The overall narrator of this portmanteau story - for Dickens co-wrote it with five collaborators on his weekly periodical, All the Year Round - expresses deep, rational scepticism about the whole business of haunting.

Among champions and such as strive for the masterie in feats of activitie, we count those for their adversaries and concurrents onely, who professe and practise the same kinde of game or exercise; for those that goe to it with fists and buffers, are commonly friends good enough to such sword-fencers as fight at sharpe to the utterance, and well-willers to the champions called Pancratiastae.

It appears to be in that strange mental condition which most of ourselves must often enough have experienced in the case of dreams — a kind of dread fascination, which enchains all the mental faculties, and causes, as it were, a failure of the faculties of the brain.

The bases of working limits for environmental contamination are the permissible limits for internal emitters. If the internal emitter is a bone-seeker (examples are plutonium, Sr⁹⁰, and the rare earths) the criterion for establishing limits is based on the history of humans who have had radium deposited in their skeletons. To experimentally find the maximum quantity of a radioactive bone-seeker that can deposit in the human skeleton without adverse effect, it is usual to compare the toxicity in experimental animals of the bone-seeker with that of radium.