<P_8E>

1 . (BOYLE-E3-H,8E.2)

The first and most general Observation is , That Electrical Bodies draw
not unless they be warm'd ; which Rule though I have now and then found
to admit of an Exception , <paren> whereof I elsewhere offer an account
, </paren> yet , as to the generality of common Electricks , it holds
well enough to give much countenance to our Doctrine , which teaches
the effects of Electrical Bodies to be perform'd by Corporeal
Emanations . (BOYLE-E3-H,8E.3)

For $'t $is {TEXT:'tis} known , that Heat , by agitating the parts of a
fit Body , solicites it as it were to send forth its <font> Effluvia
</font> , as is obvious in odoriferous Gums and Perfumes , which ,
being heated , send forth their fragrant steams , both further and more
copiously than otherwise they would . (BOYLE-E3-H,8E.4)

2 . (BOYLE-E3-H,8E.5)

Next , it has been observ'd , that Amber , &c. warm'd by the fire ,
does not attract so vigorously , as if it acquire an equal degree of
heat by being chaf'd or rub'd : So that the modification of motion in
the internal parts , and in the Emanations of <P_9E> the Amber , may ,
as well as the degree of it , contribute to the Attraction .
(BOYLE-E3-H,9E.6)

And my particular Observations incline me to adde , that the effect may
oftentimes be much promoted , by employing both these ways successively
; as I thought I manifestly found when I first warm'd the Amber at the
fire , and presently after chaf'd it a little upon a piece of cloth .
(BOYLE-E3-H,9E.7)

For then a very few rubbings seem'd to excite it more than many more
would otherwise have done : As if the heat of the fire had put the
parts into a general , but confus'd , agitation ; to which $'t $was
{TEXT:'twas} easie for the subsequent Attrition <paren> or
Reciprocation of Pressure </paren> to give a convenient modification in
a Body whose Texture disposes it to become vigorously Electrical .
(BOYLE-E3-H,9E.8)

3 . (BOYLE-E3-H,9E.9)

Another Observation that is made about these Bodies , is , That they
require Tersion as well as Attrition ; (BOYLE-E3-H,9E.10)

and though I doubt whether the Rule be infallible , yet I deny not but
that weaker Electricks require <P_10E> to be as well wip'd as chaf'd ;
(BOYLE-E3-H,10E.11)

and even good ones will have their Operation promoted by the same means
. (BOYLE-E3-H,10E.12)

And this is very agreeable to our Doctrine , since Tersion , besides
that it is , as I have sometimes manifestly known it , a kind or degree
of Attrition , frees the Surface from those adherences that might choak
the pores of the Amber , or at least hinder the emanation of the steams
to be so free and copious as otherwise it would be .
(BOYLE-E3-H,10E.13)

4 . (BOYLE-E3-H,10E.14)

$'T $is {TEXT:'Tis} likewise observ'd , That whereas the Magnetical
Steams are so subtile , that they penetrate and perform their Operation
through all kind of Mediums hitherto known to us ; Electrical Steams
are like those of some odoriferous Bodies , easily check'd in their
progress , since $'t $is {TEXT:'tis} affirm'd by Learned Writers , who
say they speak upon particular Trial , that the interposition of the
finest Linnen or Sarsnet is sufficient to hinder all the Operation of
excited Amber upon a Straw or Feather <P_11E> plac'd never so little
beyond it . (BOYLE-E3-H,11E.15)

5 . (BOYLE-E3-H,11E.16)

It has been also observed , that the effects of Electrical Attraction
are weaken'd if the air be thick and cloudy ; and especially if the
Southwind blows : And that Electricks display their vertue more faintly
by night than by day , and more vigorously in clear weather , and when
the winds are Northerly . All which the Learned <font> Kircherus
</font> asserts himself to have found true by experience ; insomuch
that those bodies that are but faintly drawn when the weather is clear
, will not , when $'t $is {TEXT:'tis} thick and cloudy , be at all
moved . (BOYLE-E3-H,11E.17)

6 . (BOYLE-E3-H,11E.18)

We have also observed , That divers Concretes , that are notably
Electrical , do abound in an effluviable matter <paren> if I may so
call it </paren> which is capable of being manifestly evaporated by
heat and rubbing . (BOYLE-E3-H,11E.19)

