Dr Neil Stanley Independent Sleep Expert
BACK Directions and Observations relative to Food, Exercise and Sleep (London, 1772), 22; Dannenfeldt, "Sleep," 430. Bullein, Newe Boke of Phisicke, 91; here  Bullein does indeed recommend six to eight hours  “sixe or eight houres will suffice nature”. Boorde, Compendyous Regyment actually states for most 6-9 hours but melancholy men can seemingly sleep as long as they like  here Fyrste, as concemynge the natiirall complexyon of man, as sanguyne and colorycke men, .vii. houres; is suffycyent for them. And nowe, consyderynge the imbecyllyte and wekenes of nature, a flemytycke man Phlegmatic may slepe .ix. houres or more. Melancoly men may take theyr pleasure, for they be receptacle and the dragges of all the other humoures. Venner, Via recta, 279–80; also does not limit sleep to 6-8 hours here From whence it may well bee concluded that for fuch as are healthfUll, and in their yonthfull and conftant age, fix, feven or  or eight houres at the moft is a fufficient time for the continuance of fleep becaufe in them the concoctions are in that fpace commonly perfected perfeaed. But fuch as are weak and fickly by nature, require a longer time of reft  as nine, ten, or eleven houres, for helping the concoction and the  reftoring of ftrengths. Directions and Observations relative to Food, Exercise and Sleep (London, 1772), 22; also recommends 6-9 hours sleep here “It is not possible to lay down any Rule as to the Length of Time necessary for Sleeping; for as this does in a great Measure depend upon Age, Habit and other Circumstances, it ought in different Persons to be different : But it seems to be agreed, that it ought not in the general to be less than six nor more than nine Hours in a Day”  Dannenfeldt, "Sleep," 430. The full passage shows that few actually recommended between 6-8 hours. (“Supper being large” is I would contend not a “special circumstance”) Montaigne wrote, "Sleeping has occupied a large part of my life, and even at this age [54] I continue to sleep eight or nine hours at a stretch." Jerome Cardan, the renowned Italian physician and mathematician, remained in bed ten hours and when in good health he slept eight hours. But, there was not general agreement among the medical authorities on the duration of a night's sleep. Pare" pointed out that the time spent sleeping should not be measured by hours but by the time needed for digestion and this varied with the individual. The longest time for complete digestion was seven or eight hours and this condition could be observed when the abdomen subsided and the urine was tinctured yellow. Incomplete digestion was shown by the extension of the stomach, acid belching, a headache, and "heaviness of the whole body." Borde advised moderation in the amount of sleep but the hours should be "measured according to the natural! complection of man," the strength or debility of the sleeper, and the sickness or health of the individual. Sanguine and choleric persons needed only seven hours of sleep, a phlegmatic man may need nine or more hours, and those of a melancholic nature "may take their pleasure." Those sick should sleep when they could but it was best to refrain from day-sleeping. Lemnius thought that sleep at night should extend for about eight hours or somewhat longer if supper was large. Bailey considered an average of seven hours of sleep as best and to sleep longer was harmful. Grataroli advised moderate amounts of sleep and considered eight hours as sufficient and perhaps too much for the magistrates and students for whom he was writing—unless the stomach was weak and slow to digest. Vaughan thought the phlegmatic and melancholic needed nine hours of sleep, while seven hours was sufficient for those of other humors. Additionally Vaughan Naturall and artificial directions for health 1600 also gives  “How many houres may a man sleepe? Seaven houres sleepe is sufficient for sanguine & cholerick men; and nine houres for fleagmaticke, and melancholick men”. here It is interesting to note that whilst these authors recommend a particular amount of sleep, none of them mention anything that suggests the idea of segmented sleep. BACK
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