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tionof Surface has in hajlening or retardingt\\t\ncTt2i{Q, 
of weight, I expos'd in the fame ^om and to the 
fame temper of the Air ( as near as I could Guefs ) three 
Drams of the fame Oyl of Vitriol inanopen fiatGlafs 
ont Inch Broad, being only i of the Diameter of that 
Glafs us'd at firft with the like quantity. The refult 
was this ; that whereas the other Surface of three 
Inches Diameter gain d ( as in the Table ) near nineteen 
Grains the firft fix hours, this lefs Surface g2imtdi a very 
little perceivable more then two grains in the fame fpace 
of time. Now fince xhzAreas ofCircles are to one another 
as the fquares of their refpetlive diameter s-^^lS one the fquare 
of the lefs is to nine the fquare of the greater Glaffe's dia* 
meter^ was the weight of a little more than two Grains 
gain'd in the narrower Glaffe to near 19 Grains gain'd 
in the broader , wherefore the time of Increafing bears 
as near as can be expelled an exad: proportion to the 
Surface of the Liquor expos'd , and the liquor in the 
lefJer Glafs having but 7^ part of the Surface of the 
greater, could not be fatiated under nine times as many 
days as the greater. From what has been faid it will 
alfo follow , that if this three Drams had a Surface in 
the fame proportion to the weight of a Sruple and 
a Grain vi^, a little more than fix Inches Diam. as 
that of ^ Inch was to three Grains, the Encrcafe of 
both would be finijh't in the fame time, and would ex- 
cufe the long attendance of any that fhall think it 
worth while to repeat the experiment. Perhaps too the 
different depth of the Glafs together with the more or lefs 
free accefs of Air ought to be attended to in this af- 
fair: But thus much for the eircumjlances of the expe- 
riment. 
The only ufe of it 1 can at prefent find will be to 
eflimate moijlure and drynefs in the which is evident- 
ly f^K^^j^^^ h ^^^'^ following obfervation That when 
the 
