Talk:Claude Louis Berthollet

Assessment comment
Substituted at 11:51, 29 April 2016 (UTC)

Inconsistancy between articles
This article claims that C.L.Berthollet "first produced" sodium hypochlorite. Yet the article on sodium hypochlorite in the section Production/Chlorination of Soda states that Berthollet produced the potassium salt and it was Antoine Labarraque who first produced the sodium compound.

The book "Modern Inorganic Chemistry" by J.W.Mellor, Longmans 1917 states (page 283 et.seq.) that potassium hypochlorite was first produced by Berthollet at Javel a suburb of Paris in 1792 and was called "Eau de Javel". It also states that A.G. Labarraque replaced potassium with sodium in 1820 and this was called "Eau de Labarraque".

In "Präparative Chemie" Band I, by Ludwig Vanino, Ferdinand Enke, Stuttgart, 1925 (first published 1913) makes the same distinction (page 329 for NaOCl, page 372 for KOCl).

The French Wiki page (https://fr.wikipedia.org/wiki/Eau_de_Javel) gets it correct in the "Historique" section.

It is certainly true that Berthollet discovered the bleaching properties of potassium hypochlorite, since he communicated this to James Watt around about the same time and Watt brought this to Glasgow. In 1798 Charles Tennant applied for a patent which used lime instead of potash. This was declared void later since lime was used for the same purpose in Lancashire before the application was made. (Mellor page 285). Since the sodium compound was not in use before 1820 Berthollet had little to do with the sodium salt.

Incidentally in France "Eau de Javel" is exclusively the sodium salt.