[ 475 ] 
mafs of the cool lava from an height upon it, which, 
far from linking into it, rebounded like a ball. Its 
motion was as flow as the common walk of a man. 
It broke out in live different places. I walk’d on it 
for about a mile, whilll near three feet of the top 
were cool’d ; but for many feet underneath as red to 
the fight as the furnace of a glafs-houfe. It cover’d 
and burnt up trees, houfes, &c. in Ihort all it found 
in its way. From, 
SIR, 
Vour dutiful fon, 
John Parker, 
LXX1X. *The Cafe of a Piece of Bone , toge- 
ther with a Stone in the Bladder >fuccefsfully 
extracted by Mr, Jofeph Warner, F,R,S • 
and Surgeo?i to GuyV Hofpital. 
Read May 28,/ ■ H E Hone in the bladder is a dif- 
17 5 2 - eafe f 0 common to both fexes, 
and the fymptoms, and circumftances attending it 
are in general fo well known, and fo much alike, 
as to render few cafes of this kind worthy of commu- 
nication. But as the following is attended with a lin- 
gular, and perhaps unparallel’d circumftance, I make 
bold humbly to offer to your confideration a Ihort 
account of the following fadt : 
Ooo 2 
Elizabeth 
