en that his luggage was all brought to the
conveyance, threw himself into a corner and closed his eyes, having
given his direction to the driver as he was stepping into the vehicle.

"Stop a moment, Jim," said the porter to the cabman, as the latter was
just jerking his reins for a start. "Here, catch hold of this bag; it
was on the top of this gent's carriage: no one else owns to it, so it
must be his'n. The gent's forgotten it, I dessay."

So saying, he threw a light, shabby-looking carpet-bag up to the driver,
who deposited it by his side, and drove off.

After sleeping for a few hours at a hotel where he was well-known, and
having urgent business in the city next morning, the doctor deposited
his luggage, which he had left with sundry rugs and shawls in charge of
the hotel night porter, at his own door on his way to keep his business
appointment, leaving word that he should be at home in the afternoon.
With the other luggage there was handed in the shabby-looking carpet-bag
which had come with it.

"What's this?" asked the boy-in-buttons, in a tone of disgust, of the
housemaid, as he touched the bag with his outstretched foot.

"I don't know, I'm sure," was the reply. "It ain't anything as master
took with him, and I'm quite sure it don't belong to mistress."

"I'll tell you what it is," said the boy abruptly, and in a solemn
voice, "it's something as has to do with science. There's something
soft inside it, I can feel. P'raps there's something alive in it--I
shouldn't wonder. Oh! P'raps there's gun-cotton in it. I'd take care
how I carried it if I was you, Mary, or p'raps it'll go off and blow you
to bits!"

"Oh goodness!" exclaimed the housemaid, "I won't touch it. Just you
take it yourself and put it into master's study; it'll be safest there."

So the boy, with a grin of extreme satisfaction at the success of his
assault on the housemaid's nerves, helped her to carry the rest of the
luggage upstairs, and then deposited the mysterious bag in a corner of
the doctor's own special sanctum. Now this study was a room worth
describing, and yet not very easy to describe.

The doctor's house itself was one of those not very attractive-looking
dwellings which are to be found by streetfuls running from square to
square in the west end of London. It had stood patiently there for many
a long year, as was evident from the antiquated moulding over the
doorway, and from a great iron extinguisher, in which th