Digitized by the Internet Archive

in 2010 with funding from

Open Knowledge Commons

http://www.archive.org/details/microscopemadeeOObake

THE

MICROSCOPE

Made

Eafy :

o R,

I, The Nature^ Ufes, and Magnifying Powers

ox the beft Kinds of Microscopes

Defcribed^ Calculated^ and Explained :

FOR THE

Inllrudion of fijch, particularly, as defire to fearch

into the V/'o^iders of the Minute Creation,
tho' they are not acquainted with Optics.

Together with

V\i(\ TW^^tftions how to prepare, apply, examine, and prejer'vi
' Sorts of Objects, and proper Cautions
to be obferved in viewing them.

II. An Account of what furprizing Bifco%wies

have been already made by the Microscope :

With ufeful Refleftions on them.

A N D A L S O

A great Variety of new Experiments and Ohfer<vationSi

pointing out many uncommon Siibjeds for the

Examination oi the Curious.

By HE K RT B A KE R, Fellow of the Royal Society,
and Member of the Society of Antiquaries, in London.

Illuftrated with Copper Plates.

"^ The FOURTH EDITION:

With an additional Plate of the Solar Microscope,
and fome farther Accounts of the Polype.

Return Natura nufi^uam magis quam in Minimis tota ejli

Plin. Nat. Hifti Lib. xi. c. 2.

LONDON:

Pf/.ited ht R. and J. Dodsley, in Pall -Mall, and Sold
by- M Cooper in Pater-nofter-Row, and J. Cuff,
C^tician, in Fleet-ftreet. 1754*

W^---^,.

At a Meeting of the Ksyat. ooctety^
OSiober 28, 1742.

IMPRIMATUR,

M. F0LKES5 Pr. R. S.

T O

' Martin Folkes, Efq\

PRESIDENT,

And to tlie

COUNCIL and FELLOWS

O F T H E

Royal Society of London*

Gentlemen,

N Attempt to excite in
Mankind a general Defire
of fearchinginto the Won-
ders of N A T u R E, will, I
perfuade myfelf, be accepted favour-
ably by You, whofe Endeavours for
the Advancement of Natural Knovi^-
ledge, according to the Purpofe of
your Inftitution^ are efteemed by all
the World,

A It

ii DEDICATION.

It is fomethino; more than an hun-
dred and twenty Years fince the M i-
' CROscopE was happily invented ;
and to the valuable Difcoveries made
thereby, we ftand indebted^ as the
following Sheets will fhew^ for a great
part of our prefent Philofophy. In
fuch a Length of Time, it is however
probable, many more Advantages
might have been reaped from it, had
not fome Difficulties and Difcourage-
ments prevented its general Ufe.

At the Beginning it was confined
to very few ; who, making a Secret
of it, endeavoured all they could to
keep it to themfelves; and, when it
became a little more publick, the
Price was fixt lb high, that the moft
Curious and Induftrious^ who have
not always the greatefl: Share of
Money, could not conveniently get
at it. Of late Years, indeed, the
Expence has been much lefs ; but
then newDifcouragements have ftart-
ed up from Miftake and Prejudice.

For

DEDICATION. Hi

For Many have been frighted from
the Ufe • of it, by imagining it re-
quired great Skill in Optics, and
abundance of other Learnino-, to
comprehend it to any Purpofe :
whereas nothing is really needful but
good Glaffes, good Eyes, a little
Tradice, and a common Underftand-
ing, to diftinguifli what is feen ; and
a Love of Truth, to give a faithful
Account thereof. Others have con-
fidered it as a nieer Play-thing, a
Matter of Amufenient and Fancy
only, that raifes our Wonder for a
Mom.ent, but is of no farther Ser-
vice : which Miftake they have fall-
en into, from being unacquainted
with any Principles whereby to form
a right Judgment of what they fee.
Many, again, have laid the Micrc-
fcope afide, after a little Ufe, for
want of knowing v/hat Objecls to
examine, where to find, how to
prepare, and in what manner to ap-

A 2 ply

iv DEDICATION.

ply them* The Trouble of manag-
ing it has alfo frighted fome.

But we are now fo fortunate as to
have this Inftrument greatly improv-
ed amongft ourfelves, the Apparatus
made much eafier as well as more
ufeful, and the Price confiderably
reduced. The Solar or Camera Ob-
fcura Microfcope, and the Micro-
fcope for viewing Objects that have
no Tranfparency, by throwing a
ftrong refleded Light upon them, are
alfo new Inventions, from whence
great Things may be expeded.

Nothing therefore is now want-
ing, but a general IncHnation to
employ thefe Inftruments, for a far-
ther Difcovery of the Minute Won-
ders of the Creation; which may not,
perhaps, improve our Knowledge
lefs than the grander Parts thereof.
Bears, Tigers, Lions, Crocodiles and
Whales, Oaks and Cedars, Seas and
Mountains, Comets, Stars, Worlds
and Suns, are the Capitals ia

Nature's

DEDICATION. v

Nature's mighty Volume, and of
them we fhould not be ignorant :
but whoever would read there with
Underftanding, muft make himfelf
Mafter of the little Letters likewife,
which occur a thoufand times more
frequently, and, if he does not know
them, will flop him fhort at every
Syllable.

The likelieft Method of difcover-
ing Truth, is, by the Experiments of
Many upon the fame Subject ; and
the moft probable Way of engaging
People in fuch Experiments, is, by
rendering them eafy, intelligible and
pleafant. To effedl this is my En-
deavour in the following Treatife,
which may ferve as the Reprefenta-
tion of an Objed for the Inftrument
I am recommending ; fmall, indeed,
and feemingly of no Confequence ;
but what, upon Examination, will
be found, perhaps, to contain as
many ufeful Parts as thofe that are
much bulkier : for, to drop the Allu-

A 3 iion

vi DEDICATION.

lion hercj I am certain, that with
half the Pains I could have made it
twice as large.

Think me not fo prefumptuous, to
dream of inftrufting you, in Matters
you are much better acquainted with
than I can pretend to be ; but give
me leave to requeft the Favour of
your Concurrence, in my Defire of
explaining, to thofe that are igno-
rant, a Science that may prove of the
moft eminent Service towards the
Advancement of True Knowledge,
and in which every body that ha^
Inclination and Opportunity may be
able to do fomething.

Excufe my Miftakps, forgive my
detaining you thus long, and permit
me the Honour to be, with all poffi--
e Refped and Veneration,

Gentlemen,
Your moft Obedient

and devoted Humble Servant^

(vii )

S^^Mi^

Contents of the Chapters.

PART the FIRST.

INTRODUCTION, p. xi.

CHAP. I. 0/ Micro/copes in gene-
ral p. I
Chap. 11. Of the Kinds of Mi cr of copes 7
Chap. III. M7\ WilsonV Single Pocket-^
Microfcope g
Chap. IV. A new Invention for fixing the
Pocket-Microfcope, and giving Light to it
by a Speculum i^j.
Chap. V. Of the Double RefeBing Mi-
cr of cope 16
Chap. VI. The Solar or Camera Obfcura
Microfcope 22
Chap. VII. The Microfcope for Opake Ob-
jeSls zy
Chap. VIII. To find the magnifying Power
ofGlaJfes employed in Single Mi cr of copes 3 2
Chap. IX. The magnifying Power of Glaffes
in the Double Microfcope 3 9

A 4 Chap.

viii Contents of the Chapters.

Chap. X. "To find out the real Size of Ob-
jects 'Viewed by Mi cr of copes p. 40
Chap. XI. I'he Area or Portion of an Ob-
jeB feen \ 48
Chap. XIL Of ObjeBs in general 50
Chap. XII I. Of examining Objects 52
Chap. XIV. Of preparing and applying Ob-

jeBs .... . 56

Chap. XV. Cautions in viewijig ObjeBs 6z

PART the SECOND.

CHAP. I. Of (be Animalcules in Fluids
68

Chap. II. To make Pepper -Water Ji

Chap. III. Of Hay-Water 76

Chap. IV. Of Eels in Pafle 8 1

Chap. V, Of Pain-Water and other Wa-
ters 83
Chap. VI. An Examination of the Blood in
Anintcils 102
Chap, VII. Some Account of the JMood^ as
examined by the Mi cr of ope 103
Chap. VIII. Of viewing the Blood with the
Microfcope iiz
Chap. IX. The Circulation of the Blood 117
Chap. X. Of viewing the Current and
Circulation of the Blood 120
Chap. XI. The Pulfation of the Heart 137
Chap. XIL Of the mtfcular or flefy Fibres
of A^iimals 139

v-'Xiapa

Contents of the Chapters, ix

Chap. XIII. Of Bones p. 143

Chap. XIV. Of the Nerves 145

Chap, XV. Of the Generation of Ani-
mals and Vegetables ^ 148
Chap. XVI. Of the Animalcules in Se-
mine Mafculino 152
Chap. XVII. Animalcules in the Teeth

167

Chap. XVIII. Of the Itch 169

Chap. XIX. Of Scales on the Human

Skin 172

Chap. XX. Of the Fores of the Skin

174
Chap. XXI. Of theLoufe ijy

Chap. XXII. Of the Wood'Loufe 185
Chap. XXIII. Of Mites 186

Chap. XXIV. Of the Flea 191

Chap. XXV, Of Spiders ig6

Chap. XXVI. Of the Gnat 203

Chap. XXVII. Of the Ox - F/y, or Gad-
Bee 207
Chap. XXVIII, Of the Stings of Infers

209
Chap. XXIX. Of a Bees Sting 210

Chap. XXX. Of the Sting of a Scorpion

Ziz
Chap. XXXI. Of the Poyfon of a Viper

215

Chap. XXXII. Of the Snail 217

Chap. XXXIII. Of the common Fly "Zic)

Chap. XXXIV. Of the Weevil, or Corn^

Beetle 221

Chap.

-^ CoNTteNTs of the Chapters.

Chap. TXXY , Of the Wolf p. 223

Chap. XXXVL Of the pearled Eyes of
InfeBs 226

Chap. XXXVII. Of the Antennae, Feelers^
-' or Horns of InfeBs 230

Chap. XXXVIII. OftheWingsoflnfeBs^iz
thap. XXXIX. Of the Balances or Fotfes
of Infers ^ ^35

Chap. XL. Of the Scales of Fijhes 236

Chap. XLL Of the Oy/ier 239

Chap. XLII. Of theLlght on Oyprs 24.1

Chap. ' XLIIL Of the Mifcle 242

Chap. XLIV. Of Hairs 245

Chap. XLV. Of the Farina of Flow-

ers '2.^7

Chap. XL VI. Of Seeds 251

Chap. XLVIL Of Leaves 256

Chap. XLVIII. Of Salts in general 259
Chap. XLIX. Of Salts in Mineral Wa-
ters 262
Chap. L. Mifcellaneous Difcoveries
and Obfervatio?is 265
Chap. " LI. 'The Works of Art arid
- Nature compared and corfidered 292
Chap. LIL Some reafonable RefeBions
on theDifcoveries made by theMicrofcope 300

THE

( xi )

THE

INTRODUCTION.

N this inquilitive Age, when the
Defire of Knovyiedge has fpread
itfelf far and wide, and we fit not
down contented, as heretofore,
with the Opinions of ancient
Times, but refolve to examine for Ourfelves,
and judge from our own Experience ; it
may not, perhaps, prove unacceptable to
point out fome proper Subjecls of Enquiry.

The Works of Nature are the only Source
of true Knowledge, and the Study of them
the moft noble Employmeut of the Mind of
Man. Every Part of the Creation demands
his Attention, and proclaims the Power and
Wifdom of its Almighty x4.uthor. The
fmalleft Seed, the minuteft Infedt fhews the

Skill

xli The INTRODVcriON.

Skill of Providence in the Aptnefs of its Con-
trivance for the Purpofes it is to ferve, and
difplays an Elegance of Beauty beyond the
utmoft Stretch of Art.

The Wife in all Ages have been fenfibic
of this Truth ; and, as far as they were able,
have ftudied and enquired into the RecefTes
of Nature ; but for want of proper Helps
have frequently been miflaken. As certain
Principles muft iirft be learned ere we can
l^ecome Mafters of any Science, fq in the
School of Nature, we muft begin with the
Minutice^ the fmalleft and moft uncom-
pounded Parts, ere we can underftand the
larger and more conliderable.

The Ancients, having only their naked
Eyes to truft to, were uncapable of any
great Difcoveries of this fort : but we are fo
happy, that, by the Help of Glaffes, we can
diftinguifh and examine Objed:s many thou-
fands of times lefs than what the fharpeft
Eye, unaffifted, can difcern. In fhort, Mi-
croscopes furniili us at it were with a
new Senfe, unfold the amazing Operations
of Nature, and prefent us with Wonders un^^
thought of by former Ages.

Who, a thoufand Years ago, would have
imagined it poflible to diftinguifh Myriads

of

rhe INTRODUCriOK xlii

of living Creatures in a fingle Drop of Wa-
ter ? Or, that the Purple Tide of Life, and
even the Globules of the Blood jfhould be
feen diftindl:ly, rolling thro' Veins and Arte-
ries fmaller than the fineft Hair ? That Mil-
lions of Millions of Animalcules fhould be
difcovered in the Semen Mafciilinum of all
Creatures ? That not only the exterior Form,
but even the internal Strud:ure of the Bow-
els, and the Motion of the Fluids in a Gnat
orLoufe^ fhould be render 'd Objed:s of Sight?
Or, that numberlefs Species of Creatures
fhould be made vifible, tho' fo minute, that
a Million of them are lefs than a Grain
of Sand ?

Thefe are noble DifcoverieSy whereon a
new Philofophy has been raifed, that en-
larges the Capacity of the human Soul, and
furnifhes a more jufl and fublime Idea than
Mankind had before, of the Grandeur and
Magnificence of Nature, and the infinite
Power, Wifdom, and Goodnefs of Nature's
Almighty Parent.

That Man is certainly the happieft, who
Is able to find out the greatefl Number of
reafonable and ufeful Amufements, eafily
attainable and within his Power : and, if fo,
he that is delighted with the Works of Na-
ture, and makes them his Study, mufl un-
doubtedly

xiv rhe INTRODUCTION^.

doubtedly be happy ; fmce every Animal^
Flower, Fruit, or Infedt, nay, almoft every
Particle of Matter, affords him an Enter-
tainment* Such a Man never can feel his
Time hang heavy on his Hands, or be weary
of himfelf, for want of knowing how to
employ his Thoughts : each Garden or Field
is to him a Cabinet of Curiofities, every one
of which he longs to examine fully ; and
he confiders the whole Univerfe as a Maga-
zine of Wonders,' which infinite Ages are
fcarce fufficient to contemplate and admire
enough.

The Invention of Glasses has brought
under our Examination the two Extreams of
the Creation, if I may be allowed to call
them fo, which were out of the Reach of
former Ages : I mean, thofe vaft and diftant
Bodies of our Syftem, theSuN andpLANETS>
whofe Dimenfions, Diftances, Motions, Re-
gularity and Order, we are become acquaint-
ed with by the Help of Telescopes : and
thofe exceedingly minute, and to them in-
vifible, and unknown, (though every where
at hand) Species of Animals, Plants, &v*
which the Microscope has difcovered to
us. I leave the Telescope to others, who
are better able to do it Juftice : my Intent
in this Difcourfe is to treat of the Micro-
scope, and encourage its more general Ufe,

by

The INTRODUCTION. xr

by Ihewing the Pleafure and Inftruftlon it
can afford us.

Mr. Boyle fays, in his Difcourfe of the
Ufefuhie/s. of Experimental Fhilofifhy^ that
his Wonder dwells not fo much on Nature^s
Clocks as on her Watches -, and, indeed, up-
on comparing the Strudlure of a Mite with
that of an Elephant y I believe we fhall con-
cur in the fame Opinion. The Largenefs
and Strength of the One may ftrike us with
Wonder and Terror, but we fhall find our-
felves quite loft in Amazement, if we atten-
tively examine the feveral minute Parts of
the Other, For the Mite has more Limbs
than the Elephant^ each of which is furniih-
ed withVeins and Arteries, Nerves, Mufcles,
Tendons and Bones : it has Eyes, a Mouth,
and a Probofcis too (as well as the Elephant)
to take in its Food -, it has a Stomach to
digeft it, and Inteftines to carry off what is
not retained for Nourifhment : it has an
Heart to propel the Circulation of its Blood,
a Brain to fupply Nerves every where, and
Parts of Generation as perfecft as the largeft
Animal. Let us now flop, look back, and
confider, as far as our Abilities can reach,
the exceflive Minutenefs of all thefe Parts ^
and if we fmd them fo furprizing and be-
yond our Ideas, what fhall we fay of thofe
many Species of Animalcule s^ to whom a

Mite

xvi ne INTRODUCTION'.

Mite itfelf, in Size, is as it were an Ele-
phant ?

All thefe, and numberlefs Wonders more,
the Microscope can exhibit to us. I fhall
therefore proceed to defcribe this noble In-
vention, fhew how far it is improved at pre-
fent, give a brief Account of what Difcove-
ries have been made, and point out fome
Objedls for the Curious to examine by it.
In doing this, I fhall avoid as much as poffi-
ble all AfFedation of Learning, or Expreffi-
ons that are not in common Speech, being
delirous that every body may underftand me.

THE

[ r 3

THE

MICROSCOPE

Made Eafy, &c:

■m

CHAP. L

Of Microscopes in General.

Y Microscopes we are under-

flood to mean, Inllriimmts of

whatever Structure or Contri"

vajice, that can make fmall Ob^

jeEls appear larger than they do to

the naked Eye ^

This is cfFeded by Glafles formed con-
vex.

B Whea

2 O/" Microscopes hiGenerah

When onlv one fuch convex Glafs or
^Lens is ufed for this intent, the Inftrument
it is fixt in, however failiioned, is called a
Single Microfcope : but if two or more
GlalTes are imployed, conjointly, to magni-
fy Objed:s more, it is then called a Double
or Compound Mic7'ofcope,

One remarkable Difference in the EfFedt
of thefe two Inftruments is, that an Objed:
view'd through a lingle convex Glafs, ap-
pears magnified, in the fame Pofition exacflly
as when feen by the naked Eye ; but when
view'd through a Double Microfcope, com-
pofed of three convex GlalSes, all Parts of it
become inverted : that is, the Top of the
Objed: appears at Bottom, the Right-fide on
the Left, and every Part in the Place moft
oppofite to its natural and true Pofition :
The Lights and Shades being alfo inverted,
the finking parts appear to rife, and the rifing
parts to fink in. '

To what Accident, to what Country, or
to whom we are obliged for the Invention

* The Word Lens properly fignifies a fmall Glafs in figure
of a Lentil ; but is extended to any Optick Glafs not very
thick, which either colledls the Rays of Light into a Point
in their Paffage thro' it, or difperfes them apart, according
to the Laws of Refradlion. \{ convex on both Sides, it is
called a Coti<vex Lens ; but if one Side be flat, a PlanO'~
Con'vex : If concave on both Sides, it is termed a Concave.
Lens', if fiat on one Side, a Flam-Coma've ; if convex on
©ne Side and concave on the other, a Qonvs?fO-Co?ica'vey or
CmcavO'Csji'vsp^t

of

Of Microscopes in General. 3

of Microfcopes, is not in me to determine : »
the Honour has been given by fome to
Drebbel a Dutchman^ by others to Fon-
TANA a Neapolitan, and by others ftill to
different People. The firft Appearance of
them however was about the Year 1621 5
iince when they have been improving down
to the prefent Time.

