ABSTRACT
The final manuscript treatise by Thomas Salmon is bound in a volume of manuscript writings and notes by Isaac Newton, some on music but most on optics. It bears the title 'The Division of a Monochord', and is in Salmon's hand. It does not seem possible to be absolutely certain that the manuscript was owned by Newton rather than inserted among his papers after his death. Estimates of the date of 'The Division of a Monochord' have varied; the online catalogue of the Newton manuscripts at Cambridge University Library places this text 'c.1670–c.1680', while Penelope Gouk has suggested that Newton acquired it 'some time from the late 1680s'. Musicall Proportions are best demonstrated upon a Monochord, because therein is no difference of cise or tension, but the different longitude alone is the cause of the variety of the Notes.