Thus we see , that most Resinous Gums , that draw light bodies , do
also , being moderately solicited by heat , <paren> whether this be
excited by the fire , or by Attrition or Contusion </paren> <P_12E>
emit steams . (BOYLE-E3-H,12E.20)

And in pieces of <font> Sulphur </font> conveniently shaped , I found
upon due Attrition a Sulphureous stink . (BOYLE-E3-H,12E.21)

And that piece of Amber which I most employ , being somewhat large and
very well polish'd , will , being rub'd upon a piece of woollen cloth ,
emit steams , which the nostrils themselves may perceive ;
(BOYLE-E3-H,12E.22)

and they sometimes seem to me not unlike those that I took notice of ,
when I kept in my mouth a drop or two of the diluted Tincture <paren>
or Solution of the finer parts </paren> of Amber made with Spirit of
Wine , or of Sal Armoniac . (BOYLE-E3-H,12E.23)

7 . (BOYLE-E3-H,12E.24)

It agrees very well with what has been said of the corporeal Emanations
of Amber , that its attractive power will continue some time after it
has been once excited . (BOYLE-E3-H,12E.25)

For the Attrition having caus'd an intestine commotion in the parts of
the Concrete , the heat or warmth that is thereby excited ought not to
cease , as soon as ever the rubbing is over , but to continue capable
of emitting <P_13E> <font> Effluvia </font> for some time afterwards ,
which will be longer or shorter according to the goodness of the
Electric , and the degree of the Antecedent commotion : which joyn'd
together may sometimes make the effect considerable , insomuch that in
a warm day , about noon , I did with a certain body , not much , if at
all , bigger than a Pea , but very vigorously attractive , move to and
fro a Steel Needle freely poysed , about three minutes <paren> or the
twentieth part of an hour </paren> after I had left off rubbing the
Attrahent . (BOYLE-E3-H,13E.26)

8 . (BOYLE-E3-H,13E.27)

That it may not seem impossible , that Electrical <font> Effluvia
</font> should be able to insinuate themselves into the pores of many
other bodies , I shall adde , that I found them subtile enough to
attract not onely Spirit of Wine , but that of {HELSINKI:'of'_missing}
the fluid aggregate of Corpuscles we call Smoak . (BOYLE-E3-H,13E.28)

For having well lighted a Wax-taper , which I preferr'd to a common
Candle to avoid the stink of the snuff , I blew out the flame ;
(BOYLE-E3-H,13E.29)

and , when the smoak <P_14E> ascended in a slender stream , held , at a
convenient distance from it , an excited piece of Amber or a chafed
Diamond , which would manifestly make the ascending smoak deviate from
its former line , and turn aside , to beat , as it were , against the
Electric , which , if it were vigorous , would act at a considerable
distance , and seemed to smoak for a pretty while together .
(BOYLE-E3-H,14E.30)

9 . (BOYLE-E3-H,14E.31)

That $'t $is {TEXT:'tis} not in any peculiar Sympathy between an
Electric and a body whereon it operates , that Electrical Attraction
depends , seems the more probable , because Amber , for instance , does
not attract onely one determinate sort of bodies , as the Loadstone
does Iron , and those bodies wherein it abounds ; (BOYLE-E3-H,14E.32)

but as far as I have yet tried , it draws indifferently all bodies
whatsoever , being plac'd within a due distance from it , <paren> as my
choicest piece of Amber draws not onely Sand and Mineral Powders , but
Filings of Steel and Copper , and beaten Gold it self </paren> <P_15E>
provided they be minute or light enough , except perhaps it be fire :
(BOYLE-E3-H,15E.33)

I employ the word <font> perhaps </font> , because I am not yet so
clear in this point . (BOYLE-E3-H,15E.34)

For having applied a strong Electric at a convenient distance to small
fragments of ignited matter , they were readily enough attracted ,
(BOYLE-E3-H,15E.35)

and shin'd , whilst they were sticking to the body that had drawn them
: (BOYLE-E3-H,15E.36)

But when I look'd attentively upon them , I found the shining sparks to
be , as it were , cloath'd with light ashes , which , in spite of my
diligence , had been already form'd about the attracted Corpuscles ,
upon the expiring of a good part of the fire ; so that it remain'd
somewhat doubtful to me , whether the ignited Corpuscles , whilst they
were totally such , were attracted ; or whether the immediate objects
of the Attraction were not the new form'd ashes , which carried up with
them those yet unextinguished parts of fire , that chanc'd to be lodg'd
in them . (BOYLE-E3-H,15E.37)

