Some eighteenth-century metals

Centuries before zinc was discovered in the metallic form, its ores were used for making brass. 

Strabo of Amasia, Asia Minor (66 B.C.-24 A.D.), said in his geography that only the Cyprian ore contained the cadmian stone, copper vitriol, and tutty, that is to say, die constituents from which brass can be made (90). He also mentioned a stone in die neighbourhood of Andeira which, when burned, becomes iron, and then, when heated in a furnace witii a certain earth, distils mocksilver [zinc] and this, with the addition of copper, makes the mixture, as it is called, which by some is called mountain-copper [orichalcum, or brass] (91). 

The Romans manufactured a copper-zinc alloy which they called orichalcum or aurichalcum. In speaking of copper, Pliny the Elder 

Metallic Zinc. Ancient metallurgists probably lost the volatile zinc metal as vapor because their apparatus was not designed for condensing it. E. O. von Lippmann, a great authority on the history of science, searched the writings of Aristotle, Plmy, and Dioscorides in vain for any mention of it, but an idol containing 87 5 per cent of that metal was found in a prehistoric Dacian ruin at Dordosch, Transylvania (2). 

According to the Rasarnava, which was published in India in the thirteenth century A.D., metallic zinc was prepared by reducing calamine in a closed crucible with organic substances such as lac or wool (94). P. C. Ray stated that the Hindu king, Madanapala, recognized zinc as a metal as early as 1374 ( 3), and it is probable that the art of smelting the ores originated m India and was carried first to China. 

---

The use of charcoal in steel making thus has a long history. Yet it was not until the eighteenth century that steel s key additive -carbon - was identified. Since charcoal was traditionally used to smelt iron from its ore, some carbon was always incorporated into the metallic product by chance. But the proportion of carbon... 

Photoinitiated electron transfer reactions are among the earliest photochemical reactions documented in the chemical literature and (ground state) electron donor-acceptor interactions have been known for over one hundred years. Some aspects of plant photosynthesis were already known to Priestly in the eighteenth century. The photooxidation of oxalic acid by metal ions in aqueous solution was discovered by Seekamp (UVI) in 1803 and by Dobereiner (Fe,n) in 1830. The electron donor-acceptor interactions between aromatic hydrocarbons and picric acid were noticed by Fritzsche in the 1850s the quinhydrones are even older,... 

But wait a minute, dear readers. Those of you who have had some high-school chemistry realize that solubilities of alcohol and salt in water are physical properties while solubilities of metals in acids are chemical properties. You would not have received a good grade from me for confusing the two. Clearly, the differences were not yet fully clear to early eighteenth-century scientists. 

The various foregoing records should in some measure bear testimony to the claim of alchemy to be a physical science based on an inner knowledge of the properties of metals. Casanova s description of St. Germain alone is evidence that as recently as the latter part of the eighteenth century, at any rate, a method of preparing a physical Stone, capable of transmuting metals and curing disease was in practice. 

---