As my Defire is, to make People fenfible
of the Pleafure and Information the Micro-
fcope can afford, and inllrud: them how to
manage and underftand it, rather than hoW
to make it, I fhall take up none of their
Time with the Manner of melting, grind-
ing, poliihing, or fetting of GlalTes 5 a Work
very few of my Readers will ever trouble
themfelves about. But, inftead thereof, I
fhall endeavour, with all the Brevity and
Clearnefs I am able, to explain the Effe<fts
of Glafles on the Sight, and lead them gra-
dually into the Nature, Ufes, and magnify^
ing Powers of Microfcopes.

When Objeftsare feen through a perfedlly
flat Glafs, the Rays of Light pals through
it, from them to the Eye, in a ilrait Direc-'
tion, and parallel to each other 5 and^ con^
fequently, the Objeftsappear very little either
diminifhed, or enlarged, or nearer, or farther
off, than to the naked Eye. But if the
Glafs they are feen through has any Degree
of Convexity, the Rays of Light are direct-
ed from the Circumference towards th«

B 2 Center,

^ Of Microscopes in General.

Center, in an Angle proportionable to the
Convexity of the Glafs, and meet in a Point,
at a greater or lefs Diftance from the Glafs,
as it is lefs or more convex. This Point,
where the Rays meet, is called the Focus \
and this Focus is nearer or farther off, ac-
cording to the Convexity of the Glafs : for
as a little Convexity throv/s it to a confi-
derable Diftance, when the Convexity is
m.uch, the Focus is very near. Its magni-
fying Power is alfo in the fame Proportion
to the Convexity : for as a flat Glafs mag-
nifies fcarce at all, the lefs a Glafs departs
from Flatnefs, the lefs of courfc it magnifies^
and the more it approaches towards a glo-
bular Figure, the nearer its Focus is, and
the more its magnifying Power.

People's different Length of Sight depends

on the fame Principle, and arifes from a

more or lefs Convexity of the Cornea and

Cryjialline Humour of the Eye : the rounder

thefe are, the nearer will the Focus or Poi?if

cf meeting Rays be, and the nearer an Ob-

jed: muft be brought to fee it well. The

Cafe of fliort-fighted People is only an over

Roundnefs of the Eye, which makes a very

near Focus 5 and that of old People is a

linking or flattening of the Eye, whereby

the Focus is thrown to a great Diftance :

fo that the former may properly be called

Eyes of too fhort, and the latterjEyes of too

long a Focus. Hence too the Remedy for

the

Of Microscopes /;; General. 5

the laft is a convex Glafs, to fupply the
Want of Convexity in the Eye itfelf, and
bring the Rays to a fhorter Focus ; w^hereas
a concave Glafs is needful for the iirft, to
fcatter the Rays, and prevent their coming
to a Point too foon.

Nothing is more common than to obferve
old People holding Objedls they v^ould exa-
mine at a great Diftance from them, for
the Reafon above-mentioned ; and every
body knows, fhort-fighted People cannot
diftinguifh any thing without bringing it
very near their Eyes. Both Extremes are
inconvenient ; but thofe whofe Eyes are flat
by Age, fhould remember with Satisfaction,
that they have enjoy 'd thePleafure of them
for many Years -, and the Short-fighted may
comfort themfelves, that they can diftin-
guifh much fmaller Objed:s than long-
fighted People : for the Objecft is magnify'd
in Proportion to the Roundnefs of the Eye
and the Nearnefs of the Focus, and confe-
quently appears four times as big to an Eye
whofe Focus is but four Inches off, as it
does to one whofe focal Diftance is at eight
Inches. They have alfo this farther Advan-
tage, that Age improves their Eyes, by the
fame Means it impairs other People's, that
is, by making them more flat.

The nearer any Objedl can be brought to
the Eye, the larger will be the Angle under
which it appears, and the more it will be

B 3 mag-

# Of MiCEOscoPES in General,

magnified. Now, that DIftance from the
naked Eye, where the generaUty of People
are fuppofed to fee fmall Objefts beft, is, at
about eight Inches $ confequently, when fuch
Objects are brought nearer than eight Inches,
(fuppofe to fix) they'll become lefs diftinftj
^nd if nearer ftill, on to four or three, they
Vv^ill fcarce be i^trv at all. But by the help
of convex Glaffes we are enabled to view
things, clearly, at much fhorter Diftances
than thefe : for the Nature of a convex Lens
is, to render an Objed; diftindly viiible to
the Eye at the Diftance of its Focus j where-
fore the fmaller a Lens is, and the more its
Convexity, the nearer is its Focus, and the
more its magnifying Power.

As it is an eafy matter to melt a Glafs
Drop or Globule of a much fmaller Dia-
meter than any Lens can poffibly be ground,
and as the Focus of a Globule is no farther
off than one quarter of its own Diameter,
and confequently it muft magnify to a pro-
digious Degree, fome Years ago People were
extremely fond of fuch Globules, and ima-
gin'd no good Microfcope could be without
them : but Experience has fince taught, that
they admit fo little Light, can fhew fuch
an e;xceedingly minute Part only of any Ob-
ject, are fo difficult to make ufe of, and
ftrain the Eyes fo much, that their Power of
magnifying, for want of due Diftindnefs^
is rather apt to produce Error than difcover

Truth :

TL

^^^/.

il ■''.;•< >cnl^>.

Of the Kinds of Microscopes, y

Truth : and therefore now they are very
rarely hnployed. f

» ■ ' ' ' - - —I — . ■ im

CHAP. II.

Of the Kinds of Microscopes.

MICROSCOPES are either Single or
Double : the Single have but one
Lens ', the Double are a Combination of
two or more. Each of thefe two Kinds has
its particular Advantage : for a fingle Glafs
fhews the Objedl nearer at hand, and ra-
ther more difiincl ; and a Combination of
Glaffes prefents a larger Field, or, in other
Words, exhibits more ofanObjedl, equally
magnified, at one View. It is difficult to
determine which of thefe to recommend,
iince each affords a different Kind of Plea-
fure. Each of them too can produce confi-
derable Authorities in its Favour 3 for Mr.
Leeuwenhoek never ufed any but J fingle

X Several Writers reprefent the GlaiTes Mr. Leeuwen-
hoek made ufe of in his Microfcopes to be little Globules
or Spheres of Glafs, which Miftake moft probably arifes
from their undertaking to defcribe what they had never feen ;
for at the Time I am writing this, the Cabinet of Micro-
fcopes left by that famous Man, at his Death, to the Rojal
Society, as a Legacy, is Handing upon my Table ; and I can
afiure the World, that every one of the twenty-fix Micro-
fcopes contained therein is a double convex Lens, and not a
Sphere or Globule. »

B 4 Micro-

8 Of the Kinds ^Microscopes."

Microfcopes ; and, on the contrary, Mr.
H o o K E made all his Obfervations with
double ones.

The famous Microfcopes of Mr. L e e u-
w E N H o E K are the moft fimple poffible,
being only a fingle Lens, fet between two
Plates of Silver perforated with a fmallHole,
with a moveable Pin before it to place the
Objeft on, and adjufl it to the Eye of the
Beholder. By thefe he made thofe wonder-
ful Difcoveries which furprized the World
fo much, and introduced a new Syftem of
Philofophy and Reafoning, as in the Courfe
of this Treatife I fhall find occalion more at
large to mention.

There are many pretty little Contrivances
fold at the Shops for the viewing of fmall
Objefts, which are entertaining as far as can
reafonably be expected from them : but to
enumerate all thefe would be a tedious Tafk,
It would alfo be a matter more of Curiofity
than Profit, to defcribe the Forms and Ap-
paratus of the feveral Kinds of Microfcopes
that have been contrived fince the firft In-
vention of them. I fhall therefore confine
myfelf to give an account of fuch only in
ufe among ourfelves at prefent, as by having
^ proper Set of GlaiTes, gradually magnify-
ing one above another, are fit to make Dif-
coveries of Confequence,

CHAP,

(9)

CHAP. III.

Of Mr. W I L s o nV Single Pocket-
Micro/cope.

THE lirft that I (hall mention, is
Mr. W ILSOJ^' s fng/e Pocket Micro-
fcope-y the Body whereof made either of Brafs,
Ivory, or Silver, is reprefented {Plate I.) by
AA. BB.

CC. is a long fine-threaded male Screw,
that turns into the Body of the Microfcope.

D. a convex Glafs at the End of the faid
Screw.

* Two concave round Pieces of thin Brafs,'
with Holes of diiferent Diameters in the
middle of them, to cover the faid Glafs, and
thereby diminifh the Aperture when the
greateft Magnifiers are employed.

EE. three thin Plates of Brafs within the
BodyoftheMicrofcope one whereof is bent
femicircularly in the middle, fo as to form
an arched Cavity for the Reception of a Tube
of Glafs, whereas the two fiat Plates are to
receive and hold the Sliders between them.

Fv a piece of Wood or Ivory, arched in
the Manner of the femicircular Plate, and
cemented thereto.

G. the other End of the Body of the
Microfcope^ where a hollow female Screw is
adapted to receive the different Magnifiers.

H

JO Wilson's /mgle Pocket Micro/cope.

H. a fpiral Spring of Steel, between the
faid End G and the Plates of Brafs ; intended
to keep the Plates in a right Pofition, and
counter-aft againfl: the long Screw CC.

I. a fmall turn'd Handle, for the better
holding of the Inftrument, to fcrew on or
off at pleafure.

To this Microfcope belong feven different
magnifying Glaffes : fix of them are fet in
Silver, Brafs, or Ivory, as in the Figure K,
and marked i. 2. 3. 4. 5. 6. the loweft
Numbers being the grcateft Magnifiers.

L. is the feventh Magnifier, fet in the
Manner of a little Barrel, to be held in the
Hand for the viewing any larger Objed;.

M, is a flat Slip of Ivory, called a Slider,
with four round Holes through it, where-
in to place Objects between two Glafles or
Pieces of Miifcovy Talc, as they appear
d d d d.

Eight fuch Ivory Sliders, and one of Brafs,
are ufually fold with this Microfcope 3 fome
with Objefts placed in them, and others
empty, for viewing any thing that may
offer ; but whoever pleafes to make a large
Collection of Objects, may have as many as
he defires.

The Brafs Slider is to confine any fmall
Objeft, that it may be viewed without
crufhing or deftroying it.

N. is a Forceps or Pair of Plyers, for the
taking up of Infecfls or other Objedtd, and
adjuiling them to the Glaffes.

Wilson's Jingle Pocket Microfcope, ii

O. is a little Hair-Brufli or Pencil, where-
with to wipe any Duft from off the GlaiTes,
or to take up any fmall Drop of Liquid one
would examine, and put it upon the Talcs
or liinglafs.

P. is a Tube of Glafs, contrived to confine
living Objecls, fuch as Frogs, Flihes, &c,
in order to difcover the Blood, as it flreams
along the Veins and Arteries,

All thefe Particulars are contained in a
little neat Box, very convenient for carrying
in the Pocket.

When an Objeft is to be vlew*d, thruft
the Ivory Slider, in which the faid Objedl is
placed, between the two flat Brafs Plates
EE : obferving always to put that fide of the
Slider where the Brafs Rings are, fartheft
from your Eye. Then fcrew on the mag-
nifying Glafs you intend to ufe, at the End
of the Inftrument G ; and lookins throuo-h
it againft the Light, turn the long Screw
CC, till your Objedl be brought to fit your
Eye ; which you will know by its appearing
then perfectly diftind; and clear. — 'Tis belt
to look at it firft, through a Magnifier that
can fhew the Whole thereof at once, and
afterv/ards to infped: the feveral Parts more
particularly with one of the greateft Magni-
fiers : for thus you will gain a true Idea of
the Whole, and of all its Parts. And tho'
the greateft Magnifiers can fhew but a mi-
nute Portion of any Objefl: at once, fuch as

the

12 WilsonV Jingle "Pocket Mtcrofcope,

the Claw of a Flea, the Horn of a Loufe,
or the like ; yet by gently moving the Slider
that contains your Objed:, the Eye will gra-
dually overlook it all : and if any Part fhould
be out of Diftance, the Screw CC will eafily
bring it to the true Focus.

As Objecfts muft be brought very near the
GhfTes when the greateft Magnifiers are
ufed, be particularly careful not to fcratch
them, by rubbing the Slider againft them
as you move it in or out. A few Turns of
the Screw CC will eafily prevent this Mif-
chief, by giving them Room enough.

You may change the Obje(5ls in your
Sliders, for what others you think proper,
by taking out the Brafs Rings with the Point
of a Pen-knife ; the Ifinglafs will then fall
out, if you but turn the Sliders 3 and after
putting what you pleafe between them, by
replacing the Brafs Rings, you will fafl:en
them as they were before. 'Tis proper to
have fome Sliders furnifh'd with Talcs, but
without any Objedls between them, to be
always in Readinefs for the Examination of
Fluids, Salts, Sands, Powders, the Farina
of Flowers, or any other cafual ObjecSls of
fuch fort as need only be apply'd to the Out-
fide of the Talc.

The Circulation of the Blood may eafieft
be it^n in theTails or Fins of Fifties, in the
fine Membranes between a Frog's Toes, or,
beft of all, in the Tail of a Water-Newt.

If

WilsonV fingle Pocket Microfcope, il

If your Objedl be a fmall Fi{h, place it with-
in the Tube, and fpread its Tail or Fin a-
gainft the Side thereof: if a Frog, chufe
fuch an one as can but juft be got into your
Tube, and with a Pen or Stick expand the
tranfparent Membrane between the Toes of
the Frog's hind Foot as wide as your are able.
When your Objecft is fo adjufted, that no
Part thereof can intercept the Light from
the Place you intend to view, unfcrew the
long Screw CC, and thruft your Tube into
the arched Cavity, quite thro' the Body of
the Microfcope j then fcrew it to the true
focal Diftance, and you'll fee the Blood paff-
ing along its Veffels with a rapid Motion,
and in a moft furprizing Manner.

Make ufe of the third or fourth Magnifier
for Frogs or Fifhes ; but for the Tails of
Water-Newts, the fifth or fixth will do;
becaufe the Globules of their Blood are twice
as large as thofe of Frogs or Fifh. The firft
or fecond Magnifier cannot well be employ-
ed to this purpofe 3 for the Thicknefs of the
Tube wherein the Objedl lies, will fcarce
admit its being brought fo near as the focal
Diflance of the Magnifier.

The Smgle Microfcope above defcribed
may be formed into a Double One^ by fcrew-
ing it to a Tube with an Eye-Glafs at the
End thereof : it is alfo made to anfwer nearly
the Purpofes of the large Double Refe&i/ig
Microfcope^ by the Contrivance following.
4 CHAP,

14 ^f ^^^ Pocket Microscope

CHAP. IV.

1^ New Invention for fixing the Pocket-
Microscope, and giving Light to it by
a Speculum. Flate 11.

IN this Plate, A is a Scroll of Brafs, fix'd
upright on a round Pedeftal of Wood,
B, fo as to ftand perfeftly firm and fteady.

C. IS a Brafs Screw, that palTes through a
Hole in the upper Limb of the Scroll, into
the Side of the Microfcope D^^ and fcrews it
faft to the faid Scroll.

E. a concave Looking-glafs or Speculum,
fet in a Box of Brafs, which hangs in the
Arch G, by two fmall Screws yy^ that fcrew
into the oppofite Sides thereof.

At the Bottom of the faid Arch is a Pin
of the fame Metal, exad:ly fitted to a Hole
h, in the wooden Pedeftal, made for the
Reception of the faid Pin,

As the Arch turns on this Pin, and the
Speculum turns on the Ends of the Arch, it
may, by this twofold Motion, be eafily ad-
jufted, in fuch a manner, as to refled: the
Light of the Sky, the Sun, or a Candle,
diredly upwards, thro' the Microfcope that
is fixed perpendicularly over it 3 and by fo
doing, may be made to anfwer almoft all
the Ends of the large "Double Rejlediing Mi-*
crofcope^ which I fhall prefently defcribe.

The

wtth a Speculum.' tj

The Body of the Microfcope may alfo be
fixt horizontally, and Objed:s may be view'd
in that Pofition, by any Light you choofe ;
which is an Advantage the Reflefting Mi-
crofcope has not.

It may alfo be rendered farther ufeful, by
means of a Slip of Glafs, one End of which
being thruft between the Plates where the
Sliders go, and the other extending to fome
Diftance, fuch Objecfts may be placed there-
on, as cannot be applied in the Sliders : and
then, having a Limb of Brafs that may faften
to the Body of the Microfcope, and extend
over the projedting Glafs a hollow Ring
wherein to fcrew the Magnifiers, all forts of
Subjects may be examined with great Con-
veniency, if a Hole be made in the Pedeftal,
to place the Speculum exadlly underneath,
and thereby throw up the Rays of Light.

The Pocket Microfcope thus fixt, is, if I
may prefume to judge, as eafy and pleafant
in its Ufe, and as fit for the moft curious
Examination of the Animalcules and Salts in
Fluids, of the Farina in Vegetables, of the
Circulations in fmall Creatures : in fliort, it
is as likely to make confiderable Difcoveries
in Objects that have fome Degree of Tranf-
parency, as any Microfcope I have ever feen
or heard of. It is alfo a material Part of the
Bolar or Ca?nera Ohfciii-a Mic7'ofccpey which
I (hall by and by defcribe.

CHAP.

i6 ^he Double Refiedling Microfcopel

CHAP. V.

Of the Double Reflecting MiceIosgopb*

TH E Double Rejle6ling Microfcope^ in
ufe at prefent, (whofe Picfture with
its Apparatus is feen Plate III.) is an Altera-
tion and Improvement by Mr* Culpeper
and Mr. Scarlet, of Mr. Marshal's
large Double Microfcope ; than which it is
lefs cumberfome, may be managed with
much more Eafe, and by means of a re-
flected Light, is capable of fhewing Objedls
in a clearer and more pleafing Manner.

The Body of this Microfcope A A A A,
being a large Tube, is fupported by three
Brafs Pillars b b by rifing from a wooden Pe-
deflal C 'y in which Pedeftal is a Drawer D,
to hold the Objedt-Glaffes and other Parts
of the Apparatus.

A lefler Tuble e e^ Aides into the greater,
and fends from its Bottom another Tube
much fmaller than itfelf, f with a male
Screw gy at the End thereof, whereon to
fcrew the Objedl-Glafs or Magnifier.

There are five of thefe Magnifiers, num-
bered I. 2. 3. 4. 5. which Numbers arealfo
marked on the inner Tube, to dired where-
about to place it according to the Magnifier
made ufe of: but if then it fits not the Eye
exacSly, Aide the inner Tube gently higher

or

^cu/e /^.

Biff '^■

HiUeM-l

"The Double RefcBhtg Microfcope, 17

or lower, turn the Screw of the Magnifier,
gradually, till the Object appears diftinft. —
Take Notice, that the greateft Magnifiers
have the linalleft Apertures and the lowefl
Numbers.

