diums$ concerning Gravity 5 concerning the Roundnefs of 
Fruits, ftones, and divers artificial bodies 5 concerning 
Springinefs and Tenacity 5 concerning the: Original of Foun- 
tains j concerning the dijjolution of Bodies into Liquors 5 
concerning Filtration 3 and the afeent of Juices in Vege- 
tables, and the ufe of their Pores . Here an attempt is made 
offolving the ftrange Phenomena of Gra/s-drops^ex periments 
are alleged to prove the Expanflon oCGlafs by heat, and 
the Contra&ion of heated- Glafi upon cooling 5 Des Cartes his 
Hypothecs of colours is examined : the caufe of Colour s y 
moft likely to the Author, is explained : Reafons are pro- 
duced, that Reflection is not neceflary to produce colours 5 
nor a double refraPlion : feme considerable Hypotlejes 
are offered , for the explication of Light by Motion $ tor 
the producing of all colors by Refra&ion 5 for reducing all 
forts of colors to two only, Fellow and Blew 5 for making the 
Air 0 a dilfolvent of all € ombuftible Bodies : and for the ex® 
plicating of all the regular figures of Saf where he alleges 
many notable inftanees of the Mathematichy of Nature , 3 as 
having even in thofe things which we account vile,rude and 
ccorfe^ fhewed abundance of curiofity and excellent Geo- 
metry and Mechanifm. And here he opens a large field for 
inquiries,and propofeth Models for profecuting them; i.By 
making a full cplleftjon of all the differing kinds of Geo- 
metrical/' figur'd bodies 5 . 2. By getting with them an exad 
Hiftory of their places where they are generated or found : 
3. By making ftore of Tryals in Diflblutions and Coa- 
gulations of feverall Cryftallizing Salts ; 4* By making 
trials onmetalls, Minerals and (tones, by difiblving them 
in fevm'all'Menflruums, and Cryffallizing them- to fee what 
Figures will arife from thofe feveral compofitums : 5. By 
compounding & coagulating feveral Salts together into the 
fame ma (s, to obferve the Figure ofthat product : 6. By .in- 
quiring the clofenes or rarity of the texture of thofe bodies, 
by examining their gravity, anc&heir rcfra&ion, &c. 7. By 
examining what operations the fire hath upon feveral kinds 
#£ Salts,, what changes it caufe&in their figures, Textures,or 
Vertucas 