But , as for flame , our Countreyman <P_16E> <font> Gilbert </font>
delivers as his Experiment , That an Electric though duly excited and
applied , will not move the flame of the slenderest Candle . Which some
will think not so easie to be well tried with common Electricks , as
Amber , hard Wax , Sulphur , and the like unctuous Concretes , that
very easily take fire : (BOYLE-E3-H,16E.38)

Therefore I chose to make my Trial , with a rough Diamond
extraordinarily attractive , which I could , without injuring it , hold
as near as I pleas'd to the flame of a Candle or Taper ;
(BOYLE-E3-H,16E.39)

and though I was not satisfi'd that it did either attract the flame ,
as it visibly did the smoak , or manifestly agitate it ; yet granting
that <font> Gilbert's </font> Assertion will constantly hold true , and
so , that flame is to be excepted from the general Rule , yet this
exception may well comport with the <font> Hypothesis </font> hitherto
countenanc'd , since it may be said , as $'t $is {TEXT:'tis} , if I
mistake not , by <font> Kirkerus </font> , that the heat of the flame
dissipates the <font> Effluvia </font> , by whose means the Attraction
<P_17E> should be perform'd . To which I shall adde , that possibly the
Celerity of the motion of the Flame upwards , may render it very
difficult for the Electrical Emanations to divert the Flame from its
Course . (BOYLE-E3-H,17E.40)

. (BOYLE-E3-H,17E.41)

We have found by Experiment , That a vigorous and well excited piece of
Amber will draw , not onely the powder of Amber , but less minute
fragments of it . (BOYLE-E3-H,17E.42)

And as in many cases one contrary directs to another , so this Trial
suggested a further , which , in case of good success , would probably
argue , that in Electrical Attraction not onely <font> Effluvia </font>
are emitted by the Electrical body , but these <font> Effluvia </font>
fasten upon the body to be drawn , and that in such a way , that the
intervening viscous strings , which may be supposed to be made up of
those cohering <font> Effluvia </font> , are , when their agitation
ceases , contracted or made to shrink inwards towards both ends ,
almost as a highly strech'd Lute-string does when $'t $is {TEXT:'tis}
permitted to retreat into <P_18E> shorter Dimensions .
(BOYLE-E3-H,18E.43)

But the Conjecture it self was much more easie to be made than the
Experiment requisite to examine it . (BOYLE-E3-H,18E.44)

For we found it no easie matter to suspend an Electric , great and
vigorous enough , in such a manner , that it might , whilst suspended ,
be excited , and be so nicely poised , that so faint a force as that
wherewith it attracts light bodies should be able to procure a Local
Motion to the whole Body it self . (BOYLE-E3-H,18E.45)

But after some fruitless attempts with other Electricks , I had
recourse to the very vigorous piece of polish'd Amber , formerly
mention'd , (BOYLE-E3-H,18E.46)

and when we had with the help of a little Wax suspended it by a silken
thread , we chafed very well one of the blunt edges of it upon a kind
of large Pin-cushion cover'd with a course and black woollen stuff ,
(BOYLE-E3-H,18E.47)

and then brought the Electric , as soon as we could , to settle
notwithstanding its hanging freely at the bottom of the string .
(BOYLE-E3-H,18E.48)

This course of rubbing on the edge of the Amber we pitch'd <P_19E> upon
for more than one reason ; (BOYLE-E3-H,19E.49)

for if we had chafed the flat side , the Amber could not have
approached the body it had been rub'd on without making a change of
place in the whole Electric , and , which is worse , without making it
move <paren> contrary to the nature of heavy bodies </paren> somewhat
upwards ; whereas the Amber having , by reason of its suspension , its
parts counterpoised by one another ; to make the excited edge approach
to another body , that edge needed not at all ascend , but onely be
moved horizontally , to which way of moving the gravity of the Electric
<paren> which the string kept from moving downwards </paren> could be
but little or no hinderance . (BOYLE-E3-H,19E.50)

