It is shown that if the first case of Fermat's last theorem fails for
an odd prime l, then the sums of reciprocals module l, s(k, N) = Sigma
1/j (kl/N < j < (k + 1)l/N) are congruent to zero modl for all intege
rs N and k with 1 less than or equal to N less than or equal to 46 and
0 less than or equal to k less than or equal to N - 1. This is equiva
lent to B-l-1(k/N) - B-l-1 = 0 (modl), where B-n and B-n(x) are the nt
h Bernoulli number and polynomial, respectively. The work can be consi
dered as a result an Kummer's system of congruences.