Hellot, Jean

Hellot, Jean (1685-1766) adjoint, 1735, pensionnaire surnumeraire 1739, pensionnaire 1743... 

Hellot, Jean, and others, The Art of Dyeing Wool, Silk, and Cotton, trans, from the French,... 

The French chemist Jean Hellot noticed that the tin smelters in Cornwall added natural bismuth, instead of the ingredients recommended m die pharmacopoeias, to make the tin haid and brilliant, and in 1737 he obtained bv fire assay of a cobalt-bismuth ore a button of the latter metal... 

Another of the early experimenters with phosphorus was the Abb6 J.-A. Nollet, who watched Jean Hellot and others demonstrate its properties before die French Academy of Sciences in 1737 (32). The procedure was described in detail in the Memoirs of the Academy of Sciences for that year and later in P.-J. Macquer s Elements of the Theory and Practice of Chymistry. Even in the eighteenth century, chemists had... 

Sympathetic Ink. Although die discovery of the cobalt sympathetic ink, which remains invisible until wanned, has often been attributed to Jean Hellot, who first made it known publicly, he was not the first person to prepare it. Hellot himself stated that a German artist of Stol-berg had shown him a reddish salt which, when exposed to heat, became blue. It had been prepared by dissolving Schneeberg cobalt in aqua regia (119). H. F. Teichmeyer of Jena was also familiar with this cobalt ink, perhaps even before Hellot made its composition public in 1737... 

Death of Caspar Neumann. Jean Hellot prepares a button of metallic bismuth and makes public the secret process for preparing phosphorus. 

In 1735, Jean Hellot prepared a salt from urine, which he regarded as a kind of gypsum F. G. Haupt described this salt in his Diatribe chemica de sale urines... 

The feebly basic oil that we now call aniline (1) was perhaps first handled, though not identified, during the 18th century by the French chemists and dye experts Jean Hellot... 

There is no translation into any other language but French and the book (which has no table of contents or index) could not compete with the more systematic ones of Beguin, Le Fevre, Glaser, and Lemery. The French versions differ considerably from the Latin the theoretical part is much abbreviated and the practical part extended and rearranged, and it is a much better book. How much of the alteration is due to the translator Jean Hellot (grandfather of the famous chemist Jean Hellot) is not clear the book makes use of very recent works, e.g. of Glauber. 

Jean Hellot (Paris 20 November 1685-15 February 1766) was intended for the church but an uncle interested him in chemistry. He was a pupil of E, F. Geoffroy. He visited England (he became F.R.S. in 1740). After his return to France he was elected to the Academy in 1735 member of various... 

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