And agreeably to this we found , that if , as soon as the suspended and
well rubb'd Electric was brought to settle freely , we applied to the
chafed edge , but without touching it , the lately mention'd Cushion ,
which , by reason of its rough <font> Superficies </font> and porosity
, was fit for the Electrical <P_20E> <font> Effluvia </font> to fasten
upon , the edge would manifestly be drawn aside by the Cushion steadily
held , and if this were slowly removed , would follow it a good way ;
(BOYLE-E3-H,20E.51)

and when this body no longer detain'd it , would return to the posture
wherein it had settled before . (BOYLE-E3-H,20E.52)

And this power of approaching the Cushion by vertue of the operation of
its own steams , was so durable in our vigorous piece of Amber , that
by once chafing it , I was able to make it follow the Cushion no less
than ten or eleven times . (BOYLE-E3-H,20E.53)

Whether from such Experiments one may argue , that $'t $is {TEXT:'tis}
but , as $'t $were {TEXT:'twere} , by accident that Amber attracts
another body , and not this the Amber ; and whether these ought to make
us question , if Electricks may with so much propriety , as has been
hitherto generally supposed , be said to <font> Attract </font> , are
doubts that my Design does not here oblige me to examine .
(BOYLE-E3-H,20E.54)

Some other <font> Phaenomena </font> might be added of the same
Tendency with <P_21E> those already mention'd , <paren> as the
advantage that Electrical Bodies usually get by having well polish'd or
at least smooth Surfaces , </paren> (BOYLE-E3-H,21E.55)

but the Title of this Paper promising some <font> Experiments </font>
about the <font> Production </font> of Electricity , I must not omit to
recite , how I have been sometimes able to produce or destroy this
Quality in certain bodies , by means of alterations , that appear'd not
to be other than Mechanical . (BOYLE-E3-H,21E.56)

<heading>

EXPER. I . (BOYLE-E3-H,21E.58)

</heading>

And first , having with a very mild heat slowly evaporated about a
fourth part of good Turpentine , I found , that the remaining body
would not , when cold , continue a Liquor , but harden'd into a
transparent Gum almost like Amber , which , as I look'd for , proved
Electrical . (BOYLE-E3-H,21E.60)

<P_22E>

<heading>

EXPER. II . (BOYLE-E3-H,22E.63)

</heading>

Secondly , by mixing two such liquid Bodies as <font> Petroleum </font>
and strong Spirit of Nitre in a certain proportion , and then
distilling them till there remained a dry mass , I obtain'd a brittle
substance as black as Jet ; and whose Superficies <paren> where it was
contiguous to the Retort </paren> was glossie like that Mineral when
polished ; (BOYLE-E3-H,22E.65)

and as I expected I found it also to resemble Jet , in being endowed
with an Electrical Faculty . (BOYLE-E3-H,22E.66)

<heading>

EXPER. III . (BOYLE-E3-H,22E.68)

</heading>

Thirdly , Having burnt Antimony to ashes , and of those ashes , without
any addition , made a transparent Glass , I found , that , when rubb'd
, as Electrical Bodies ought to be to excite them , it answer'd my
expectation , by manifesting a not inconsiderable Electricity .
(BOYLE-E3-H,22E.70)

And this is the worthier of notice , because , that <font> as </font> a
<P_23E> Vitrum Antimonii , that is said to be purer than ordinary , may
be made of the <font> Regulus </font> of the same Mineral , in whose
preparation you know a great part of the Antimonial Sulphur is
separated and left among the Scoriae ; <font> so </font> Glass of
Antimony made without additament , may easily , as experience has
inform'd us , be in part reduced to a <font> Regulus </font> , <paren>
a Body not reckon'd amongst Electrical ones . </paren>
(BOYLE-E3-H,23E.71)

And that you may not think , that $'t $is {TEXT:'tis} onely some
peculiar and fixt part of the Antimony that is capable of <font>
Vitrification </font> , let me assure you , that even with the other
part that is wont to flye away , <paren> namely the Flowers </paren> an
Antimonial Glass may without an addition of other Ingredients be made .
(BOYLE-E3-H,23E.72)

<heading>

EXPER. IV . (BOYLE-E3-H,23E.74)

</heading>

Fourthly , The mention of a Vitrified Body brings into my mind , that I
more than once made some Glass of Lead per se , <paren> which <P_24E> I
found not very easie work </paren> that also was not wholly destitute
of an Electrical Vertue , though it had but a very languid one .
(BOYLE-E3-H,24E.76)

