Name Robert Porrett | Died 1868 | |
Robert Porrett (1783–1868) was an English amateur chemist and antiquary.
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Life
The son of Robert Porrett, ordnance storekeeper at the Tower of London, he was born in London on 22 September 1783. He began work in his father's department as an assistant. He was appointed in 1795, promoted later to be chief of his department, and retired on a pension in 1850, when his services received official acknowledgment. He died on 25 November 1868, unmarried. Robert Collier, 1st Baron Monkswell was his nephew.
Works
Porrett was elected Fellow of the Society of Antiquaries of London on 9 January 1840, and Fellow of the Royal Society in 1848. He was an original fellow of the Chemical Society, and also a fellow of the Astronomical Society. He was an authority on armour, on which he contributed several papers to Archæologia and the Proceedings of the Society of Antiquaries. His subordinate at the Tower, John Hewitt, was encouraged to take an interest in the national collection of arms and armour there, and produced a pioneering guide.
Chemist
In chemistry, towards the end of 1808, Porret found that by treating prussic acid with sulphuretted hydrogen a new acid was formed, which he first termed prussous acid. For this investigation he was awarded a medal by the Society of Arts. In 1814 he discovered the qualitative composition of the acid, and showed that it was formed by the union of prussic acid and sulphur, and termed it "sulphuretted chyazic acid". The later name "sulpho-cyanic acid" was given by Thomas Thomson,and its quantitative composition was determined in 1820 by Berzelius.
In 1814 Porrett also made the discovery of ferrocyanic acid, which he termed "ferruretted chyazic acid". He showed by the electrolysis of the salts, then known as triple prussiates, and by the isolation of the acid itself, that the iron contained in the salts must be regarded as forming part of the acid, thus confirming a suggestion previously put forward by Claude Louis Berthollet. He examined the properties of the acid, and showed that it can easily be oxidised by the air, Prussian blue being formed at the same time; this observation was later utilised in dyeing.
Porrett attempted to determine the quantitative composition of prussic acid: he showed that when it is oxidised the volume of carbonic acid formed is exactly twice that of nitrogen, but his other data were erroneous. The problem was solved shortly by Joseph Louis Gay-Lussac. Porrett in 1813 made experiments with Rupert Kirk and William Wilson on the dangerous substance chloride of nitrogen.
His Observations on the Flame of a Candle (1816) supported Humphry Davy's view of the structure of flames. According to Porrett, the light is mainly due to free carbon formed in the flame by the decomposition of hydrocarbons.
Physicist
Porrett's contribution to physics was the discovery of electric endosmosis in 1816. The phenomenon had, according to Gustav Heinrich Wiedemann (Galvanismus und Elektricität, 1st ed. i. 376), been observed previously by Ferdinand Friedrich von Reuss, but Porrett's discovery was independent, and the phenomenon for a period went in Germany by his name.
Publications
The following is a list of Porrett's scientific papers:
In Nicholson's Journal:
In Philosophical Transactions:
In Thomson's Annals of Philosophy:
In the Chemical Society's Memoirs: