( $171 ) l<lumh. 91, 
PHILOSOPHICAL 
TRANSACTIONS. 
March 25. 1673. 
The C O N T E N T S. 
' . ■ .- / 
A freface to this Ninth Tear. A Difcoviry of two New Planets 
about Saturn^ made by Signor Caffiai. An ExtraB of a Let- 
ter of Dr. Von der Beck to Dr. Laogelot concerning the Prin* 
ciples and Caufes of the Volatilifation of salt of tartar and 0- 
ther f ixed Salts. Some Ohfrvations touching the nature of 
Snow, prefentedto theK. Society by Dr. Grew. A Confir'- 
mation of what was deliver d in Numb. 90. about the Strange 
Freezing in Somerfetfhire* An Accomp of two Boo^s : 
I, TraSs written by R. Boyle Ejquire^ containing New Expe- 
riments touching the Relation betwixt Flame and Air^ and 
about ExplcfoHs : An Hydrojiatical Difcourfe occa^on'd by 
feme OhjeBions of Dr. More j to which k annex t an Hydro- 
fiatical Letter^ about a Way of W&ighing^ater in water l^em 
Experiments^ of the Popiveor Relative tevity of Bodies un- 
der water '-^ of the Air's Spring on Bodies under "water and 
about the Differing Prejfure of Heavy Solids and Fluids. In 
which Accompt is occa^onaliy imferted the Publifiers Reply to 
Mr^ George Sioclair's Paper ^ called a Vindication of the Pre- 
face of his Jixs Nova 5t Magoa Gravitatis & Levitaris. 
II* Experience intorno d diverfe cofe Naturali ^ fatte cU 
Fraoccfco R.edi. 
Yyyyy 