And it is not here to be overlook'd , that this Glass might easily be
brought to afford again malleable Lead , which was never reckon'd ,
that I know of , among Electrical Bodies . (BOYLE-E3-H,24E.77)

<heading>

EXPER. V . (BOYLE-E3-H,24E.79)

</heading>

Fifthly , Having taken some Amber , and warily distill'd it , not with
Sand , or powder'd Brick , or some such additament as Chymists are wont
to use , for fear it should boyl over or break their Vessels ; but by
it self , that I might have an unmixed Caput mortuum ; Having made this
Distillation , I say , and continued it till it had afforded a good
proportion of phlegm , Spirit , Volatile Salt , and Oyl , the Retort
was warily broken , (BOYLE-E3-H,24E.81)

and the remaining matter was taken out in a lump , which , though it
had quite lost its colour being <P_25E> burnt quite black , and though
it were grown strangely brittle in comparison of Amber , so that they
who believe the vertue of attracting light Bodies to flow from the
substantial form of Amber , would not expect it in a Body so changed
and deprived of its noblest parts : Yet this Caput mortuum was so far
from having lost its Electrical Faculty , that it seemed to attract
more vigorously than Amber it self is wont to do before it be committed
to Distillation . (BOYLE-E3-H,25E.82)

And from the foregoing Instances afforded us by the Glass of Antimony ,
we may learn , that when the form of a Body seems to be destroyed by a
fiery <font> Analysis </font> that dissipates the parts of it , the
remaining substance may yet be endowed with Electricity , as the Caput
mortuum of Amber may acquire it ; as in the case of the Glass of
Antimony made of the <font> Calx </font> and of the Flowers .
(BOYLE-E3-H,25E.83)

And from the second Example abovementioned , and from common Glass
which is Electrical , we may also <P_26E> learn , that Bodies that are
neither of them apart observed to be endowed with Electricity , may
have that Vertue result in the compounded substance that they
constitute , though it be but a factitious Body . (BOYLE-E3-H,26E.84)

To the foregoing Experiments , whose success is wont to be uniform
enough , I shall adde the Recital of a surprising <font> Phaenomenon
</font> , which , though not constant , may help to make it probable ,
that Electrical Attractions need not be suppos'd still to proceed from
the substantial , or even from the essential Form of the Attrahent ;
but may be the effects of unheeded , and , as it were , fortuitous
Causes . (BOYLE-E3-H,26E.85)

And however , I dare not suppress so strange an Observation ,
(BOYLE-E3-H,26E.86)

and therefore shall relate that which I had the luck to make of an odd
sort of Electrical Attraction <paren> as it seem'd , </paren> not taken
notice of <paren> that I know of </paren> by any either Naturalist or
other Writer , (BOYLE-E3-H,26E.87)

and it is this . (BOYLE-E3-H,26E.88)

<P_27E>

<heading>

EXPER. VI . (BOYLE-E3-H,27E.91)

</heading>

That false Locks <paren> as they call them </paren> of some Hair ,
being by curling or otherwise brought to a certain degree of driness ,
or of stiffness , will be attracted by the flesh of some persons , or
seem to apply themselves to it , as Hair is wont to do to Amber or Jet
excited by rubbing . Of this I had a Proof in such Locks worn by two
very Fair Ladies that you know . (BOYLE-E3-H,27E.93)

For at some times I observed , that they could not keep their Locks
from flying to their Cheeks , and <paren> though neither of them made
any use , or had any need of Painting </paren> from sticking there .
(BOYLE-E3-H,27E.94)

When one of these Beauties first shew'd me this Experiment , I turn'd
it into a Complemental Raillery , as suspecting there might be some
trick in it , though I after saw the same thing happen to the others
Locks too . (BOYLE-E3-H,27E.95)

But as she is no ordinary <font> Virtuosa </font> , she very <P_28E>
ingeniously remov'd my suspicions , (BOYLE-E3-H,28E.96)

and <paren> as I requested </paren> gave me leave to satisfie my self
further , by desiring her to hold her warm hand at a convenient
distance from one of those Locks taken off and held in the air .
(BOYLE-E3-H,28E.97)

