Re: Litre

[Patrick Orvane <patorvan@xxxxxxxxxxxxxxxx>]

Jean Fontaine a écrit :

> Oui, le symbole officiel est « l », mais le SI tolère « L » à cause des
> confusions possibles. Mais pas de « l » minuscule cursif (hampe en forme de
> boucle), comme on voyait souvent (en Amérique, du moins).
>

Les abréviations d'unités prennent une majuscule dans le système internationnal
lorsque leur nom est dérivé de celui d'un scientifique célèbre.
Dans le cas contraire, la minuscule s'impose. Le litre ne doit pas déroger à
cette règle.
Ainsi, il y a déjà quelques années, sont parus les éléments de la désormais
nécessaire biographie de Jean-Baptiste Litre :-D

Claude Emile Jean-Baptiste Litre

As every scientist knows (or should know) the official abbreviation of the liter
is an uppercase L. To cope with the tradition that an uppercase letter comes
from the name of an author, K. A. Wolner relates in this paper the life and
works of the French instrument-maker Claude Emile Jean-Baptiste Litre
(1716-1778). Born in the village of Margaux in the Médoc region of France, and
the descendent of an old family of wine-bottle makers, Litre invented a series
of accurately graduated glasswares which became famous in all Europe, and
probably contributed to the success of Lavoisier, although they did not survive
the experiments of Humphry Davy, who made nitrogen trichloride [an explosive
compound] in them.

In his Etudes Volumétriques Litre had chosen, for his standard volume, a measure
very close to the old flacon royal of Henri IV, introduced in 1595 to
standardize the taxation of wine. However, he recognized the arbitrariness of
this unit, and suggested that in any rationalized system of units, volume
could be specified in terms of a standard mass of a standard liquid. He
suggested mercury. But Litre's dream of a rationalized system of units did not
start
to materialize until 15 years after his death, when the mathematician Lagrange
(1736-1813) was appointed to head a commission to draw up such a
system. And in 1795 the metric system was born. Litre's method of specifying
volume was adopted, although the commission decided to use distilled water
rather than mercury as the standard liquid. The chemist Antoine de Fourcroy
(1755-1809), who had studied instrument-making in Litre's factory before
his great work in nomenclature with Lavoisier, was apparently the first to
suggest that Litre's name be used for the unit of volume.


K. A. Woolner, Chem 13 News, 1978, 95
repris sur:  http://ourworld.compuserve.com/homepages/JDebord/humour.htm#Litre