Insomnia, and other disorders of sleep / by Henry M. Lyman.

Date:
1885
Catalogue details

Licence: Public Domain Mark

Credit: Insomnia, and other disorders of sleep / by Henry M. Lyman. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    of a second are necessary. It is, therefore, perfectly reasonable to suppose that when the “ explosive ma- terial ” of the brain has been sufficiently “ dampened ” by the accumulation of acid refuse which accompanies prolonged cerebral effort, the impressions of sense may no longer suffice to excite in the cortical protoplasm vibrations of sufficient length, or following each other in sufficiently rapid succession, to sustain conscious- ness. The cortex of the brain may then be likened to a body of water into which bubbles of partially soluble gas are introduced from below. When the bubbles are large, and when they follow each other rapidly, a con- tinual effervescence is maintained upon the surface of the water. But if the size of the bubbles be reduced, or if the solvent capacity of the liquid be increased, the surface will become almost, if not quite, perfectly tranquil. In some such way, without any great dan- ger of error, may we picture forth the manner in which the generation of ideas in the field of consciousness is related to the molecular movements in the space occu- pied by the protoplasmic substance of the brain. Re- turning, now, to the rapid induction of sleep, we find that it is usually the experience of people who lead an active life in the open air, and are compelled to endure frequent interruption of their rest. The sailor who is trained to work four hours on deck, and then to sleep four hours below, has been virtually transformed by this habit into a denizen of a planet where the days and the nights are each but four hours long. His bodily functions become accommodated to this condi- tion ; his nervous organs store up in sleep a supply of oxygenated protoplasm sufficient only for an active