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thcre may be\ all vthich Compounded together xvouid make H'hite-f (stc. TIris, iffeems, is takcn for my Hypothefis. ’Tis true, that from my Tbeory I arg ilethe Corporiety of Light ; but I do it without any absolute positiveneß, as’the Word perhaps intimates ; and malte it at moli but a very plausible conso-quenceof the Doctrine,and not a Fundamental Supposition, nor so mach as anypart of it ; which was wholly comprehended in the precedent Propositions.And I (omewhat wonder, how the Objector could imagine, that, whcn I haddsserted the Theory v.ith the greatcst Rigour, I (lrould be so forgetful as aftcr-wards to allere the Fundamental Supposition it (elf wirh no moro thun a per-haps. Had I intended any (sich Hypothehs, I (hould somewhere have cy-plained it. But 1 knew, that the Properties, which I declared of Light, wcrein some mcalure capable of being explicated, not only bynhat, but by many otheriVlechanical Hypotlrcles. And thereforc I choso to decline them ali, and to(pcak of Light in gcneral terms, conlidering it abstractlv, as something orother propagated every way in streiglrt Lines from Luminous Bodies, withoutdctermtning wlrat that thing is ; whether a confuled Mixture of Di (formQualitics, or Modcsof Bodies, or of Bodies t hem solves, or ot any Virtues,Powers, or Beings wlratsocver. And for the länre reason l chofe to (peak ofColours according to the Information of our Sensos, as it they were Qualt-ties of Light without us. Whercas by that Hypothehs, I rauft have confr-dered them rathet as Modesof Sensation, excited in the Mind by various Mo-tions, Figures, or Si 7 .cs of the Corpusolcs of Light, making various Mccha-nical impreliions on the Organ of Senso ; as I exprefled it in that place, whcre1 (pake of the Corporiety of Light.

But (iipposing I had propounded that Hypothehs, I underftand not, whythe Objector (hould so much endeavour to oppose it. For certainly it has amuch greater Affinity with bis own Hypothehs, dran he (eems to be awarcof; the Vibrations of the jEther being as usofi.il and neeeflary in this, as inIris. For, aflunring the Rays of Light to Ire (mall Bodies, emittcd every wayfronr shining Substances, tlrose, when they impinge on any Refracting orRe-fiecting Superficies, muft as neceflarily excite Vibrations in the /Ether, as Stonesdo in \V 7 ater wlren thrown into it. And lüpposing theso Vibrations to be of(everal Deptlrs or Tlricknesles, accordingly asthey are excited by the (aid cor-puscular Rays of various Si/es and Velocities; of wlrat uso they will be forexplicating the mannet of Reflection and Refraction, the Production of Heatby the Sun-beanrs, the Enrillion of Light from Burning, Putrifying, or otherSubstances, whole parts are vehenrently agitated, the Phaenomena ot thin tran-sparent Plates and Bubbles, and of all natural Bodies, the Männer of Vision,and the Difterence of Colours, as also their Harmony and Disoord ; I stral!leave to their Grnsideration, wlro may tlrink it wortlr their endeavour, to ap-ply this Hypothehs to the Solution of Phtenomena.

In the ficond place, I told you, That the Objector’s Hypothefis, as to theFundamental part of it, isnotagainst me. That Fundamental Suppositionis;That the parts of Bodies , xvhen brishjy agitated, do excite Vibrations in the v£-ther-) which are propagated every 1 vay from these Bodies in streight Lines , and'caufe a Cenfation of Light ly beating and dajhing against the bottom of - the-Vol. I. V stomethino