[ 5 r 3 3 
enfue. Bat why does not a Ball of Gold, Silver, 
Iron, Copper, or any of the other Bodies which I have 
tried unfuccefsfully, tho’ 1000 times heavier, equally 
caufe this Concultion, and break the GlafTes ) Shall 
it be faid, It is becaufe they are not elaftic ? Copper, 
Iron, Silver, and Ivory, are elaftic ; and as much fo 
as Flint and Porcellanej and furely much more fo 
than the End of one’s Finger. 
It appears to me, thar, before we undertake to 
give the Solution of thefe Phenomena., we fhould 
apply ourfelves to the making a much greater Variety 
of Experiments about them 5 that we fhould both try a 
greater Number of GlafTes, and thofe with a greater 
Variety of differing Bodies, that we may be able 
thence to colled at laft, in what ClafTes the feve- 
ral Bodies are to be ranged, that are either fit or 
unfit for thefe Purpofes : And then it may, perhaps, 
be Time to inquire, Whether it is from the Prin- 
ciples of Chemiftry, or from thofe of Mechanics, or 
any other Branch of Natural Philofophy, that we 
are to feek for the Reafons of the feveral Fads. 
AFTER the reading of this Paper, the Prefident 
produced before the Society feveral of the Phials 
themfelves, which he had received from Holland , to- 
gether with fome others he had caufed to be made at Mr. 
Ceiled Glafs houfe in White-Fryars. He acquainted the 
Company, that he diad yet made himfelf but few 
Trials of thefe GlafTes, as he was defirous to preferve 
them till he could have the Satisfadion of fhewing 
them to the Society , and repeating fome of Monfieur 
Allamand’s chief Experiments in their Prefence : 
That he had defignedly broken only four of his 
U u u foreign 
