Translations for filth in French

Here are paragraphs from public domain books translated:

Could it be possible that the back pearl had been cast into the mud and filth of the gutter to be picked up by the first comer? The black pearl—a fortune!	Se pouvait-il qu’elle y fût ! La perle noire jetée dans la boue d’un ruisseau, à la disposition du premier venu ! La perle noire… une fortune !
The Extraordinary Adventures of Arsene Lupin, Gentleman Burglar, by Maurice Leblanc	Arsène Lupin gentleman-cambrioleur, de Maurice Leblanc