CHAP. I.
The reaſon why the Author choſe the Explication of Whiteneſs and Blackneſs ([93].) Wherein Democritus thought amiſs of theſe ([94].) Gaſſendus his Opinion about them ([95].) What the Author approves, and a more full Explication of White, makinig it a Multiplicity of Light or Reflections ([96], [97].) Confirm'd first by the Whiteneſs of the Meridian Sun, obſerv'd in Water ([98].) and of a piece of Iron glowing Hot ([99].) Secondly, by the Offenſiveneſs of Snow to the Travellers eyes, confirm'd by an example of a Perſon that has Travell'd much in Ruſſia ([100].) and by an Obſervation out of Olaus Magnus ([100].) and that the Snow does inlighten and clear the Air in the Night, confirm'd by the Moſco Phyſician, and Captain James ([101].) But that Snow has no inherent Light, prov'd by Experience ([102].) Thirdly, by the great ſtore of Reflections, from white Bodies obſerv'd in a darkned Room, and by their unaptneſs to be Kindled by a Burning-glaſs ([103].) Fourthly, the Specularneſs of White Bodies is confirm'd by the Reflections in a dark Room from other Bodies ([104].) and by the appearance of a River, which both to the Eye and in a darkned Room appear'd White ([105], [106].) Fifthly, by the Whiteneſs of diſtill'd Mercury, and that of the Galaxie ([107], [108].) and by the Whiteneſs of Froth, rais'd from whites of Eggs beaten; that this Whiteneſs comes not from the Air, ſhew'd by Experiments ([109], [110].) where occaſionally the Whiteneſs of Diſtill'd Oyls, Hot water, &c. are ſhew'd ([111].) That it ſeems not neceſſary the Reflecting Surfaces ſhould be Sphærical, confirm'd by Experiments ([112], [113].) Sixthly, by the Whiteneſs of the Powders of tranſparent Bodies ([114].) Seventhly, by the Experiment of Whitening and Burniſhing Silver. ([115], [116].)
Chap. 2. A Recital of ſome Opinions about Blackneſs, and which the Author inclines to ([117].) which he further inſists on and explicates ([118], [119].) and ſhews for what reaſons he imbrac'd that Hypotheſis ([120].) Firſt, from the contrary Nature of Whiteneſs and Blackneſs, White reflecting moſt Beams outwards, Black ſhould reflect moſt inward ([120].) Next, from the Black appearance of all Bodies, when Shadow'd; And the manner how this paucity of Reflection outwards is caus'd, is further explicated, by ſhewing that the Superficial parts may be Conical and Pyramical ([121].) This and other Conſiderations formerly deliver'd, Illuſtrated by Experiments with black and white Marble ([122], [123].) Thirdly, from the Black appearance of Holes in white Linnen, and from the appearance of Velvet ſtroak'd ſeveral ways, and from an Obſervation of Carrots ([124], [125].) Fourthly, from the ſmall Reflection from Black in a darkned Room ([125], [126].) Fifthly, from the Experiment of a Checker'd Tile expos'd to the Sun-beams ([127].) which is to be preferr'd before a Similar Experiment try'd in Italy, with black and white Marble ([128].) Some other congruous Obſervations ([129].) Sixthly, from the Roaſting black'd Eggs in the Sun ([130].) Seventhly, by the Obſervation of the Blind man lately mention'd, and of another mention'd by Bartholine ([130].) That notwithſtanding all theſe Reaſons, the Author is not abſolutely Poſitive, but remains yet a Seeker after the true Nature of Whiteneſs and Blackneſs. ([131], [132].)
Experiments in Conſort, touching Whiteneſs and Blackneſs.
The firſt Experiment, with a Solution of Sublimate, made White with Spirit of Urine, &c. ([133], [134].)
The ſecond Experiment, with an Infuſion of Galls, made Black with Vitriol, &c. ([135], [136].) further Diſcours'd of ([137].)
The third Experiment, of the Blacking of Hartſhorn, and Ivory, and Tartar, and by a further Calcination making them White ([138], [139].)
The fourth Experiment, limiting the Chymiſt's principle, Aduſta nigra ſed peruſta alba, by ſeveral Inſtances of Calcin'd Alabaſter, Lead, Antimony, Vitriol, and by the Teſtimony of Bellonius, about the white Charcoles of Oxy-cædar, and by that of Camphire. ([140], [141], [142].) That which follows about Inks was miſplac'd by an Errour of the Printer, for it belongs to what has been formerly ſaid of Galls ([142], [143].)
The fifth Experiment, of the black Smoak of Camphire ([144].)
The ſixth Experiment, of a black Caput Mortuum, of Oyl of Vitriol, with Oyl of Worm-word, and alſo with Oyl of Winter-Savory ([145].)
The ſeventh Experiment, of whitening Wax ([146].)
The eighth Experiment, with Tin-glaſs, and Sublimate ([147], [148].)
The ninth Experiment, of a Black powder of Gold in the bottom of Aqua-fortis, and of the Blacking of Refin'd Gold and Silver ([148], [149].)
The tenth Experiment, of the ſtaining Hair, Skin, Ivory, &c. Black, with Cryſtals of Silver ([150], [151].)
The eleventh Experiment, about the Blackneſs of the Skin, and Hair of Negroes, and Inhabitants of Hot Climates. Several Objections are made, and the whole Matter more fully diſcours'd and ſtated from ſeveral notable Hiſtories and Obſervations (from the [151] to the [167].)
The twelfth Experiment, of the white Powders, afforded by Precipitating ſeveral Bodies, as Crabs Eyes, Minium, Coral, Silver, Lead, Tin, Quick-ſilver, Tin-glaſs, Antimony, Benzoin, and Reſinous Gumms out of Spirit of Wine, &c. but this is not Univerſal, ſince other Bodies, as Gold, Antimony, Quick-ſilver, &c. may be Precipitated of other Colours ([168], [169], [170].)
The thirteenth Experiment, of Changing the Blackneſs of ſome Bodies into other Colours ([171], [172].) and of Whitening what would be Minium, and Copper, with Tin, and of Copper with Arſnick, which with Coppilling again Vaniſhes; of covering the Colour of that of 1/3 of Gold with 2/3 of Silver melted in a Maſs together ([173], [174])
The fourteenth Experiment, of turning the black Body of Horn into a White immediately with Scraping, without changing the Subſtantial form, or without the Intervention of Salt, Sulphur, or Mercury ([176].)
The fifteenth Experiment, contains ſeveral Inſtances againſt the Opinion of the Chymiſts that Sulphur Aduſt is the cauſe of Blackneſs, and the whole Matter is fully diſcuſs'd and ſtated (from [176] to [184])