L. is a circular Plate of Brafs, fixt hori-
zontally between the three Brafs Pillars, and
in the Center thereof a round Hole M. is
adapted to receive a proper Contrivance N,
for holding Ivory Sliders wherein Objedls are
placed : v/hich Contrivance confifts of a fpi-
ral Steel Wire confined between three Brafs
Circles, one whereof is moveable for the
Admiffion of a Slider.

O. is a round Brafs Plate, v/ith feveral
Holes for placing Objedls in, fome of which
are ufually furnifli'd with them at the Shops :
but two Holes are commonly referved for
fmall concave Glafi^es, whereon to place a
Drop of any Liquid, in order to viev/ the
Animalcules, &c. There is alfo a Piece of
white Ivory, and a Piece of black Ebony,
of the fame Size and Shape as the Holes for
Objedis : the Ivory is to put opake Objects
on that are black, and the Ebony is to re-
ceive fuch as are white ; by which Contra-
riety of Colours they will be feen more

clearly. At the Bottom of this Obje<ft-

Plate is a Button to flip into a Slit P. that
fits it, on the circular Plate of Brafs : snd by
turning it round on this Pin, all the Objeds

1 8 T^he Double RefieBing Micro/cope.

may be examin'd fucceffively with very little
Trouble.

Q^ is a concave Looking-glafs, fet in a
Box of Brafs, and turning in an Arch R.
upon two fmall Screws s s. From the Bot-
tom, of the Arch comes a Pin, which be-
ing let down into a Hole /. in the Center
oi the Pedeftal, enables the Looking-glafs to
turn vertically, or horizontally, and refled:
the Light, either of a Candle, or the Sky,
dire(flly upwardson the Objecfl to be viewed.

V. is a Plano-convex Lens, which by
turning on two Screws **, v/hen the Pin at
the Bottom of it is placed^he Hole W.
for its Pvcception in the circular Plate L. will
tranfmit the Light of a Candle, to illuminate
any opake Objed: that is put on the round
piece of ivory, or on the Ebony, for Exami-
nation : and it may be moved higher or low-
er IS the Light requires. This Glafs is of
good fervice to point the Sunfhine, or the
Light of a Candle upon any opake Objed 5
but in plain Day-light it is of no great ufe.

X. a Cone of black Ivory, to fallen on a
Shank underneath the Brafs circular Plate L.
principally, when the firft or fecond Magni-
fier is made ufe of, and the Objed very
tranfparent : for Experience- teaches, that
fuch Objeds are rendered much more dif-
tindly vifible, by intercepting fome part of
the obUque Rays refleded from the concave
Lookine^-glafs.

The

■VC^'r^i^/^e J^l.,i.u

7he Double RejieBing Mlcrofcope. 1 9

• The Brafs Fifli-pan Y. is, to faften a Smelt,
Gudgeon, or any fuch fmall Fifh upon, to
fee the Blood circulate in its Tail. For
which purpofe, the Tail of the Fifh muft
be fpread acrofs the oblong Hole at the
fmalleft End of the Pan : then by flipping
the Button on the Backlide of the Pan into
the Slit P. through the circular Plate L. the
Spring that comes from the Button will make
it fteady, and prefent it well to View.

But if it be a Frog, a Newt, or Eel, in
which the Circulation is delired to be fhewn,
a Glafs Tube i. is fitted for the purpofe.
The Tail of a Newt, or Eel, or, in a Frog,
th€ Web between the Toes of the Hind-
Feet, are the Parts where it may be feea
beft. When the Object is well expanded on
the Infide of the Tube, Aide the Tube along
under the circular Brafs Plate L. (where there
are two Springs and a Cavity made in the
Shank to hold it) and bring your ObjecTt di-
rectly under the Magnifier.

There are three of thefe Glafs Tubes^
fmaller one than another, and the Size of
the Obje(5t muft diredl which to ufe ; but in
general, the lefs Room the Creature has to
move about in, the eafier it may be ma-
naged, and the quieter it will lye to be ma-
naged.

The Cell 2. with a concave and a plain
Glafs in it, is intended to confine Fleas,
Lice^ Mites, or any fmall living Objeds,

C 2 "^ during

20 "The Double RejleBing Mi cr of cope,

during pleafure ; and by placing it over the
Hole M. in the middle of the circular Brafs
Plate, they may be viewed with much Con-

veniency. Three loofe Glaffes, viz, one

plain, and two concave, belong alfo to this
Microfcope, and are defigned to confine
Objects, or place them upon occafionally.

The long Steel Wire 3. with a pair of
Plyers at one End, and a Point at the other,
to hold faft, or flick Objecfts on, flip back-
wards or forwards in a Brafs fhort Tube,
whereto a Button is faftened, which fits in-
to the little Hole z^ near the Edge of the
Brafs Plate L: and^ then, the Obje(ft may be
readily brought to a right Pofition, and a
Light be cafl upon it, either by theLooking-
glafs underneath, or, if it be opake, by the
Plano-convex Lens V.

4. is a flat Piece of Ivory called a Slider,
with four round Holes through it, and Ob-
jects placed in them betvv^een Mufcovy Talcs
or Ifmglafs, kept in by Brafs Wires.

It is proper to have a Number of thefe
Sliders filled with curious Objed:s, always
ready, as well as fome empty ones, for any
new thing that offers. When made ufe of,
thruft them between the Brafs Rino-s of the
Contrivance on purpofe for them, N. which
jflioots into the round Hole M. in the Center
of the, Brafs Plate L. This keeps them
fteady, and at the fame time permits them
to be moved to and fro for a thorough Exa-
mination. A

I'he Double RefeBing Micro/cope, "* 2 1

A little Ivory round Box 5. to hold pieces
of Jlino-hifs for the Sliders.

6. afmall Hair Brufli, to wipe any Durt:
off the Glafs, or to apply a Drop of any
Liquid.

7. a pair of Nippers, to take up any Ob-
jcdl to be examined.

The twoMicrofcopes I iliall defcribe next,
viz, the Sola?% or Camera Oh fair a Micro-
J cope ^ and the Microjcope for Opake ObjeBs,
are of a foreign Invention, and but lately
known to us. We are, indeed, obliged for
them both to a Gentleman of PruJJia^ the
ingenious Dr. LfBERKHUN, who when
he was in Englafid, in the Year "1740,
ihewed an Apparatus for each of thefe Pur-
pofes, to feveral Gentlemen of the Royal
Society J and alfo to fome Opticians; amongft
whom, Mr. Cuff, againft Serjea?its-In7i
Gate, in Fleet-fir eef^ has taken great Pains
to improve and bring them to Perfection :
and therefore I fliall give a Defcription of
them, as made and fold by him.

C3 CHAP.

22 Of the S OL A Rj or

CHAP. VI.

The Solar, or Camera Obscura
Microfcope.

HIS Microfcope depends on theSun^.
fliine, and muft be made ufe of in a
darken'd Chamber, as its Name implies.

It is compofed of a Tube, a Looking-^
glafs, a convex Lens, and Wilson's iingle
Pocket Microfcope before defcribed, p. 9.

The Sun's Rays being direded by the
Looking-glafs through the Tube upon the
Objedl, the Image or Fidure of the Obje<^t
is thrown, diftinftly and beautifully, upon a
Screen of white Paper, or a white Linen
Sheet, placed at fome Diftance to receive
the fame ^ and may be magnified, to a Size
beyond the Imagination of thofe vv^ho have
not feen it : for the farther off the Screen is
removed, the larger will the Obje(ft appear;
infomuch, that a Loufe may be magnified
to the Length of five or fix Feet, or even a
great deal more : but it is indeed more di-
ftind:, when not enlarged to above half that
Size-f*. ■ ' <^ The

-f- Having, in the Second Ed'iUonQ)i\}!\\?,^ox\L, inferted a
carious Draught of the Solar Microfcope, which was not in
the former Impreffion, and given a more particulaf De-
fcription of that Inftrument, and its Apparatus, than I
poiTibly could before : left the Purfhafers of the frf Edition
|hoald have found Reafon to complain of being unkindly

iife^

Camera Obscura Micro/cope.

The Apparatus for this Purpofe, as rcpre-
fented in the Plate annex'd, is as follows.

A. a fquare wooden Frame, thro' which
two long Screws pafs, and, afnfted by a cou-
ple of Nuts I.I. faflen it firmly to a Win-
dow-lhutter, wherein a Hole is made for its
Reception ; the two Nuts being let into the
Shutter, and made faft thereto.

A circular Hole is made in the middle of
this Frame, to receive a piece of Wood of
a circular Figure, B, whofe Edge, that pro-
jedls a little beyond the Frame, compoies a
fliallow Groove 2, wherein runs a Cat-gut 3 3
w^hich by twifting round, and then croffing
over a Brafs Pulley, 4, (the Handle whereof,
5, paffes thro' the Frame) affords an eafy
Motion for turning round the circular Piece
of Wood B, with all the Parts thereto affixt.

C. is a Brafs Tube cover'd with Seal-Skin,
which fcrewing into the Middle of the cir-
cular Piece of Wood, becomes a Cafe tor
the uncovered Brafs Tube D. to be drawn
backw^ards or forwards in.

E. a fmaller Tube of about one Inch in
Length, cemented to the End of the larger
Tube D.

ufed, I took care that the faid Drawing and Defcrlption, with
what other little Additions appeared neceflary to render the
Book more perfecl, fhould be prefented to them gratis, up-
on applying to thofe they bought them of. But no luch
Care is requifite at prefent, this third JmpreJJion being printed
from t\iQfecond without any Difference of Confequence.

C 4 F is

bf the Solar, of^

. F. IS another (liort Brafs Tube, made to
fllde over the above-defcribed Tube E. To
the End hereof the Microfcope muft be
fcrewed when we come to ufe it.

5. a convex Lens, whofe Focus is about
twelve Inches, defigned to colled: the Sun's
Ra^s, and throw them more ftrongly upon
the Obje6l.

G. a Looking-glafs of an oblong Figure,
fet in a wooden Frame, faften d by Hinges
to the circular Piece of Wood B, and turn-
ing about therewith, by means of the above-
mentioned Cat-gut.

H. a jointed Wire, partly Brafs and partly
Iron : the Brafs part whereof, which is flat,
6, being faftened to the Looking-glafs, and
the Iron part, which is round, 7, paffing
through the wooden Frame, enable the Ob-
ferver (by putting it backwards or forwards)
to elevate or decline the Glafs according to
the Sun's Altitude.

I . a Brafs Ring at the End of the jointed
Wire^ whereby to manage it with the greater
A^aie.

N. B. The Extremities of the Cut-gut are
faftened to a Brafs Fin, by turning of which
it may be braced up, if at any time it
becomes too flack. This Pin lying behind
could not be fhewn in the Pidure.

When this Microfcope is employed, the
Room muft be render'd as dark as pofiible :
for on the Darknefs of the Pvoom, and

the

Camera Obscura Microfcopc. 23

the Brightncfs of the Sun-fliine, depend the
SharpiK'ls and Pcrfccftion of your Image.
Then putting the Looking-glafs G. through
the Hole in your Window-fhutter, faflen
tlie fquare Frame A. to the faid Shutter by its
two Screws and Nuts, i . i .

This done, adjuft your Looking-glafs to
the Elevation and Situation of the Sun, by
means of the jointed Wire H. together with
the Cat-gut and Pulley 3. 4. For the firft
of thefe raifing or lowering the Glafs, and
the other mclining it to either Side, there
refults a- twofold Motion, which may eafily
be fo managed as to bring the Glafs to a
right Poiition, that is, to make it refledl the
Sun's Rays diretflly through the Lens 5. up-
on the Paper Screen, and form thereon a
Spot of Light exadlly round *.

As foon as this appears, fcrew the Tube
C into the Brafs Collar provided for it in the
Middle of your Wood- work, taking care not
to alter your Looking-glafs : then fcrewing
the Magnifier you chufe to employ to the
End of your Microfcope, in the ufual Man-

* Though obtaining a perfeft circular Spot of Light
upon the Screen before you apply the Microfcope, is a cer-
tain Proof that your Looking-glafs is adjufled right, that
Proof mull not always be expeded : for the Sun is fo low
in Winter, that if it (hines in a diredl Line againft the Win-
dow, it cannot then afford a Spot of Light exaftly round.
But if it be on either Side of you, a round Spot may be
obtained even in December,

3 n^f"?

24 ^f ^^^ Solar, or

ner, take away the Lens at the other End
thereof, and place a Slider, containing the
Objed: to be examined, between the thin
Brafs Plates, as in the other Ways of ufing
the Microfcope.

Things being thus prepared, fcrew the
Body of your Microfcope to the fhort Brafs
TubeF. which flip over the fmalleft End E.
of the Tube D. and pull out the faid Tube

D. lefs or more, as your Obje6l is capable of
enduring the Sun's Heat. Dead Obje6ts may
be brouo^ht within about an Inch of the
Focus of the convex Lens, 5; but the Di-
fiance muft be ihorten'd for living Creatures,
or they will foon be killed.

If the Light falls not exa(fl:ly right, you
may eaiily, by a gentle Motion of the jointed
Wire and Pulley, dired it through the Axis
of the microfcoptic Lens.

The fhort Tube F, which your Micro-
fcope is fcrewed to, enables you, by Aiding
it backwards or forwards on the other Tube

E. to bring your Objeds to their true fo-
cal Diftance 3 w^hich will be know^n by the
Sharpnefs andClearnefs of their Appearance:
they may alfo be turned round by the fame
Means, without being in the leaft diforder'd.

The Magnifiers moft ufeful in the Solar
Microfcope are, in general^ the fourth, fifth,
orfixth. ' ^

Mention having been often made of a
Screen to throw the Images of Objeds on,

it

Camkra Obscura Micro/cope. 25

It is proper tr) inform the Reader, that fuch
a Screen is ufiially compofed of a Sheet of
the largeft Elephant Paper, flrained on a
Frame, which Hides up, or down, or turns
about at pleafure on a round wooden Pillar,
in the manner of fome Firc-fcreens. Larger
Screens are Hkewife made fometimes, with
feveral Sheets of the fame Paper parted to-
gether on Cloth, and let down from the
Ceiling with a Roller, like a large Map.

This Microfcope is the moft entertaining^
of any ; and, perhaps, the moft capable of
making Difcoveries, in Objecfls that are not
too opake : , as it fliews them much larger
than can be done any other way. There
arc alfo feveral Conveniencies attendinof it.
which no other Microfcope can have : for
the weakeft Eyes may ufe it without the
leaft Straining or Fatigue : Numbers of Peo-
ple may view any Objed:, together, at the
fame Time, and, by pointing to the parii-
cular Parts thereof, and difcourling on what
lies before them, may be able better to un-
derftand one another, and more likely to
find out the Truth, than when, in. other
Microfcopes, they muft peep one after an-
other, and perhaps fee the Objedl neither in
the fame Light, nor the fame Poiition. Such
too as have no Skill in Drawing, may, by
this Contrivance, eafily fketch out the exadl
Figure of any Objed: they have a mind to
preferve a Pidure of 3 fince they need only

fafter^

^6 Of the Solar Microscore.^

faften a Paper upon the Screen, and trace it
out thereon either with a Pen or Pencil, as
it appears before them.

It is worth their while, who are defirous
to take many Draughts this Way, to get a
Frame, wherein a Sheet of Paper may be
put or taken out at pleafure ; for if the
Paper be lingle, the Image of an Objed will
be feen as plainly almoft on the back as on
the fore Side, and by ftanding behind the
Screen, the Shade of the Hand will not ob-
ftrud: the Light in Drawing, as it mull in
fome degree when one ftands before it,

I muft obferve, that Dr. Liberkhun's
Solar Microfcope had no Looking-glafs be-
longing to it, and therefore was of ufe a few
Hours only in a Day, when the Tube could
be placed dired:ly againft the Body of the
Sun, and even then not without a good deal
of Trouble ; but by this lucky Contrivance
of a Looking-glafs, the Sun's Rays may be
reflected thro' theTube, whatever its Height
or Situation be, provided it fhines at all up-
on the Window, and that too with much
£afe and Advantage,

CHAP,

[ 27 ]

CHAP. VII.

Of the Mia^ofcope for Opake Objc^s.

THISMicrofcope remedies the Inconve-
nience of having the dark Side of an
Objedl next the Eye, which has hitherto
been gn unfurmoun table Obftruclion to the
making Obfervations on opake Objefts with
any conliderable Degree of Exacftnefs or Sa-
tisfa6lion : for in all other Contrivances com-
monly known, the Nearnefs of the Inftru-
ment to the Objecft (when Glaffes that mag-
nify much are ufed) unavoidably overflia-
dows it fo much, as to render its Appearance
obfcure and undiftindt. And, notwithftand-
ing Ways have been tried to point Light
upon an Objed:, from the Sun, or a Candle,
by a convex Glafs placed on the fide there-
of: the Rays from either can be thrown
upon it in fuch an acute Angle only, that
they ferve to give a confufed Glare, but are
infufficient to afford a clear and perfedView
of the Objed,

But in this new Microfcope, by means of
a concave Speculu?n of Silver, highly polifh-
ed, in whofe Center a magnifying Lens is
placed, fo dired: and ilrong a Light is re-
flected upon the Objed, that it may be
examined with all imaginable Eafe and Plea-

fure.

The

'^8 Of the Ml cr of cope

The Apparatus for this Purpofe (as in the
Plate^ Numb, IV.) has afforded me more
Delight and Satisfacftion than I am able to
defcribe 5 and whoever trys it, will I believe
join in my Opinion, that he never before
faw an opake Objed: with fo much Clear-
nefs, and in fo perfeft and true a manner.

The feveral Parts of thislnftrument, made
either of Brafs or Silver, are as follows.

Through the firft fide, A. paffes a fine
Screw B. the other End whereof is fattened
to the moveable fide C.

D. is a Nut adapted to the faid Screw,
by the turning of which the two fides A.C.
are gradually brought together.

E. is a Spring of Steel, that feparates the
faid two fides when the Nut is unfcrewed.

F. a piece of Brafs turning round in a
Socket, whence proceeds a fmail SpringTube
moving upon a Rivet, through which Tube
there runs a Steel Wire, one End whereof
terminates in a fharp Point G. and the other
hath a pair of Plyers H. faftened to it. — The
Point and Plyers are to thrufl: into or take
up and hold any Infed or Objed; : and either
of them may be turned upwards, as fuits
your Purpofe befl:.

I. a Ring of Brafs with a female Screw
within it mounted on an upright piece of
the fame Metal, which turns round on a
Rivet, that it may be fet at a due Difl:ance

when

for Opake Obje&s. 29

wlicn the leall Magnifiers are employed,
— This Ring receives the Screws of all the
Masrnifiers.

K. a concave Speculum of Silver, poliflied
as bright as poffihle, in the Center of which
a double convex Lens is placed, with a pro-
per Aperture to look through it. On the
Back of this Speculum a male Screw L. is
made fit to the Brafs Ring I. to fcrew into
the faid Ring at pleafure.

There are four of thefe concave Specula,
of different Depths, adapted to four Glaffes
of different magnifying Powers, to be ufed
as Objedls to be examined may require. The
greateft Magnifiers are known by having the
leaft Apertures.

M. a round Objed-Plate, one fide white
and the other black, intended to render Ob-
je(fts the more vifible, by placing them, if
black on the white, and if white on the
black fide. A Steel Spring N. turns dovv^n
on each fide to make any Objed: fafi: : and
iffuing from the Objeft-PIate is a hollow-
Pipe to fcrew it on the Needle's Point G.