For as soon as she did this , the lower end of the Lock , which was
free , applied it self presently to her hand : which seem'd the more
strange , because so great a multitude of Hair would not have been
easily attracted by an ordinary Electrical Body , that had not been
considerably large , or extraordinarily vigorous . (BOYLE-E3-H,28E.98)

This repeated Observation put me upon inquiring among some other young
Ladies , whether they had observed any such like thing ,
(BOYLE-E3-H,28E.99)

but I found little satisfaction to my Question , except from one of
them eminent for being ingenious , who told me , that sometimes she had
met with these troublesome Locks ; but that all she could tell me of
the Circumstances , which I would have been inform'd about , was , that
they seem'd to her <P_29E> to flye most to her Cheeks when they had
been put into a somewhat stiff Curle , and when the Weather was frosty
. (BOYLE-E3-H,29E.100)

Some years after the making the Experiments about the Production of
<font> Electricity </font> , having a desire to try , whether in the
Attractions made by Amber , the motions excited by the air had a
considerable Interest , or whether the Effect were not due rather to
the Emission and Retraction of Effluvia , which being of a viscous
nature may consist of Particles either branch'd or hookt , or otherwise
fit for some kind of Cohesion , and capable of being stretch'd , and of
shrinking again , as Leather Thongs are : To examine this , I say , I
thought the fittest way , if $'t $were {TEXT:'twere} practicable ,
would be , to try , whether Amber would draw a light Body in a Glass
whence the air was pumpt out . (BOYLE-E3-H,29E.101)

And <font> though </font> the Trial of this seem'd very difficult to
make , and we were somewhat discouraged by our first attempt , wherein
the weight of the ambient air broke our Receiver , which chanced to
prove too weak , when the internal air had been with extraordinary
diligence pumpt out ; <font> yet </font> having a vigorous piece of
Amber , which I had caus'd to be purposely turn'd and polish'd <P_30E>
for Electrical Experiments , I afterwards repeated the Trial ,
(BOYLE-E3-H,30E.102)

and found , that in warm Weather it would retain a manifest power of
attracting for several minutes <paren> for it stirred a pois'd Needle
after above 1$$4 of an hour </paren> after we had done rubbing it .
Upon which encouragement we suspended it , being first well chafed , in
a Glass Receiver that was not great , just over a light Body ;
(BOYLE-E3-H,30E.103)

and making haste with our Air-Pump to exhaust the Glass , when the Air
was withdrawn , we did by a Contrivance let down the suspended Amber
till it came very near the Straw or Feather , (BOYLE-E3-H,30E.104)

and perceived , as we expected , that in some Trials , upon the least
Contact it would lift it up ; and in others , for we repeated the
Experiment , the Amber would raise it without touching it , that is ,
would attract it . (BOYLE-E3-H,30E.105)

You will probably be the less dispos'd to believe , That Electrical
Attractions must proceed from the Substantial Forms of the Attrahents ,
or from the Predominacy of this or that Chymical Principle in them , if
I acquaint you with some odd Trials wherein the Attraction of light
Bodies <P_31E> seem'd to depend upon very small circumstances .
(BOYLE-E3-H,31E.106)

And though forbearing at present , to offer you my thoughts about the
cause of these surprising <font> Phaenomena </font> , I propose it
onely as a Probleme to your self and your curious Friends ,
(BOYLE-E3-H,31E.107)

yet the main circumstances seeming to be of a Mechanical Nature , the
recital of my Trials will not be impertinent to the Design and Subject
of this Paper . (BOYLE-E3-H,31E.108)

<heading>

EXPER. VII . (BOYLE-E3-H,31E.110)

</heading>

I Took then a large and vigorous piece of Amber conveniently shaped for
my purpose , and a downy feather , such as grows upon the Bodies , not
Wings or Tails of a somewhat large Chicken : (BOYLE-E3-H,31E.112)

Then having moderately excited the Electrick , I held the Amber so near
it , that the neighbouring part of the feather was drawn by it and
stuck fast to it ; (BOYLE-E3-H,31E.113)

but the remoter parts continued in their former posture .
(BOYLE-E3-H,31E.114)

