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* जिंक metal is included in most single tablet over-the-counter daily vitamin and mineral supplements. It is believed to possess anti-oxidant properties, which protect against premature aging of the skin and muscles of the body. In larger amounts, taken as जिंक alone in other proprietaries, it is believed by some to speed up the healing process after an injury. Preparations include [[जिंक acetate]] and [[जिंक gluconate]].
* [[जिंक gluconate glycine]] and [[जिंक acetate]] are also used in [[throat lozenge]]s or [[tablet]]s to reduce the duration and the severity of cold symptoms.<ref>Ananda S. Prasad, MD, PhD; James T. Fitzgerald, PhD; Bin Bao, MD, PhD; Frances W.J. Beck, PhD; and Pranatharthi H. Chandrasekar, MD. "Duration of Symptoms and Plasma Cytokine Levels in Patients with the Common Cold Treated with जिंक Acetate: A Randomized, Double-Blind, Placebo-Controlled Trial." Annals of Internal Medicine [http://www.annals.org/cgi/reprint/133/4/245.pdf]</ref>
== इतिहास ==
प्राचीन भारतय् जिंकयु शोधनज्या सिक्क हे येक्व जुगु खने दु। Many mine sites of [[Zawarmaala]] were active even during 1300-1000 BC. There are references of medicinal uses of zinc in the [[Charaka Samhita]] (300 BC). The [[Rasaratna Samuccaya]] (800 AD) explains the existence of two types of ores for zinc metal, one of which is ideal for metal extraction while the other is used for medicinal purpose.<ref>http://metalrg.iisc.ernet.in/~wootz/heritage/zn.html</ref> Zinc alloys have been used for centuries, as brass goods dating to [[1000s BC|1000]]–[[1400s BC|1400 BC]] have been found in [[Israel (region)|Israel]] and zinc objects with 87% zinc have been found in prehistoric [[Transylvania]]. Because of the low boiling point and high chemical reactivity of this metal (isolated zinc would tend to go up the chimney rather than be captured), the true nature of this metal was not understood in ancient times.
The manufacture of [[brass]] was known to the [[Ancient Rome|Ebi]] by about [[30 BC]], using a technique where [[Calamine (mineral)|calamine]] and [[copper]] were heated together in a crucible. The [[zinc oxide]]s in calamine were reduced, and the free zinc metal was trapped by the copper, forming an [[alloy]]. The resulting [[calamine brass]] was either cast or hammered into shape.
Smelting and extraction of impure forms of zinc was accomplished as early as [[1000]] AD in [[India]] and [[China]]. In the West, impure zinc as a remnant in melting ovens was known since Antiquity, but usually discarded as worthless. Strabo mentions it as ''pseudo-arguros'' — "mock silver". The [[Berne zinc tablet]] is a votive plaque dating to [[Roman Gaul]], probably made from such zinc remnants.
=== Metallic zinc in the West ===
The English metallurgist Libavius received in 1597 a quantity of zinc metal in its pure form, which was unknown in the West before then. Libavius identified it as Indian/Malabar lead. [[Paracelsus]] ([[1516]]) was credited with the name "zinc". It was regularly imported to [[Europe]] from the orint in the [[17th century]], but was at times very expensive.
The isolation of metallic zinc in the West may have been acheived independently by several people:
* Dr [[John Lane]] is said to have carried out experiments, probably at [[Landore]], prior to his bankruptcy in [[1726]]. [[Postlewayt]]'s Universal Dictionary, the most authentic source of all technological information in Europe, did not mention zinc before 1751.
* In [[1738]], [[William Champion (metallurgist)|William Champion]] patented in [[Kingdom of Great Britain|Great Britain]] a process to extract zinc from calamine in a smelter, using a technology somewhat similar to that used at Zawar zinc mines in [[Rajasthan]]. However, there is no evidence that he visited the orient.<ref>Rhys Jenkins, 'The Zionc Industry in England: the early years up to 1850' ''Transactions of the Newcomen Society'' 25 (1945-7), 41-52. </ref>
* The discovery of pure metallic zinc is also often credited to the German [[Andreas Sigismund Marggraf|Andreas Marggraf]], in the year [[1746]], though the whole story is disputed.{{Fact|date=February 2007}}
Before the discovery of the [[zinc sulfide]] [[flotation process|flotation]] technique, [[calamine]] was the mineral source of zinc metal.
[[किपा:Foodstuff-containing-Zinc.jpg|thumb|250px|Foods and spices that contain the essential mineral zinc]]
== Biological role ==
Zinc is an essential element, necessary for sustaining all life. It is estimated that 3000 of the hundreds of thousands of proteins in the human body contain zinc [[prosthetic groups]], one type of which is the so-called [[zinc finger]].{{Fact|date=February 2007}} In addition, there are over a dozen types of cells in the human body that secrete zinc ions, and the roles of these secreted zinc signals in medicine and health are now being actively studied. Intriguingly, brain cells in the mammalian forebrain are one type of cell that secretes zinc, along with its other neuronal messenger substances. Cells in the salivary gland, prostate, immune system and intestine are other types that secrete zinc.{{Fact|date=February 2007}}
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