The Sun. — 1862-03-03 (London, England)

ROYAL INSTITUTION.  " SLEEPING AND DREAMING."  There was a crowded meeting of the members of the Royal Institution and their friends on Friday evening, on which occasion Mr. A. E. Durham delivered a lecture " On Sleeping and Dreaming." In his preliminary observation on the beneficial effects of sleep as a restorer of the exhausted energies of the brain and nerves, Mr. Durham said that the daily average duration of sleep required by an adult is eight hours ; that persons advanced in life require more, and that for younger persons a still longer proportion of sound slumber is necessary. Many persons, he said, can do with less sleep than others, but that generally a healthy state cf body cannot be maintained with a less proportion of sleep than eight hours in the 24. He did not think it very material whether the necessary quantity of sleep be taken in the night or during the day, though it is desirable that the mind when in an active state should be invigorated by the oxygenising rays of the sun. He mentioned many facts showing the necessity of sleep to sustain life, and among ethers the sentence of death inflicted on a murderer in China of being kept awake till he died. The torture of such a death is extreme, and on the eighth day the convict implored the attendants to kill him. After the eighth day he became partially insensible, and died on the 16th. Mr. Durham took a material view of the action of sleep, regarding it as a chemical process during which the brain tissue regains from the blood the power that had been exhausted during the activity of the mind. He said that to enable him to ascertain the condition of the brain in the states of sleep, of dreaming, and of complete activity, he administered chloroform to a dog, and when the animal was insensible he removed a portion of the skull and substituted for it a piece of glass, by which means he could see the different conditions of the brain. He found that when the dog was asleep the blood vessels were comparatively empty ; the arteries lost their bright red colour, and assumed in some degree the blue colour of the veins; whilst the brain-tissue collapsed, leaving a space within the skull which was filled with cerebrous spinal fluid. When the dog was roused from slumber the blood-vessels resumed their functions, and the brain filled the whole cavity of the skull; and when rendered partially insensible by chloroform, a modified collapse of the brain occurred. For the purpose of showing the action of the capillary vessels, through the agency of which the oxygen of the arterial blood is distributed throughout the body and the carbon is removed, the foot of a frog was shown, magnified on a screen by the electric lamp, by which means the circulation of the blood was made visible to the whole audience. There were also exhibited for illustration numerous models and diagrams of the brain, showing the ramifications of minute blood-vessels in every part ; and it is, he said, on the state in which those vessels are with respect to the activity of the heart that the conditions of sleep and of dreaming depend. The subject of dreaming, however, Mr. Durham was obliged to pass over almost unnoticed, in consequence of 'his having occupied too much time in the preliminary observations on the nature and effects of sleep.  211 E