It takes a good deal to surprise a really seasoned medical practitioner, and still more to arouse in him an abiding curiosity. But at the time when I took charge of Dr. Humphrey's practice in Osnaburgh-street, Regent's Park, I was far from being a seasoned practitioner, having, in fact, been qualified little more than a year, in which short period I had not yet developed the professional immunity from either of the above mental states. Hence the singular experience which I am about to relate not only made a deep impression on me at the time, but remained with me for long after as a matter of curious speculation.