1852.] OF THE ROYAL INSTITUTION. 149 
reality of this domination ; thus a biologized subject may be brought 
to feel the apartment so intensely hot, that a perspiration breaks out 
upon his skin; or he may be so persuaded of its coldness, that he 
forthwith begins to shiver; and sleep may often be induced, by 
assuring him that in a few minutes he will be obliged to give way 
to it. Ina case witnessed by the Lecturer, a lady to whom chloro- 
form had been twice administered (so that she was aware of the 
the mode of its action) was made to believe that she was again in- 
haling it; she soon passed into the usual insensibility, and remained 
perfectly unconscious for a few minutes, after which she came to 
herself in the manner she would have done if she had really been 
under the influence of chloroform. 
The same general statement applies to what has been designated 
as ‘control over the memory.’ The subject is assured that he cannot 
remember the most familiar thing, his own name for example; and 
he is prevented from doing so, not by the will of the operator, but 
by the conviction of the impossibility of the mental act, which en- 
grosses his own mind, and by the want of that voluntary control 
over the direction of his thoughts, which alone can enable him to 
recal the desiderated impression. And the abolition of the sense 
of personal identity,— Mr. A. believing himself to be Mrs. B., or 
Mrs. C. believing herself to be Mr. D., and acting in conformity with 
that belief,—is induced in the same mode; the assurance being 
continually repeated, until it has taken full possession of the mind 
of the ‘subject,’ who cannot so direct his thoughts as to bring his 
familiar experience to antagonize and dispel the illusive idea thus 
forced upon him. 
Now almost every one of these peculiar phenomena has its parallel 
in states of mind whose existence is universally admitted. Thus the 
complete subjection of the muscular power to the ‘ dominant idea’ 
is precisely what is experienced in nightmare; in which we are 
prevented from moving so much as a finger, notwithstanding a 
strong desire to do so, by the conviction that the least movement is 
impossible. The misinterpretation of sensory impressions is con- 
tinually seen in persons who are subject to absence of mind, who make 
the most absurd mistakes as to what they see or hear, taste or feel, 
in consequence of the pre-occupation of the mind by some train of 
thought, which renders them unable rightly to appreciate the objects 
around them. In such persons, too, the memory of the most fami- 
liar things,—as the absent man’s own name, for example, or that 
of his most intimate friend,— is often in abeyance for a time; and it 
requires but a more complete obliteration of the consciousness of the 
past, through the entire possession of the mind by the intense con- 
sciousness of the present, to destroy the sense of personal identity. 
This, indeed, we often do in effect lose in ordinary dreaming and 
reverie. The essential characteristic of both these states, as of the 
‘ biological’ condition, is the suspension of voluntary control over the 
current of thought, so that the ideas follow one another suggestively ; 
