The letter is not about removing camp followers from the army. It is about refugess.

Here's the letter in French, still without names :
http://books.google.com/books?id=SZkfAAAAMAAJ&pg=PA274

Translating the French word "filles" as "women of bad character" and "loose women" is rather over the top. The translator also removes the phrase "venant d'Espagne" which serves to make their refugee status less clear.
"La Saltpêtrière" may refer to the huge 78-acre facility outside Paris, an asylum or hospital for aged, "insane", epilleptic, "mentally disabled" women.

The letter is about dealing with the results at Bayonne on the border and in the French départments adjacent to Spain of the influx of female refugees. The French government of Spain was being evacuated, and the border being readied for defense, if you recall. Bayonne itself and the "places frontières" were put into a formal state of siege in early July.
http://books.google.com/books?id=BMkdAAAAYAAJ&pg=PA193

"Le général L'Hullier [à Bayonne] ordonna de faire passer au-delà de la Garonne les femmes des généraux, officiers et employés d'administration venant d'Espagne, pour soustraire aux représailles d'un ennemi en furreur."
http://books.google.com/books?id=hTMVAAAAYAAJ&pg=PA142

I know, the letter is not so amusing when seen as it was written and in the correct context. It is so much more fun to think of the hapless French army encumbered with their fluzzies. Sorry.