This done , I applyed my fore-finger to these erected <P_32E> downy
feathers , (BOYLE-E3-H,32E.115)

and immediately , as I expected , they left their preceeding posture ,
(BOYLE-E3-H,32E.116)

and applied themselves to it as if it had been an Electrical Body .
(BOYLE-E3-H,32E.117)

And whether I offered to them my nail , or the pulpy part of my finger
, or held my finger towards the right hand or the left , or directly
over , these downy feathers that were near the little Quill did nimbly
, and , for ought appear'd , equally turn themselves towards it , and
fasten themselves to it . (BOYLE-E3-H,32E.118)

And to shew that the steams that issued out of so warm a Body as my
finger were not necessary to attract <paren> as men speak </paren> the
abovementioned feathers , instead of my finger , I applied to them ,
after the same manner , a little Cylindrical Instrument of Silver , to
which they bowed and fastened themselves as they had done to my finger
, though the tip of this Instrument were presented to them in several
postures . (BOYLE-E3-H,32E.119)

The like success I had with the end of an Iron Key , and the like also
with a cold piece of polish'd black Marble ; (BOYLE-E3-H,32E.120)

and sometimes <P_33E> the feathers did so readily and strongly fasten
themselves to these extraneous and unexcited Bodies , that I have been
able <paren> though not easily </paren> to make one of them draw the
feather from the Amber it self . (BOYLE-E3-H,33E.121)

But it is diligently to be observ'd , that this unusual attraction
happened onely whilst the electrical operation of the excited Amber
continued strong enough to sustain the feathers . (BOYLE-E3-H,33E.122)

For afterwards , neither the approach of my finger , nor that of the
other bodies , would make the downy feathers change their posture .
(BOYLE-E3-H,33E.123)

Yet as soon as ever the Amber was by a light affriction excited again ,
the feather would be disposed to apply it self again to the
abovementioned Bodies . (BOYLE-E3-H,33E.124)

And lest there should be any peculiarity in that particular feather , I
made the Trials with others <paren> provided they were not long enough
to exceed the sphere of activity of the Amber </paren>
(BOYLE-E3-H,33E.125)

and found the Experiment to answer my expectation .
(BOYLE-E3-H,33E.126)

<P_34E>

I made the Experiment also at differing times , and with some months ,
if not rather years , of interval , but with the like success .
(BOYLE-E3-H,34E.128)

And lest you should think these <font> Phaenomena </font> proceed from
some peculiarity in the piece of Amber I employed , I shall add , that
I found uniformity enough in the success , when , in the place of Amber
, I substituted another Electrick , and particularly a smooth mass of
melted Brimstone . (BOYLE-E3-H,34E.129)

These are the <font> Phaenomena </font> I thought fit to mention at
present of this unusual way of drawing light bodies ,
(BOYLE-E3-H,34E.130)

and with this Experiment I should conclude my Notes about Electricity ,
but that I think it will not be amiss before I take leave of this
Subject , to give this Advertisement , That the event of Electrical
Experiments is not always so certain as that of many others , being
sometimes much varied by seemingly slight circumstances , and now and
then by some that are altogether over-look'd . (BOYLE-E3-H,34E.131)

This Observation may receive credit from some of <P_35E> the
particulars above recited <paren> especially concerning the interest of
the weather , &c. in Electrical <font> Phaenomena </font> . </paren>
(BOYLE-E3-H,35E.132)

But now I shall add , that , not onely there may happen some variations
in the success of Trials made with Electrical Bodies , but that it is
not so certain as many think , whether some particular Bodies be or be
not Electrical . (BOYLE-E3-H,35E.133)

For the inquisitive <font> Kircherus </font> reckons Crystall among
those Gems to whom Nature has denyed the attractive power we are
speaking of ; (BOYLE-E3-H,35E.134)

and yet I remember not , that , among all the trials I have made with
native Crystall , I have found any that was destitute of the power he
refuses them . (BOYLE-E3-H,35E.135)

Also a late most learned Writer reciting the Electricks , reckon'd up
by our industrious Countryman <font> Gilbert </font> , and increasing
their number by some observed by himself , <paren> to which I shall now
add , besides white Saphyrs , and white English Amethysts , the almost
Diaphanous spar of Lead Ore </paren> denies Electricity to a couple of
transparent Gems , the Cornelion and the Emrald . (BOYLE-E3-H,35E.136)

