'I most heartily thank you for your List of the Golden coins of Scotland, which is much more complete than I could have had from any other hand. I am at a Litle losse in knowing what to make of your Drop. I took it to be the same with our penny weight, and yet (I see) it will not agree with that. I have K Charles the Firsts Scotch Broad piece (R his praesum ut prosim) which you sayes weights 5 drops and 5 Gr:, wheras in our Money weight, it carryes 6 de.w. and 17 gr: My Lord AB of York has a small coin of Q Marys (R crucis arma sequamur) which weighs with us two penny weight and 5 grains, it must be the same with what you say weighs one Drop and 24 gr: Be pleased in your next to tell me what number of graines make your Drop.'
(NLS, MS 33.3.19, f.24v; Burnett 2020b, p. 1541)