Notes.

1 L. Annæ Senecæ Natur. Quest. l. 6. c. 5.

2 He that desires more instances of this kind and matter, that according to this doctrine may much help the Theory of colours, and particularly the force both of Sulphureous and volatile, is likewise of Alcalizate and Acid Salts, and in what particulars, Colours likely depend not in the causation from any Salt at all, may beg his information from M. Boyle who hath some while since honoured me with the sight of his papers concerning this subject, containing many excellent experiments, made by him for the Elucidation of this doctrine, &c Dr. R. Sharrock in his ingenious and usefull History of the Propagation and Improvement of Vegetables, published in the yeare 1660.

3 See the Discourse of the Nature of Whiteness and Blackness.

4 Since for his eminent Qualities and Loyalty Grac'd, by his Majesty, with the Honour of Knighthood.

5 Exercitat. 325 Parag. 4

6 Album quippe & agrum, hoc quidem asperum esse dicit, hoc vero læve. de Sensu & Sensib. 3. 3.

7 Epist. 2. pag. 45.

8 Gent. Septen. Histor. lib. 4 cap. 13.

9 Hist. Anatom. Cent. 3. Hist. 44.

10 Olearius Voyage de Mosco. et de Perse liv. 3.

11 Piso Nat. & Med. Hist. Brasil. lib 1. in fine.

12 Purchas Pilgrim. Second part, Seventh Book 3. Chap. Sect 5.

13 Purchas. Ibid.

14 Purchas Ibid. in fin

15 See Scaliger Exercit. 325. Sect. 9.

16 Nicolaus Monardes lib simplic. ex India allatis, cap. 27.

17 Kircher. Art. Mag. lucis & umbræ, lib. 1. part. 3.

18 Herbarists are wont to call this Plant Cyanus vulgaris minor.

19 Paracelsus de Mineral. tract. 1. pag. m. 243

20 See Parkinson Th. Boran. Trib. 9. cap. 26.

21 Parkinson, Thea. Bot. Trib. 4 cap. 12.

22 Beguinus, Tyr. Chy. Lib. 2º. Cap. 13º.

23 Libr. 2^do Cap. 34.

24 See the latter end of the fiftieth Experiment.

25 The Curious Reader that desires further Information concerning Lakes, may Resort to the 7th Book of Neri's Art of Glass, Englished (6 or 7 years since the Writing of this 49th Experiment) and Illustrated with Learned Observations, by the Inquisitive and experienc'd Dr. Charles Merret.

26 Boetius de Boot. Gem. & Lapid. Histor. Lib. 3. Cap. 8.

27 Musæi Wormiani. Cap. 17.

28 Purchas's Pilgrim. lib. 1. cap. 4. pag. 104.

29 In the year 1619.

30 Benvonuto Cellini nell Arte del Gioiellare, Lib. 1. pag. 10.

31 The Narrative in the Authors own words, is this. Ego (sayes he) sanctè affirmare possum me unam aureo Annulo inclusam perpetuo gestare, cujus facultatem (si gemmæ est) nunquam satis admirari potui. Gestaverat enim ante Triginta annos Hispanus quidam non procula puternis ædibus habitans. Is cum vitâ functus esset, & ipsius suspellex (ut moris apud nos est) venum exposita esset, inter cætera etiam Turcois exponebatur. Verum nemo (licet complures eo concurrissent, ut eam propter Coloris Elegantiam, quam vivo Domino habuerat emerent) sibi emptam voluit, pristinum enim nitorem & Colorem prorsus amiserat, ut potius Malachites, quam Turcois videretur. Aderat tum temporis gemmæ habendæ desiderio etiam parens & frater meus, qui antea sæpius gratiam & elegantiam ipsius viderant, mirabundi eam nunc tam esse deformem, Emit eam nihilominus pater, satisque vili pretio, qua omnibus contemptui erat, ac presentes non eam esse quam Hispanus gestarat, arbitrarentur. Domum reversus Pater, qui tam turpem Gemmam gestare sibi indecorum putabat, eam mihi dono dat, inquiens; Quandoquidem, fili mi, vulgi fama est, Turcoidem, ut facultates suas exercere possit, dono dari debere tibi eam devoveo, ego acceptam Gemmam sculptori trado, at gentilitia mea insignia illi, quamadmodum fieri solet, in Jaspide Chalcedono, aliisque Ignobilioribus Gemmis, insculperat. Turpe enim existimabam, hujusmodi Gemmâ ornatus gratia, dum gratiam nullam haberet, uti. Paret Sculptor redditque Gemmam, quam gesto pro annulo Signatorio. Vix per mensem gestaram, redit illi pristinus color, sed non ita nitens propter Sculpturam, ac inæqualem superficiem. Miramur omnes gemmam, atque id præcipuè quod color indies pulchrior fieret. Id quià observabam, nunquam fere eam à manu deposui, ita ut nunc adhuc candem gestem.

32 Olaus Wormius, in Musæ. 18º pag. 186.

33 Musæ. Worm. pag. 99.

34 Arte Vetraria, lib. 7 cap. 102.

35 These were brought in and Read before the Royal Society, (the Day following) Oct. 28. 1663.

36 The Stone it self being to be shown to the Royal Society, when the Observations were deliver'd, I was willing (being in haste) to omit the Description of it, which is in short, That it was a Flat or Table Diamond, of about a third part of an Inch in length, and somewhat less in breadth, that it was a Dull Stone, and of a very bad Water, having in the Day time very little of the Vividness of ev'n ordinary Diamonds, and being Blemished with a whitish Cloud about the middle of it, which covered near a third part of the Stone.

