(436 ) 
found by direct division or by the method of § III, that the prime 
numbers under 97 are non-divisors of G, we can immediately draw 
the conclusion that G possesses at most two factors, a 4-fold + 1 
and a 4-fold — 1. 
Then it is only necessary to apply the operation to 13 Xx 5 & 3G. 
Such like methods as the one under consideration could be applied 
to the other data of the theory of numbers: the decomposition of a 
number into the sum of a square and a twofold, threefold or fivefold 
of a square. 
(February 19, 1902). 
