Middle Ages

Several Europeans, while not alchemists themselves, contributed to setting the stage for modern chemistry. Albertus Magnus (1200-1280), also known as Albert the Great, played an important role in intro- 

Paracelsus attacked the established medical community of his time. His criticism was harsh, and he alienated many of his established fellow physicians with his bombastic writings. Yet, many of his practices were sound, and more importantly, those physicians who did ascribe to his practices achieved better results than when using traditional methods. Paracelsus works were not published and distributed widely until some twenty years after his death. By the end of the sixteenth century, Paracelsus methods had attracted a number of followers, and his methods formed the new basis of standard medical practice. Paracelsus followers became known as the iatrochem-ical physicians. They used a variety of drugs and treatments that depended on specific dosages of medicine prepared with specific purity. His ideas on chemical purity and for- 

Several other individuals made important contributions at about the same time as Paracelsus, ftuther establishing chymia as a science apart from alchemy. Vannoccio 

Woodcut print of chemical lecture from 1653. Small furnace sits on table and various glassware used for distillation rests on shelves above stove in background. Image from Edgar Fahs Smith Collection, University of Pennsylvania Library. 

By the start of the seventeenth century, the stage had been set for transformation in the study of chemistry. Up to this time, chemistry played a central role in the arts and crafts, but as a science, it had made only modest advances from the days of Aristotle. This started to change as individuals adopted a scientific approach and subjected the ideas of Aristotle to experimental testing. By 1700, the walls of unquestioned authority concerning scientific thought had been shattered by individuals such as Galileo, Isaac Newton, and Francis Bacon. The time was now ripe for rapid changes in the study of chemistry. 

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Of the various tempera, egg was the most important in European painting, both in wall and panel painting. It was Htde used outside Europe. The main period of its use was in the Middle Ages and early Renaissance. After the sixteenth century, however, it was rarely used, as drying oils (qv) had become the preeminent media. 

Gold [7440-57-5] Au, is presumably the first metal known and used by humans. It occurs ia nature as a highly pure metal and is treasured because of its color, its extraordinary ductility, and its resistance to corrosion. Early uses ia medicine and dentistry date to the ancient Chinese and Egyptians. In the Middle Ages the demand for gold led to the iatense, unsuccesshil efforts of alchemists to convert base metals iato gold. These pursuits became the basis for chemical science. The search for gold has been an important factor ia world exploration and the development of world trade. 

The first reported use of nickel [7440-02-0] Ni, was in a nickel—copper—2inc alloy produced in China in the Middle Ages and perhaps earlier. Alloys of nickel may have been used in prehistoric times. The metal was first isolated for analytical study in the mid-1700s by Axel Cronstedt, who named it nickel, which derives from the German word kupfemickel, or false copper. 

Before the invention of the Bessemer process for steelmaking in 1856, only the cementation and cmcible processes were of any industrial importance. Although both of the latter processes had been known in the ancient world, thek practice seems to have been abandoned in Europe before the Middle Ages. The cementation process was revived in Belgium around 1600, whereas the cmcible process was rediscovered in the British Isles in 1740. 

Through its committees, divisions, and chapters, the American Vacuum Society has produced a nearly complete bibhography (to 1996) (8), a dictionary of terms (9), a monograph series, and a number of other useful pubHcations (10). Another source of information is the Association of Vacuum Equipment Manufacturers. A history of vacuum ideas and technology development from the Middle Ages to Newton has been given (11). 

E. Grant, Much Mdo Mbout Nothing Theories of Space and Vacuum from the Middle Ages to the Scientific devolution, Cambridge University Press, New York, 1981. 

Cordials were said to be produced in ancient Egypt and Athens. Commercial production started in the Middle Ages when alchemists, physicians, and monks were searching for the "elixir of life." Many wek-known cordials were developed in this period, such as Benedictine and Chartreuse, both bearing the names of the monasteries where they were first developed. 

Bricks are the oldest manufactured building material in use. Sun-dried bricks were manufactured as eady as 6000 BC, and fired bricks were used during the Middle Ages. Today s bricks differ very Htde except in the efficiency of manufacture they ate stiU made from clay or shale, a clay-based sedimentary rock that is kiln-fired. 

A nobleman of the Middle Ages derived great pleasure from watching the mowing of his estate. Each month he would summon a mower from the nearby town and would then sit and watch the mowing. This typically took four hours. The nobleman reasoned that if he were to get two mowers, the mowing would be completed in two hours. This he verified the next month. He then reasoned that if he obtained the services of every mower in the country, the mowing would be completed within a matter of three seconds. 

Age Prehistoric and early days Ancient times Middle Ages Age of rationalism Modern Age ... 

Sulfur dioxide Bleached spots, bleached areas between veins, chlorosis insect injury, winter and drought conditions may cause similar markings Middle-aged leaves most sensitive oldest least sensitive Mesophyll cells 0.3 785 8 hr... 

Nifrogen dioxide Irregular, white or brown collapsed lesions on intercostal tissue and near leaf margin Middle-aged leaves most sensitive Mesophyll cells 2.5 4700 4 hr... 

Early records also indicate that cast mouldings were prepared from shellac by the ancient Indians. In Europe the use of sealing wax based on shellac can be traced back to the Middle Ages. The first patents for shellac mouldings were taken out in 1868. 

Figure 14.3. Portraits of Kotaro Honda as a young man and in middle age (courtesy of Reiner...

HgCl2 is the corrosive sublimate of antiquity, formerly obtained by sublimation from HgS04 and NaCl and used as an antiseptic. It is, however, a violent poison and was widely used as such in the Middle Ages. ... 

Thus in the presence of an excess of NH4+, which suppresses this forward reaction, and counteranions such as NOa" and C104, which have little tendency to coordinate, complexes such as [Hg(NH3)4] +, [Hg(L-L)2] + and even [Hg(L-L)3] + (L-L = en, bipy, phen) can be prepared. But, in the absence of such precautions, amino, or imino-compounds are likely to be formed, often together. Because of this variety of simultaneous reactions and their dependence on the precise conditions, many reactions between Hg and amines, although first performed by alchemists in the Middle Ages, remained obscure until the application of X-ray crystallography and, still more recently, spectroscopic techniques such as nmr, infrared and Raman. 

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