37 Hast made me forget to take notice that I went abroad the same Morning, the Sun shining forth clear enough, to look upon the Diamond though a Microscope, that I might try whether by that Magnifying Glass any thing of peculiar could be discern'd in the Texture of the Stone, and especially of the whitish Cloud that possest a good part of it. But for all my attention I could not discover any peculiarity worth mentioning.

38 V. For it drew light Bodies like Amber, Jet, and other Concretes that are noted to do so; But its attractive power seem'd inferiour to theirs.

39 IX. We durst not hold it in the Flame of a Candle, no more than put it into a naked Fire; For fear too Violent a Heat (which has been observ'd to spoil many other precious Stones) should vitiate and impair a Jewel, that was but borrow'd, and was suppos'd to be the only one of its Kind.

40 XV. We likewise Plung'd it as soon as we had excited it, under Liquors of several sorts, as Spirit of Wine, Oyl both Chymical and express'd, an Acid Spirit, and as I remember an Alcalizate Solution, and found not any of those various Liquors to destroy its Shining property.

41 XVI. Having found by this Observation, that a warm Liquor would not extinguish Light in the Diamond, I thought fit to try, whether by reason of its warmth it would not excite it, and divers times I found, that if it were kept therein, till the Water had leisure to communicate some of its Heat to it, it would often shine as soon as it was taken out, and probably we should have seen it Shine more, whilst it was in the Water, if some degree of Opacity which heated Water is wont to acquire, upon the score of the Numerous little Bubbles generated in it, had not kept us from discerning the Lustre of the Stone.

42 I after bethought my self of imploying a way, which produc'd the desir'd Effect both sooner and better. For holding betwixt my Fingers a Steel Bodkin, near the Lower part of it, I press'd the point hard against the Surface of the Diamond, and much more if I struck the point against it, the Coruscation would be extremely suddain, and very Vivid, though very Vanishing too, and this way which commonly much surpris'd and pleas'd the Spectators, seem'd far more proper than the other, to show that pressure alone, if forcible enough, though it were so suddain, and short, that it could not well be suppos'd to give the Stone any thing near a sensible degree of Warmth, as may be suspected of Rubbing, yet 'tis sufficient to generate a very Vivid Light.

43 We afterwards, try'd precious Stones, as Diamonds, Rubies, Saphires, and Emeralls, &c. but found not any of them to Shine except some Diamonds, and of these we were not upon so little practice, able to fore-tell before hand, which would be brought to Shine, and which would not; For several very good Diamonds, either would not Shine at all, or much less than others that were farr inferiour to them. And yet those Ingenious Men are mistaken, that think a Diamond must be foul and cloudy, as Mr. Claytons was, to be fit for Shining; for as we could bring some such to afford a Glimmering Light, so with some clear and excellent Diamonds, we could do the like. But none of those many that we try'd of all Kinds, were equal to the Diamond on which the Observations were made, not only considering the degree of Light it afforded, but the easiness wherewith it was excited, and the Comparatively great duration of its Shining.

Transcriber's notes.

The Errata of the printed book have all been corrected. They were as follows:

Pag. 142. l. 20. These words, And to manifest, with the rest of what is by a mistake further printed in this fourth Experiment, belongeth, and is to be referred to the end of the second Eperiment, p.137. pag. 145. l. 1. leg. matter. 146. l. 4. leg. Bolts-head. pag 161. in the marginal note l. 2. dele de ib. l. 3. lege lib 1. p 163. l. ult. insert where between the words places and the. p. 164 l. 1. dele that. ibid, l. 8. leg Epidermis. ibid. l. 19 leg. 300. for 200. p. 169. l. 22. leg. into it. p. 170. l. 23. & 24. leg. Some Solutions hereafter to be mentioned, for the Solutions of Potashes, and other Lixiviate Salts. p. 171. l. 6. insert part of between the words most and dissolved p. 176. l. ult. insert the participle it between the words Judged and not p. 234. l. 4. leg. Woud-wax or Wood-wax. p. 320 l. 29. leg. urine for urne.

In addition I have corrected the following original typos:

The preface: I devis'd tbem -> I devis'd them The preface: make Expements -> make Experiments The Publisher to the reader: made of Eperiments -> made of Experiments I. Ch. III.6 divers Expements -> divers Experiments I. Ch. III.13 epecially with some sorts -> especially with some sorts II. Ch. II.8 Slightet Texture -> Slightest Texture II. Exp. I two Colonrs -> two Colours II. Exp. XIII were the change of Colour ... is attempted -> where the change (etc.) III. Exp. XII avoiding of Ambignity -> avoiding of Ambiguity III. Exp. XXIX Juice of this Sipce -> Juice of this Spice III. Exp. XL forty second Expement -> forty second Experiment III. Exp. XLIV keep them swimning -> keep them swimming III. Exp. XLVI it seem'd propable to me -> it seem'd probable to me III. Exp. XLVII where not comprehended -> were not comprehended III. Exp. XLVIII frequent Igintion -> frequent Ignition III. Exp. L I could tell yon -> I could tell you A Copy of the Letter: nemo unqnam vere asserere -> nemo nunquam vere asserere (ib.): what is reladed -> what is related Observations: carefulsy drawn -> carefully drawn

- and emended Phœnomenon/a to Phænomenon/a 10 times and Cœruleous etc. -> Cæruleous 20 times

EXPERIMENTS AND CONSIDERATIONS Touching COLOURS.

Firſt occaſionally Written, among ſome other Eſſays, to a Friend; and now ſuffer'd to come abroad as