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Topic: [HM] question about term "normal"
Replies: 13   Last Post: Dec 7, 2006 4:19 PM

 Messages: [ Previous | Next ]
 JUHEL Alain Posts: 29 Registered: 12/3/04
Re: [HM] Cauchy
Posted: Dec 7, 2006 4:19 PM

At 16:52 14/11/2006, Gunnar Berg wrote:

>Dear all.
>In perusing Cauchys "Cours d'analyse" (1821) I have come across the
>following (p.35):
>
> "Enfin, lorsqu'un fonction f(x) cesse d'etre continue dans le voisinage
> d'une valeur particuliere de la variable x, on dit qu'elle devient
> alors discontinue, et qu'il y a pour cette valeur particuliere
> solution de continuite."
>
>What puzzles me is the last phrase - "solution de continuite" -
>I simply cannot make any sense of it. What can Augustin-Louis mean?

Dear Gunnar, dear all,

It does not require a thorough knowlegde of Cauchy's work, but a rather
thorough one of
French language! Many people in France use these words today, thinking that
it means
"an evolution, whithout any break"; but they are quite wrong.
"Solution" is to be understood as "DISsolution", as in a chemical meaning:
there,
the continuity disappears, like sugar in coffee, for instance !
It goes back to 1314 and was used in surgery at the time: a broken arm or
leg was a
"solution de continuite"...
I refer to the authoritative French Dictionnary Robert; our cousins from
Quebec will tell
you the same tale on this page
http://66.46.185.79/bdl/gabarit_bdl.asp?Th=3&id=2554
In "Le Robert" one could find two examples of a right use, one by Balzac
and one by Hugo.
Here is Hugo, "Les Misérables":
"Une révolution, qu'est ce que ça prouve? Que Dieu est à court. Il fait un
coup d'état,
parce qu'il y a solution de continuité entre le présent et l'avenir, et
parce que lui, Dieu,
il n'a pas pu joindre les deux bouts".
This proves that Cauchy was aware of the right meaning of these words.

Greetings from Lille, France
Alain Juhel

Date Subject Author
10/23/06 Tummers P (FDCW)
10/23/06 jim farned
10/23/06 Dr A W F Edwards
10/28/06 Fred Shapiro
10/23/06 William C Waterhouse
10/28/06 Fernando Q. Gouvea
11/14/06 Gunnar Berg
11/22/06 cl.marti
11/22/06 Joao Filipe Queiro
11/22/06 Jean-Luc Gautero
11/22/06 William C Waterhouse
12/7/06 Bruand Francois
12/7/06 JUHEL Alain