"Certain. If you care to call at my place later to-day I can show you
some _cash._ Bring the envelope with you and you will see that the
coins correspond to the impression in the wax. The inscriptions vary
in different provinces, but the form of all _cash_ is the same."

"Very good. Thanks for letting me know at once. It seems to establish
a link with China, don't you think?"

"It does, but it merely adds to the mystery."

Coming out of the call-box, Stuart proceeded home, but made one or two
professional visits before he actually returned to the house. He now
remembered having left this particular _cash_ piece (which he usually
carried) in his dispensary, which satisfactorily accounted fro his
failure to find the coin in his waistcoat pocket. He had broken the
cork of a flask, and in the absence of another of correct size had
manufactured a temporary stopper with a small cork to the top of which
he had fixed the Chinese coin with a drawing-pin. His purpose served
he had left the extemporized stopper somewhere in the dispensary.

Stuart's dispensary was merely a curtained recess at one end of the
waiting-room and shortly after entering the house he had occasion to
visit it. Lying upon a shelf among flasks and bottles was the Chinese
coin with the cork still attached. He took it up in order to study
the inscription. Then:

"Have I cultivated somnambulism!" he muttered.

Fragments of black sealing-wax adhered to the coin!