( H35 ) 
Now when I law that but very few more Bubbles arofe from 
the Silver, I could perceive very plainly that maft of thofe 
Air-bubbles that had been extrafted, did not only grow lefs 
before they arrived at C, but vvrere quite vanifht. 
Now that the Silver was vifibly united to. the Aquafortis^ 
and had remain u fo„ 24 hours^ there was as much Air in the 
Clafs at C as would fill the Tpice of .3 or, 4 Pins heads ^ 
whereas^there arofe fach a vaft number of Air- bubbles from 
the Silver curing its diilblution, that I wasamazd what was 
became ofthem^ feeing they were in a manner vaniftiLj wiiLh-« 
out leaving any Traces behind them. 
' I caused the kit in C to diflodge out of the Orifice F. by 
raifing the Glafs perpendicularly, -and then I threw in three 
times as much Silver, whereupon an unfpeakable number of 
Air-bubbles conunually afcended towards C. but were dif- 
patch'd before they could arrive at the top^and fuch ot them 
as were bigger, and held out till they came to C.'didihea 
bur ft in pieces, without leaving any marks behind them, ex- 
cept' always as much Air as would fill the fpace of three or 
four Pins heads. 
Furthermore,! put 50 grains of Silver into the (aid Water, 
without obferying any more remarkable difference, fave 
that there remain d at C* as much Air in bigriefs as an ordi- 
nary Pea. 
In thefe my obfervations I have like wife taken notice, 
that the larger the Air-^bubbles are.which arife Irom the Sil- 
ver, the tafter they mount towards the top of the Glafs 5 
and this has place alfo I imagine in that air which the Learn- 
ed call Aer Snbtilis^ 7jiz. how much the larger the Particles 
of Air be that perfpire from our bodies, the fafter they af- 
cend 3 and folikewife in the defcent of all heavy bodies to- 
wards the Earthy as for inftance, take two Iron Balls, one 
of an Inch in diameter, and the other of 5 Inches, and Jex 
thefe two Iron Balls fall at once frbm a certain eqUal heighth, 
my pofition is, that that Ball whofe Axis, is 5 Inbhes, muft 
cut thro a Column of Air 25 times greater than the Column 
of 
