[ 694 ] 
LXVII. An Account of a Jlony Concretion 
taken from the Colon of an Horfe ; by Mr . 
H. Baker, F. R. S. 
Read May 8, I Have now the honour to lay before this 
1760. 
Royal Society one half of a flony con- 
cretion, formed in the colon of an horfe, which was 
lately fent me from Norwich, by my very curious 
friend Mr. William Arderon, F. R. S. This horfe, 
he informs me, was twenty-five years old, had been 
often ill, and under the farrier’s care ; which made 
him defire to have it opened, when dead. 
The whole ftone, when firfi: taken out, weighed 
ten pounds and half ; and he caufed it to be fawed 
in two, that a better judgment might be made of the 
manner of its formation. Several fmaller concretions 
were alio found in the colon, fome whereof are fhewn 
herewith j but they are much lefs folid, and more 
irregular, than the large one. 
This ball is full feven inches in diameter, and con- 
fifts of many laminae, or coats, which form a num- 
ber of concentric circles, around a nucleus in the 
center, which feems to be a fmall fhiver of black 
flint. Fifteen or fixteeen of thefe coats are eafily di- 
ftinguifhable, and fome have been broken off : they 
vary fomething in colour, and are, in general, fo 
ftony, that they v/ould probably take a pretty good 
polifh. The coats differ in thicknefs, according, per- 
haps, to the time they were in forming : for it fliould 
feem, if conjedture may be allowed, that each coat 
was formed in a longer or fliorter time, according to 
2 its 