O. a fmall Box of Brafs, with a Glafs on
each fide, contrived to confine any hving
Objed, in order to examine it : this alfo has a
Pipe to fcrew upon the End of the Needle G.

P. a turned Handle of Wood, to fcrew
into the Inftrument when it is made ufc of.

Q^a pair of Brafs Plyers, to take up any
Objed, or manage it with Conveniencv,

R.

of the Micro/cope

R. a foft Hair Brufh, to clean the GlafTes
or Specula, or apply a Drop of any Liquid
to the Ilinglafs of the Box O. in order t©
view the Animalcules.

S. a fmall Ivory Box for Ifinglaffes, to be
placed vv^hen wanted in the fmall Brafs Box
O.

When you would viev/ any Objed:, fcrew
the Speculum, w^ith the Magnifier you think
beft to ufe, into the Brafs Ring I. Place your
Objed: either on the Needle G. in the Plyers
H. on the Objed-Plate M. or in the Brafs
hollow Box O. as may be moft convenient,-
according to the Nature and Condition of it :
then holding up your Inftrument by the
Handle P. look againft the Light, through
the magnifying Lens, and by means of the
Nut D. together wdth the Motion of the
Needle, by managing its lower End, the
Objed: may be turned about, raifed, or de-
prefled, brought nearer the Glafs, or put
farther from it, till you hit the true focal
Diftance, and the Light be feen refleded
from the Speculum ftrongly upon the Ob-
jed: : by which means, it will be fhewn in
a manner furprizingly diftind and clear.
And for this purpofe, the Light of the Sky,
or of a Candle, will anfwer to your Satif-
fadion.

This Microfcope is principally intended
for opake Objeds, but tranfparent ones may
alfo be viewed by it : obferving only, that

when

/'. ////I

for Opahe OhjcBs, 3!

When fuch come under Examination, it Will
not always be proper to throw on them the
Light retie(fl:ed from the Speculum : for the
Light tranfmitted through them meeting the
reflected Light, may, together^ produce too
gi*eat a Glare. A little Pra6]:ice will teach
how to regulate both thefe Lights to good
Advantage.

There is Reafon to exDedl great Difcove^
ries may be made by the Apparatus above
defcribed, as OpakeObjefts are a large Fields
but little hitherto exarnin'd, by reafon of the
great Difficulty in doing it.

Having given a Defcription of the feveral
Sorts of Microfcooes in ufe amon^ift us at
prefent;, and ihewn what particular Advan-
tages may be expeded from each, I fliall
proceed to inftru6t the Ignorant in thefe
Things, with all the Clearnefsl can, to find
out the magnifying Powers of the Glafles
they make ufe of, and calculate how many
times they enlarge the Diameter, the Super-
ficies, and the * Cube or folid Square of any
Objed: under Examination. And this, I
perfuade myfelf, will be highly fatisfadory,-

* Some, perhaps, may diflike my fappofing the Cubs of
ari Objctl to be magnified, fince in reality the Superficies
only can be feen : but the NecefTity of fueh a Suppofiticri
•ivill appear plainly in the Progrefs of this Work, when.
we come to confider the true Size of iVIicrofcopical ObjeSlsy
\>j compiaring them with larger Bodies.

D and

S 2 7he Magnifying Power of Glajfes.

and induce many People to be fond of this
moft delightful and inftruftive Study, when
the Difficulties they imagined in it are re-
moved, and they perceive it to be as eafy as
it is pleafant y when they find themfelves
able to judge of what they fee, not by meer
random Guefs, but by certain and plain
Principles.

CHAP. VIIL

Ti? fnd the Magnifyifig Power of Glajfes
employed in Single Microjcopes.

r 1"^ H E Appearance of any Objedl, as to
J^ Magnitude, is according to the Angle
it is feen under ; or, in other Words, ac-
cording to the Nearnefs it can be brought
to the Eye : for the lefs the Diftance it can
' be view'd at is, the more it will appear en-
larged.

The naked Eye is unable to diftinguiili
any Objed; brought exceedingly near it : but
looking through a convex Lens, however
near the Focus of that Lens be, there an
Objed: may be diftind:ly feen: and the fmall-
er the Lens is, the nearer will be its Focus,
and in the fame Proportion the greater muft
be its magnifying Power.

From

The Magjiifying Voijoer -of Glaffes. 33

From thefc Principles, it is cafy to find
the Reafon, why the firit or greateft Mag-
nifiers are fo extremely minute ; and alfo to
calculate the magnifying Power of any con-
vex Lens employed fmgly in a Microfcope.
For fuch as the PVoportion of the natural
Sight to the Focus of the Lens is, fuch will
be its Power of magnifying. If the Focus
of a convex Lens (for Example) be at one
Inch, and the natural Sight at eight Inches^
w^hich is the common Standard, an Objed:
may be feen through that Lens at one Inch
diftant from the Eye ; and will appear, in
its Diameter, eight times larger than to the
naked Eye. But as the Objedl is magnified
every way equally, in Length, as w^cll as
Breadth, we muft fquare this Diameter to
know really how much it appears enlarged ;
and we fliall then find, that its Superficies
is indeed magnified fixty-four times*

Again : Suppofe a convex Lens whofe
Focus is at one Tenth of an Inch diftant
from its Center : In eight Inches there ard
eighty fuch Tenths of an Inch ; and there-
fore an Object may be ictn through this
Lens, eighty times nearer than it can di-
ftindlly by the naked Eye. It will confe-
quently appear eighty times longer, and
eighty times broader than it does to common
Sight 3 and as eighty multiplied by eighty
makes fix thoufand and four hundred, io
many times it really appears magnified.

D 2 To

34 'The Magnifying Power of Glaffesc

To go one ftep farther : If a convex Glafs
be fo fmall, that its Focus is no more than
one twentieth of an Inch diftant ; we fhall
find, that eight Inches, the common Di-
ftance of Sight, contains an hundred and fixty
of thefe twentieth Parts ; and, in confe-
quence, the Length and Breadth of an Ob-
jed:, when feen through fuch Lens, will each
be magnified an hundred and iixty times ;
which multiplied by an hundred and iixty,
to give the Square, will amount to twenty-
five thoufand fix hundred : and fo many
times, it is plain, the Superficies of the Ob-
jed: muft appear larger than it does to the
naked Eye at the Diftance of eight Inches.

Therefore, in a fingle Microfcope, to
learn the magnifying Power of any Glafs,
ixo more is neceffary than to bring it to its
true Focus ; the exa^ft Place whereof will
be known, by an Objedl's appearing perfed:-
ly diftind: and fharp when placed there.
Then, with a pair of fmall Compaffes, mea-
fure, as nearly as you can, the Diftance from
the Center of the Glafs to the Objecl you
v/as vlew^ing, and afterwards applying the
Compaffes to any Ruler with a Diagonal
Scale of the Parts of an Inch marked on it^
you will eafily find how many Parts of an
Inch the faid Diftance is : When that is
known, compute how many times thofe
Parts of an Inch are contained in eight
Inches, the common Standard of Sight, and

that

The Mcignifyi?ig Pouter of Glajes- 35

that will give you the number of times the
Diameter is magnified : fquaring the Dia-
meter will give you the Superficies -, and if
it be an Objed^ whofe Depth or whole Con-
tents you would learn, multiplying the Su-
perficies by the Diameter will ihew the Cube
or Bulk.

The Superficies of one Side only of an
ObjecSt can be feen at one view ; and to
compute how much that is magnified is
moft commonly fuiHcient. But fometimes
it is fatisfadlory to know how many minute
Obje^Jls are contained in a larger : as, fup-
pofe, for Inflance, I defire to know, how
many Animalcules would make up the Big-
nefs of a Grain of Sand : To anfwer this,
the Cube as well as the Superficies of the
Animalcules muft be taken into the x-^c-
count ', as will be fhewn in the next Chap-
ter.

As thisTreatife is chiefly intended for
thofe who underftand but little of fuch Mat-
ters, it may neither be needlefs nor unac-
ceptable, to give a Table of the magnifying
Powers of the convex Glaffes commonly
ufed in fingle Microfcopes, according to their
different Focus : v/hereby, upon meafuring
what the beft Dillance from the Glafs to
view the Objed is, its Power of magnifying
the Diameter, the Superficies, and the Cube
of aq Object v/ill be found in one Line.

D 3 Sec

36 The Magnifying Power of Glaffes.

See the Table *.

As this Table is given in round Num-
berSj it is fo clear and eafy, that I believe
whoever can but divide and multiply a few-
Figures will readily underftand it.

I have taken no Notice of any Magnifier
whofe Focus is at a greater Diftance than the
half of an Inch 5 becaufe Glaffes that mag-
nify lefs than that, may very eafily be calcu-
lated by the Rules above laid down : Nor,
when I come to the greateft Magnifiers, have
I mentioned any of a ihorter Focus than
the one hundreth part of an Inch ; fince it
is fo difficult to grind a Lens to a Smallnefs
beyond^ or even fo minute as this, that per-
haps few of my Readers may ever meet with
fuch an one. And thouo;h Globules of Glafs
may be melted fo extremely little, as to
have their Focus at not half this Diftance,
and confequently their magnifying Powers
prodigioufly greater ; the ufe of them is fo
troublefome, and attended with fuch want
of Light, fuch Undiftindnefs and Uncertain-
ty, that indeed they are of very little Ser-
vice.

The magnifying Powers of the Glaffes
employed in Wilson's Pocket Microfcope^
and alfo of thofe belonging to the opake Mi-
croicope, are to be calculated in the forego-
ing Manner, And as People will, no doubt,
" ■ ^ 4 ' be

To he placed aftir Page ^6.

* A TABLE of the MAGNIFYING POWERS of CONVEX GLASSES,

employed in Single Microscopes, according to the Diftance of their Focus ;

Calculated by the Sca/e of an Inch divided into an Hundred Parts :

Shewing how many times the Diameter, the Superficies, and the Cube of an Objedt is magnified,

when viewed through fiich Glajfes, to an Eye whofe natural Sight is at Eight Inches,

or Eight Hundred of the Hundredth Parts of an Inch.

Magnifies

Magnifies

Magnifies the

the Dia-

the Su-

Cube of an

meter,

perficies,

Oijea,

t> or

50I 16

256

4,096 '

.

t\, or

40

20

400

8,000

To, or

30

26

676

^7^S1^

h or

20

40

1,600

64,000

15

- 53

2,806

148,877

H

« F

3 = 249

185.193

13

■-1 61

3,721

226,981

12

S 66

4.356

287,496

The Focus of

jz, or

1 1

10

/^ 72
>^ 80

5,184
6,400

373.248
512,000

)■ Times.

a Glafs at

9

1 88

7.744

681,472

8

^ 100

10,000

1,000,000

7

Si 114

12,996

1,481,544

6

§ 133

17,689

2,352,637

/o, t or 5

H; 160

25,600

4,096,000

4

20c

40,000

8,000,000

3

266

70,756

1^,821,096

i-o, or

2

400

160,000

64,000,000

L

1.

8001640,000

5I2,0O0,00OJ

t The greateft_ Magnifier in Mr. Leewenhoek's Cabinet of Microfcopes, prefentcd to the
Koyali>ocuty, has its /■«««, as nearly as can well be meafuled, at one rwentieth of an Inch Diftance

Tfje Magnifying Power of Glujfes. 3 7

be pleafed to know certainly what the Pow-
ers of their GlalTcs arc, and confcqucntly
what may be expedcd from them, it would
be much better if the Mi crofcopc- Makers
would grind their Glafles according to fome
fettled Standard, and not work by guefs, as
they ufually do at prefent, whereby no two
Sets of Magnifiers can be fuppofed exactly
alike. Such a Standard, which would afford
a very ufeful Set of Glaffes, magnifying one
more than another in due Degrees, is, I
think, as follows.

The FOCAL DISTANCES of

Six Magnifiers for Mr, Wilson'-s
Pocket Micrcfcope,

Dift. of
>the Fo-<(

cus at-

50, or 2

hy or 5
8

16
-i%,or 30
.h or 50.

c
• o

Magnifies
the Diam.

— 400^

— 160

— <co

50 ^

26

-16J

Magnifies the
Superficies,

--i6o,coo

— 25,600 i

lOjCOO V p

— 2,500
6-6

256,

D 4

rhe

g.^ The Magnifying Pow..er of Giajjes.

rbe FOCAL D ISrjtNCE S of

Four Magnifiers for the Microfcope
for Opake Objcfe.

ipcpts. of
an Inch.

2.

4 J

Dift. of ! ,

the Fo-J -^^^ ^^ 30

TO' or 60
I Inch

ca^ at

Magnifies
theDiam.

JOO"|

-26

13 ip

}

Magnifies the;
Superficies,

1 0,000 ~)
— 676

169 I P

64J

The magnifying Power of the Solar Mi-
crofcope muft be calculated in fomewhat 4
different Manner. For here, the Difference
between the Focus of the Magnifier, and
the Diftance of the Screefi, or Sheet where-
on the Image of an Objed: is cafl", is the Pro-
portion qf its being magnified. Suppofe, for
Inftance^ the Lens made ufe of has its Focus
at half an Inch, and the Screen be placed
at the Diftance pf five Feet : The Objed:
l^dll then appear enlarged in the Proportion
of five Feet to half an Inch : And as in five
Feet there are one hundred and twenty half
Inches, the Diameter will be magnified one
hundred and twenty times, which multi-
plied by one hundred and twenty, fhews the
Superficies to be magnified fourteen thou-
faad and four hundred times : and by put==

ting

The Magnifying Pcivc?- ofGhiJfcs. 39

ting the Screen at farther Uiftances, you
may magnify your Objetft to ahnoft what
Size you pleal'e. But I would advire all
who ule this Sort of Microfcope, to regard
Dillindnefs more than Bigncfs, and place
the Screen juft at that Diilance where the
Object is feen moft Iharp and clear.

CHAP. IX.

Of the Magnifying Tower of Glafes in the_
Double Microfcope,

I Should now fhew the Method of com-
puting the magnifying Power of our
double Microfcope, as I have done of the
finp-le ones : but a Calculation of the Powers

o

of three combined Glaffes, would appear fo
intricate and unintelligible to People unac-
quainted with Optics (for whofe Service
chiefly I intend this Treatife) that I believe
they will readily excufe my perplexing them
with it : and as for the learned in that Sci-
ence, they probably will be better pleafed
to calculate for themfelves.

The double refledling Microfcope, defcri-
bed p. 16. is the only Inftrument at prefent
made amongft us for this Purpofe, wherein
fuch a Combination of Glafles is employed.
Here, indeed, the magnifying Power of the

ObjecT:-

40 The Size of Objedts

Objed:-Lens is greatly increafed by the Ad-
dition of two Eye-Glafles 5 but as no Objedl-
Lens can be ufed with them of fo minute a
Diameter, or that magnilSes of itfelf near fo
much as the Lenfes we can ufe alone, upon
the whole, the Glaffes of this double Micro-
fcope magnify little or nothing more than
thofe of Mr. Wilson's fmgle one. And
the fame Table which ihews the Powers of
the Glaffes belonging to that Microfcope,
may ferve for thefe alfo. For thtjirft Glafs^
JecondGlafsy &c. of either Microfcope, mag-
nify pretty much alike ; and the chief Ad-
vantage arifing from a Combination of Glaf-
fes, is, the fight of a large Field or Portion
of an Objed, magnified in the fame Degree,

CHAP X.

To find out the real Size of ObjeBs feen
by Microfcopes,

rTT^HO' by the preceding Diredlions the
j[ magnifying Powers of Micro/cope^
Glajfes may eafily be underftood, it will flill
remain uncertain, (if the Objects we examine
are exceedingly minute) what the real Big-
nefs of them is. For though we may know
they are magnified fo many thoufand times,
we can make by that Knov/ledge but a very
irnperfed Computation of their natural aild

true

■Paa. 41

viewed by Mi cr of copes. 41

true Size; nor can we, indeed, come to any
certain Conclufion as to that, but by the
Alediation of fome larger Objedl, whole
Dimenfions we really know. For as Bulk
itfelf is meerly comparative, the only way
we can judge of the Bignefs of any thing, is,
by comparing it with fomething elfe, and
iinding out how many times the lefler is
contained in the larger Body. To do this
in Microfcopical Objedls, feveral ingenious
Methods have been contrived ; of which,
fuch as are come to my Knowledge, and
are plain and practicable, I iliall lay before
the Reader.

Mr. Leeuwenhoek's Way of comput-
ing the Size of Salts in Fluids, of the Ani-
malcules i?i Semine MafculinOy in Pepper-
IFater^ See. was, by comparing them with
the Bignefs of a ;}; Grain of Sand ; and his
Calculations were made in the following
Manner.

% N. B. It is proper to inform the Reader, that where-
ever in this Treatife, Microfcopical Objedls are compared
with a Grain of Sand, which commonly was the Meafure
Mr. Leeuwenhoek made ufe of, we mull underftand it to
mean a Grain of coarfe Sea -Sand (ufually called Scouring-
SandJ which is equal in Bignefs to feveral Grains of our
common Inland Hrufe-Sand^ or H^riting-Sand. Cut to make
our Calculation Hill more certain, we mufl: fuppofc them of
fuch a Size, that an hundred of them, placed in a Row,
l]..ill extend an Inch in Length.

o

H«

^Z The Size of OBje^s

He view'd through his Microfcope a fin--
gle -f- Grain of Sand, \vhich we'll fuppofc to
be magnified as the round Figure ABCD.
Then obferving the Animalcule fwimming,
or running acrofs it, or coming near it,
(which we'll imagine to be of the Size i.)
coniidering and meafuring this by his Eye,
he concludes, that the Diameter of this Ani-
malcule is lefs, by a twelfth Part, than the
Diameter of the Grain of Sand : confe-
quently, according to the common Rules,
the Superficies of the Grain of Sand is one
hundred forty- four times, and the whole
Contents thereof one thoufand feven hun-
dred and twenty-eight times larger than this
Animalcule.

Suppofe, again, that he fees among thefe
another and fmaller Species of Animalcules ;
one of which [2.] he likewife meafures with.
his Eye, by the help of a good Microfcope 5
and computes its Diameter to be five times,
but, to be within compafs, he reckons it
only four times lefs than the former Animal-
cule I, According then to the foregoing
Rules, the Diameter of this will be fixteen,
and the whole Bulk fixty-four times lefs
than the Animalcule i.

If farther, upon a nicer View, he difco-
vers a third fort of Animalcule [3.] fo ex-

f Vide Lesuwen. fxperim. &c Contempl. Tom. iV.
pa-. 23.

ceedingly

viewed by Micro/copes, J^-

ccedingly minute, that, examining it in the'
former IVLmner, he concludes that the Dia-
meter thereof is ten times fmaller than the
fecond fort : it will then follow, that a
thoufand of thefe are but equal ia Bignefs
to one of that fecond fort.

The firft fort multiplied by iihe fecond,
and the fecond by the third, will plainly de-
mon ftrate how many of this third and mi-
nuteft fort are requiiite to make up the
Bulk of a fingle Grain of Sand : the Procefs
of which is a^ follows.

Firft fort, i . whofe Diameter is- lefs
than that of a Grain of Sand'

12 times,

12 •

144

Of the firft fort,' 1,728 in a Grain of Sand,

Second fort, 2. whofe Diameter is lefs than
that of the firft fort

4 times.

