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Edward Charles Howard – Explosives, Meteorites, and Sugar
Abstract
To Edward Charles Howard (1774-1816), a self-educated scientist without formal education in chemistry, we owe the (accidental) discovery of mercury fulminate, the finding that meteorites contain nickel and have a composition different from any material originated in the earth, and the design of the vacuum evaporator and other accessories that resulted in a substantial improvement in the economic balance of sugar production.
... Además, el Hg puede ser transformado a Hg orgánico, incluyendo el monometilmercurio (MeHg + ), lo que vamos a discutir a detalle más abajo. (Bakir et al., 1973;Das et al., 2008;Das et al., 2016;De Guise et al., 1995;Fitzgerald y Clarkson, 1991;Iqbal y Asmat, 2012;Lalancette et al., 2003;Lian et al., 2020;Lian et al., 2021;Rustagi y Singh, 2010;Van Hoomissen et al., 2015;Wujastyk, 2015 ). Además, la concentración de Hg orgánico en los tejidos biológicos está influenciada por muchos factores ecológicos importantes (estructura de la cadena alimentaria, hábitat de alimentación, etc) y biológicos (metabolismo, tasa de crecimiento, etc) que determinan las tasas de bioacumulación c y biomagnificación d de Hg (Barwick y Maher, 2003;Newman et al., 2015). ...
This work focuses on the historical and scientific investigation of a presumed meteorite fall that occurred in the Sicilian township of Marsala in 1834. Preliminary studies have classified this phenomenon as a “doubtful meteorite.” This term describes, according to the Nomenclature Committee of the Meteoritical Society, an object for which there was significant uncertainty over whether it was a real meteorite or, in some cases, whether it ever existed. Thanks to the analysis of untapped sources, the first objective of this work is to clarify the nature of the event. Subsequently, the results of the minero‐chemical analyses that were performed, in 1835, on two fragments recovered after the event are discussed for the first time. This work then shows the collecting history of one of the presumed meteorite specimens. Based on the results presented here, this work highlights the role of doubtful meteorites as a fundamental resource for the history of meteoritics and meteorite collecting as well as for studying the processes that have led to the scientific study of meteorites.
Edward Charles Howard, a notable chemist of the early nineteenth century, was a descendant of the patrician House that has for generations held the premier Dukedom of Norfolk, and the office of Earl Marshal of England. When, as a younger son, he took up an independent profession, his inclination decided him on a career in science. In his relatively brief career - he died at the early age of 42-Howard made original discoveries in three widely different fields of chemical research, each of which proved of lasting influence. In 1800, he discovered the highly explosive fulminates, an achievement that gained him the coveted Copley Medal of the Royal Society. He next demonstrated the characteristic nickel contentof meteorites, thus helping to establish their - so far controversial - cosmic origin. Over the next few years he effected a veritable revolution in sugar manufacturing by his invention of the vacuum evaporation technique and other fundamental improvements. Howard's seminal researches blazed a trail that was taken up to great effect by subsequent researchers and contributed significantly to the rise of the modern explosives industry and sugar manufacture. His outstanding record entitles him to an enduring place in the history of chemical science and technology.
On the 23th of April I learned, by a printed notice* sent to Mr. Knox, that a substance, which was announced as a new metal, was to be sold at Mr. Forster’s, in Gerrard-street. The mode adopted to make known a discovery of so much importance, without the name of any creditable person except the vender, appeared to me unusual in science, and was not calculated to inspire confidence. It was therefore with a view to detect what I conceived to be an imposition, that I procured a specimen, and undertook some experiments to learn its properties and nature. I had not proceeded very far, when I perceived that the effects produced by this substance, upon the various tests, were such as could not be referred, in toto , to any of the known metallic substances. I immediately returned to Mr. Forster, and became possessed of the whole quantity which had been left in his hands for sale. I could not obtain any information as to its natural state, or any trace that might lead to a probable conjecture.
The travels in which I have been employed, by order of our empress, since the year 1768, have interrupted the correspondence I had the pleasure to entertain with some of the Fellows of the Royal Society of London, particularly the worthy Mr. Collinson; and as this ingenious man, in the mean time, has left this world, I make so free as to address myself to you directly, for the leave of communicating from time to time, to the Royal Society, such observation or papers, which I am not bound to deliver to the Academy here. I would have before this observed that duty, to which the honour of being a foreign member of the Royal Society obliges me, had not the distance in which I have lived thees seven years, mostly out of Europe, and the troublesome manner of travelling in these countries, together with the distractions and duties of my employment, rendered it impossible.
We learn from the introduction to this paper, that mercury, and most, if not all, its oxides, may, by treatment with nitric acid and alcohol, be converted into a crystallized compound, possessing all the inflammable properties of gunpowder, as well as many others peculiar to itself. After stating the gradual steps by which he arrived at this discovery, Mr. Howard describes the following process and manipulations, which he found best calculated for producing this powder. One hundred grains, or a greater proportional quantity, of quicksilver, are to be dissolved with heat in a measured ounce and a half of nitric acid. This solution being poured cold upon two measured ounces of alcohol, a moderate heat is to be applied, until an effervescence is excited. A white fume then begins to undulate on the surface of the liquor, and the powder will be gradually precipitated Upon the cessation of action and re-action. This precipitate is to be immediately collected on a filter, well washed with distilled water, and carefully dried in a heat not much exceeding that of a water-bath. This immediate edulcoration of the powder is material, it being liable to the re-action of the nitric acid, which, while any of that acid adheres to it, renders it subject to the influence of light. The quantity of the powder produced varies according to the nature of the ingredients; 100 grains of quicksilver yielding from 120 to 132 grains of the compound.
The molecular structure of mercury fulminate was investigated at B3LYP level of theory using a large and a small core scalar relativistic pseudopotential for mercury. In accord with recent X-ray studies the connectivity in mercury fulminate is ONC–Hg–CNO and not CNO–Hg–ONC as previously predicted. Whereas mercury fulminate, ONC–Hg–CNO, has a C2 structure in the solid state with an Hg–C–N angle of 169°, as an isolated molecule it is perfectly linear and possesses D∞h symmetry. The VB structure which corresponds best to the calculated and observed bond lengths belongs to the type of increased-valence VB structures.