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Notes - John Dalton, a colour-blind botanist, & English Lakeland botanists 23of a local Museum' in Keswick, isCrosthwaite's one (see Wood 1970). The titlepageof the first volume is inscribed 'HortusSiccus: seu Plantarum diversarum in AgrisKendal vicinis sponte nascentium Specimina.Opere et Studio Joannis Dalton collecta', and isdated l79l. The second is dated 1793, while thetitle reads: 'Hortus siccus: seu Plantarum diversarumin locis Kendal vicinis sponte nascentiumSpecimine. Vol. 2. Opere & Studio JoannisDalton collecta'. According to Wood (1970)there are 112 species in the first volume and 53in the second, but none was localized, except for'in Agris Kendal' or 'in locis Kendal' on therespective title-pages. Other plants were addedto the second volume after Dalton hadcompleted it, presumably by Crosthwaite,including ,... 6 Plants ... found by P.Crosthwaite 3 , on the top of He Iv ell in, & were allhe could meet with on a careful search', and' ...17 Rare Plants .. , collected, & Presented by theReyd. Mr. Harryman 4 (F. L. S.) of Egleston,County of Durham ...' (Wood 1970).Dalton also kept a herbarium collection for hisown use. Eleven volumes containing specimens('several species to a page, each ... accompaniedby a note of locality, ... many of the specimens... small and incomplete') which were in thepossession of the Manchester Literary andPhilosophical Society were catalogued byAdamson and Crabtree (1920). Most unfortunately,these were subsequently destroyed byenemy action during the Second World War.They evidently differed from the Edinburgh setwhich is arranged in order of flowering. TheManchester herbarium, dated 1790, wasarranged according to the Linnaean System,'secundum Classes et Ordines disposita' (seeWood 1970). There are also specimenscollected by Dalton in LIV (J. Edmondson,pers. comm.).1790 is the date given by Dalton himself, in aremarkable paper he read to the ManchesterLiterary and Philosophical Society on 31October 1794, as the year in which hecommenced 'the occasional study of botany ...'- oddly, it was also the year, according to Gross(2004), that saw the end of his association withthe blind John Gough.Dalton moved to Manchester in 1793 'at thesuggestion of several leading Manchestercitizens and of Gough' (Greenaway 2004), tobecome a tutor in mathematics and naturalphilosophy at New College, Manchester, aninstitution that had been established by dissenters.He kept in touch with his friends in theLake District and in a letter to Elihu Robinson,whom he addressed as 'Dear Cousin', dated (inQuaker style) '2d moo 20th 1794', John gave thefirst indications of 'a very curious investigation':... I discovered last summer with certainty,that colours appear different to me to whatthey do to others: The flowers of most of theCranesbills appear to me in the day, almostexactly sky blue, whilst others call them deeppink; but happening once to look at one in thenight by candle light 1 found it of a colour asdifferent as possible from day light; itseemed then very near yellow, but with atincture of red; whilst no body else said itdiffered from the daylight appearance, mybrother excepted, who seems to see as I do.[Dalton 1794]What might have happened in the summer of1793 to lead Dalton to such a discovery? Mostprobably it was the move to Manchester, 'atown which ... surprised him, when he got toknow it, as being made mostly of brick'(Greenaway 2004). Manchester was not hometerritory, a place where he and any eccentricitieshe possessed were so well known that they werelikely to be indulged or just ignored. Undoubtedlyhe soon met others interested in scientificmatters, if not in plants. In the past, during hisdialogues about botany with John Gough,shape, form and texture (and perhaps smell andtaste) were the only characters that would haveany meaning; Gough, being blind, would havehad no apprehension of colours. This was atruly bizarre coupling: the blind Gough tutoringthe colour-blind. Jonathan, his brother, whenthey discussed plants, saw what John saw, andso they would have agreed about colours. Otherpeople had thought Dalton was joking when hedisputed whether a flower was red or blue: 'Ihave often seriously asked a person whether aflower was blue or pink, but was generallyconsidered to be in jest' (Dalton 1798). But,John Dalton was now in Manchester wherepeople with like interests were neither totallyblind nor afflicted by deficient vision, nor didthey think he was joking; where, ifhe remarkedthat a garden pink (Dianthus cultivar) had a blueflower, he surely provoked his interlocutor toexclaim that it was in fact red (Dalton 1798).Dalton had been elected a member ofManchester's Literary and PhilosophicalSociety on 3 October 1794, and four weeks laterdelivered his historic lecture entitled'Extraordinary facts relating to the vision ofcolours: with observations'. Having completedhis investigations, he happily admitted that hehad grown up thinking that there was 'a perplex-