.'4

16

4

64 in one of the firft fort.

Third

44 The Siz-E. of ObjeBs

Third fort, 3. whofe Diameter is lefs than
that of the fecond fort

10 times,
10

100
10

1000 in one of the fecond fort.

1728 of the firft fort in a Gr. of Sand.
64 of the 2d fort in i of the firft.

6912
10368

110,592

1000 of the3dfortin i of the 2d.

1 10,592,000 of the 3d fort in a Gr. of Sand.

After this manner, the comparative Size
of all Sorts of Objedts may very eafily be
computed, only fubftituting (for fuch as are
Icfs minute) a fmall Seed, . or fome other
Body whofe Size we are well acquainted
with, in the room of a Grain of Sand.
And, particularly, by the Solar Microfcope,
our Calculations may be made with great
Certainty j fince the Image of the Obje(fl:

enquired

'vie'wcd by Micro/copes, 45

enquired after, and of the Grain of Sand,
the fmall Seed, or whatever elfe is thought
proper to compare with it, may be really
meafured by a Ruler, or a pair of Compafles,
and the Difterence of their Diameters moft
exadly found.

The Method Mr. Hooke made ufe of,
to know how much an Objedl appears mag-
nified, I fliall give in his own Words.

Having (fays he) reftified the Microfcope,
to fee the defired Objed: through it veiy
diftinftly -, at the fame time that I look
upon the Objed: through the Glafs with
one Eye, I look upon other Obje<^s at
the fame Diftance with my other bare
Eye : by which means I am able, by the
help of a Ruler divided into Inches and
" fmall Parts, and laid on the Pedeftal of
the Microfcope, to caft as it were the
magnified Appearance of the Objed: upon
the Ruler, and thereby exaftly to mea-
fure the Diameter it appears of through
the Glafs 5 which being compared with
the Diameter it appears of to the naked
Eye, will eafily afford the Quantity of its
being magnified. — This, for Multitudes
of Objedls, is a ready and good Way; and
I can declare from my own Experience, that
a little Pradice will render it exceeding eafy
and pleafant.

Another very curious Way for this Pur-
pofe,is defcribed by theingeniousDr. Jurin,

in

<(

cc
<c
cc
cc
cc
cc
cc

cc
cc
cc
cc
cc
cc
cc
cc

46 71^^ Size ofObjeBs

in the 45th Page of his Phyjlco-Mathefnatical
Dijfertatiofjs ', the Manner whereof is thus i
Wind a Piece of the fineft iSilver Wire you
can get a great many times about a Pin, or
fome other fuch flender Body, fo clofely as
to leave no Interval between the Wire--
Threads ; to be certain of which, they muft
be carefully examined with a Glafs. Then,
with the Points of a fmall Pair of Compaffes
meafure exactly what Length of Pin the
Wire covers : and applying the Compaffes
with that Meafure to a diagonal Scale of
Inches, you'll find how much it is ; after
which, by counting the Number of Wire-
Rounds contained in that Length, you'll ea-
fily difcover the real Thicknefs of the fingle
Wire. 7 his being known, cut it into very
fmall Pieces, and when you examine an
Objedl, if it be opake, ftrew fome of thefe
Wires upon it; if tranfparent, under it; and
with your Eye compare the Parts of the
Objed: with the Thicknefs of fuch Bits of
Wire as lye faireft to your View.

By this Method Dr. Jurin obferved, that
four Globules of human Blood would gene-
rally cover the Breadth of a Wire, w^hich he
had found to be -4-8 jth Part of an Inch ; and
confequently, that the Diameter of a fingle
Globule was Tsroth Part of an Inch. Which
was alfo confirmed by Mr. L e e u w e n^
HOE k's Obfervations upon human Bloodj
made with a Piece of the fame Wire, fent

to

"Clewed by the Microfcope, \j

to him by Dr. Jurin. Vide Phikfophical
T7'anfa5lioyn^ Numb. 377.

Mr. Martin, in his Optics, gives ano-
ther Way, fufficiently eafy and ready on all
Occafions. On a circular Piece of Glafs,
iet a Number of parallel Lines be drawn
carefully with the fine Point of a Diamond,
at the Diftance of one fortieth Part of an
Inch from each other. If this be placed in
the Focus of the Eye-glafs of a Microfcope,
the Image of the Obieft will be feen upon
thefe Lines, and the Parts thereof may be
compared with the Intervals, whereby its
true Magnitude, or Dimenfions, may be very
nearly know^n : for the Intervals of thefe
Lines, tho' fcarce difcernable to the naked
Eye, appear very large through the Micro-
fcooe. A Contrivance of this Kind may alfo
he invented for fuch Microfcopes, as a Glafs
cannot be apply'd to in the above manner,
by placing it under or behind the Obje(fl,
which will anfwer the fame Purpofe.

Here it will be eafy to find what Pro-
portion an Objed, or any Part thereof, bears
to an Interval between two Lines, and then
determine it in Parts of an Inch : for if the
Width of an Objed: appears juft one Inter-
val, we fhall know it to be juft one fortieth
Part of an Inch ; if half an Interval, the
eic^hticth; if a Quarter of an Interval, the
one hundred and fixtieth ; if one fifth, only
the two hundredth Part of an Inch.

E Dr.

^8 ^he Area of ObjeBs. -

Dr. Smith has an Invention akin to this^^
for taking exadl Draughts of Objedls, view-^
ed in double Microfcopes : for he advifes,
to get a Lattice made with fmall Silver
Wires, or fmall Squares drawn upon a plain
Glafs by the Strokes of a Diamond, and to
put it into the Place of the Image formed
by the Objedi-Glafs. Then, by transferring
the Parts of the Objed: feen in the Squares
of the Glafs or Lattice upon fimilar corre-
fponding Squares drawn on Paper, the Pic-
ture thereof may be exadly taken.

There are fome other forts of Microme-
ters, or Inventions for meafuring the fmall
Objects feen in Microfcopes -, but as they -
are more complex and difficult, I ihall not
fwell this Volume with them.

CHAP XI.

Of the Area or Portion of an Oh]td:feen.

1

"^ H E vifible Area, Field of View, or
Portion of any Objedl feen through a
Microfcope, is in Proportion to the Diameter
and Area of the Lens made ufe of, and its
Power of magnifying, and may be thereby
determined: lince, if the Lens is extreamly
fmall, it magnifies a great deal, and, con-
fequently, a very minute Portion only of an

Objedt

The Area ofObjeBs, 4^

Objecfl can be diftinguidied through it. For
which Reafon the grcatefh Magnifiers never
fliould be emj?]oyed but for the moft minute

Objeds. This Confideration will direcft

how to fuit the Magnifiers to the Size of
the Objedts to be examin'd, which is of the
utmofl: Confequence in Microfcopical Ob-
fervations , and may ferve to recflify the
Miftake of abundance of People unexperi-
enced in Glafles, who, upon feeing a Mite
or a Loufe greatly magnified, are apt to cry
out with much Surprize, O that we had a
Cricket, a Frog, or fome other Creature 5
how finely that would appear ! Whereas, in
truth, fuch large Obje6ts would intirely cover
the Lens, and could not be feen at all.

Microfcopes very happily affift us when
Objedls are fo fmall as to evade our Sights
but it would be trifling and unnecefTary to
employ them on fuch large Things as we can
fee without their Help.

I fhall not trouble the Unfkilful with per--
plexing Calculations about the Area or Field
of Objedls feen by each Magnifier, but give
this fhort Rule in general, that it differs.not
greatly from the Size of the Lens made ufe
of, and that the Whole of anyObjecfb, much
beyond that Size, cannot conveniently be
viewed through it.

There is fome Difference, as to the vifible
Area of an Objed, between fin gle and double
Microfcopes ; for the double fhew a larger

E z Portion

50 O/'.Objects in Generdl.

Portion of it than the iingle, tho' magnified
as much*

Having fhewn the Strudlure and Pdwers
of Microfcopes, I proceed now to defcribe
the Manner of chufing, preparing, and ap-
plying Objects to them.

CHAP. XII.

Of Objects in General.

Roper Objedls to be examined by Mi-
crofcopes, are (as Mr Hooke veryju-
dicioufly diftinguiilies) " exceedirigfmallBo-
^^ dies, exceeding fmall Pores, or exceeding
*^ [mail Motions,''

Exceeding fmall Bodies, muft either, be
the Parts of larger Bodies : or Things, the
Whole whereof is exceedingly minute ;
fuch as fmall Seeds, Infedls, Sands, Salts,
&c.

Exceeding fmall Pores, are the Interftices
between the folidParts of Bodies, as in Stones,
Minerals, Shells, &c, or the Mouths of mi-
nute Veffels in Vegetables, the Pores in the
Skin, Bones, &c, of Animals.

Exceeding fmall Motions, are the Move-
ments of the feveral Parts or Members of
minute Animals^ or the Motion of the Fluids

contained

Of Objects /;; General, 51

contained cither in animal or vegetable Bo-
dies.

Under one or other of thcfe three Heads
almoit every thing around us affords Matter
of Examination, and may conduce both to
our Amufement and Inftrucftion ; as I hope
more particularly to fliew.

Many, even of thofe who have purchas'd
Microfcopes, are {o little acquainted with
their general and extenfive Ufefulnefs^ and
io much at a lofs for Objed:s to examine by
them ; that after diverting themfelves and
their Friends, fome few times, with what
they find in the Sliders bought with them,
or two or three more common Things, the
Microfcopes are laid afid^ as of little farther
Value: and, a Suppofition that this mufl be
the Cafe, prevents many others from buying
them ; whereas, among all the Inventions
that ever appeared in the World, none can
perhaps be found fo conftantly capable of
entertaining, improving, and fatisfying the

Mind of Man. To evince this, ^nd excite

thofe whofeTime andCircumftances permit,
to this delightful Study, is the Intention of
my writing; and, asCuriofity, the univerfal
Paffion of Mankind, may this way continu-
ally be gratified, I hope I fhall not write in
vain. And if I can hereby induce any to
pafs thofe leiiure Hours agreeably and ufe^
fully in contemplating the Wonders of the

E 3 Creation^

S^ Of Examining Objects.

Creation, which otherwife would be fpent
in tirefome Idlenefs, or, perhaps, fome fa-,
ihionable and expenlive Vice, I fhall think
thefe Sheets very happily beftowed.

CHAP. XIII.

Of Examining Objects.

N Examination of Objedls, in order to
difcover Truth, requires a great deal
of Attention, Care, and Patience, together
with fome confiderable Skill and Dexterity
(to be acquired by Practice chiefly) in the
preparing, managing, and applying them to
the Microfcope. What little Knowledge in
thefe Matters I may have gained, either
from the Accounts of others, or my own
Experience, after being converfant many
Years therein, I fhall readily communicate :
in hopes my Pains may clear the way to
Difcoveries that will prove of Confequence
to the World, and render this Study both
defirable and eafy.

When any Objeft comes to be examined,
the Size, the Contexture, and Nature of it
ihould be duly coniider'd -, in order to apply
it to fuch GlafTes and in fuch a Manner as
may fhew it beft. The firft Step towards
this, conftantly fhould be, to view it through

a Mag-.

Of Examhiing Objects. 53

a Magnifier that can take in the Whole at
once : for by obfcrving how the Parts he as
to one another, we fliall find it much eafier
to examine and judge of them feparately, if

there be occafion. After having made

ourfelves acquainted with the Form of the
Whole, we may divide it as we pleafe, and
the fmaller the Parts into which it is divided,
the greater muft be the Magnifiers where-
with to view them.

The Tranfparency or Opakenefs of an
Obje(ft muft alfo be well regarded, and the
Glaffes made ufe of, muft be accordingly
fuited thereto; for a tranfparcnt Objed: will
bear a-much greater Magnifier than one that
is opake ; fince the Nearnefs a Glafs that
magnifies much muft be placed at, una-
voidably darkens an opake Objed:, and pre-
vents its being feen, unlefs by the Micro-
fcope on purpofe for fuch Subjed:s,defcribed
page 27. Moft Objeds, however, become
tranfparent by being divided into extreamly
thin or minute Parts, Contrivance there-
fore is necefl^ary, to reduce them into fuch
Thinnefs or Smallnefs, as may render them
moft fit for Examination.

The Nature of the Objedt,whether it be
alive or dead, a Solid or a Fluid, an Ani-
mal, a Vegetable, or a Mineral Subftance,
muft likewife be confidered, and all the
Circumftances of it attended to, that we may
apply it in the moft convenient Manner. If

E 4 it

'54 Of Examining Objects.

it be a living Animal, care mufl: be taken to
fqueeze, hurt, or difcompofe it as little as
poffible, that its right Form, Pofture, and
Temper may be difcover'd. If a Fluid, and
too thick, it muft be thinned with V/ater :
if too thin, v/e (hould let fome of its watery
Parts evaporate. Some Subftances are fitteft
for Obfervation when dry, others again when
moiftened; fome when freili, and fome after
being kept a while.

Light is the next thing to be taken care
iof, for on this the Truth of all our Examina-
tion depends 3 and a very httle Experience
will Ihew how different Objects appear in
one Poiition and Kind of it, to what they
do in another. So that we ihould turn them
every w^ay, and view them in every Degree
of Light, from Brightnefs even to Obfcurity;
and in all Pofitions to each Degree ^ till we
are certain of their true Form, and that we
are not deceived. For, as Mr. FIooke
fays, in many Objeds it is very difficult to
difdnguilh betwxen a Prominency and a
Deprefilon ; between a Shadow and a black
Stain ; and in Colour, between a Refled:ion
and a Whitenefs. The Eye of a Fly, for
'Example, in one kind of Light, appears like
a Lattice drilled through with Abundance
of Holes; in the Sun-ihine, Hke a Surface
covered with golden Nails : in one Pofition,
like a Surface covered with Pyramids, in

another

Of Examining Objects. r^

another with Cones, and in other Pofitions
of quite other Shapes.

The Degree of Light muft be duly fuit-
ed to the Objed: ; which, if dark, v/ili be
feen beft in a full and ftrong Light ; but if
very tranfparent, the Light fhould be pro-
portionably weak : for which Reafon there's
a Contrivance, both in the fnigle and double
Microfcope, to cut off abundance of its Rays,
when fuch tranfparent Objeds are examined
by the greateft Magnifiers.

The Light of a Candle, for many Objefls,
and efpecially fuch as are exceedingly minute
and tranfparent, is preferable to Day-light 5
and for others Day-light is beft : I mean the
Light of a bright Cloud. As for Sun-fhine,
it is refleded from Objeds with fo much
Glare, and exhibits fuch gaudy Colours,
that nothing can be determined by it with
Certainty : and therefore it's to be account-
ed the worfl Light that can be had.

This Opinion of Sun-fhine muft not,
however, be extended to the Solar Micro-
fcope, which cannot be ufed to Advantage
without its brighteft Light ; for in that
way, we fee not the Obj eel itfelf whereon
the Sun-fl:iine is caft, but only the Image or
Shadow of it exhibited upon a Screen -, and,
therefore, no Confufion can arife by the
glaring Reflexion of the Sun's Rays from
the Objed; to the Eye, which is the Cafe in
other Microfcopes. But then, in that Solar

Way,

5^ Of preparing and applying O-R^zcT^,

Way, we mull reft contented with viewing
the true Form and Shape of an Obje(fl, with^
out expedling to find its natural Colour, fince
no Shadow can poffibly wear the Colours of
the Body it reprefents.

CHAP. XIV.

Of preparing and applying .0^]'ECT^,

O S T Objedls require fome Manage-
ment, in order to bring them proper-
ly before the Glaffes. If they are flat and

tranfparent, and fuch as will not be injured
by Preflure, the beft Method is to inclofe
them in Sliders, between two Mufcovy Talcs
or Ifinglafs. This Way the Feathers of
Butterflies, the Scales of Fifties, the Farinae
of Flowers, &c, the feveral Parts, and even
wliole Bodies of minute Infe(fls, and a
thoufand other Things, may very conve-
niently be preferved. Every curious Obferver
will therefore have them always ready to
receive any accidental Object, anU fecure it
for future Examination : and a Dozen or
two of thefe Sliders, judicioufly furniflied,
are a fine natural Hiftory, where we may
read delightful LeflTons of the high Perfection
of God's Works, and his Wifdom in their
Contrivance.

In making a Colledion of Objedls, the
Sliders fliould not be filled promifcuoufly,

but

Of preparing and applying Objects. 57

but Care taken to fort the Objedts according
to their Size and Tranfparency : in fuch
manner, that none be put together in the
fame Slider, but what may properly be ex-
amined by the fame Magnifier : and then
the Slider fliould be marked with the Num-
ber of the Magnifier its Objects are fitteil
for : that is, the mod transparent, or mi-
nuteft Objeds of all, which require the firft
Magnifier to view them by, fhould be pla-
ced in a Slider, or Sliders marked with Num-
ber I. Thofe of the next Degree in Sliders
marked with Number II. and io of the reft.
This Method will fave Abundance of Time
and Trouble in fhifting the Magnifiers,
which, without fuchSortment, muft perhaps
be done two or three times in overlooking
a fingle Slider *". The Numbers marked
upon the Sliders will likewife prevent our be^
ing at any lofs what Glafs to apply to each.

Small living Objecfts, fuch as Lice, Fleas,
Gnats, fmall Bugs, minute Spiders, Mites,
^c. may be placed between thefe Talcs,
without killing or hurting them, if care be
taken not to prefs down the Brafs Rings
that keep in the Talcs : and will remain a-

* In placing your Objeils in Sliders, a convex Glafs of
about an Inch Focus, to hold in the Hand, and thereby
adjuft them properly between the Talcs, before you faften
them down with the Brafs Rings, will be found very con-
venient.

live

5^ Of preparing and applying Objects.^

live even Weeks in this Manner. But if
they are larger than to be treated thus, either
put them in a Slider with concave Glaffes,
intended for that Ufe, and defcribed pag.
lo. or in the Cell pag. 19. or elfe examine
them ftuck on the Pin, or held between
the Flyers 5 either of which Ways they may
be viewed at pleafure.

If Fluids come under Examination, to
difcover the Animalcules that may be in
them, take up a fmall Drop with your Pen
or Hair-pencil, and place it on a iingle Ifin-
glafs, (which you fhould have in a Slider
ready) or elfe in one of the little concave
Glafles, and fo apply it. But in cafe, upon
viewing it, you find, as often happens, the
Animalcules fwarming together, and fo ex-
ceedingly numerous, that running continu-
ally over one another, their Kinds and real
Form cannot be known -, fome Part of the
Drop mufl: be taken off the Glafs, and then
a little fair Water put to the reft, will make
them feparate, and iliew them diftindt and
well. And this Mixture of Water is parti-
cularly requifite in viewing the Semen Maf-
culinum of all Creatures : for the Animal-
cules therein contained are unconceivably
minute, and yet crowded together in fuch
infinite Numbers, that unlefs it be diluted
a great deal, they cannot be fufficiently fe-
parated to diftinguifli their true Shape.

But,

Of preparing and applying Objects. 59

But, if we view ;i Fluid, to find what
Salts it may have in it, a Method quite con-
trary to the foregoing mull be employed :
for, then, the Fluid muft be fuffcrcd to
evaporate, that the Salts being left behind up^
on the Glafs, may more eafily be examined.

