164. Persons capable of perceiving the presence of spirits by a vague impression, a kind of feeling through- out the whole body, for which they can give no reason, are thus designated. This variety has no very decided character; all mediums are necessarily impressible: impressionability is rather a general than a particular quality; it is the rudimentary faculty indispensable to the development of all the others; it differs from purely physical and nervous impressionability, with which it must not be confounded ; for there are per- sons who have not delicate nerves, and who yet feel, more or less, the presence of spirits ; and others, very irritable, who have not the slightest perception of them.
This faculty is developed by habit, and may acquire such a subtilty that the person endowed with it recognizes, by the-impression he feels, not only the good or bad nature of the spirit at his side, but even his individuality, as a blind person recognizes, by a certain unknown sense, the approach of this or that person ; he becomes, in relation to spirits, a veritable sensitive plant A good spirit always makes a gentle and agreeable impression ; that of a bad spirit, on the contrary, is painful, anxious, and disagreeable; there is, as it were, a scent of impurity.
