Robert Boyle (1627-91): Work-diary XXXIX ('Distinguish'd Experiments or more Private Observations Continu'd from [Septem]ber 29th 1688/9')

Content: Experimental notes and accounts, one involving gems and one detailing an interesting way of calculating the relative landmass of continents

General Information


Work-diary entries

/BP 26, fol. 3/

[Authorial heading]:
Distinguish'd Experiments
Or more
Private Observations
Continu'd from
<September the> 29th 1688/9

Entry 1: Editorial notes:
Later marginal endorsements:

I have elsewhere endeavor'd to show, that divers if not most are the real vertues of some gems, for there are too many fabulous ones ascrib'd to them, proceed from the particles of mineral juices <that were admitted [d] whilst the matter> was yet in [d] solutis principiis or at least soft, and afterwards coagulated with the Lapidiscent part of the [d] stone. In confirmation of this conjecture we shall now observe, that having upon some grounds not necessary to be here mention'd, suspected that [d] Granates contain som of them besides som [d] other metalline substances, divers corpuscles of a martial nature, I [d] made choice of some small ones, which by their deep & almost dark colour, (to name [d] no other signs) I guess'd to contain somwhat of <Iron or> Steel [d] and applyd to them a pretty vigorous Loadstone, which as I expected, readily took them up, & to which they constantly stuck afterwards til I forcibly separated them from it. But thô I try'd this upon more parcels of Garnets than one or two, yet I found that there was not many in one heap that would easily adhere to the Magnet.


Entry 2: Editorial notes:
Later marginal endorsements:

Another Instance of the Unlikely uses to which [d] an Experiment or practice may be apply'd may be found in that which follows. One would not easily suspect that a ballance should be aplycable to the [d] resolveing of some Querys in Geography, that the [d] Professors of that Science have not <that I know of> attempted to answer, & seem not [d] so much as to have thought determineable without much Labour, & good skill in the Geodeticall part of Geometry. And yet I remember <at> that when <[d]> there hath been <as it not rarely happens> questions nov'd which of two or three [d] Countrys discoursed of was the biggest, or by how much one of them exceeded the other, or fell short of it, I bethought myself of a way, which tho not accurate May afford at least a Tollerable resolution of the Question. /BP 26, fol. 3v/

<the> Countryes propos'd <being for Instance> England & Ireland If [d] <you> take a map of a moderate size, containeing as many do the [d] Geographicall Deliniations of both these Countrys, [d] upon as even & uniforme a Paper as you can make choice, of & with sharp pair of Sisers follow <close> the outlines or Boundaries of each of those Countries, how crooked soever those lines happen to bee, clipping off & laying aside, whatever parts of the paper are not comprehended within [d] those bounding lines, & if when this <is> done you lay each of [d] these thus prepar'd [blank space in MS, 6-7 characters] Maps in a good Ballance one after another, you will not only quickly perceive <by the preponderancys> which [d] <of the two Countrys> is of greater extent, but by compareing their respective weights you may make at least a Tollerable Estimate <of the proportion> wherein one exceeds the other in extent. And tho I readily acknowledge that this way of measureing Countries is not accurate yet since [d] if it come but pretty near the Truth, it [d] may not be useless on an occation, on [d] which tis difficult to find and practice a method that is exact.


Entry 3: Editorial notes:
Later marginal endorsements:

In the Adiaphorous mixture to a Couple of Ounces of Salt of Tartar and as much volatile Salt mingled together we imployd about seven ounces and about an halfe to satiate them seemingly in the Cold. But upon the Destillation of this mixture the ascention of some volatile salt and the urinous tast of the first spoonfuls of Liquor that came over, argued that there had not been Spirit: enough put to the salt.


Entry 4: Editorial notes:
Later marginal endorsements:

Upon an Ounce of Salt of Tartar we put by degrees spirit of Venus till the Salt was dissolv'd & there was no more conflict between them & found that {ounce} 3 of the spirit -- {drachm} 1; -- 12 gr did dissolve & satiate the ounce of the Salt.


Entry 5: Editorial notes:
Later marginal endorsements:

An ounce of the volatile Salt of Sal armoniac did take of the Spirit of Verdigreece to dissolve it {ounce} 4 -- {drachm} 3 -- 44 graines.