Another, and indeed the moft curious
Way of examining Fluids, is, by applying
them to the Microfcope, in exceedingly
imall capillary Tubes made of the thinnell
Glafs poflible. This was Mr. Leeuwen-
hoek's Method for difcovering the Shapes
of Salts floating in Vinegar, Wine, and feve-
ral other Liquors j and fuch Tubes fhould
be always ready to ufe as occafion requires.

For the Circulation of the Blood, Frogs,
Newts, or Fillies, are commonly made ufe
of; and there are Glafs Tubes in the fingle
Microfcope, and a Fifli-pan as well as Tubes
in the double one, on purpofe to confine
thele Creatures, and bring the proper Parts
of them to view : which, in Newts and
Fiflies, are the Tails, and in Frogs the fine
filmy Membrane between the Toes of the
hinder Legs. Though, if we can contrive
to faften down the Creature, and bring our
Objecft to the Magnifier, the Circulation can-
not pofiibly be feen fo plainly any where, as
in the Mefentery, or thin tranfparent Mem-
brane that joins the Guts together; and this
Part, by pulling out the Gut a little, may
eafily be adjufted to the Magnifier.

I " To

6d Of preparing and applying Objects;

To diffed: minute Infeds, as Fleas, LicCj'
Gnats, Mites, fffc. and view their internal
Strucfture, requires a great deal of Patience
and Dexterity : yet even this may be done,
in a very fatisfaftory Manner, by means of
a fine Lancet and Needle, if they are placed
in a Drop of Water : for their Parts v^ill
then be feparated v^ith Eafe, and lie far be-
fore the Microfcope, fo that the Stomach and
other Bowels may plainly be diftinguifhed
and examined.

We fhould always have ready for this
Purpofe little Slips of Glafs about the Big-
nefs of a Slider, to place Objedls on, oc-
cafionally > fome of which Slips fhould be
made of green, blue, and other different co-
loured Glafs ; many Objeds being much
more diftinguifhable when placed on one
Colour than on another. Wa fhould like-
wife be provided with Glafs-Tubes of all
Sizes, from the finefl Capillaries that can be
blown, to a Bore of half an Inch Diameter.

I believe there is no better way of pre-^
ferving tranfparent Objeds in general, than
by placing them between clear Ifinglafs in
Sliders : But opake Bodies, fuch as Seeds,
Sands, Woods, &c, require different Ma-
nagement ; and a Colledlion of them fhould
be prepared in the following Manner.

Cut Cards into fmall Slips, about half an
Inch in Length, and the tenth of an Inch
broad : wet them half their Length with a

flrong

^

J*a^.^i

T/nte. n

- '■ : _ .__ 1

1

1
1

!

1

i

1

i ! ' ' ■ 1

I

1

,

i

i

\
\

1

.....

_

Of preparing ajid applying Objects. 6x

ftrong but very tranfparcnt Gum-water, and
with that flick on your Objcdl. As the Spots
of Cards are red and black, by making your
SUps of fuch Spots you will obtain a Contraft
to Objeds of almofl: any Colour : and by
fixing black Things on the white, white on
the black, blue or green on the red or white,
and all other coloured Objects on Slips moft
contrary to themfelves, they will be fhewn
to the beft Advantage. Thefe Slips are in-
tended chiefly for the new-invented Micro-
fcope for opake Objedls, to be applyed between
the Nippers : but they will alfo be proper
for any other Microfcope that can fhew opake
Bodies. A little fquare Box fliould be con-
trived to keep thefe Slips in, with a Num-
ber of very fhallow Holes juft big enough
to hold them. If fuch Holes were cut
through Pieces of that Paftboard Covers of
Books are made of, exadlly fitted to the Box,
and a Paper was pafted on one Side of each
to ferve for a Bottom to it, three or four
fuch Paftboards ftored with Objeds might
lye one upon another in the fame Box, and
contain an hundred or more Slips with Ob-
jects faftened on them, always ready for Ex-
amination. It will not be found amifs to
provide fome Slips larger than others, for
the Reception of different fized Objed:s :
But the Patternhere to annexed [Plate VJ.)
will better explain my Meaning. The Box
fhould likewife be furnifhed with a Pair of

Plyers,,

62 Cautions in viewing Objects.

Plyers, to take up and adjuft the Slips;' and
therefore a convenient Place is contrived
therein to hold them, as the Plate before
you fhews.*

CHAP. XV.

Cautions in viewing O ejects o

lEv^are of determining and declaring

\ your Opinion fuddenly on any Objed ^

for Imagination often gets the Start of Judg-
ment, and makes People believe they fee
Things, which better Obfervations v^ill con-
vince them could not poffibly be feen : there-
fore aiTert nothing till after repeated Experi-
ments and Examinations^ in all Lights, and
in all Poiitions.

When you employ the Microfcope, fliake
off all Prejudice, nor harbour any favourite
Opinions; for, if you do, 'tis not unlikely
Fancy will betray you into Error, and make
you think you fee what you would wifh to fee.

Remember that Truth alone is the Mat-
ter you are in fearch after ; and if you have
been miftaken, let no Vanity feduce you to
periift in your Miftake.

* Mr. Cuff, in Fleet-fireet^ can fupply thofe who don't

care to give themfelves the Trouble of making them, with

Boxes after this Pattern, which are found by Experience to

be extremely ufeful: He likewife makes and fells all the

" ' -^ofcopes with ^€ix A^faratui mentioned in this Treatife.

Pafs

Cautioiis 171 viewing Objects.' 63

Pafs no Judgment upon Thing over-ex-
tended by Force, or contracted by Drynefs,
or in any Manner out of their natural State,
without making fuitable Allowances.

There is no Advantage in examining any
Objc<fl with a greater Magnifier than what
ihews the fame diftindlly ; and therefore, if
you can fee it well with the third or fourth
Glafs, never ufe the firft or fecond ^ for the
lefs a Glafs magnifies, the better Light you'll
have, the eafier you can manage the Objecft:,
and the clearer it will appear.

It is much to be doubted, whether the
true Colour of Objedis are to be judged of,
when feen through the greateft Magnifiers :
for as the Pores or Interftices of an Objedt
muft be enlarged, according to the magnify-
ing Power of the Glafs made ufe of, and the
component Particles of Matter^ muft by the
fame means appear feparated many thou-
fands of times farther afunder than they do
to the naked Eye, their Reflecftions of the
Rays of Light will probably be different, and
exhibit different Colours. And indeed, the
Variety of Colouring fome Objedls appear
dreft in, may ferve as a Proof of this.

The Motions of living Creatures them-
felves, or of the Fluids contained within
them, as feen through the Microfcope, are
likewife not to be determined without due
Confideration : for as the moving Body and
the Space wherein it moves are magnified,the

F Motion

04 Cantiom in viewing Objects.

Motion muft probably be fo too. And there-
fore, that Rapidity, wherewith the Blood
feems to pafs along through the Veffels of
fmall Animals, muft he judged of according-
ly. Suppofe for Inftance, a Horfe and a
Moufe move their Limbs exactly at the fame
Moment of Time : if the Horfe runs a Mile
while the Moufe runs fifty Yards (tho' the
Number of Steps are in both the fame) we
fliall readily, I believe, allow the Horfe's
Motion to be fwifteft. The Motion of a
Mite viewed through a Microfcope, or feen
by the naked Eye, is, perhaps, not much
Icfs different.

Some People have made falfe Pretences
and ridiculous Boafts, of feeing, by their
Glaffes, the Atoms of Epicurus, the fub-
tile Matter of Des Cartes, the * Effluvia of
Bodies, the Emanations from the Stars, and
other fuch like Impoffibilities ; but let no
ingenious and honeft Obferver give credit to
thefe romantic Stories, or mif-pend hisTime,
and bewilder his Brains, in following fuch
idle Imaginations, when there lies before
him an Infinity of real Objed;s, that may be
examin d with Eafe, Profit, and Delight.

* Dr HiGHMORE pretends that the EfRuvia of the Load-
ftone have been feen by Glaffes, iffuing from it in the form
of a Mifl: : And all the relt of the above Extravagancies have
been boafled of by others. Via. Leeuwen. Arc. Nat. Tom. ii.

The Microscope made Eajy :

O R, A N

ACCOUNT

Of what furprizing

DISCOVERIES

Have been already Made by the

MICROSSOPE;

WITH

Ufeful Reflections on them.

TOGETHER WITH

A great Variety of new Experiments
and Observations, pointing out many
uncommon Subjects to the Enquiry of the
Curious.

PART II.

F 2

[ 67 ]

THE

MICROSCOPE

Made Eafy, &c.

PART 11.

AVING defcribed the moft ufe-
ful Kinds of Microscopes
made amongft us^ fliewn how to
calculate the 7nagnijying Powers
of Glasses, and the real Size of Objects ;
taught the Ways of prefarmg, exa77ii?ii?2gy
and preferviJjg Objects ; and given proper
Cautions in our judging of what we view ;
I come now to the Second Part of my
Defign, which is, to fhew what yz/r/rm/Tg-
Difcoveries have been already made by the
Microscope, with ufeful RefeBio72s on
them : and alfo to fet forth a great Variety
of new Expef^i?jie?2ts and OhfervationSy point-
ing out many uncommon Subje&s for the Ex-
amination of the Curious.

F

C^AP.

[68]

CHAP. I.

Of the Animalcules in Fluids.

9 I '^HE the fmallefl; living Creatures yet
j^ known are the Animalcules in Fluids :
whereof many Kinds have been difcover'd by
the Microfcope of fuch an exceeding Mi-
nutenefs, that a Million of them would not
equal the Bignefs of a large Grain of Sand ^
and, it is probable, there may be numberlefs
Species of a Size much lefs than thefe. It is
alfo likely, that there are as many, or even
more Kinds of thefe Invijibks (if I may ufe
the Term) than of thofe whofe Size is difcern-
able by the naked Eye. Here, therefore, is
abundance of Scope for Enquiry and Admi-
ration, fince every Drop of Water, or other
Liquor, (excepting Oils and Spirits) either
does already, or, upon llanding expofed a
few Days, will appear full oi livingCreatureSy
of various Sizes and Forms. Some kinds of
thefe Animalcules feem to be really Fifh, and
are natural Inhabitants of the Water all
their Lives : others live there but occafion^
ally, in the manner of Gnats, which, from
Eggs dropped by their Parents in the Water,
become fwimming Animals ; but, after a
v/hile, fhed their Skins, appear in a Form
that bears no Refemblance to what they wore

before.

Of the Animalcules hi Fluids, 69

before, take Wing, and turn Creatures of
the Air.

We mav thus account how Water where-
in Pepper, Hay, OtJts, Wheat, or other vege^
table Sublia?ice5 are infufed, will foon be-
come full of Life : for thofe minute and in-
vijible little Flies ^ which are every where
hovering in the Air, and fecking places to
depofit their Eggs, when a Fluid offers well
ftored with proper Nouriiliment for their
future Offspring, may be fuppofed to refort
to it in Swarms, and lay their Eggs there,
Thefe Eggs being foon hatched, the Infant
Brood fwim about and live happily in the
Fluid ; till grown to their ftated Sizef they,
in due Time, change their Forms, employ
their Wings, and fly away.

The Truth of this I have often experien-
ced: for after obferving fome kinds oi A?ii'
pialcides in feveral Fluids to be grown to a
certain Bignefs, on a fudden I have found
them all gone away, and only a much fmal-
ler, and confequently a younger Race of the
fame Kinds remaining ; which alfo, when
grown to a like Size, have foon after in the
fame manner been gone too. Beiides, if
tlie Infufion be covered, tho' with a Muf-
lin or fine Lawn, I have conftantly found
that k\N Anijnalciiles will be produced there-
in ; but upon taking off the Cover, in a few
Days it will be full of Life ; which feems to
prove, that the Eggs whence thefe Animal-

F 4 ciiles

70 Of the Animalcules in Fluids.

cules come, mull either be depoiited by their
own Parents, as I above fuppofe, or be
brought along with the Air. And, indeed,
both thefe Ways may poffibly be : for as
the Eggs of fuch minute Creatures are lighter .
than Air, Millions of them may continual-
ly float therein, and, being wafted every
where indifferently, may perifh in places
unfuitable to their Nature, but hatch and
thrive v/hen they happen to be lodged in a
proper Nidus for them. Some People ima-
ginCj, that the Eggs of thefe little Creatures
are lodged in the Pepper ^ Hay\ or whatever
elfe is put into the Water : but, were it fo,
I cannot think a thin Covering of Lawn,
which does not exclude the finer Part of the
Air, would prevent their being hatch'd 5 and
therefore muft conclude it a Mifliake.

Tho' Water that ftands at reft, and ex^
pofed in the open Air, will, after a few Days,
have fome Animalcules m it, they will be
found in no degree fo numerous as when
vegetable Bodies have been fteeped therein :
for no Creatures feem able to fubiift on meer
Water onty, and what little Particles belides
may accidentally happen in it can maintain
BO great Number : ^ut, when, by Infufion
of the abovementioned Subftances, Water
is ftored with their proper Food, the Micro-
fcope can £hew Myriads of liviitg Creatures

in every little

iiS

Pepper-WaieK 71

As every curious Perfon will be defirous
to view thcfe Wonders with his own Eyes,
and communicate them to his Friends, the
following Diredions for making Pepper^
Water, &:c. to he kept always ready for
Obfervation, may not perhaps be unaccept-
able.

CHAP. II.

To make P e p p e r-W a t e r, ajid of the
Animalcules joiind therei?i.

PU T common Black Pepper, grofsly
bruifed, into an open VefTel, to cover
the^ Bottom of it about half an Inch in
Thicknefs, and pour thereon Rain or River-
Water, till it rifes above the Pepper an Inch
or thereabouts. Shake or flir the Water and
Pepper very well together when firft you
mix them, but afterwards not at all. Ex-
pofe your VeiTel to the Air uncovered, and
in a few Days you'll perceive a little Pellicle
or Skin upon the Surface of the Water, re-
fleding Prifm Colours. This Skin, exa-
mined by the Microfcope, will be found to
contain Millions of Animalcules, fcarce dif-
cernable at firft, even by the greateft Mag-
nifier, but continually growing bio-o-er till
they come to their full Size. Their Num-
bers too will every Day increafe exceedingly,

till

j^ Pepper-Wafer,

till at lengtii almoft the whole Fluid fecms
alive : though in reality, they lie chiefly on
the Surface ot the Water, and go not deep
therein, unlefs frighted or difturbed ; but
when that happens, they'll fometimes dart
down all at once, and not appear again for
fome time. In warm Weather this Skin
rifes on the Surface fooner, and you'll per-
ceive them grow fafter than in cold : tho\
even in the midft of Winter, if the Water
be not frozen, the Experiment will fuc-
ceed.

About the Quantity of a Pin's Head of
this Scum, taken up with the Nib of a new
Pen, or a fmall Hair-Pencil, and applied on
a iingle Ifinglafs, firft to the third Magnifier,
then to the fecond, and then to the firft,
will fhew feveral Sorts of Animalcules lefler
each than other, and differing a great deal
in Shape as well as Size.

The Sorts that have been obferved in
Pepper-Wafer^ are,

Fir/i\ The largeft Sort of all, (reprefented
Plate VII. Fig. I.) '* The Length of thefe is
about the Diameter of a Hair, and three or
four times more than their Breadth. Their
Bodies are very thin and tranfparent, but
that Side which feems the Back is darker
than the other. They turn themfelves in

* P^'i^>/;7, franf. Numb. 284.

4 the

•N

N

M»

\

Vs

"^^

u-"^

^

!^'

<N

s

^

s?"^

^ "X

L^-"^
^

* ^

F-73-

3

Fu;. VM.

F7^-

Fu/.jur.

Fcppcr- Water. 7 3

the Water often, and fliew both Back and
Belly, as 1.2. Their Edges are fringed, as
it were, with a great Number of exceeding-
ly minute Feet, which are chiefly feen about
the two Extremities : At one End there are
likewife fome Briftles longer than the Feet,
refembling a Tail. Their Motion is fwift ;
and by their Turns, Returns, and fudden
Stops, they feem continually to be hunting
about for Prey. They can employ their
Feet in running as well as fwimming ; for
upon putting a Hair amongft them, they'll
often creep along it from End to End, bend-
ing in feveral odd Poftures.

Secondly, A pretty common fort, whofe
Length is about one Third of a Hair's
Breadth, with Tails five or fix times as long,
and fometimes more. Fig. II. i. exhibits
one of them with the Tail extended. 2. re-
prefents another with its Tail in a Screw-
like Form, as they appear very frequently.
Sometimes, when they lye ftill, they thrufl
out and pull back again a fringed or beard-
ed Tongue ; and a Current runs conftantly
towards them, which is caufed probably by
the nimble Motion of fome minute Fins or
Legs too fine to be difcerned.

Thirdly, A Sort about the Size of the laft,
but without TailS; appearing fometimes in
an oval ShapOj, as Fig. III. i. and fometimes
a little longer, refembling a Flounder, in the
Manner of 2 . Their little Feet may be fccn

plainly

74 Fepper 'Water,

plainly when the Water is juft evaporating,'
for then they move them nimbly. Now
and then tw^o of them are feen conjoyned,
as 3. ' ^

Fourthly^ Another fort appear like flender
Worms, about fifty times as long as broad,
and whofe Thicknefs is about the one hun-
dredth Part of a Hair. Their Motion is
equable and flow, waving their Bodies gene-
rally but little in their Progreffion. They"
fwim with the fame Facility backwards or
forwards, and being every where of the
fame Thicknefs, it is difficult to diftinguifh
which End the Head is placed at. See
Fig. IV.

A ffth Sort is fo amazingly fmall, that
an Hundred of them in a Row would not
equal the Diameter of a Grain of Sand, and,
confequently, a Million of them are but
equal to a Grain of Sand in Bignefs : their
Shape is almoft round.

A Jixih Sort J are about the Thicknefs of
the foregoing, but almoft tvv^ice as long :
and, befides thefe, there are doubtlefs other
Sorts which have not duely been attended
to.

It is agreeable enough, while thefe little
Creatures are before the Microfcope, to ob-
ferve the different Effeds feveral kinds of
Mixtures produce among thdn. For Ex-
ample, putting to them the fmalleft Drpp
imaginable of Spirit of Vitriol upon the Point

of

Vepper-Water. 7j

of a Pin, they immediately fprcad them-
felves, and appear to tumble down dead.
Diflblved Salt kills them, but with this Dif-
ference, that inftead of becoming flat as in
the former Cafe, they flirink into oval
Forms. Tindure of Salt of Tartar throws
them into convulfive Motions, after which
they foon grow faint and languid, and then
dye without any Change of Shape. Ink
kills them as foon as Spirit of Vitriol, but
feems to contracft them feveral Ways. Frefli
Blood, Urine, and Spittle kill them in a
little while. Sugar diflblved does the fame ;
but thereby fome dye flat, and others
round '^.

If the Water be permitted to dry away
without any Mixture, fome Sorts of the
Animalcules will burfl:, but others not : and
if a frefh Drop of Water be put to them, in
a little while many of them w^ill revive and
fwim about again.

* Pbilofoph. franf. Numb. 203.

CHAP.

[76]
CHAP. III.