And I do the less wonder he should do so to the former , because I have
my self in vain tried to make any attraction with a piece of Cornelion
so large and fair , that $'t $was {TEXT:'twas} kept for a rarity ;
(BOYLE-E3-H,35E.137)

and yet with divers other fine Cornelions I have been able to attract
some light bodies very manifestly , <P_36E> if not briskly ;
(BOYLE-E3-H,36E.138)

and I usually wear a Cornelian Ring , that is richly enough endowed
with Electricity . (BOYLE-E3-H,36E.139)

But as for Emralds , as I thought it strange that Nature should have
denied them a Quality she has granted to so many other Diaphanous Gems
, and even to Crystal , so I thought the assertion deserved an <font>
Examen </font> , upon which I concluded , that at least it does not
universally and constantly hold true . (BOYLE-E3-H,36E.140)

I had indeed seen in a Ring a Stone of price and great lustre , which ,
though green , I found to be , <paren> as I guess'd it would prove
</paren> vigorously enough Electrical . (BOYLE-E3-H,36E.141)

But this Experiment , though seemingly conclusive , I did not look upon
as a fair trial , because the Stone was not a true Emrald , but , which
is rare , a green Saphir . (BOYLE-E3-H,36E.142)

And I learned by inquiry of the skillful Jeweller that cut it , that it
was so far from having the softness of an Emrald , that he found it
harder than blew Saphyrs themselves , which yet are Gems of great
hardness , and by some reputed second to none , but Diamonds .
(BOYLE-E3-H,36E.143)

Without therefore concluding any thing from this Experiment , save that
, if the assertion I was to examin were true , the want of an
Electrical faculty might be thought a Concomitant rather of the
peculiar Texture of the Emrald than of its green colour , I proceeded
<P_37E> to make trial with three or four Emralds , whose being true was
not doubted , (BOYLE-E3-H,37E.144)

and found them all somewhat , though not equally , endow'd with
Electricity , which I found to be yet more considerable in an Emrald of
my own , whose colour was so excellent , that by skilful persons $'t
$was {TEXT:'twas} look'd on as a rarity . (BOYLE-E3-H,37E.145)

And though , by this success of my inquiry , I perceived I could not ,
as else I might have done , shew the Curious a new way of judging of
true and false Emralds , yet the like way may be , though not always
certain , yet oftentimes of use , in the estimating whether Diamonds be
true or {HELSINKI:of} counterfeit , especially , if , being set in
Rings , the surest way of trying them $can $not {TEXT:cannot}
conveniently be employed . (BOYLE-E3-H,37E.146)

For whereas Glass , though it have some Electricity , seems , as far as
I have observed , to have but a faint one , there are often found
Diamonds that have a very vigorous one . (BOYLE-E3-H,37E.147)

And I do not remember I met with any Electrick of the same bulk , that
was more vigorous than a rough Diamond I have , which is the same that
I formerly mentioned to have moved a Needle above three minutes after I
had ceased to chafe it . (BOYLE-E3-H,37E.148)

And this brings to my mind , that it has been observed , that Diamonds
draw better whilst rough , than they do after they are cut and <P_38E>
polish'd ; which seeming to contradict what has been observed by others
and by us also , that Amber , for instance , attracts more vigorously
if the surface be made very smooth than otherwise , it induces me to
conjecture , that , if this Observation about Diamonds be true , as
some of my trials have now and then inclined me to think it , and if it
do not in some cases considerably depend upon the loss of the <paren>
Electrical </paren> Substance of the Stone , by its being cut and
ground , the Reason may possibly be , that the great rapidness with
which the Wheels that serve to cut and polish Diamonds must be mov'd ,
does excite a great degree of heat , <paren> which the senses may
easily discover </paren> in the Stone , and by that and the strong
concussion it makes of its parts , may force it to spend its
effluviable matter , if I may so call it , so plentifully , that the
Stone may be impoverish'd and perhaps also , on the account of some
little change in its Texture , be rendred lesse disposed to emit those
<font> effluvia </font> that are Instruments of Electrical Attraction .
(BOYLE-E3-H,38E.149)

But as I willingly leave the matter of Fact to further Trial , so I do
the Cause of it , in case it prove true , to farther Inquiry .
(BOYLE-E3-H,38E.150)

Finis . (BOYLE-E3-H,38E.151)

