13. Before I ſaw the Notes that afforded me the precedent Narrative, I confeſs I ſuſpected this man might have thus diſcriminated Colours, rather by the Smell than by the Touch; for ſome of the Ingredients imployed by Dyers to Colour things, have Sents, that are not ſo Languid, nor ſo near of Kin, but that I thought it not impoſſible that a very Critical Noſe might diſtinguiſh them, and this I the rather ſuſpected, becauſe he requir'd, that the Ribbons,
whoſe Colours he was to Name, ſhould be offer'd him Faſting in the morning; for I have obſerv'd in Setting Doggs, that the feeding of them (especially with ſome ſorts of Aliments) does very much impair the exquiſite ſent of their Noſes. And though ſome of the foregoing particulars would have prevented that Conjecture, yet I confeſs to you (Pyrophilus) that I would gladly have had the Opportunity of Examining this Man my ſelf, and of Queſtioning him about divers particulars which I do not find to have been yet thought upon. And though it be not incredible to me, that ſince the Liquors that Dyers imploy to tinge, are qualifi'd to do ſo by multitudes of little Corpuſcles of the Pigment or Dying ſtuff, which are diſſolved and extracted by the Liquor, and ſwim to and fro in it, thoſe Corpuſcles of Colour (as the Atomiſts call them) inſinuating themſelves into, and filling all the Pores of the Body to be Dyed, may Aſperate its Superficies more or leſs according to the Bigneſs and Texture of the Corpuſcles of the Pigment; yet I can ſcarce believe, that our Blind man could diſtinguiſh all the Colours he did, meerly by the Ribbons having more or leſs of Aſperity, ſo that I cannot but think, notwithſtanding this Hiſtory, that the Blind man
diſtinguiſh'd Colours not only by the Degrees of Aſperity in the Bodies offer'd to him, but by Forms of it, though this (latter) would perhaps have been very difficult for him to make an Intelligible mention of, becauſe thoſe Minute diſparities having not been taken notice of by men for want of touch as Exquiſite as our Blind Mans, are things he could not have Intelligibly expreſs'd, which will eaſily ſeem Probable, if you conſider, that under the name of Sharp, and Sweet, and Sour, there are abundance of, as it were, immediate peculiar Reliſhes or Taſts in differing ſorts of Wine, which though Critical and Experienc'd Palats can eaſily diſcern themſelves cannot make them be underſtood by others, ſuch Minute differences not having hitherto any Diſtinct names aſſign'd them. And it ſeems that there was ſomthing in the Forms of Aſperity that was requiſite to the Diſtinction of Colours, beſides the Degree of it, ſince he found it ſo difficult to diſtinguſh Black and White from one another, though not from other Colours. For I might urge, that he ſeems not conſonant to himſelf about the Red, which as you have ſeen in one place, he repreſents as ſomewhat more Aſperous than the Blew; and in another, very Smooth: But becauſe he ſpeaks of this Smoothneſs in that place,
where he mentions the Roughneſs of Black, we may favourably preſume that he might mean but a comparative Smoothneſs; and therefore I ſhall not Inſiſt on this, but rather Countenance my Conjecture by this, that he found it ſo Difficult, not only, to Diſcriminate Red and Blew, (though the firſt of our promiſcuous Experiments will inform you, that the Red reflects by great Odds more Light than the other) but alſo to diſtinguiſh Black and White from one another, though not from other Colours. And indeed, though in the Ribbonds that were offer'd him, they might be almoſt equally Rough, yet in ſuch ſlender Corpuſcles as thoſe of Colour, there may eaſily enough be Conceiv'd, not only a greater Cloſeneſs of Parts, or elſe Paucity of Protuberant Corpuſcles, and the little extant Particles may be otherwiſe Figur'd, and Rang'd in the White than in the Black, but the Cavities may be much Deeper in the one than the other.
14. And perhaps, (Pyrophilus) it may prove ſome Illuſtration of what I mean, and help you to conceive how this may be, if I Repreſent, that where the Particles are ſo exceeding Slender, we may allow the Parts expos'd to the Sight and Touch to be a little Convex in compariſon of the Erected
Particle of Black Bodies, as if there were Wyres I know not how many times Slenderer than a Hair: whether you ſuppoſe them to be Figur'd like Needles, or Cylindrically, like the Hairs of a Bruſh, with Hemiſphærical (or at leaſt Convex) Tops, they will be ſo very Slender, and conſequently the Points both of the one ſort and the other ſo very Sharp, that even an exquiſite Touch will be able to diſtinguiſh no greater Difference between them, than that which our Blind man allow'd, when comparing Black and White Bodies, he ſaid, that the latter was the leſs Rough of the two. Nor is every Kind of Roughneſs, though Senſible enough, Inconſiſtent with Whiteneſs, there being Caſes, wherein the Phyſical Superficies of a Body is made by the ſame Operation both Rough and white, as when the Level Surface of clear Water being by agitation Aſperated with a multitude of Unequal Bubbles, do's thereby acquire a Whiteneſs; and as a Smooth piece of Glaſs, by being Scratch'd with a Diamond, do's in the Aſperated part of its Surface diſcloſe the ſame Colour. But more (perchance) of this elſewhere.
15. And therefore, we ſhall here paſs by the Queſtion, whether any thing might
be conſider'd about the Opacity of the Corpuſcles of Black Pigments, and the Comparative Diaphaneity of thoſe of many White Bodies, apply'd to our preſent Caſe; and proceed, to repreſent, That the newly mention'd Exiguity and Shape of the extant Particles being ſuppos'd, it will then be conſiderable what we lately but Hinted, (and therefore muſt now ſomewhat Explane) That the Depth of the little Cavities, intercepted between the extant Particles, without being ſo much greater in Black Bodies than in White ones, as to be perceptibly ſo to the Groſs Organs of Touch, may be very much greater in reference to their Diſpoſition of Reflecting the imaginary ſubtile Beams of Light. For in Black Bodies, thoſe Little intercepted Cavities, and other Depreſſions, may be ſo Figur'd, ſo Narrow and ſo Deep, that the incident Beams of Light, which the more extant Parts of the Phyſical Superficies are diſpos'd to Reflect inwards, may be Detain'd there, and prove unable to Emerge; whilſt in a White Body, the Slender Particles may not only by their Figure be fitted to Reflect the Light copiouſly outwards, but the intercepted Cavities being not Deep, nor perhaps very Narrow, the Bottoms of them may be ſo Conſtituted, as to
be fit to Reflect outwards much of the Light that falls even upon Them; as you may poſſibly better apprehend, when we ſhall come to treat of Whiteneſs and Blackneſs. In the mean time it may ſuffice, that you take Notice with me, that the Blind mans Relations import no neceſſity of Concluding, that, though, becauſe, according to the Judgment of his Touch, Black was the Rougheſt, as it is the Darkeſt of Colours, therefore White, which (according to us) is the Lighteſt, ſhould be alſo the Smootheſt: ſince I obſerve, that he makes Yellow to be two Degrees more Aſperous than Blew, and as much leſs Aſperous than Green; whereas indeed, Yellow do's not only appear to the Eye a Lighter Colour than Blew, but (by our firſt Experiment hereafter to be mention'd) it will appear, that Yellow reflected much more Light than Blew, and manifeſtly more than Green, (which we need not much wonder at, ſince in this Colour and the two others (Blew and Yellow) 'tis not only the Reflected Light that is to be conſidered, ſince to produce both theſe, Refraction ſeems to Intervene, which by its Varieties may much alter the Caſe:) which both ſeems to ſtrengthen the Conjecture I was formerly propoſing, that there was ſomething elſe
in the Kinds of Aſperity, as well as in the Degrees of it, which enabled our Blind man to Diſcriminate Colours, and do's at leaſt ſhow, that we cannot in all Caſes from the bare Difference in the Degrees of Aſperity betwixt Colours, ſafely conclude, that the Rougher of any two always Reflects the leaſt Light.