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23. There are few phenomena relative to glass more- 

 hard to be accounted for, than that of the Bologna 

 bottle, so called because it was first discovered at , 

 Bologna. If you let these bottles fall from some height 

 on a brick floor, they will not be broken ; tut drop into 

 them some hard body, and they will burst in pieces.. " I 

 took one of these," says Dr.. I. " which held near a pint, 

 and let it fall five feet and a half on a brick floor, and 

 it was not broken. I dropt into it a bit of flint, weighing 

 eleven grains, and immediately it burst in pieces. 



" I dropt into another bottle a ball of lead, weighing 

 one hundred and forty grains, into a third a piece of 

 brass weighing three hundred grains,, and neither of 

 them was broken. 



* c These glasses only differ from common phials in this,, 

 they have not cooled gradually in what is called the 

 nealing furnace, but are exposed to the open air as soon 

 as forn.'ed. They resist hard* blows from without. I 

 have given to some violent strokes with a mallet, and 

 they have not broke. They likewise do not break, 

 though several heavy bodies be dropt into them. I have 

 dropped into them, from the height of three feet, musket 

 balfs, and pieces of iron, brass, gold, without any effect; 

 but when I dropt into if, from the height of three inches, 

 a shiver of flint no bigger than a small pea, in about two 

 seconds the glass flew. Having tried the experiment on 

 several others with the same piece of flint, most pf theni 

 broke in the moment of the stroke, the rest one or two. 

 seconds after it. 



" I let fall into several glasses a flint of half the size,, 

 and they flew in like manner. I let fall into one a flint 

 DO larger than a grain of sand, shook the glass, and set 

 it dowti. I did the sarnie with four ethers. In about half 

 an hour one of them flew, and the other four soon after,. 

 " 1 let fall into one a sapphire set in a ring : and though 

 the bottom of the glass was near an inch thick, the 

 sapphire passed through it as through a spider's web.- 

 The glass flew all ways, and the ring remained on the 

 tabk* just where it fell. 



'< A bit of china, half a line thick ami two lines broad, 

 broke several glasses ; so. did a bit of glass of the same 



