CENTURY VIII. 31 



cold doth shut in and hinder : for we see that in great 

 colds one can scarce draw his breath. Another cause 

 may be, for that cold calleth the spirits to succour; 

 and therefore they cannot so well close and no together 

 in the head ; which is ever requisite to sleep. And for 

 the same cause, pain and noise hinder sleep ; and dark 

 ness (contrariwise) furthereth sleep. 



745. Some noises (whereof we spake in the hundred 

 and twelfth experiment) help sleep ; as the blowing 

 of the wind, the trickling of water, humming of bees, 

 soft singing, reading, &c. The cause is, for that they 

 move in the spirits a gentle attention ; and whatsoever 

 moveth attention, without too much labour, stilleth the 

 natural and discursive motion of the spirits. 



746. Sleep nourisheth or at least preserveth bodies 

 a long time, without other nourishment. Beasts that 

 sleep in winter (as it is noted in wild bears) during 

 their sleep wax very fat, though they eat nothing. 

 Bats have been found in ovens, and other hollow close 

 places, matted one upon another : and therefore it is 

 likely that they sleep in the winter time and eat noth 

 ing. Quaere, whether bees do not sleep all winter, and&quot; 

 spare their honey ? Butterflies, and other flies, do not 

 only sleep, but lie as dead all winter ; and yet with a 

 little heat of sun or fire revive again. A dormouse, 

 both winter and summer, will sleep some days to 

 gether, and eat nothing. 



Experiments in consort touching teeth and hard sub 

 stances in the bodies of living creatures. 



To restore teeth in age, were magnale naturce. 

 It may be thought of. But howsoever the nature 



