(5o) 
with water^ and expofed to the cold Air,[do burft ^ and where 
alfo the weight is expreffedj that will be removed by the expan- 
live force of Freezing? Whereunto an Inquiry is fubjoined,, 
whence the prodigious forcej obferved in water, expanded by 
Glaciation, (hould proceed? And whether this Pbtenomenon 
raay be folved , either by the Cartejian, or Epicurean Hypo- 
thefis ? 
1 1 5 What is the Sphere of AUivity of Cold, or the Space , to 
whofe extremities every way the Action of a cold Body is able 
to reach: where the difBeuIty of determining thefe limits, to- 
gether with the caufes thereof, being with much circumfpecfti. 
on mentioned, it is obferved, that the Sphere of ABivky of 
Cold is exceeding narrow^ not onely in comparifon of that of 
HeatinFire^ but in comparifon of, as it were, Atmsfphere 
of many odorous Bodies > and even in comparifon of the 
Sphere of ABivity of the more vigorous Loadftones , infomuch, 
that the Author hath doubted, whether the Senfe could difcern 
a Cold Body, otherwife then by immediate Contra<St. Where 
feveral Experiments are delivered for the examining of thi^ 
matter, together with a curious relation of the way ufed in P^r'- 
l^a, though a very hot Climate, to fnrnifti their Confervatories 
with folid pieces of Ice of a confiderable thicknefs : To which 
is added an Obfervation, how far in Earth and Water the Froft 
will pierce downwards, and upon what accounts thedeepnefs 
of the Froft may vary. After which, the care is inculcated, 
that muft be had, in examining, whether Cold may be diffufed 
through all Mediums indefinitly, not to make the Trials with 
Mediums of two great thicknefs : where it is made to appear, 
that Cold is able to operate through Metalline VelTels, which is 
confirmed by a very pretty Experiment of making ley Cups to 
drinkin; whereof the way is accurately fet down. Thenare re- 
lated the Trials, whether^ or how. Cold will be diffufed through 
Medium^ ih^it fome wozild think ^Vacuum, and which to (?/5^^r/ 
would fcem much lefs difpofed to affift the diffufion of Cold , 
thanCommon Air it felf. After which follows a curious Ex- 
periment, {hewing whether a Cold Body can operate through 
