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Received February 13, 177 2 * 
XXII. K 02 KIN 0 N EPATO 20 ENOY 2 . 
O R, 
The Sieve of Eratofthenes. 
Being an account of his method of finding all 
the Prime Numbers , by the Rev. Samuel 
Horfley, F. R. S. 
Read May 7, y* Prime number is fuch a one, as hath' 
/ \ no intregral divifor but unity. 
A number, which hath any other integral divifoiy 
is Compofite. 
Two or more numbers, which have no common 
integral divifor, befides unity, are faid to be Prime 
with refpeft to one another. 
Two or more numbers, which have any commons 
integral divifor befides unity, are faid to be 
Compofite with refpedt to one another. 
The diftindiion of numbers into Prime ancl 
Compofite, is fo generally underflood, that I flip- 
pofe it is needlefs to enlarge upon it. 
To determine, whether feveral numbers propofed 
be Prime or Compofite with re [peel to one another T 
is an eafy Problem. The folution of it is given by 
Euclid, in the three firfl propofitions of the 7th' 
5 book 
