( t^oT ) 
C^iantities that firfV rekht the fftn } Iron taking • 
firey by their flame making an Explofibn of the whole, at 
once blowing up the Recipient, akho the weight ot Air 
incumbent on it was equal to 144 /. accounting the Re- 
ceiver at 3 inches ~ diaoieter, but was fomething more , 
which docs fufficiently allow for the want of height of 
Mercury. The Gage then ftanding at 29 inftead of 
30, from which the CakulatioB, is made. The Gun- 
powder us'd was the common Glased fort 5 and the weight 
of the fix quantities, which remov'd the Recipient, with 
fo great a Preflure incumbent on t, was but 7- grains, each 
Quantity weighing fomething more than one. I did not 
obferve the Recipient to be broke before it rrach'd the 
Floor. It was thick lin*d with Sulphureous and Nitrous 
Steams, fo that the flafhes of Fire thro the Clowdinefs of 
the Glafs feem'd very much to refemble iaint Lightnings. 
The Content of the Receiver . was equal to about 25 
ounces i of Water, allowing for the Bulk of Iron and 
Pedeftal. 
VII. An Account of m Experiment made Deccmb. the 
t6thy 1704. To try the Quality of Air^ prodncd 
from Gunpowder y fir d Vacuo Boyliano. (By 
Mr Fr. Hauksbee. 
* I Pen making the late Experiment of firing Gun* 
I powder in Facno^ it was hinted as well worthy of 
tryal, Whether the Faflitious Air of fird Gunpowder 
was endu'd with any Qpality differing from Common 
Air. In order to the fatisfiftion of the Query, On Dc- 
ce^kr 26th about noon I includ cda Candcnt Iron in 
