Vitruvius

Corrosion protection using bitumen coatings reaches back into antiquity. The most ancient occurrence of bitumen deposits was in Mesopotamia. Many writers of antiquity, such as Dido, Strabo, and Vitruvius, mention that asphalt was obtained for many years near Babylon. About 5000 yeare ago, the streets of Ur, capital of the Sumerians (north of present-day Kuwait), were lit at night with mineral oil. Natural gas was reported to be used for lighting in the Middle East and China. 

The Phoenicians were building water ducts and pipelines of clay, stone, or bronze about 1000 B.c. and the construction of long-distance water pipelines flourished in imperial Roman times. The water supply lines of Rome had a total length of about 450 km, and consisted mainly of open or covered water ducts. The Roman writer Vitruvius gives a fairly accurate description of the manufacture of lead pipes [8]. The pipes were above ground and were often laid beside the roadway or in ducts inside houses [9]. 

Marcus Vitruvius, architect and engineer under the Emperor Augustus, was familiar with the toxicity of lead and observed that the laborers in the smelters have pale complexions because of their prolonged exposure to lead dust and vapor (209). 

But whatever doubt may rest on this point, it te certain that the ancients, in later times at least, were acquainted with the method of extracting gold and silver from ths ores or earths by amalgamation, for this process te mentioned both by Vitruvius and Pliny, writers who lived about tho beginning of the Christian era and, indeed, it is described by Pliny in terms which show that it was practised nearly in the same manner ns at the present day. The mercury employed in this operation, meroly combines with the... 

Davy found that he could reproduce the blue glass above mentioned by fusing together fifteen parts of sodium carbonate, twenty parts powdered flint and three of copper filings. This is of interest in connection with a statement of Vitruvius to which reference will be made later. 

B. C.), Vitruvius, a Roman architect of the first century B. C., Dioscorides Pedanus, a Greek physician of the first century A. D., and the Elder Pliny, also of the first century A. D. Some brief allusions are contained also in the writings of Plato (died 347 B. C.), Aristotle (384-322 B. C.), Diodorus Siculus (about the first century B. C.), and Strabo, the geographer, though Dioscorides and Pliny have incorporated in their later writings the important facts of these writers. 

The allusions to Democritus by Vitruvius, writing a century or more before Pliny, seem to apply to the real Democritus. Vitruvius says he wrote several works on the nature of things. Seneca attributes to him the invention of the reverbatory furnace, and the art of imitating natural gems, particularly the emerald, though it is probable that here also the real Democritus is confused with the pseudo-Democritus. 

In the first century B. C., as nearly as the internal evidence of his writings establishes their date, a Roman architect, Vitruvius, wrote the work through which he is known, Ten Books on Architecture.SB... 

In the discussion of the materials used in various structures, and of pigments and colors used in their decorations, he often furnishes more specific information than is contained in earlier Greek or Latin writers. Pliny mentions him among his authorities and apparently cites him at times quite literally. It is also quite evident that Vitruvius does not always depend upon knowledge gained by personal observation or experience, but himself depends upon previous writers. In particular, it is evident that while he is familiar with the use of pigments, he is often dependent upon previous writers for his accounts of their sources and methods of preparation. He was, in other words, in no sense a practical chemist of the period. Nevertheless his contributions to our knowledge of the chemical arts of the time are valuable. 

The natural cement now known as Pozzuolan is clearly described by Vitruvius ... 

Gypsvun, lie says, should not he used in stucco, because it sets too rapidly and thus interferes with even drying. Vitruvius, like Theophrastus, uses the word gypsum not in the sense of the native mineral, but rather to indicate what we call the plaster of paris which is produced by its burning. ... 

The term minium, as used by Vitruvius, denotes the red sulphide of mercury or cinnabar. 

Four pints of quicksilver, says Vitruvius, will be found to weigh one hundred pounds.37... 

Pliny, a hundred years later, gives this process in much the same terms, but in place of the cloth (pannum), says skins that have been well tawed. It may well be that Vitruvius may have originally written pellem instead of pannum, and some later copyist may have ignorantly or inadvertently changed the word. 

It is interesting to note that neither Vitruvius nor Pliny mentions the further necessary step of driving off by heat the mercury from the amalgam which is separated from the liquid mercury by the process they describe. Though this necessarily was done, they may have been uninformed upon that detail. 

It may be recalled that Theophrastus uses the word cinnabar as we use it to-day, while Vitruvius uses the word minium to denote our cinnabar. There was much confusion in the writings of the ancients due to their difficulty in recognizing fundamental differences in many of the substances used as red pigments. So Vitruvius, still discussing his minium, explains that when used in... 

Assuming the sextarius to be 34.4 cubic inches, and the pondo centum to be 495,000 grains (Encycl. Brit, article, Weights and Measures ), the specific gravity of mercury would be from the data of Vitruvius 14.2 as against present value of 13.59, a fair approximation. The value of the libra or pound varied more or less at different times. The value above given may not have been exactly the one used by Vitruvius. 

Vitruvius gives a test for detecting adulterations or substitutions for minium by heating a sample upon an iron plate until the plate is red hot. When the heat makes the color change and turn black, remove the plate from the fire, and if the minium returns to its former color, it is unadulterated if it remains black, it is adulterated. 

Vitruvius knows of the formation of a red substance obtained by heating white lead, but calls it a kind of sanda-rach, not minium. 

Chrysocolla, Vitruvius says, is a green pigment brought from Macedonia and dug up in the vicinity of copper mines. As with Theophrastus, this is doubtless our malachite. Vitruvius states that those who cannot use chrysocolla on account of its cost employ a blue color (coeruleum) mixed with the plant called lutum, and obtain a very vivid green. Pliny also states this fact, but adds that it gives a very inferior color. 

Armenium, a blue pigment, merely alluded to by Vitruvius, is probably azurite, for Pliny says that armenium is a thinner color than coeruleum and very much cheaper. 

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