Note on Dr Muir's Paper, “A Problem of Sylvester's in Elimination”

Extract

I in part reproduce this very interesting paper for the sake of a remark which appears to me important. I write (a, b, c, f, g, h) in place of Muir's (A, B, C, A′, B′, C′), and take as usual (A, B, C, F, G, H) and K to denote (bc − f², ca − g², ab − h², gh − af, hf − bg, fg − ch) and the discriminant abc − af² − bg² − ch² + 2fgh.