You Can Call Me Al
Aluminium, despite being the third most abundant element on the earth’s crust after oxygen and silicon, and the second most used metal after iron, is, curiously, one of the more recently discovered metals. Chemically bound to other ores, particularly bauxite, it is not found in its purest form naturally. However, alums, hydrated salts containing aluminium and sulphur, have been used for almost five thousand years as a mordant to fix dyes, to preserve leathers, for dressing wounds, and as an early form of deodorant.
When, in 1750, Andreas Margraff developed an alum without sulphur, scientists began to speculate whether there was a previously undiscovered base metal within it, tentatively named “alumine” by Guyton de Morveau in 1761. These suspicions were not confirmed until 1807 when Humphrey Davy used his newly developed electrolysis process to try to isolate aluminium from its mineral source.
Although he failed in his objective, he wrote in a paper published in the Royal Society’s Philosphical Transactions the following year that “had I been so fortunate as to have obtained more certain evidences on this subject, and to have procured the metallic substances I was in search of, I should have proposed for them the names of silicium, alumium, zirconium, and glucium”.
By the time he penned his Elements of Chemical Philosophy in 1812 Davy was calling it aluminum, a name that the Americans use to this day. The suffix -um rather than the more pleasing -ium offended the classically trained sensibilities of the British scientific community, who coined “aluminium”, a term first appearing in the Royal Society’s review of Davy’s experiments in 1811 and used this side of the Atlantic ever since.
Davy’s dream of producing a sample of elemental aluminium was realised in 1825 by Hans Christian Ørsted, although it was too small to conduct even the most basic analysis on and his methodology was difficult to replicate. It took until 1845 for Fredrich Wőhler to produce a “grey metallic powder…[with] small tin-white globules [of aluminium], some as large as pins’ heads”, by heating potassium and aluminium chloride together.
By 1854 Henri Deville, a French chemist, had developed a chemical process for extracting aluminium from bauxite, an expensive process which yielded small quantities of metal, leading him to lament that “every clay bank is a mine of aluminium, and the metal is as costly as silver”. It was even more expensive than that, its use reserved for ostentatious displays such as the aluminium breastplate, spoons, and baby’s rattle commissioned by Napoleon III, and the 100-ounce aluminium pyramid at the tip of the Washington Monument.
Siblings Charles and Julia Hall, intrigued by Deville’s methodology, thought that harnessing the power of the industrial-sized batteries that were now available through electrolysis would produce larger quantities of aluminium more cheaply than Deville’s chemical separation method. They were right, Charles producing marble-sized pellets of aluminium on February 23, 1886, by running an electric current through a solution of aluminium oxide mixed with melted cryolite would ease the process of extracting aluminium and bring down its cost.
