Microcrapnia. 
fecondly, the Reafon of the apparition of many Suns may not be found 
out, by confidering how the Raysof theSun may fo be reflected, as to 
defcribe a pretty true Image of the body,as we find them fromany regu- 
Jar Superficies. Whether alfo thismay not be found to caufe the appa- 
"-gition of fome of thofe Pare/i7, or counterfeit Suns, which appear colous 
red,by refracting the Rays fo, asto make the body of the Sun appear in 
quite another place thenreally it is. But of this more‘elfewhere. 
5. Whether the Phenomena of the Clouds may not be made out by 
this diverfity of denfity in the upper and under parts of the Air, by 
fuppofing the Air above themto be much lighter then they themfelves 
are, and they themfelves to be yet lighter then that whichis fubjacent 
tothem, many of them feeming to be the fame fubftance with the Cob- 
webs that fly in the Air after a Fo! 7 +3 ‘b 
Now that fuch a conftitution of the Air and Clouds, if fuch there be, 
may be fufficient to perform this effect, may be confirm'd by this Expe- 
timent. ely 
Make as ftrong a Solution of Sale as you: are able, then filling a Gla 
of fome depth half full withit, fill the other half with freth Water, and 
poyle alittle Glafs-bubble, fo as that it may fink pretty quick in frefh 
Water, which take and put into the aforefaid Glaf, and you fhall find 
it to fink till it comes towards the middle, where it will remain fixt, 
without moving either upwardser,downwards, And by afecond Ex 
periment, of poifing fuch a bubble in waters whofe.upper part is warmer, 
and confequently lighter, then the under, which is colder and-heavier 5 
the manner of which follows in this next Query, whichis, 
6. Whether the rarifaGtion and condenfation of Water be trot made 
after the fame manner, as thofe effects are produc’din the Air by heats © 
for Lonce pois'da feal'd up Gla&-bubble fo exactly, that never fo imal 
an addition would make it fink, and as {mall a detraction make it {wim, 
which fuffering to reft in that Veflel of Water for fome time , Talwayes 
found it about noon to beat the bottom of the Water, ee nights one 
in the morning, at the top: Imagining this to proceed from the Ka 
faction of the Waters caus d by the heat , Imadetryal, and found moft 
true; for Iwas able at any time, either to deprefs, or raifeit, by heat 
and cold ; for if I let the Pipe ftand for fome time in cold water, I 
could eafily raife the Bubble from the bottom, whither I had a littlea- 
fore detruded it, by putting the fame Pipe into warm Water. And a 
way [have been able, for a very confiderable time, to keep a Bubble 
poys'd in the Water, asthatit fhould remain in the middle, anid neither 
fink, nor {wim : For gently heating the upper part of the Pipe ail 
Candle, Coal, or hot fron, till I perceived the Bubble begin to a end, 
then forbearing, Ihave obferved it to defcend to fuch ot fuch a ftation, 
‘and there toremain fafpended for fortie hours, till the heat by ae 
“were quite vanifhed , when it would again afcend to its former a dhe 
This [have alfo often obferved naturally performed eh a aed ed 
Air, which being able to rarifie the upper parts of the . Of a ; re 
then the lower, by reafon of its Se contatt, the heat 9 
i 2 
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