‘Here some may desire to know whether it bee altogether vnwholesome to sleepe after dinner. Whereunto I answer, that sleeping at noones is condemned as most hurtfull to the body, because it overmoistneth the braine, and filleth the head full with vaporous superfluities. And the reason why it filleth the head with superfluous moisture, is, because the night hath sufficiently moistned it, as that it needeth not to be moistned againe by sleepe in the day, but ought rather to be dryed by watchings and motions of the body. And from hence it is that sleeping at noones causeth heavinesse of the head, dulnesse of wit, distillations, defluxions of humours, lethargies, and other cold diseases of the braine, and palsies, by relaxing the sinewes. Moreover it hurteth the eyes, spoileth the colour, puffeth up the Spleene with winde, maketh the body unlusty, and prepareth it for Fevers and Impostumes.
Yet notwithstanding all these hurts which are incident to them that wil needs sleepe in the day time, sleeping at noones is not alwayes, nor to all bodies to be prohibited, so as it be admitted with the cautions hereafter assigned. For if the night shall be unquiet, or without sleepe, or the body wearied with extraordinary labour, or the spirits exhausted, and the strengths dejected by immoderate and excessive heat, as it oftentimes chanceth in the hot seasons of the yeare, it is not amisse to sleepe at noones: for by it the spirits are collected into the inner parts, the mind freed of cogitation, and the whole body consequently very much refreshed.’
Tobias Venner, Viæ rectæ ad vitam longam, pars secunda. VVherein the true vse of sleepe, exercise, excretions, and perturbations is, with their effects, discussed and applied to euery age, constitution of body, and time of yeare (1623)