MifceUaneaCuriofa. 301 



quor v thus a Cubick Inch of Iron being hea- 

 vier than a Cubick Inch of Aqua-Fonis, and 

 each Particle (how fmall foever) of Iron be- 

 ing heavier than a like Particle of Aqua-Fort is - 

 Iron being put into Aqua-Fortis Ihould fink, 

 and yet we find, that Iron being difiblved in 

 a convenient quantity of Aqua-Fortis floats 

 therein, and does not fall to the Bottom, 

 The Reafon which my Brother gives for this 

 is, That the internal Motion of the Parts of 

 the Liquor, does keep up the Particles of the 

 dillblved Solid, for they being fo every Mi- 

 nute, are movable by the leafl: force imagi- 

 nable, and the Action of the Particles of the 

 Menftruum, is fufficient to drive the Atomes 

 of the dillblved folid Body from place to 

 place ^ and confequently , notwithftanding 

 their Gravity, they do not fink in the Liquor 

 lighter than themfelves. As a Proof of this 

 in the 7 th Article of Janvier 1685. he offers 

 an Experiment known in Chymiftry, that a 

 Menftruum over a digefting Fire (as the Chy- 

 mifl fpeaks) will difiblve a greater quantity 

 ©f a Body put into it, than when 'tis off the 

 Fire, and if it be taken olF the Fire, and fuf- 

 fered to cool, a great Portion will precipi- 

 tate of that which was perfectly dillblved, 

 whilfi: the Menftruum continued hot. For, 

 fays he, the Particles pf the Menftruum ac- 

 quire a more violent agitation by the Fire, 

 and are therefore able to raife and keep up 

 a greater Quantity of the difiblved Body, or 

 hereby they are able to refill: a greater Gra- 

 -vity. 



It has been objected againft this Notion, 

 that the common Experiment of precipita- 

 tion, 



