Translations for perfidious in French

Here are paragraphs from public domain books translated:

"Madame," replied Bonacieux, "your august mistress is a perfidious Spaniard, and what the cardinal does is well done."	— Madame, reprit Bonacieux, votre auguste maîtresse est une perfide Espagnole, et ce que le cardinal fait est bien fait.
The Three Musketeers, by Alexandre Dumas	Les Trois Mousquetaires, de Alexandre Dumas