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This list excludes tools and tool use attributed to non-hominin species. See Tool use by non-humans. Since there are far too many hominin tool sites to list on a single page, this page attempts to list the 6 or fewer top candidates for oldest tool site within each significant geographic area.
Berthollet first produced a modern bleaching liquid in 1789 by passing chlorine gas through a solution of sodium carbonate – the result was a weak solution of sodium hypochlorite. Another strong chlorine oxidant and bleach which he investigated and was the first to produce, potassium chlorate (KClO 3 ), is known as Berthollet's Salt.
The oldest known iron objects used by humans are some beads of meteoric iron, made in Egypt in about 4000 BC. The discovery of smelting around 3000 BC led to the start of the Iron Age around 1200 BC [15] and the prominent use of iron for tools and weapons. [16] Recognised as an element by Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy ...
1625 – First description of hydrogen by Johann Baptista van Helmont. First to use the word "gas". 1650 – Turquet de Mayerne obtains a gas or "inflammable air" by the action of dilute sulphuric acid on iron. 1662 – Boyle's law (gas law relating pressure and volume). 1670 – Robert Boyle produces hydrogen by reacting metals with acid.
This validated his belief that air/gas has mass, creating pressure on things around it. The discovery helped bring Torricelli to the following conclusion: We live submerged at the bottom of an ocean of the element air, which by unquestioned experiments is known to have weight. This test was essentially the first documented pressure gauge.
It was first used to describe applied arts, but it is now used to describe advancements and changes that affect the environment around us. [ 1 ] New knowledge has enabled people to create new tools, and conversely, many scientific endeavors are made possible by new technologies , for example scientific instruments which allow us to study nature ...
The Greek philosopher Empedocles (c. 450 BC) was the first to propose the four classical elements as a set: fire, earth, air, and water. [9] He called them the four "roots" (ῥιζώματα, rhizōmata). Empedocles also proved (at least to his own satisfaction) that air was a separate substance by observing that a bucket inverted in water did ...
Stone tool use – early human (hominid) use of stone tool technology, such as the hand axe, was similar to that of primates, which is found to be limited to the intelligence levels of modern children aged 3 to 5 years. Ancestors of homo sapiens (modern man) used stone tools as follows: Homo habilis ("handy man") – first "homo" species.