CENT CRY VIII. 41 



moved have, by impulsion or by the motion of gravity 

 continued, a compression in them as well downwards, 

 as they have, when they are thrown or shot through 

 the air, forwards. I conceive also that the quick loose 

 of that motion preventeth the resistance of the body 

 below : and priority of the force always is of great 

 efficacy ; as appeareth in infinite instances. 



Experiment solitary touching titillation. 



766. Tickling is most in the soles of the feet, and 

 under the arm-holes, and on the sides. The cause is, 

 the thinness of the skin in those parts, joined with the 

 rareness of being touched there. For all tickling is a 

 light motion of the spirits, which the thinness of the 

 skin, and suddenness and rareness of touch, do further: 

 for we see a feather, or a rush, drawn along the lip or 

 cheek, doth tickle ; whereas a thing more obtuse, or a 

 touch more hard, doth not. And for suddenness, we see 

 no man can tickle himself: 1 we see also that the palm 

 of the hand, though it hath as thin a skin as the other 

 parts mentioned, yet is not ticklish, because it is ac 

 customed to be touched. Tickling also causeth laugh 

 ter. The cause may be the emission of the spirits, 

 and so of the breath, by a flight from titillation ; for 

 upon tickling we see there is ever a starting or shrink 

 ing away of the part to avoid it ; and we see also, that 

 if you tickle the nostrils with a feather, or straw, it 

 procureth sneezing : which is a sudden emission of the 

 spirits, that do likewise expel the moisture. And tic 

 kling is ever painful, and not well endured. 



1 See Arist. Prob. xxxv. 2. and 6. ; and compare Scaliger, Exercit, adv. 

 Cardanum, 317. 5. 



