"Wait a bit," said Matherfield. "That's of no great importance—yet. Dr. Charles Ambrose, eh? Have you his address?"
"Aye, to be sure!" answered the chemist. "His address is 38, Number 59, John Street."
"Adelphi!" suggested Matherfield.
"Adelphi, precisely—38, Number 59, John Street, Adelphi," repeated Macpherson. "That's in the books, too."
Matherfield suddenly became silent, staring at the floor. When he looked up again it was at Hetherwick.
"Didn't Granett exclaim that he knew of a doctor, close by, when he rushed out of that train at Charing Cross Underground?" he asked. "Gave the impression that he knew of one close by, anyway?"
"He said distinctly close by," answered Hetherwick. "Why, are you thinking——"
Matherfield interrupted him with a wave of the hand, and turned again to the chemist. "You've seen this Dr. Charles Ambrose?" he asked abruptly.
"Oh, I have, Mr. Matherfield, many a time and often," replied Macpherson. "But now I come to think of it, not lately."
"When—last?" demanded Matherfield.