382 ESSAYS anp OBSERVATIONS 
its nucleus was a chalky or limy fubftance 
about the fize of a common pea. 
Hift. 3. Dr John Stevenfon phyfician 
gave me a concretion fix inches in cir- 
cumference, the muclus of which is a 
plumb {tone, taken out of the inteftines of 
a boy of five years old. Though the 
ftone had been fwallowed long before the 
boy’s death, the kernel of it was freth 
when the ftone was taken from the mid- 
dle of the ball. A clyfter had brought 
away feveral other plumb-ftones from this ~ 
boy fome months after the plumbs had 
been eat. 
iif. 4. Dr Stevenfon alfo gave me a= 
nother fuch concretion, which has four 
flat fides with feveral depreflions in them, 
meafuring about five inches in circum- 
ference, formed alfo on a burnet plumb- 
itone, which he took out of the inteftines 
of a girl. 
Hifi. 5. ¥rom the fame gentleman I 
likeways had a third concretion pretty 
like to, but a little larger than the one 
defcribed and painted by Dr Simfon in 
Med, Eff. vol. 1. art. 32. which, with 
three 
