A MYSTERY is, in a popular sense, that which cannot be easily explained; a circumstance that cannot be readily accounted for. Something is, but how or why we cannot tell. The mysteries of modern London are as the sands of the seashore. The mighty city itself is a mystery. The lives of thousands of its inhabitants are mysteries. In the glare and clamour of the noonday, as in the darkness and silence of the night, the mysteries arise, sometimes to startle the world, sometimes to attract so little attention that the story of them never reaches the public ear.

There are mysteries blazoned forth with all the glamour that the contents-bill and the headline can give them, and there are mysteries that are jealously guarded by those high in authority, lest public curi-osity should seek to fathom them.
There are mysteries in splendid mansions and in squalid garrets which contain all the elements of criminal romance, and yet pass with the police and the press as matter-of-fact incidents of London's daily life.

The great river hides more mysteries than ever the Seine gave up to the Paris Morgue, and many of them end with a little rest in a quiet mortuary, a "found drowned" hand-bill posted for a day or two on a police-station notice-board, an inquest, an open verdict, and a pauper's funeral.

But among the victims have been men and women the story of whose doing to death would have thrilled the masses and the classes alike; in some instances would have revealed the presence in our midst of active agents of the most desperate secret societies in the world.

There are no mysteries of modern London more terrible than its unrecorded ones. There are disap-pearances that are never chronicled; murders that are never discovered; victims of foul play who go certified to the grave as having succumbed to "natural causes."