The Platinum Group Metals and Other Discoveries
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PARA QU ITARLE EL POLVO La química en la historia, para la enseñanza. William Hyde Wollaston The platinum group metals and other discoveries Jaime Wisniak Resumen Reverend Francis Wollaston (rector of East Dereham) and William Hyde Wollaston (1766-1828), inicialmente educado Althea Hyde. como médico, fue uno de los más consumados químicos de In 1762, his father with his wife and newborn son, Francis su tiempo. Nos dejó importantes contribuciones en un am- John, moved from London to become rector of the parish in plio rango de actividades: patología, fisiología, química, East Dereham, a village 16 miles from Norwich. The Wollas- electroquímica, óptica, mineralogía, cristalografía, electrici- tons were a distinguished, well to do and well known family dad, mecánica y botánica. Wollaston desarrolló el primer in ecclesiastical, medical, and scientific circles. Great grand- método viable para aislar el platino y hacerlo dúctil, descu - father William, a distinguished clergyman, had published a brió el paladio y el rodio, desarrolló una regla de cálculo para book The Religion of Nature Delineated (Wollaston, 1722) in 1722 calcular equivalentes. Introdujo un prisma que lleva su nom- which went through many editions, and his reputation was bre, un goniómetro reflexivo para medir los ángulos de un one reason why the younger William preferred to use Wil - cristal, demostró que el agente de la electricidad de fricción liam Hyde in all official literature. Francis’s younger brother, es el mismo que el de la pila, introdujo un refractómetro de George, became a clergyman and fellow of the Royal Soci- lectura directa y desarrolló lentes para usos ópticos. Además, ety, while another brother, Charlton, practiced medicine at estudió los cálculos biliares e identificó la cistina. Bury St. Edmunds and in 1764 was appointed Physician-in- Ordinary of Queen Charlotte (1744-1818; consort of George Abstract III). From East Dereham the family moved to Chislehurst, William Hyde Wollaston (1766-1828), initially educated as a Kent, where in 1777 Francis served as precentor of St. David’s physician, was one of the most accomplished chemists of his and in 1779 rector of the united parishes of St. Vedast, Foster time. He left us with significant contributions in a wide range Lane, and St. Michael-le-Querne, Aldersgate, Kent, until is of activities: pathology, physiology, chemistry, electrochem- death in 1815. Despite the load of domestic and parochial istry, optics, mineralogy, crystallography, astronomy, elec- duties, Francis Wollaston wrote on theological topics, be- tricity, mechanics, and botany. He developed the first viable came Fellow of the Royal Society, practiced as an amateur method for isolating platinum and making it malleable, he astronomer, compiled a catalogue of circumpolar stars (Wol- discovered palladium and rhodium, developed a slide rule laston, 1800) and with a barometer and thermometer col- for calculating the chemical equivalents, introduced a prism lected data for obtaining mean monthly weather readings that carries his name, a reflective goniometer for the meas - throughout the year based on his own observations (King, urement of crystal angles, demonstrated that the agent of 1954). frictional electricity was the same as that in a pile, introduced At the age of six William Hyde was sent to a private a direct reading refractometer, and developed glasses for school at Lewisham, London, and two years afterwards to different optical use. He studied urinary calculi and identi- Chartehouse School (then located in London), a school fied cystine. situated a few minutes away from his grand parents home, for a further four years of education. On July 6, 1782 he was admitted as pensioner of Gonville & Caius College, Cam - Life and career (Cragg, 1966; Gilbert, 1952; Halsted, bridge, to study medicine. He was appointed a senior fellow 1849; King, 1954; Wayling, 1927) of the College in 1787, a fellowship, which he retained until William Hyde Wollaston (Figures 1 and 3) was born on his death. He received his Medicine Bachelor degree in 1787 August 6, 1766 in East Dereham Norfolk, the third son of and Medicine Doctor in 1793, having waited the stipulated five years. He was also Tancred student, held the offices of Greek and Hebrew lecturer, and was repeatedly appointed * Department of Chemical Engineering, Ben-Gurion University of the to make the Thurston speech. At Cambridge, Wollaston Negev, Beer-Sheva, Israel 84105. attended lectures in astronomy and mathematics. Among his Recibido: 3 de agosto de 2005; aceptado: 5 de septiembre de 2005. classmates in the course of Astronomy were John Brinkley 130 Educación Química 17[2] PARA QUITARLE EL POLVO (1766-1835), who would become Astronomer Royal for Ire - scientists in those land, and John Pond (1767-1836), who would be appointed days. Astronomer Royal at Greenwich, in succession to Neville In 1800 Wollas- Maskelyne (1732-1811) (King, 1954). George Peacock (1791- ton formed a secret 1858) says that Wollaston “was a good geometer, a good partnership with optician, and thorough master of mechanical principles, as Smithson Tennant far as his limited knowledge of analysis would enable him to (1761-1815), another apply them” (Peacock, 1855). non-practicing physi- In 1787 Wollaston moved to London to forward his cian of independent medical studies by attending lectures and walking the hospi- means with who he tals, and eventually, in 1789, he took up practice for only a had become friend at few months at Huntington. From there he moved to Bury St. Cambridge, to share Edmunds where his uncle, Dr. Charlton Wollaston, had expenses and in- practiced. Here he met the Rev. Henry Halsted (1771-1852), come from chemical fellow of Christ’s College, Cambridge, who became a life- manufacturing busi- long friend. Years after Wollaston’s death, Halsted would ness. One of the first write his biography and give personal information about enterprises they ad- their friendship (Halsted, 1849). On May 9, 1793, Wollaston dressed to was the Figure 1. William Hyde Wollaston (1766- was elected Fellow of the Royal Society. His certificate possibility of manu- 1828). describes him as “William Hyde Wollaston, of Huntington, facturing malleable doctor in physics, of the University of Cambridge”, and has platinum. They were aware that if they succeeded, malle- 13 names attached to it, among which appears Henry able platinum could replace gold in a number of applications Cavendish (1731-1810), William Herschel (1738-1822), and where an inert, noble metal was required. Many scientists two Wollastons, his father and his uncle. On March 30, 1795, had recognized the commercial market for malleable plati- Wollaston became Fellow of the Royal College of Physicians, num before, but none had succeeded in developing a satis - of which he became censor in 1798 and member on February factory commercial procedure. Within five years Wollaston 13, 1824, after the death of James Harvey (King, 1954). had discovered a process for producing pure platinum and In 1797, after several lucrative years as a physician in for rendering it malleable (Wollaston, 1809a; 1829). Briefly Huntington and Bury St. Edmunds, he moved to London the process took place by dissolving native platinum in aqua where he set up practice at 18 Cecil Street, Strand. Here he regia, precipitating ammonium chloroplatinate with ammo- wrote his first paper (Wollaston, 1798) for the Royal Society, nium chloride, decomposing it by heat, washing the finely dealing with gouty and urinary concretions; an investigation divided residue of platinum, compressing the moist pow- of the chemical composition of calculi, which resulted in the der, beating while hot and hammering to an ingot which discovery by Wollaston, of cystic oxide, now called cystine. could be beaten into foil or drawn into wire. This method About the same time he became a candidate for the post of was the first application of powder metallurgy. Wollaston physician to St. George’s Hospital but was defeated by the showed that very fine wires of platinum could be drawn election of his principal opponent, Dr. Pemberton. In 1800 inside a silver sheath and the silver afterwards dissolved Wollaston decided to retire from medical practice because off in dilute nitric acid. Using this method Wollaston was able he was over-sensitive about the conditions of his patients, to produce without difficulty wires of a diameter 0.00005 constant anxiety over their welfare made light work a heavy inches (Wollaston, 1813b). These wires, called Wollaston’s burden, and was deeply affected by trivial illnesses. In 1799 wires, are still made commercially by the same method, and his brother George, who had inherited the estate of their used as marks in optical instruments. mother’s heirless brother General West Hyde, gave him Platinum became a valuable commercial metal in 1805 £8000 in Bank of England stock and in 1801 his uncle when Wollaston began marketing it through William Cary Frederick, the Rector at Bury St. Edmunds, died and left him (1759-1825), an instrument maker in the Strand, London. The enough money, so that Wollaston, now without financial primary use of malleable platinum was in the making of worries, was at liberty to follow his scientific inclinations and vessels for the distillation of sulfuric acid. It was thus of great undertake private chemical research. In 1801 he purchased commercial value and earned Wollaston quite a sizable a house near Fitzroy Square, and at the back set up a fortune from various manufacturers (Cragg, 1966). Accord - laboratory. To equip and maintain a private laboratory and ing to King (King, 1954) in addition to this venture, royalties give private classes was a common activity among European on his other processes and inventions added considerably to Abril de 2006 131 PARA QU ITARLE EL POLVO Wollaston’s income so that at his death he was estimated By 1804 he had delivered a Bakerian Lecture, had been to be worth between £200,000 and £300,000.