The fortuitous or casual concourse of atoms.
Source, in full
Sermons, vii. Works, Vol. iii. p. 147 (1692). Compare: "That fortuitous concourse of atoms", "Review of Sir Robert Peel's Address", Quarterly Review, vol. liii. p. 270 (1835); "In this article a party was described as a fortuitous concourse of atoms,—a phrase supposed to have been used for the first time many years afterwards by Lord John Russell", Croker Papers, vol. ii. p. 54.