to opencast rather than underground mining, given the dangers to the miners in confined spaces.

Pliny's description of gold mining methods^[16] has been confirmed by field work and archaeology, especially the use of water power in sluicing alluvial gold ores, both in Britain at Dolaucothi in South Wales and at Las Médulas and many other mines in northern Spain. His description of construction of the aqueducts needed to prospect for gold-bearing ore by removing overburden and work the alluvial deposits bears the hallmarks of the eyewitness, and he served as Procurator in northern Hispania when the region, in 73 AD, was experiencing a gold rush. The memory must thus have been fresh in his mind when he wrote Book xxxiii. As the mines grew, more water was supplied simply by building new aqueducts along the line of the original, and the remains of such multiple systems are still visible at Dolaucothi and Las Médulas.

Such methods of hydraulic mining were used widely during the gold rushes of California and Australia in the Victorian period. By contrast with aqueducts providing potable water for towns and cities, those used in mining had a higher gradient so as to provide a faster stream to speed operations, and consequently a shorter life. It seems clear that the methods of hydraulic mining such as hushing were a Roman innovation, nothing comparable being known in previous times. No doubt their skills at aqueduct building promoted their less well-known use in large-scale mining, as attested by Pliny.

The research at Dolaucothi has shown how aqueducts could be used not just for prospection, but also for removing waste rock. A large tank would be built at the end of the aqueduct, and once a vein found, it was attacked using fire-setting (building a fire against the rock, then dousing with water) and the precious ore-bearing minerals extracted by hand. The waste or barren rock surrounding the vein was then washed away, again by using the wave of water from a full tank to scour the waste away. Pliny actually recommends a particular size of tank (200 by 200 feet, and 10 feet deep), but those found on the ground at Dolaucothi vary greatly in size and are smaller than he says. The same water supply was then used as a gentle stream to wash the crushed ore, the gold particles being collected in riffle boxes. At least two of the tanks used at the gold mine still hold water, a tribute to their builders nearly 2000 years ago.

“	Gangadia or quartzite is considered the hardest of all things—except for the greed for gold, which is even more stubborn.	”
—Pliny was famously scathing about the search for precious metals and gemstones.

Quotations

Some of Pliny's most famous adages^{[citation needed]} include:

Among these things, one thing seems certain – that nothing certain exists and that there is nothing more pitiful or more presumptuous than man.

Because of a curious disease of the human mind, it pleases us to enshrine in history records of bloodshed and slaughter, so that those ignorant of the facts of the world may become acquainted with the crimes of mankind.

See also

• Dolaucothi
• Hierapolis sawmill
• Las Médulas
• List of Roman watermills
• Mining
• Naturales quaestiones
• Pliny the Younger
• Roman agriculture
• Roman art
• Roman architecture
• Roman aqueducts
• Roman engineering
• Roman mining
• Roman sculpture
• Roman technology
• Theophrastus
• Johann and Wendelin of Speyer

References

1. ^ "XXXVII.77". Natural History. 
2. ^ xxxiii.154–751
3. ^ xxxiv
4. ^ xxxv.15–941
5. ^ 151–851
6. ^ xxxvi
7. ^ xxxvii
8. ^ Praef. 21
9. ^ N.H. 35.80
10. ^ Pliny the Younger. "viii.20, ix.33". Letters. 
11. ^ Pliny the Elder. "ii.209, ix.26". Natural History. 
12. ^ Pliny the Younger. "III.5". Letters. 
13. ^ Epp. 103, Jaffé
14. ^ Available at the [1] University of Chicago site
15. ^ Pliny the Younger (1894). "xxviii. c.23". Natural History. http://books.google.com/?id=R5QVAAAAYAAJ&pg=PA262&lpg=PA262&dq=hailstorms+whirlwinds+and+lightnings+will+even+be+scared+away+by+a+woman+uncovering+her+body#v=onepage&q&f=false. 
16. ^ N.H. 33.21

Bibliography

• Burnham, Barry C. (1997). "Roman Mining at Dolaucothi: the Implications of the 1991-3 Excavations near the Carreg Pumsaint". Britannia (Britannia, Vol. 28) 28: 325–336. doi:10.2307/526771. JSTOR 526771. 
• French, Roger and Greenaway, Frank, Science in the Early Roman Empire: Pliny the Elder, his Sources and Influence, Croom Helm (1986).
• Healy, John F. (1999). Pliny the Elder on science and technology. Oxford University Press. ISBN 0198146876. 
• Hodge, A.T. (2001). Roman Aqueducts & Water Supply (2 ed.). London: Duckworth. 
• Isager, Jacob (1991). Pliny on Art and Society: The Elder Pliny's Chapters on the History of Art. London & New York: Routledge. ISBN 0-415-06950-5. 
• Jones, G.D.B.; I.J. Blakey; E.C.F. MacPherson (1960). "Dolaucothi: the Roman aqueduct". Bulletin of the Board of Celtic Studies 19: 71–84 and plates III–V. 
• Jones, R. F. J.; Bird, D. G. (1972). "Roman gold-mining in north-west Spain, II: Workings on the Rio Duerna". Journal of Roman Studies (The Journal of Roman Studies, Vol. 62) 62: 59–74. doi:10.2307/298927. JSTOR 298927. 
• Lewis, P. R. (1977). The Ogofau roman gold mines at Dolaucothi. The National Trust year book 1976–77. Llandeilo: The National Trust. 
• Lewis, P. R.; Jones, G. D. B. (1969). "The Dolaucothi gold mines, I: the surface evidence". The Antiquaries Journal 49 (2): 244–72. 
• Lewis, P. R.; Jones, G. D. B. (1970). "Roman gold-mining in north-west Spain". Journal of Roman Studies (The Journal of Roman Studies, Vol. 60) 60: 169–85. doi:10.2307/299421. JSTOR 299421. 
• H. Rackham, W.H.S. Jones & D.E. Eichholz (translators), Pliny – Natural History, 10 volumes, Loeb Classical Library, 1938–1962.
• Wethered, H. N. (1937). The Mind of the Ancient World: A Consideration of Pliny's Natural History. London: Longmans Green. 

External links

Text

• Complete Latin text at LacusCurtius
• Complete Latin text with translation tools at the Perseus Digital Library
• First English translation, by Philemon Holland, 1601
• Second English translation, by John Bostock and H. T. Riley, 1855; complete, including index
• Free audio book version of the English translation by J. Bostock and H. T. Riley, from LibriVox (incomplete)

Secondary material

• Pliny the Elder: rampant credulist, rational skeptic, or both? from the Skeptical Inquirer

 This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press. 

• Chapter summaries
• Life and career
• Pliny's Natural history