SLEEP. 601 



a few moments are required for us to recover from our surprise 

 and find we are awake. When slow, we for a little while are 

 sleepy, gape and yawn, but half open our eyes, scarcely perceive 

 what is around us or understand what is said ; and have imperfect 

 power over the muscles, so that we stagger and perform all 

 movements awkwardly : and, if still slower, the same delirium is 

 experienced as while going slowly to sleep, and for a little longer 

 we are still sleepy. 



Sleep appears much more profound at the beginning than 

 towards the end, and, I presume, because the fatigue is then 

 greatest and gradually lessens as sleep continues. In the same 

 manner, transpiration, we have seen, is at first greatest, and 

 gradually lessens as the body loses its excess of fluid ; and ab- 

 sorption gradually lessens as the body becomes charged with 

 fluid. 



In some diseases of the nervous system persons may pass 

 many days, and even entire weeks, with little or no sleep. I 

 have known this sleeplessness to' be the only disease, and recur 

 on several occasions in the same individual :. usually after ex- 

 cessive corporeal or cerebral excitement. Great wretchedness, 

 debility, and restlessness of body and brain took place. 



The duration of sleep is various. Youth and young adults 

 will habitually sleep soundly and uninterruptedly for eight or 

 nine hours. Infants and old people sleep for shorter periods. Some 

 persons are constitutionally sound and long sleepers : others 

 light and short sleepers. Infants sleep far more in the twenty- 

 four hours than adults: when very young, having but recently 

 come into the waking state from the womb, they are awake but 

 for short periods ; and for very many months require to go to sleep 

 several times, and for the first two or three years more than 

 once, in the twenty-four hours. Old people sleep lightly and 

 frequently ; and altogether but little, unless lethargic disease 

 comes upon them, which is very common. 



I heard Baxter the coachmaker declare he never took more than 

 three hours sleep during the most active period of his life. " The 

 celebrated General Elliot" " never slept more than four hours out 

 of the twenty-four ; and his food consisted wholly of bread, water, 

 and vegetables." Sir John Sinclair mentions a James Mackay, 

 ' a remarkably robust and healthy man," " who died in Strathnaver 

 in 1797, aged ninety-one, and only slept, on an average, four 



