Naturalis Historia (Latin for "Natural History") is an encyclopedia written circa AD 77 by Pliny the Elder. It is one of the largest single works to have survived from the Roman empire to the modern day, and was one of the first reference works developed in the Classical period to examine natural and man-made objects, both organic and mineral, as well as many natural phenomena. It 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 was dedicated to Titus. It is the only work by Pliny to have survived.
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 possibly 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 (viii. 20, ix. 33), has apparently forgotten that both are to be found in his uncle's work (ii. 209, ix. 26). 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."
The possible absence of the author's final revision may partly account for many repetitions, and 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.
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).
The scheme of his great work is 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
And he admits the problems of writing such a work:
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.
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.
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.
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:
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.
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 which 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.
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 diatribe about the greed for gold, such as the "criminal act" of first 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. However, 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. And 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.
Gold is the most resistant of all materials to heat and corrosive fluids, so worthy of its high status. Given its 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.
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
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, most 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 method of that metal. He says mercury is used for gilding copper. Antimony is found in silver mines, and is used as an eyebrow cosmetic. 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 which were as tall as towers; the most famous being the Colossus of Rhodes. He personally saw the massive statue of Nero in Rome, but 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:
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.
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 presumable 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 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.
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.
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.
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 connexion with architecture, which was included in his Disciplinae.
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, and 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 text books of Xenocrates and on the biographies of Duris and Antigonus. He shows no special aptitude for art criticism; in several passages, however, 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.
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.
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 bath-house 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 (river) 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.
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 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.
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.
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.
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 Hollands 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.
Some research on Pliny has concentrated on the investigation of his authorities, especially those which he followed in his chapters on the history of art - the only ancient account of that subject which has survived. One artwork in particular inspired many artists in the Renaissance when it was rediscovered: Laocoön and his Sons. It was the same statue described by Pliny, and which was probably originally commissioned for the home of a wealthy Roman. It was unearthed in 1506 near the site of the Golden House of the Emperor Nero (who reigned from 54 to 68 AD), and it is possible that the statue belonged to Nero himself. It was acquired by Pope Julius II, an enthusiastic classicist, soon after its discovery and was placed in the Belvedere Gardens at the Vatican, now part of the Vatican Museums.
When the statue was discovered, Laocoön's right arm was missing, along with part of the hand of one child and the right arm of the other. Artists and connoisseurs debated how the missing parts should be interpreted. Michelangelo suggested that the missing right arms were originally bent back over the shoulder. Others, however, believed it was more appropriate to show the right arms extended outwards in a heroic gesture. The Pope held an informal contest among sculptors to make replacement right arms, which was judged by Raphael. The winner, in the outstretched position, was attached to the statue. In 1957, however, the original right arm of Laocoön himself, with a snake coiled about his wrist, was found by L. Pollack in a builder's yard in Rome, and was in the position which had been suggested by Michelangelo. The arm has now been rejoined to the statue.
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.