A TreAtife of B O D I E S. Chap, i 8 . 



ty be extra&ed out of a mixed body, efpecially, by the virtue of 

 fire; it muft have Icfc pores of fiich figures, as the humidity that 

 is drawn out of them,is apt to be cut into (for every humide bo- 

 dy not being abfoluteJy humide, but having certain dry parts 

 mixed with it, is more apt for one kind of figure and grcatnefTe, 

 thf n for another;)and by con{equencc,whenloever that humidi- 

 ty fhall meet again with the body it was fevered from; it will ea- 

 fily run through and into it all, and will fill exaclly the cavities 

 and pores it poflefled before. 



The laft quality, in which bodies that are to confift long to- 

 gether, do agree, is the bignefle of the humide and dry parts of 

 the fame body : for if the humide parts be too big for the dry 

 ones, it is clear that the dry ones muft needs hangloofcly toge- 

 ther by themjbccaufe their glew is in too great a quantity.But if 

 the humide parts be too little for the dry ones, then of neccflity 

 fome portion of every little dry part muft beunfurnifhtofglew, 

 by means whereof to ftick unto his fellow ; and fo the flicking 

 parts not being conveniently proportioned to one another, their 

 adhefion cannot be fo folid as if each of them were exactly fitted 

 to his fellow. 



CHAP. XVI IT. 

 Of another motion belonging to particular bodies, called Attr*- 



ftion- and of certain operations, termed, JWagicall. 

 .TT Aving thus ended the two motions of rarefaction and of 

 *! condenfation ; the next that offer themfelves, are the lo- 

 whenccit pro. call motions which fbme bodies have unto others. Thefc are 

 fotretimes performed by a plain force in the body towards 

 which the motion is : and other whiles by a hidden caufe, 

 which is not foeafily dilcerned. The firft, is chiefely that which 

 is ordinarily faid to be done by the force of nature to hinder va- 

 cMum and is much praftifed by naturcjas in drawing our breath, 

 in fucking, and in many other naturall operation*, which are 

 imitated by art in making of pumpes, fyphons, and fiich other 

 jjiftrumcnts ; and in that admirable cxperimeat of taking up a 

 heavy marble ftonc merely by another lying flat and fmoothly 

 upon itjwithoutany other connexion of the two ftoncs together; 

 as alfo by that {port of boycs, when they fpread a thin moiftncd 

 leatlicr upon a fmooth broad ftone, and prcffe it all over clolc 

 to it,, and then by pulling of a firing faftncd at the middle of the 



leather^ 



