What if the nerve-thrills passing through the whole system of the animal propagate themselves to a certain distance without any more regard to intervening solids than is shown by magnetism?  A sieve lets sand pass through it; a filter arrests sand, but lets fluids pass, glass holds fluids, but lets light through; wood shuts out light, but magnetic attraction goes through it as sand went through the sieve.  No good reasons can be given why the presence of a cat should not betray itself to certain organizations, at a distance, through the walls of a box in which the animal is shut up.  We need not disbelieve the stories which allege such an occurrence as a fact and a not very infrequent one.

If the presence of a cat can produce its effects under these circumstances, why should not that of a human being under similar conditions, acting on certain constitutions, exercise its specific influence?  The doctor recalled a story told him by one of his friends, a story which the friend himself heard from the lips of the distinguished actor, the late Mr. Fechter.  The actor maintained that Rachel had no genius as an actress.  It was all Samson’s training and study, according to him, which explained the secret of her wonderful effectiveness on the stage.  But magnetism, he said,—­magnetism, she was full of.  He declared that he was made aware of her presence on the stage, when he could not see her or know of her presence otherwise, by this magnetic emanation.  The doctor took the story for what it was worth.  There might very probably be exaggeration, perhaps high imaginative coloring about it, but it was not a whit more unlikely than the cat-stories, accepted as authentic.  He continued this train of thought into further developments.  Into this series of reflections we will try to follow him.

What is the meaning of the halo with which artists have surrounded the heads of their pictured saints, of the aureoles which wraps them like a luminous cloud?  Is it not a recognition of the fact that these holy personages diffuse their personality in the form of a visible emanation, which reminds us of Milton’s definition of light: 

  “Bright effluence of bright essence increate”?

The common use of the term influence would seem to imply the existence of its correlative, effluence.  There is no good reason that I can see, the doctor said to himself, why among the forces which work upon the nervous centres there should not be one which acts at various distances from its source.  It may not be visible like the “glory” of the painters, it may not be appreciable by any one of the five senses, and yet it may be felt by the person reached by it as much as if it were a palpable presence,—­more powerfully, perhaps, from the mystery which belongs to its mode of action.