Enclosed with it was the slip of paper with the notes of the trains, which he had, for the moment, forgotten. He now examined it minutely and was once more struck by the intense blackness of the ink; and he recalled that a similar intensity of blackness had been noticeable in the address on Mr. Penfield’s envelope. It had appeared almost like the black of a carbon ink, but he had decided that it was not. So it was with the present specimen; but now he had the means of deciding definitely. Fetching the microscope, he laid the paper on the stage and examined it, first by reflected, then by transmitted light. The examination made it clear that this was an iron-tannin ink of unusual concentration with a “provisional” blue pigment—probably methyl blue. There was only one letter—P—and this he tried to compare with the P on Penfield’s envelope, so far as he could remember it, but he could not get beyond a belief that there was a resemblance; a belief that would have to be tested by a specimen of Purcell’s handwriting.
Having finished with the paper he returned to the hair. He decided to write to Margaret, asking for a description of her missing husband, and had just reached out to the stationery case when an elaborate and formal tattoo on the small brass knocker of the inner door arrested him. Rising, he crossed the room and threw the door open, thereby disclosing the dorsal aspect of a small, elderly gentleman. As the door opened the visitor turned about and Thorndyke immediately, not without surprise, recognized him. It was Mr. Penfield.
Chapter IX.
In Which Mr. Penfield Receives a Shock
Mr. Penfield greeted Thorndyke with a little stiff bow and bestowed upon the extended hand a formal and somewhat rheumatic shake.
“I must apologize,” he said, as his host ushered him into the room, “for disturbing you by this visit, but I had a little matter to communicate to you and thought it better to make that communication personally rather than by correspondence.”
“You are not disturbing me at all,” Thorndyke replied. “On the contrary, I expect that your visit will save me the necessity of writing a letter.”
“To me?” asked Penfield.
“No; to Mrs. Purcell. I was on the point of writing to her to ask for a description of her husband. As I have never met him I thought it as well that I should get from her such details of his appearance as might be necessary for purposes of identification.”
“Quite so,” said Mr. Penfield. “Very desirable indeed. Well, I think I can tell you all you want to know, unless you want very minute details. And it happens that your inquiry comes rather opportunely in respect of the matter that I have to communicate. Shall we dispose of your question first?”
“If you please,” replied Thorndyke. He took from a drawer a pad of ruled paper, and, uncapping his fountain pen, looked at Mr. Penfield, whom he had inducted into an easy chair.