Mercury discovery

The discovery of aqua regia by the Arab alchemist Jabir Ibn Hayyan (ad 720—813) provided a new extraction technology. Amalgamation of silver in ores with mercury was extensively used during the late fifteenth century by the Spaniards in Mexico and BoLvia. In 1861 the complex ores of the Comstock Lode, Nevada, were ground together with mercury, salt, copper sulfate, and sulfuric acid, and then steam-heated to recover the silver. 

We return now to the mercuro-de-diazoniation. Nesmeyanov s school continued the work on metallo-de-diazoniations from 1929 to 1953 (see summary by Nesmeyanov, 1972). A major discovery was made at the very beginning, namely the influence of copper powder (Nesmeyanov, 1929 b Nesmeyanov and Kahn, 1929). With this addition metallic mercury was not required instead the double salt of the diazonium chloride and mercuric chloride was used. The copper reacts stoichiometrically as an electron donor. Therefore, either arylmercuric chlorides (Scheme 10-87) or diarylmercury compounds (Scheme 10-88) can be obtained. These reactions are called Nesmeyanov reactions. Specific examples are the syntheses of di-2-naphthyl-... 

Aurifontina chymica or, a collection of fourteen small treatises concerning the first matter of philosophers for the discovery of their (hitherto so much concealed) Mercury. Which many have studiously endeavoured to hide, but these to make manifest, for the benefit of mankind in general. London Printed for William Cooper, at the Pelican in Little-Britain, 1680. [22], 272, [4] p. 

Rasmussen, L.D., Zawadsky, C., Binnerup, S.J., Oregaard, G., Sprensen, S.J., and Kroer, N., Cultivation of hard-to-culture subsurface mercury-resistant bacteria and discovery of new merA gene sequences, Appl Environ Microbiol, 74 (12), 3795-3803, 2008. 

Why have companies been allowed to discharge mercury into rivers and lakes The reason is that the discovery of such high concentration levels was a surprise to nearly everyone. It was not until 1965 that a Swedish scientist discovered that inorganic mercury could be converted under natural conditions to methyl mercury. 10 Also, as has just been noted, it was not until very recently that a method for easily measuring mercury at very low levels was available. Once the danger was recognized in 1970, the industry responded very quickly. For instance, Dow Chemical reduced its discharge of mercury from 200 lb/day(90 kg/day) to 0.5 lb per day (0.25 kg/day) in less than 12 months.12... 

Further evidence for surface effects upon the stereochemistry of electrochemical reduction of ketones comes from the discovery that the nature of the cathode material may effect stereochemistry. Reduction of 2-methylcyclo-hexanone affords pure trans-2-methylcyclohexanone at mercury or lead cathodes, a mixture of cis and trans alcohols (mostly trans) at nickel, and pure cis alcohol at copper 81 >. Reduction could not be effected at platinum presumably hydrogen evolution takes place before the potential necessary for reduction of the ketone can be reached. 

The discovery of superconduction was made at Leiden University, by Heike Kamerlingh Onnes back in 1911 whilst experimenting with the electrical resistance of mercury, cooled to liquid helium temperature. His efforts were recognised with the Nobel Prise for Physics in 1913 and much later, a... 

The transit method requires that the central star, the planet and the observer are connected by a line of sight. The dark planet passes across the light source and thus diminishes its light intensity to some extent. Observation is only possible when observer, star and planet are in a favourable position, i.e., the planet lies between the star and the observer. In spite of this requirement, the method permits the discovery of planets of about the size of the Earth information is also available on the size, mass and density of the planet as well as on its orbit. Because of its limits of applicability, this method is not often used. In the case of the star OGLE-TR-56, it was possible to detect an extrasolar planet, the orbit of which is very close to its sun only a twentieth of the distance of Mercury away from it. The temperature of the planet was determined to be around 1,900 K its diameter is about 1.3 times larger than that of Jupiter, its density about 500 kg/m3 (Brown, 2003 Konacki, 2003). 

Voltammetry is a part of the repertoire of dynamic electrochemical techniques for the study of redox (reduction-oxidation) reactions through current-voltage relationships. Experimentally, the current response (i, the signal) is obtained by the applied voltage (.E, the excitation) in a suitable electrochemical cell. Polarography is a special form of voltammetry where redox reactions are studied with a dropping mercury electrode (DME). Polarography was the first dynamic electrochemical technique developed by J. Heyrovsky in 1922. He was awarded the Nobel Prize in Chemistry for this discovery. 

Mercury and nickel salts form many stable complexes with biologically important molecules such as those containing sulphydryl groups Chapter 5 stresses the importance and the dangers of these being formed in the skin from topical contact. The last 10 years have been a highly fertile and productive period in the discovery of antibacterial quinolones (reviewed in Chapter 6) which inhibit target enzymes at the molecular level. 

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