Date: 1803

"How shall I touch his iron soul with pain, / Who hears unmoved a multitude complain?"

— Chatterton, Thomas (1752-1770)

Date: 1803

"Charms with soft words, and sooths with amorous wiles, / Her iron-hearted Lord,--and Pluto smiles."

— Darwin, Erasmus (1731-1802)

Date: 1803

"Sermons, though flowing from the sacred lawn, / Are flimsy wires from reason's ingot drawn."

— Chatterton, Thomas (1752-1770)

Date: [1805?] 1810, 1812, 1818

"Where bloody Butler's iron-hearted crew, / Doomed to the flames the weak submitting few"

— Wilson, Alexander (1766-1813)

Date: 1820

"And they [Stewart, Tracy, Cabanis] ask why may not the mode of action called thought, have been given to a material organ of peculiar structure, as that of magnetism is to the needle, or of elasticity to the spring by a particular manipulation of the steel."

— Jefferson, Thomas (1743-1826)