What happened?
Foreigners brought out four editions of this French book which in France was proscribed, and they gained about 1,800,000 crowns.[154] In a monotonous world it is a pity to spoil a striking effect, yet one must be vigilant.

It has escaped the attention of writers who have reproduced this lively scene, that Madame de Pompadour was dead before the volumes containing Powder and Rouge were born.

The twenty-one volumes were not published until 1765, and she died in the spring of the previous year.

But the substance of the story is probably true, though Voltaire has only made a slip in a name.
As to the reference with which Voltaire impatiently concludes, we have to remember that the work was being printed at Geneva as it came out in Paris.

It was afterwards reprinted as a whole both at Geneva (1777) and at Lausanne (1778).