Suicide of the World by André Saglio (tr. Michael Shreve) in The Last Man Anthology, edited by H. J. Liguore, forward by Michael D. C. Drout, Sword & Saga Press, 2010.
Nothing was more wonderful than this immense, endless day, when everything was exquisitely, violently reborn. When the couples were weary, they stretched out wherever they had aimlessly wandered, in the perfume of young plants, and slept holding hands. Near them, without fear, birds nuzzled their tiny heads in their ruffled feathers and insects stood motionless in the soft pollen on the calyx of flowers.
No one dreamed that this golden minute of eternity would end, except old Orgouzalam. At the same time that the machines were digging up the worn out corpse of the Earth, he was shut up with the books of past ages that guarded the secret of chemical inventions, so destructive that, in common accord, men had once renounced war to save the race. But the formulae of this devastating matter, as complicated as they were, were still quite infantile for a brain that collected the knowledge of the whole of humanity.