220 
of theStarrs, though much quicker: which two» Phexouena (for I thal! 
MicROGRAPHIA. 
fpirit of Wine, for the proportion of the fame Water, to the fanie very 
well rectify dfpirit of Wine was, as21.to19.  . pee 
~ Sovas to'Refration,Water is more Denfe then Ice; for] have found 
by amoft certain Experiment, which I exhibited before divers illuftrions 
Perfons of the Royal Society, that the Refraction of Water was greater 
ther that of Ice, though fome confiderable Authors have affirm’d the con- 
trary, and though the Ice be avery hard, and the Water a very fluid 
body. 
| "Phat the former of the two preceding Propofitions is true,may be ma- 
nifefted by feveral Experiments: As firft,if you take any two liquors differ- 
ing from one another in denfity,but yet fuch as will readily mix:as SaltWa- 
ter,or Brine,& Frefh;almoft any kind of Salt diffolv'd in Water,and filtra- 
ted, fo that it be cleer,{pirit of Wine and Water; nay, fpirit of Wine,and 
fpirit of Wine, one more highly re¢tify'd then the other, and very many 
other liquors; if(Ifay) you take any two of thefe liquors, and mixing 
them ina Glafs Viol, againft one fide of which you have fix'd or glued a 
fall round piece of Paper, and fhaking them well together (fo that the 
partsof themmay be fomewhat difturb'd and move up and down)you 
endeavour to fee that round piece of Paper through the body of the li- 
quors; youfhall plainly perceive the Figure to wave, and to be indented 
much after the fame manner as the limb of the Sun through a Telefeope 
feemsto be,fave onely that the mutations here,are much quicker. And if, 
in {teed of this bigger Circle, you take a very fmall {pot, and faften and 
view it asthe former, you will find it to appear much like the twinklin 
“— 
take notice ofno more at prefent, though I could inftance in multitudes 
of others) muft neceflarily be caus d by an znfieFiow of the Rays within 
the terminating fuperficies of the compounded medium, fince the furfaces 
_ ofthe tranfparent body through which the Rays pafs to the eye, are not 
atall altered or chang’d. igs : 
This z#fle&ion (if1 may fo call it) limagine to be nothing elfe, but a 
multiplicate refradion, caufed by the unequal dexfity of the conftituent 
parts of the medium , whereby the motion, a¢tion or progrefs of the Ray 
of light is hindred from proceeding in a ftreight line, and sufleced or de- 
flected by a curve. Now, that itis a curve line is manifeft by this Expe- 
' riment : [took a Box,fuchas A D GE, inthe farft Figure of the 37.Scheme, 
whofe fides ABCD, and EF GH, were made of two {mooth flat 
plates of Glafs, then filling it half full with avery ftrong folution of 
Salt, I filled the other half with very fair frefh water, then expofing 
the opacous fide, D HGC, tothe Sun, I obferv'd both the refradion and 
_ inflection of the Sun beams, D & K H, and marking as exactly as I,.could, 
the points, P, N, O, M, by which the Ray, K H, pafied through the com- 
pounded medium, I found them to bein a curve line; for the parts ofthe 
_ medium being continually more denfe the neerer they were to the bot- 
tom, the Ray p f was continually more and more deflected downwards 
from the ftreight line. | } Serr 
© This Infleétion may be mechanically explained, cither by Monfiewr 
= | ag “i Des 
+ 
