“I do not want this to become known to Inspector Quercy, of the Police Judiciaire.”

“He is a good man.”

“There is a personal reason.”

“ Entendu. He will know nothing about it.”

“It is urgent.”

“I will close the shop and take the book over at once myself. I will have a report for you within two hours.”

The Saint fingered the medallion in his pocket.

“There is one other thing I can do while you are gone,” he said. “Do you have an accommodating friend who is a doctor, who would have a microscope that I can use for a few minutes?”

“I can find one. Let me telephone first.”

Louvois retired to the back of the shop and returned in a few minutes with a name and address written on a slip of paper.