( «94« ) 
difBcalt to judge to a nicety in fo fudden a motion 5 but 
there was a fenfible difference betwixt the rebound of 
thofe dropt in Vacuo, and thofe in Air condensed. I could 
not obferve that thefmall difference in the vr eight of the 
Marbles made any difcernable alteration in their Refiliti- 
ons. 
V. An Experiment on the de/cent of Malt dujl in the 
Evacuated ^eaivery at Grcfliam College. !By Mr 
Fr. Hauksbec. 
I Took fome Maltduft, and having well dryed the fame, 
put a quantity of it into a fine Muflin Bag, where be- 
ing loofely inclos d, would upon (baking difcovcr it felf 
plentifully in the open Air, undulating and floating a con* 
fiderable time before it would defcend 5 but being in- 
cluded within a Receiver, from which the Air was well 
cxhauftedj and then ftiaken, the duft defcended asa pon» 
derousBody, precipitating in ftrait lines from the top to 
tl^e bottom of a tall Keceiverr 
London^ Printed for Sam. Smith and Benj> Walfird^ Prin- 
ters to the Rojal Societ/^ at the Princes Arms in St PauVs 
Xbfrclhjardf 1705« 