0/* Hay-Water, &c*

'AY, Straw, Grafs, Oats, Wheat, Barley,
or any other vegetable Produftion,
being infufed in Water, in the Manner ad-
vifed before, after fome Days a fort of
whitifh Scum or Motherinefs will appear
upon the Surface, which, examined by a
Microfcope, will be found to contain inex-^
preffible Numbers of minute living Creatures
of various Sizes, Forms, and Kinds.

And of thefe fome are the fame exadly
as were }uft now defcrib'd in Pepper-Water :
for it is to be obferved, that certain Kinds
of thefe Animalcules are met with, univer-
fally, in all Waters that have flood any con-
liderable Time expofed to the open Air.
The moft general among them is an oval
fort of Animalcule^ fomewhat in the Shape
of an Emmet's Egg (See Fig. V. Plate VIL)
They are extreamly nimble, and in a conti-
nual fwift Motion backwards and forwards :
but fometimes they flop on a fudden, and
turn round on their own Axis numberlefs
times with furprizing Velocity, iirfl one way,
and afterwards the contrary ^. This Gyra-

* The Solar Microfcope has difcovered, that this ftrangc
Motion is produced by the Aftion of a great Number of
Legs or Fins, placed in » circular Order.

tion.

Hay-JVata'y &c. yy

tion, orTwirling round as it were on a Point
I have taken notice of in other Kinds alfo of
the Animalcules found in Fluids.

Another pretty common Sort, and In
Shape fomewhat refembling the foreo-oin^,
is fhewn (Fig. VI.) Their Motion is very
fwift, and always with the fliarp End fore-
moft, whence one may reafonably fuppofe
it to he the Head. Some of them are clear
from End to End, but curioufly ribbed in
tlie Manner of a Melon : Others are tranf-
parent at their fmall Extremity only, but
have their Bottle-End opake. No Legs or
Fins can be difcerned in either.

We find another fort, as long almoft as
the largeft in Pepper -Wafer, which are very
brifk and ad:ive, and have a Power of con-
tracting or extending themfelves as they
fwim along. At the End that feems to be
the Fore-part, feveral Feet are vifible ; but
efpecially when the Water is almoft evapo-
rated : for then they fl:irink into a Globular
Form, and their Feet Handing out may be
perceived to move very nimbly. Fig. VII. i .
reprefents one of thefe Animalcules at its full
Length : 2. fhews another of them when
contracted .

There's likcwife a Species o^ A7ii7naJculei
whofe Bodies are Spherical, but pointed
fomewhat like a Pear, and refembling Blad-
ders fiird with Water, wherein a vaft Num-
ber of dark Particles feem in a continual

Agitation,

yS Hay-Wafer, &c.'

Agitation. Their Motion is chiefly a re-s
volving one, turning round perhaps above an
hundred times in a Minute, firft one way^
and then the contrary ; and all this without
moving a Hair*s Breadth out of their Place.
But fometimes they move forward very
brifkly, turn, return, and fetch a large Com-
pafs with feveral Deviations : keeping how-
ever, throughout their whole Progreffion,
their pointed End always foremoft. See
Fig. VIII.

I once difcover'd in the Scum oh the Sur-
face of Hay 'Water a kind oi ??iinute Ser^
penfs ', for fo I call them from their Motion,
which was like that of a Serpent, and from
their coiling up themfelves in the manner
Serpents do. I kept this Water fome Weeks,
and fhewed them to feveral of my Friends,
but fince that time have never met with
them in any Infuiion of the fame fort, or in
any other Fluid. Their manner of moving
forward, and alfo of coiling themfelves up,
is ihewn Fig. IX. 1,2. They were larger
than any of the Eel-ki?tds dl Animalcules,
their Motion very different, and not near fo
quick. The End that feem'd to be the Head
was thicker and fomewhat more opake than
the other.

Animalcules in the Shape of Eels are fre-
quently met with in many of the Infufions
I am now mentioning, and likewife in fe-
veral other Liquors, The Bignefs of them

is

Hay 'Water, &c, 7p

Is very diffcrentj forne being an hundred
times larger than others, and probably they
may differ alio very much in Kind. They
have in general a nimble '^'^rigglihg Motion :
but fome Sorts of them are more adtive and
vigorous than others.

Vinegar after {landing a few Days unco-
vered, and efpeciallyin the Summer Seafor),
will frequently abound with a kind of thefe
Eels, large enough to be difcerned by the
naked Eve : which has encouraged fome
People erroneoufly to affert, that the Sharp-
nefs of Vinegar is owing to nothing elfe but
the ftriking of thefe Creatures upon the
Tongue and Palate with their pointed Tails :
Whereas it is very certain, that many times
hone of them can be difcerned even in the
fourell Vinegar; and befides, Mr. Lee u-
\VenhoeK: has demonftrated, that its Sharp-
nefs proceeds only from the pointed and pe-
netrating Figure of the Salts floating in it,
as I Ihall find occafion to obferve more fully
by and by.

The Shape of thefe Eel-like Animalcules
is delineated Fig. X.

Dr. Power tells us, "*' Tliat if Vinegar
wherein Eels abound, be but moderately
heated at the Fire, they will all be killed,
and fink dow^n to the Bottom : but that Cold
does them no Injury. For after fuch Vine-

. t, ^ -T- ^— _■»■■■ .-I ■ I. -■ -, « ••^^ ■— — .— ■■-■^— -■■■■I ■ ., ««

* Power's Micrc/ccj^. Oh/crv. pag. 35.

G • ga^

So Hay-Wafer^ &c.

gar had been expofed a whole Night to the
fevereft Froft, and was frozen, and thawed,
and frozen again, and fo feveral times over,
they were as brifk as ever. He Hkewife in-
forms us, that, in cold Weather, he put
fome Vinegar full of thefe Reh into a Glafs,
and poured thereon about the fame Quantity
of Oyl, which floating on the Vinegar, all
the Eich would conftantly creep up into the
Oyl when the Vinegar began to freeze > but
upon thawing the Vinegar, they as conftant-
ly returned to it again. Thefe are pretty
and curious Experiments,

A Drop of Oyl of Vitriol mixed with the
Vinegar kills them in the fame manner as
Fire does.

If fome Grains of Sand be put among the
"Eeh before the Microfcope, it will be high-
ly entertaining to fee them ftruggling and
embarrafled, as it were, amongft large
Stones.

CHAP.

' [ 8i ]

CHAP. IV.

0/ Eels in Paste.

TTTPIoEVER is defirous to be furnifli'd
V V with minute Eels always ready for the
Mlcrofcope, needs only boil together a little
Flour and Water, and make fuchPafte there-
of as Bookbinders commonly ufe 3 or it may
be bought of them. It fhould neither be
very ftiff, nor very watery, but of a mode-
rate Confluence. Expofe it to the Air in an
open Veffelj and prevent its hardening or
becoming mouldy on the Surface, by beat-
ing it well together when you find any
Tendency that way -, for if it grows hard or
mouldy, your Expec^lation will be difappoint-
ed. After fome Days it will turn four, and
then if examined attentively, you'll difcern
Multitudes of exceeding fmall, long, flen-
der, wriggling Ani7nalcu]es^ which grow
larger daily, till you'll be able to fee therrx
with the naked Eye.

To promote their coming forward, pour
every now and then a Drop of Vinegar on
your Pafte : and after they are once pro-
duced you may keep them all the Year, by
putting to them fometimes a little Vinegar,
or Water, if the Palle becomes too dry, and
fometimes a little Supply of other four
Pafte y taking care continually to preferve

G 2 the

82 E^Js in Fajle.

the Surface in a right Condition, which will
eafily be done when it i§ well flocked with
thefe Animalcules : the continual Motion of
them preventing any Mouldinefs thereon.

A Water-Glafs, or fome other Glafs Vef-
fel, is the moft convenient to keep your
Pafte in ; for by holding it up againft the
Light, you'll oftentimes perceive the Reh
wriggling themfelves above the Surface of
the Pafte upon the Sides of the Glafs, and
may be able to take feveral of them with a
Pen or Flair Pencil, much more difengaged
from the Pafte, and confequently fitter for
View, than if you are obliged to examine
the Pafte itfelf in order to find them in it.

Apply them to your Microfcope upon a
fingle Talc or Ifinglafs, after having firft put
on it a very fmall Spot of Water for them to
fwim about in. The thicker your Pafte is,
and the more they are invelop'd in it, the
greater Proportion of Water will be requifite
to dilute it, that they may difentangle them-
felves, and be rendered diftindlly vifible.

They are very entertaining Obje(fls, exa-
min d by any kind of Microfcope, but par-
ticularly the Solar one, by which I have
magnified them fometimes to an Inch and
half, or two Inches in Diameter, with a'
Length proportionable, and have found 'em
anfwer exa(Sly the Appearance of fuch fized
Eels. The internal Motion of their Bowels
may very plainly be diftinguifh'd, and when

the

Of Rahi'Wiitcr, Sec. ^

the Water is dry'd alinofl: away, and they
are near expiring, their Mouths may be (ggh
opening to a conlidcrable Width.

CHAP. V.

Of Rain-Water a?2d other Waters.

MR. Leeuwenhoek fays, that at firft
he could dilcern no lhi?ig Creatures
in Rain-Water ; but after ftanding fome
Days, he difcovered innumerable-.-^/z/W/a^/i^i
many thoufand of times lefs than a Grain of
Sand, and in Proportion to a Mite as a Bee is
to a Horfe.

In other Rain-Water, which had hkewife
ftood fome time, he found the fmalleft fort
he had ever (tQ,n -, and in a few Days more,
met with others eight times as big as thefe,
and almoft round.

In another Quantity of Rain-Water, that
had been expofed Uke the former, he difco-
vered a kind oi Animalcules with two httle
Horns, in continual Motion. The Space be-
tween the Horns was flat, tho' the Body was
roundifh, but tapering a little towards the
End, where a Tail appeared four times as
long as the Body, and the Thicknefs of a
Spider's Web. He obferved feveral Hun-
dreds of thefe within the Space a Grain o/
Sand would occupy. If they happen'd on the

G 3 leaft

$^ Of Rain-Water^

leaft Filament or String, they v/ere entang-
led in it, and then would extend their'Bodies
into an oblong Round, and ftruggle hard to
difengage their Tails. He obferved a fecond
fort of an Oval Figure, and imagined the
Head to ftand at the fharpeft End. The
Body was flat, with fever al fmall Feet mov-
ing exceeding quick, but not difcernable
without a great deal of Attention, Some-
times they changed their Shape into a perfed:
Round, efpeciaily when the Water began
to dry away. He met alfo v/ith a third fort
twice as long as broad, and eight times
fmaller than the fir ft -, yet in thefe he dif-
cerned little Feet, whereby they moved very
nimbly. He perceived likewife a fourth
fort, a thoufand times fmaller than a Loufe's
Eye, and which exceeded all the reft in
Brifknefs : he found thefe turning them-
felves round, as it were upon a Point, with
the Celerity of a Top. And he fays, there
were feveral other Sorts.

It is common, in Summer-time, for the
Water that ftands in Ditches to appear fome-
times of a "^ greenifh and fometimes of a
reddifh Colour, which, upon Examination

with

* The [nfefts that moft commonly difcolour the Waters
are of the Shrimp- Kind, called by Swammerdam Pulex
fquaticus arborefcens, from the branching out of their little
"Horns i they are often fo numerous in ftagnating Waters,
in May or Jujie, at which time they copulate, as to make

thtm

and other Wafers, '" 85

\^m'thc Microfcope^ is found intirely owing
to infinite Millions of Animalcules crowded
together on the Surface of it, and giving it
fuch Appearance. Their Bodies are oval,
and transparent at both Ends, but the Mid-
dle either green or red, according to the Co-
lour of the Water they are fwimming in.
This middle Part, viewed with the firft or
fecond Magnifier, feems compofed of Glo-
bules, and bears fo near a Refemblance to
the Rows or Spawn of Fifhes, that 'tis rea-
fonable to believe it really may be the fame :
and the more fo ftill, as they are found after
fome time perfedlly clear and colourlefs, and
therefore may be prefumed to have fhed
their Spawn.

The Water that drains from Dunghills,
and looks of a deep brown Colour, is fo
thronged with Amnmlades, that it feems to
be all alive ; and muft be ; diluted with Water
before they can be fufficiently feparated to
diftinguiih their various Kinds. Amongfl
thefe one Sort is found, which I don't re-
member to have feen elfewhere, and there-
fore give a Draught of (Plate VIII. Fig. XI.)
Their middle Part appears dark, and befet
with Hairs, but both Ends of them tranf-

them appear of a pale or deep Red, and fometimes of a
yellow Colour, according to the Colour of themfelves. The
green Scum fo commonly feen on the top of Handing Wa-
ters in Summer-time, is nothing but innumerable green Ani-
malcules. Vid. Derham's Phyjic, ^heolog. pag. 178.

G 4 parent :

86 \dnimalcuies in Waters.

arent : their Tails are tapering with a long
Sprig at the Extremity, and their Motion is
flow and waddling. This Dunghill-Water
abounds alfo with a fort of capillary Eels,
that are extreamly aftlve.

An Infufion of any Herby Grain, Fruity
or Flower y made in common Water, will be
found after a few Days to contain fome
Kinds of Animalcules peculiar to itfelf \ and
this, tho' aftoniihing, may be accounted for
in a very reafonable manner 5 for a little Ob-
fervation will fhew, that every Herb, Grain,
Fruit, or Flower, is allotted by Providence to
be the Food of fome particular fort of Bird,
Beafl, or Infed:, of the vifible and larger
Kinds ; and we may fuppofe it, in like man-
ner, when infufed in Water, to afford alfo a
proper Nourifhment for fome or other of
thofe numberlefs Species of minute Creatures,
which are invijible' to the naked Eye, and
not to be difcovered without a good Micro-
fcope. And as to this Particularity oi Ani-
malcules, I refer the Curious (who have not
yet been convinced by Trials of their own)
to the Obfervations of Moniieur Joblot,
(ProfeJJor Royal of the Mathematicks, and
of the Royal Academy of Painting afid Sculp-
ture at V akis) on the various Kinds difco-
vered by him in the feveral Infufion s follow-
ing : the Pifl:ures of which Animalcules he
has given, as well as a Defcription of them»
He examined th^ Infufions oi Pepper, blacky

white.

Animalcules in Waters. 87

white, and long : of Senna^ of Pinksy of
Cya?2us or Blewioftle, of Rofes, ^ejfamiji^
Rajlerry-Stalksy Tea, Barberries^ Fennel
and Sage, Alarigold-Flowers, four Grapes^
and Mellion Kind ; and found different Ani-
inalcides in them all. Hay, new and old,
abounded with many Kinds ; Rhubarby
MuJl^roomSy fweet Bafil, Ciiron-Floiuers, had
their particular Animalcules, The Anemo-
ny afforded fome very wonderful * , Ce-
lery produced many Kinds : Wheat-Ears and
Straw, many Kinds : Straw of Barley, Rye,
Oats, and Turkijlj Corn, many Kinds : Oak-
Bark, new and old, afforded great Variety.
Some of thefe Infufions he kept a whole
Year round, and obferved, not only that
each Infufion had Animalcules of Shapes
quite different from thofe in others ; but,
likewife, that in the fame Infufion diff^erent
Kinds ci Animalcules appeared at different
times.

A^. B, It is highly probable, that the Place
where Infufions are niade, in a City, or in
the Country, expcfed to the open Air, or
fliut up within a Houfe, as alfo the Seafon
of the Year, and its Temper as to Heat or
Cold, may cccaiion great Differences in the

* Mr. Joblot's Draught of the Animalcules in this In-
fufion rcprefents an exaft Satyr's Face upon their Backs: I
X(;commend the Trial to the Curious.

Kinds

88r Ammakules in Wafers.

Kinds oi. Animalcules to be found In the
fame Infufions.

We fometimes find in our Infufions of
^e^etable Produclio?2S, and in other Waters
that have ftood a while uncovered, an Ani-
mal much larger than any before defcribed,
of a very (ingular and furprizing Form, as
pidured Plate VII. Fig. XII. This little
Creature is in its middle State -, it lately was
a Worm, and will foon become a Gnat.
For * Gnats depoiit their Eggs in a kind of
flimy Matter on the Surface of the Water,
and fallen them to fomething that may pre-
vent their being waihed away or feparated
too foon. From thefeEg-p-s proceed a num-
ber of minute V/orms, which finking to the
Bottom of the Water, make for themfelves
Cafes or Coverings of fine Sand or Earth ce-
mented together with a fort of Glew, but
open at both Ends, for them to come out of
or retire into, as they find occafion. After
a time, quitting thefe Habitations, and the
Figure of Worms, they re-afcend to the top
of the Water in the Shape now before us,
fhelled all over, with a large Head and
Mouth, aCoupleof black Eyes, two Horns,
feveral Tufts of Hairs or Briftles on different
Parts of the Body, and a Tail with a Bruih
of Hair at the End of it, which being

* SpeSlacle de la Nature^ EngUp Edit. i2mo, pag. 123.
Hooke's MzVrc^, p. 186.

fmeared

Animalcules in Wafer's. 89

fmcared over with an oily Fluid, ferves like
;i Cork to keep them above Water ; their
Heads being fometimcs lifted into the Air,
and fometimes plunged into the Water, while
the Tail Hides along the Surflice. And if the
Oil on the Tail begins to dry, they fhed
from their Mouth a new fupply upon it,
which reftores its Ability of fleering where
they pleafe, without being wetted or preju-
diced by the Water. After living in this
Manner the Time appointed by Providence,
a flranger Change fucceeds : for refigning
their Eyes, Horns, and Tail, and cafling off
their whole Skin, there iffues forth a Race
of Infe6ts of a quite different Element : the
moft beautiful and delicate Plumage adorns
their Heads 3 their Limbs are conftituted
with the iineft Texture : they have Wings
curioufly fringed and ornamented ; their
whole Bodies are inverted with Scales and
Hair, and they are actuated by a furprizing
Agility : in fhort, they become Gnats^ and
fpring into the Air. And, what is moft
amazing, a Creature that but a Minute iince
was an Inhabitant of the Water, would now
be drowned if it were plunged therein.

I have been the more particular in my
Account of this Met amor phofis^ as I appre-
hend many forts of the Animalcules in Fluids
undergo Changes in fomewhat a like man-
ner. I fhall only add here, that the
little Creature, whofe Picflure I have given,

is

^o Animalcules in Waters.

is a delightful Objed: for the Mi cr of cope ; its
white Heart beating diftindtly, and the Mo-
tion of all its Inteftines being perfectly vifi-
ble and extraordinary.— -Of the G;?^/ 1 ihall
fpeak farther in its proper Place.

The Waters every where abound with
Life, and are an endlefs Subject of Employ-
ment for the Microfcope : Seas, Rivers,
Ponds, Ditches, and almoft every Puddle
can by its Afliftance prefent us with living
Wonders never before difcovered : for fuch
Examinations have as yet been but little at-
tended to, even by People that have got
thefe Inftruments, and alfo a Genius to ufe
them. But I am in hopes this Treatife may
excite them to be more induftrious, and not
fuffer a little Difficulty, or a few Difappoint-
ments, to difcourage them from a Study that
can fo amply reward their Pains.

