During the Royal Society balloting process for John Dollond’s election, it became apparent that Dollond had omitted any acknowledgement to Samuel Klingenstierna who had supplied Dollond with the vital clue which underpinned his refrangibility experiments. When this error of etiquette was realised, Dollond’s contribution was reduced in value. Dollond’s sense of self-importance did not allow him to remain quiet and through Benjamin Wilson and Torbern Bergman, Klingenstierna came to learn of Dollond’s claims. Klingenstierna then wrote to Dollond on 30 May 1761, taking him to task over his despicable behaviour. Two additions were added to the basic letter: (i) Extract 1 is part of the critique levelled at Dollond, attempting to reason with him over the errors of his way; (ii) Extract 2 is a further letter (undated) and dispatched with that of 30 May 1761 in which Klingenstierna entreats Dollond to appreciate the need for absolute integrity and openness in all matters of science. Source: Klingenstierna’s correspondence with Dollond is reprinted in full in Nordenmark and Nordström, Lychnos, 5 (1939), pp. 313-384.