Experiments and considerations touching colours first occasionally written, among some other essays to a friend, and now suffer'd to come abroad as the beginning of an experimental history of colours / by the Honourable Robert Boyle ...

Part the Second. Of the Nature of Whiteness and Blackness.

CHAP. I. THe reason why the Author chose the Expli∣cation 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, making 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 Tra∣vellers 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 ap∣pearance

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 oc∣casionally the Whiteness of Distill'd Oyls, Hot water, &c. are shew'd (111.) That it seems not necessary the Reflecting Surfaces should be Sphaerical, confirm'd by Experiments (112, 113.) Sixthly, by the Whiteness of the Powders of trans∣parent Bodies (114.) Seventhly, by the Expe∣riment 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 expli∣cates (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 Sha∣dow'd; And the manner how this paucity of Re∣fection outwards is caus'd, is further explicated, byshewing that the Superficial parts may be Coni∣ca and Pyramical (121.) This and other Con∣sidrations formerly deliver'd, Illustrated by Expe∣riments with black and white Marble (122, 123.) Thirdly, from the Black appearance of Holes in whit 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 Expe∣riment try'd in Italy, with black and white Mar∣ble (128.) Some other congruous Observations (129.) Sixthly, from the Roasting black'd Eggs in the Sun (130.) Seventhly, by the Observa∣tion 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 Secker after the true Nature of Whiteness and Blackness. (131, 132.)

Experiments in Consort, touching Whiteness and Blackness.

The first Experiment, with a Solution of Subli∣mate, 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 Hrts∣horn, and Ivory, and Tartar, and by a father Calcination making them White (138, 139.

The fourth Experiment, limiting the Chmist's principle, Adusta nigra sed perusta a••a, by several Instances of Calcin'd Alabaster Lead,

Antimony, Vitriol, and by the Testimony of Bel∣lonius, about the white Charcoles of Oxy-caedar, 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 Cam∣phire (144.)

The sixth Experiment, of a black Caput Mor∣tuum, of Oyl of Vitriol, with Oyl of Worm-wood, 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 Inhabi∣tants of Hot Climates. Several Objections are made, and the whole Matter more fully discours'd,

and stated from several notable Histories and Ob∣servations (from the 151 to the 167.)

The twelfth Experiment, of the white Pow∣ders, afforded by Precipitating several Bodies, as Crabs Eyes, Minium, Coral, Silver, Lead, Tin, Quick-silver, Tin-glass, Antimony, Ben∣zoin, and Resinous Gumms out of Spirit of Wine, &c. but this is not Universal, since other Bo∣dies, 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 Va∣nishes; of covering the Colour of that of ⅔ of Gold with ⅔ 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 In∣stances 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.)