68 
POPULAR SCIENCE REVIEW. 
receive external impressions in a perfect natural state, it is 
necessary that the nervous organisation, like a musical stringed 
instrument, should be accurately attuned, its various minute 
parts, its fibres, tense, yet not unduly strained. This tension 
is maintained by the pressure of the blood, the silent, purely 
mechanical, streaming current, that is ever, in life, in circuit, 
filling up vacuities, supplying new portions of matter, supply- 
ing fluids to be distilled ever by receiving organs and regulating 
pressures. To the brain this blood may come in equal streams, 
or it may ebb, or it may enter like a tide ; so that the tension 
may vary from low to high, with varying phases of mental 
change following upon varieties of tension. 
When, under any circumstances, the blood current ebbs, so 
that the brain is indifferently supplied with blood, external im- 
pressions rush in through the senses in such disturbed profusion, 
that a new existence may seem to have opened itself to the mind, 
with flashing,flickering manifestations of the past, over which the 
will loses its steady command. The light of day is insupportable 
in its brilliancy ; sounds the faintest are exaggerated into torrents, 
or peals, or blasts ; faint odours are overpowering, and other 
physical impressions, not appreciated by the healthy bystander, 
are recognised by the prostrated organism. A woman who was 
saved from drowning*, and who, from what seemed the uncon- 
sciousness of death was restored to life, once related to me her 
experiences of the phenomena I have named with wonderful and 
simple fidelity. As she sank the noises of the water, — though 
it was still water, — and of the voices of persons who were 
calling for her rescue were appalling from their intensity — 
“ they were like thunder.” The touch of the water seemed as 
if it were creating the dissolution of her body ; and, at last, as 
if being distributed into some immeasurable expanse, she was 
lost, knowing no more until she found herself, hours afterwards, 
in a warm bed, with friendly hands supporting her, and friendly 
voices pressing her to try and swallow nourishment. The ex- 
tasies of the starving or festive person, often so poetically 
described, are of this order of phenomena, but in minor degree. 
There is an opposite condition of brain to the above, in which 
the tension is unduly increased by pressure of blood. Under this 
condition the tendency is not to receive the impressions of the 
outer world into the nervous organisation in overwhelming con- 
fusion, but to project certain of the impressions it has received into 
the external world. A perfect illustration of this perversion is 
supplied in the narrative of Nicolai, a bookseller of Berlin, who 
himself describes what he experienced. Nicolai had been ac- 
customed to be bled twice in the year, as was the fashion in his 
day ; but at the close of the year 1790 the process was omitted. 
In the beginning of the year 1791 he was affected in his mind 
