"No ... or rather, yes.... Yes, I remember the face showed brown patches
which I did not see on the occasion of my first visit."

"Brown patches? That confirms my supposition Cosmo Mornington was
poisoned."

"But how?" exclaimed the Prefect.

"By some substance introduced into one of the phials of
glycero-phosphate, or into the syringe which the sick man employed."

"But the doctor?" M. Desmalions objected.

"Maître Lepertuis," Perenna continued, "did you call the doctor's
attention to those brown patches?"

"Yes, but he attached no importance to them."

"Was it his ordinary medical adviser?"

"No, his ordinary medical adviser, Doctor Pujol, who happens to be a
friend of mine and who had recommended me to him as a solicitor, was ill.
The doctor whom I saw at his death-bed must have been a local
practitioner."

"I have his name and address here," said the Prefect of Police, who had
turned up the certificate. "Doctor Bellavoine, 14 Rue d'Astorg."

"Have you a medical directory, Monsieur le Préfet?"