( 1121 ) 
this manner it was again put into the Water,and fufpended 
as before on the Ballance, and it then weigh’d but 175 
Grains and a half , which Subftra&ed from the firft 
Weight, gave 183 Grains the Difference 3 and was the 
weight of the Quantity of the Air drawn from the Bottle 
by the Pump. Then opening a Cock under Water, the 
Water was at firft violently Imped’d in the Bottle, ( but 
Abating Gradually of its force, ) till fuch a quantity was 
enter’d as was equal to the bulk of Air withdrawn. (So 
that by Making the Experiment after this manner, a per- 
fon need not be very follicitous in the nice Exhaufion of 
the Receiver, for it muft of neceflity Aafwer Recipro- 
cally to the Refpe&ive Quantities taken out, the Remain- 
ing Air bung weigh’d at laft as well as at firft and no 
greater quantity of Water can Enter the Receiver, than 
what will fupply the fpace deferted by fo much Air. ) 
The Bottle now being again weigh’d, it was found to be 
16.213 2 Grains. From which 175 Grains and a half be- 
ing fubftrafted, ( which is the weight of the Bottle more 
than its like bulk of Water) there r rnain’d 161956 
Grains and a half, which being divided by 183 Grains, 
the weight of the Air taken out of the Receiver, gave 
the Proportion as 885 to 1. The Averdupoize Weights 
being brought to Ounces, I reduc’d to Grains, by multi- 
plying them by 438, the juft number of Grains contain’d 
in an Ounce of that Weight, The Column of Mercury 
in the Barometer at the fame time Meafuring 09.7 Inches. _ 
The Seafon of the Year is to be confider’d, (which was 
May,") and I doubt not but if, the Experiment be Repeated 
in December or January, a fenfible difference willenfue. 
