The Evidence Reviewed

"And your own investigations?"

"Have given negative results for the most part. I found Doctor Norbury, at the British Museum, very friendly and helpful; so friendly, in fact, that I am thinking whether I may not be able to enlist his help in certain private researches of my own, with reference to the changes effected by time in the physical properties of certain substances."

"Oh; you haven't told me about that," said Jervis.

"No: I haven't really commenced to plan my experiments yet, and they will probably lead to nothing when I do. It occurred to me that, possibly, in the course of time, certain molecular changes might take place in substances such as wood, bone, pottery, stucco, and other common materials, and that these changes might alter their power of conducting or transmitting molecular vibrations. Now, if this should turn out to be the case, it would be a fact of considerable importance, medico-legal and otherwise; for it would be possible to determine approximately the age of any object of known composition by testing its reactions to electricity, heat, light and other molecular vibrations. I thought of seeking Doctor Norbury's assistance because he can furnish me with materials for experiment of such great age that the reactions, if any, should be extremely easy to demonstrate. But to return to our case. I learned from him that John Bellingham had certain friends in Paris--collectors and museum officials--whom he was in the habit of visiting for the purpose of study and exchange of specimens. I have made inquiries of all of these, and none of them had seen him during his last visit. In fact, I have not yet discovered anyone who had seen Bellingham in Paris on this occasion. So his visit there remains a mystery for the present."