"By 3000 BCE the Sumerians, perhaps while heating copper to make it more malleable, had discovered that more copper could be retrieved from the fire if the metal were heated with certain types of dirt and stones—that is, certain earths. These earths were the metal s, and the process they discovered, ', reduced metal salts to pure metal by the action of in the fire. The process of changing metal salts into pure metal is known as reduction because the metal without the accompanying oxygen, , or of the salt weighs less than the ore. Eventually metal workers learned to distinguish various metal-bearing ores by color, texture, weight, flame color, or smell when heated (such as garlic odor of ores) and they could produce a desired material on demand."
Quote Details
Added by wikiquote-import-bot
Unverified quote
0 likes
Original Language: English
Available Languages (1)
Sources
Cathy Cobb, Harold Goldwhite, Creations of Fire: Chemistry's Lively History from Alchemy to the Atomic Age (1995) p. 8.
https://en.wikiquote.org/wiki/Earth_(historical_chemistry)
Revision History
No revisions have been submitted for this quote.
Categories
Earth (historical chemistry)
50 quotes on TrueQuotesView all quotes by Earth (historical chemistry) →
Related Quotes
"The Earths are white, inodorous, tasteless, and uninflammable substances—non-conductors of electricity, insoluble in …"
"What made silica so interesting was that... it did not seem to follow the established rules of chemical combination. …"
"Earth is one of the four simple substances called elements, or primitive principles; because they are indeed the most…"
"These general considerations are sufficient to convince us, that in nature a substance exists whose properties are di…"
"Earth is not found so pure as the other elements, fire, air, and water, which, though not entirely free from mixture,…"
"But we cannot say the same of earth; for a considerable number of substances are called earths, because they possess …"
"The most general and most probable opinion is, that as only one kind of fire, of air, and of water, so only one kind …"
"Some of the best philosophical chemists have rather chose to admit different kinds of elementary earths, than to inve…"
"Mr. Pott, examining the principal natural earths, divides them into four kinds, the vitrifiable, the , the argillaceo…"
"Pliny recorded processes involving metals, salts, , glass, mortar, soot, ash, and a large variety of s, earths, and s…"