In feveral of * Mr. Leeuwenhoek's
Letters to the "Royal Society^ we meet with
an Account of fome furprizing Animalcules
found adhering to the Roots of the Lens
Falujiris^ or Duck-Weed^ (which in Summer-
time floats plentifully on the Surface of
Ponds and Ditches) as examined by him in.
a Glafs Tube filled with Water. One Sort

* Vid. Thih Tranf. Numb. 283, 295, 337.

of

r^.i^O

^•^•^- iy

^l^iry, ^^

^T^V's^

Ty. 71 ^1.^3

jry.m.^t.^3

raif.^o

riatemr

r^.r^i-S^

y.^./t.^i

Tia.JU./i^-t

-F^.Urn ox

^tf-"-/'

SF^jr.r/t^x

ru^.n^.^3

-F,y.m./i^.^3

I'yr.mr.^i.ffs

JlHimakules i?i loafers, 91

of thefb was fliaped like Bells, with long
Tails, wliercby they failened themfelves to
the Root of thcfe Weeds ; and fomctimcs
twenty of thefe were fecn together, gently
extending their long Tails and Bodies, and
then, in an Inftant, contrading them again.
See the Draught, Plate VIII. Fig. I.

A, reprefents a Root of Duck-Weed with
the Tails of many Animalcules adhering to it.

b h bb^ &c. fliew their Bell-like Bodies.

c c c c, their long tails.

Another extraordinary Kind oi Animalcule
(which fee Fig. II.) appears in a Sheath or
Cafe, ^, b^ c, the End whereof it faftens to
the Duck'Wecd Roots. This little Creature
has two feeming Wheels with a great many
Teeth or Notches, coming from its Head,
and turning round as it were upon an Axis,
J, e. At the leail Touch it draws the Wheel-
work into its Body, and its Body into the
Sheath, after which it appears as Fig. III.
But when all is quieti it thrufts itfelf out
again, and the Rotation of the Wheel-work
is renew'd. Mr. Leeuwenhoek took no-
tice of one of thefe, whofe Cafe feem'd com-
pofed of minute Globules (Fig. IV. ^, b.)
and in this he difcover'd the Wheel- work to
confift of four roundifh Parts with little Di-
vifions between each, thouo-h onlv three of
thofe roundifli Parts could be feen, the fourth
lying behind, as reprefented Fig. V. This
convinced him how much he had been mif-

taken.

g2 Animalcules in Waters,

taken, in believing them, from their com-
mon Appearances, to be two Wheels, where-
as the real Form of this Wheel- work is as at
Fig. V.

To find thefe Animalcules ^ choofe Duck-
Weed that has long Roots ; for young Plants
with fhort Roots feldom afford any. Be
careful too that they are not cover'd with a
rough Matter, or tending to Decay, as they
will often be. Let the Roots fink gently
down in a Glafs Tube filled with Water,
and fo apply them to the Microfcope. Two
or three Animalcules will be found fometimes
adhering to one Root ; and at other times
you may examine feveral, and not be able
to meet with any.

In the Water, or flimy Matter found in
Leaden Pipes or Gutters, Mr. Leeuwen-
HOEK met with various Kinds of Animal-
cules^ and, among the reft, with Multitudes
that appear 'd to have a fort of Wheel- work,
turning round fomewhat in the former man-
ner -f*. Thefe Creatures, when the Water
dries away, contract their Bodies into a glo-
bular or oval Figure and reddifh Colour, and
become fixt in the dry Dirt, which grows
as hard as Clay : but whenever a Piece of
fuch Dirt is put in Water, in about half an
Hour's Time they open, and by degrees ex-

t FhlL Tranfaa, Numb. 289, LeeuWEN. Jrcan, Nat,
Tom. II. Epiit. 149.

I tend

-Pcuf.y^.

-P^M.

j^t^.jr./>.g^

F^.K;,.

Fi^. JW./'.

A?iimalcules in Waters. 93

tend their Bodies, and fwiin about : and this
they did after fome of this Gutter-Dirt had
been kept dry for twenty-one Months toge-
ther. Whence he conchides, tliat the Pores
of their Skin are clofed fo perfectly, as to
prevent all Perfpiration, by v/hich means
they are preferved till Rain falls, when they
open their Bodies, fwiin about, and take in
Nourifliment.

Fig. VI. VII. fhew two of thefe Animal-
cules in different Pofitions.

Fig. VIII. is the Form they appear in
when dry and contracted.

We may find in the Waters of our Ditches
feveral Species both of Teftaceous and Cruf-
taceous Anifnalcules : two of the latter fort,
which aremoft remarkable, are fhewn (Plate
IX. Fig. I. and II.) in a fwimming Pofture,
with their Backs towards the Eye. Their
Legs are fomewhat like Shrimps or Lob-
fters, but of a much more curious Strufture.
They are lefs than a very fmall Flea, but
are all Breeders, and carry their Spawn either
under their Tail, or in two feeming J Bags
hanging from their Sides, as in Fig. II.
Thefe Bags may fometimes be obferved
broken, and the Spawn (confifting of Glo-
bules very large in Proportion to the Crea-

t Jrcan. Nat. Tom. II. Epill. 121. Philo/oph. Tranfaa.
Numb. 28?.

ture)

i^^. Animalcules in tVafers,

ture) fcatter'd about the Water. There rS
alfo a third Sort, as beautiful as the forego-
ing, but not near fo large ; its Shape more
refembles a Shrimp, and it carries its Spawn
as the Shrimp does. Thefe three Species of
Animalcules appear to have only one Eye,
and that placed in the middle of the Fore-
head, without fo much as the leaft Trace of
even a dividing Line. They are often to be
found fo tranfparent, that the Motion of
their Bowels is feen difl:in(ftly by the Mici'o-
fcope^ together with a regular Pulfation in a
little Part, which therefore we may fuppofe
to be the Heart.

I fhall finifh this Head, with defcribing
a very wonderful Kind of minute Animal^
the extraordinary Form whereof (about
thrice the Bignefs it appeared to the naked
Eye) whilft in the Water and fafteiied to
the Root of a Weed, is given Fig. III. This
was a large one of the Sort, and had eight "
Hcirns ; whereas the fmaller ones have fel-
dom more than fix. It is likewife ihewn
here as extended to its full Length, but
when contracted is not a fourth Part fo long.
It fixes by the Tail to the Roots or Stalks of
Water-Plants. On the Upper Side a very
fmall Animalcule (a) is reprefented coming
out of the other's Body. This was fuppof-
ed at firft to have fattened itfelf there by
fome Accident j but by obferving it nar-
rowly.

'Am?)JciIcules in Water,, 9'^

rowly, It was difcover*d to be a young one
in the Birth : for tho* it had but four very
fmall Horns when firft feen, after fixteen
Hours its Horns and Body were grown much
larger ; and in four Hours more it was quite
exckidcd its Mother's Body. Againft this,
on the Upper fide, appeared a Httlc round
Knob, which gradually increafed in Bignefs,
and in a few Hours became pointed as at (b).
Thirteen or fourteen Hours after, it was
grown much laro;er, and alfo had two Horns.
In twenty-four Hours four Horns were {^^x\
upon it, one whereof was fmall, the fecond
larger, and the other two Very large, ex-
tending and contracting more vigorouflythari
their Fellows. Three Hours afterwards this
AnimalcitJc likewife fell off from its Mother,
and fliifted for itfelf.

The above Account is the Subftance of
Mr. Leeuwenhoek's Letter to the Royal
Society^ PhiL Tra?if, Numb. 283. — And in
Numb. 288. we meet with a farther De-
fcription of the fame Animalcule by an Rn-
glijlo Gentleman, whom Mr. Leeuwen-
hoek's Relation had put upon hunting after
it. He fays, he difcovered one of them in
feme clear Water taken out of a Ditch, but
with the utmoftAttention coiild find nomore
therein. It appeared the firft Day as in Fig.
IV. but he tells us, it varied every Moment,
and the Knob (a), which looks like the

H Gut

o6 Animalcules in Waters,

Gut Ccecum^ was fometimes a little longer*
Two or three Days after he perceived fome
white Fibres at the Extremity of the Knob,
and on the fourth Day it lay extended at full
Length, and appeared as in Fig. V. and he
was then convinced, that what he imagined
an Excrefcence, was in Reality a young
Animalcule of the fame Species, ifTuing from
the old one, and having fix Horns. Next
Day he found it in the Water entirely fepa-
rated,and about a third of its Parent's Length.
The Horns come out like Radii, not from
the Extremity, but quite round a fmallKnob,
which probably is the Head : They have a
vermicular Motion, and can extend or con-
trad themfelves either fmgly or all together.
The other End is flat, and by that it often
faftened to the Bottom or Side of the Glafs
wherein he kept it. It alfo contracts and
dilates its Body, and can bring both Body
and Horns into a fmall Compafs, as in
Fig. VL and Fig. VIL The Horns are per-
fectly white, the Body yellowifli, and not
eafily difcernable by the naked Eye ; being,
when extended, no thicker than a large
Horfe-Hair.

Monf. BuFFON, in a Letter to Martin"
FoLKES, Efq; late President of the Royal
Society^ dated at the Garden of VerfailleSy
1 8 July 1 74 1, fends an Account (as a new
Difcoveryin Natural Hiftory) of a Creature

called

.V,

Animalcules in IVafert 97

called a -fPo/ypc, found adhering to the Lens
PalultriSy which, being cut through the
Middle, from the upper Half a Tail pro-
ceeds, and from the lower Half a Head : fo
that one Animal becomes two. If it be di-
vided into three, the middle Part (hoots forth
a Head and Tail, the upper Part a Tail, and
the lower Part a Head y and all three be-
come as perfedl Animals as the firft. Whence
he concludes, that in the boundlefs Variety
of the Works of Providence, every thing
that can be, is.

Another Letter to the fame Gentleman,'
dated at the Hague, Sept, 1 5. 1741, from the
Honourable William Bentinck, Efq;
fays. That a young Man of Geneva, looking
for fmall Infedts in Water, faw fome little
Things which he took for Plants : but exa-
mining them carefully, he perceived fome
Motions in them, and found them contract
when touched. It was a long while, how-
ever, before he could determine whether they
were Plants or Animals : for he faw feveral
young Shoots coming out upon them, and
that as far as four GenerationSj hanging to
one another. But he has fince found them

f The Name Polypus, or Mary Feet, is given to feveral
Fifhes of the Star-Fijb or Cuttle-Fifo Kind, feme whereof,
befides feveral Claws, have two long Trunks, which they
can extend to a great Diftance to feize their Prey : and this
Animalcule^ I fuppofe, is called ?oly^^ from its having fome-
what of a like Form.

H z to

^8 Animalcules in Waters.

to eat Infefts, and even raw Meat. They
faften themfelves by one Extremity to fome
Plant, or the Side of a Glafs, and have at the
other End fix or eight Horns, wherewith
they hold their Prey.

Fig. VIII. is taken from a Drawing fent
with this Account.

He cut one of thefe Creatures to fee what
would become of it, and fome Days after
found new Arms growing out where others
had been cut away. Since that, he has di-
vided them the long way, the broad way,
oblique, and every way poffible, all with
the fame Succefs. He has alfo gone on fub-
dividing them, and has not found them pro-
pagate any other Way than by Shoots, and
without Copulation.

Both thefe Letters feem to mean the fame
"Animalcule Mr. Leeuwenhoek defcribes:
tho' with farther extraordinary Particulars,
which I believe the Curious will judge it
worth theirwhile carefully to examine into*.

Upon

* Since thfe Publication of the above Accounts, fuch far-
ther Particulairs concerning t\i\s Ani7nalculeh2.v& been received
both from Holland and France^ in anfwer to the ingenious
Enquiries of Martin Folkes, Efq; Prefident of the
Royal Society, and by him communicated to the faid
Society, that it would appear an unpardonable Neglect
ihouid I take ho Notice of them.

The Honourable William Bentinck, Efq; F. R. S.
in a Letter from the H^gue, dated i ^th January N. S. 1743.
inclofes fbitte Obfervations and Experiments drawn up by
Mr. Trembley (the young Gentleman mentioned p. 97.
as the ilril Difcoverer of the Singularity of this Infedl, wh®

now

Animalcules in IVaters.

Upon the Whole, this Animalcule appears
to be Ibmewhat of the Sta?'-Fijh Kind, or
between that and the Sea-Majhrooni^ or
Anctnone : which is a little Animal found

frequently

row refides in Holland) and Mr. Bentinck adds, that he
can anfwer for the Trutii of the Facts therein contained, as
there is rot one ol them but what he has fcen repeated above
twenty times.

Mr. Tremblev gives a Drawing of the Polype, with
eleven Horns, or Arms, and adhering to the Tail by a little
Twig, but in all other Refpeds exadly conformable to Fig.
IV. and V. Plate IX. Fhe Horns, he fays, ferve for Legs
and Arms, and at the End whence they come out, is a Mouth
or Paflage into the Stomach, which extending the whole
Length, forms a Body like a Pipe or Gut, open at both
Ends. He knows two Species, and has feen fome flretch
their Bodies to an Inch and half in Length, but that is rare ;
few, even of the larger Kind, being above nine or ten Lines
long : and fuch can contract themfelves to not above a fingle
Line, flopping, if they plcafe, at any Degree, between the
utmoft; Contradion and the utmoft Extenfion. Their Horns
differ lo Length according to the Species: one Sort can ex-
tend them feven Inches: Their Is umber of Horns is alfo
different, but a full grown Polype has feldora lefs than fix.

They don't fwim, but crawl, either upon the Ground, on
aquatic Plants, Pieces of Wood, Leaves, i^c. all which are
to be taken from the Bottom, Surface, Edges, or Middle of
Pitches (when we hunt after thefe Animals) and put into a
Glafs of clear Water; where, after a little Reft, if there be
any Polypes, they will be feen to extend their Arms, which
they contracted upon being difturbed.

Their common Pofture is, to faften their Tails to fomething,
and then extend the Body and Arms into the Water : and
they make ufe of their progrefhve Motion to place themfelves
coveniently for this Purpofe. Their Arms are fo many
Snares, Itretched out to catch fmall Creatures in the Water :
and when any Infed happens to touch an Arm, it is caught^
and convey'd to the Mouth by the contradting of that Arm,
or if the Creature ftruggles the other Arms affill.

They are voracious .Animals: A Polype can fwaiiow a
Wcrm, whole, twice or thrice its own Length. If the Worm

H 3 comes

Animalcules in Waters.

comes Endways, it is fwallowed in that Manner, otherwife It
goes down double, and makes feveral Foldings in the Sto-
mach, which dillends wonderfully for its Reception. The
Worm foon dies there, and after it has been fqueezed or
fucked, is voided by the Mouth. They eat more or lefs,
feldomer or oftenerj as the Weather is hotter or colder, and
grow in Proportion to what they eat : they can live whole
Months without Food, but walle proporcionably to their
Falling.

He fays, the Account (in the VhilofophicalTranf anions be-
fore quoted p. 95.) of the Manner how thefe Infeds multiply,
is true and exatl, and the more one fearches into it, the more
evidently it will appear to be done by a true Vegetation. The
Fulype brings forth its Young from the exterior Parts of the
Body, and that not always a fmgle young one at once : it is
common to fee 5 or 6, nay fometimes 9 or 10 at the fame
time ; and when one drops off, another comes in its Place.

For two Years, thoufands of them have been under his Eye,
but he could never obferve any thing like Copulation amongft
them. And left it fhould happen in fome fecret manner be-
tween the Old and Young, he has feveral times cut off a
young one from its Parent, and kept it in a Glafs alone ;
notwithftanding which it bred vtxy plentifully. And that no
Copulation might poiTibly be performed between the young
ones themfelves, he has cut them off, one by one, as they
fprouted out, and has kept each of them alone, and that for
feven fucceffive Generations, but without finding any Diffe-
rence as to their Tncreafe. He has likewife feen a Polype
bring forth young ones, and thofe again producing others,
before the fird has been feparated from its Parent. They
anultiply more or lefs in proportion to their Feeding, and
the Warmnefs of the Weather.

But the moil amazing Part of Mr. Tremble y's Account,
is, what he tells us, concerning his Operations on thefe Crea-
tures. If one of them be cut in two, tranfverfiy, the Fore-
Part, which contains the Head, Mouth and Arms, lengthens
itfelf, creeps, and eats, on the very fame Day. The Tail-
Part forms a Head and Mouth at the wounded End, and
Ihoots forth Arms, more or lefs fpeedily as the Heat is fa-
vourable. In Summer they will be fhoc out in 24 Hours,
and the new Head perfected in a few Days.

Cut a Folyfe where or in what Parts you pleafe, tranf-

verfly, each Part becomes a compleat Polype. But being too

fmaii an Animal to admit of being divided into ir.any Parts an

^ once.

Animalcules in Waters.

once, he firft cut one into four Quarters, and let them grow ;
then divided each Quarter, and proceeded fubdividing, till
he obtained fifty out of one: and has flill by him fevcral
Piece, of the fame Pclype thus cut above a Year ago, which
have produced Numbers of young ones.

Jf a Polype be cut the long Way, through the Head, Sto-
mach and Body, each Part is half a Pipe, with half a licad,
half a Mouth, and fome of the .'^^rms at one of its Ends.
The Edges of thefe half Pipes gradually round thcmfeivcs,
and unite, beginning at the Tail-End ; and the h:il Mouth
and half Stomach of each becomes compleat. All this he
has 'icitw done in lefs than Hour, and tiie f.vo Po/ypcs thus
formed difFer'd nothing from who^eones, but in havin*'- fewer
Arms; which Defe6l a few Days fupplied. A Polype has
been cut, lengthways between 7 and 8 in the Morning, and
between 2 and 3 in the Afternoon each Part has devoured a
Worm as long as itfelf.

Cutting a Polype, lengthways, through the Head and Body,
but not quite through the Tail, in a fhort T'ime there will be
two perfect Heads and Bodies with but one Tail : which
Heads and Bodies may, foon after, be again divided in like
manner: and thus Mr. Tremble y fays, he has produced a
Polype with feven Heads and Podies conjoined by one Tail,
Thefe feven Heads being cut off at once, feven others grew
in their ftead : and each of the feven Heads fo cut off, put-
ting forth a new Body, became a compleat Polype.

He cut a Polybe^ tranfverlly, afunder, and putting the tu-o
Parts clofe together, they united where they had been cut.
The Creature eat the next Day, is grown fince, and has mul-
tiplied. The Fore-Part of one Polype united in the fame
manner to the Hind Part of another. This compound Ani-
mal eat likewife the next Day, and has fi nee produced voun?^
ones from each of the Farts that formed it. But thefe two
Experiments don't always fucceed.

'Twas And before, that the Body of a Polype is a fjrt of
hollow Gut or Tube : this he has found means to turn inHde
out, as one may turn a Stocking; and has feveral, at prcfcnr,
by him, whofe Infides remain to be their Outfides ; notwith-
ftanding which, they eat, grow, and multiply, as if nothing
had been done to 'em. He has repeated all thefe Experi-
ments feveral time?, with the utmoll Precaution, Affiduiiy
and Attention ; and might appeal, he fays, to the Qua'icy
and Number of the Perfons who have feen them made by
him, as well as of chofe who have made the fame thenifclvcs.

H 4 He

^Animalcules in Wafers]

Hp adds, that in the Hiftory of the Polype, which he has \^
Hand, 'all the Methods and Contrivances ufed by him in his
Obfervations will be defcribed, but even before its Publication
he is ready and willing to communicate any Information that
may enable others to perform the like.

Mr. Reaumur, Fellow of the Roy^l Academy of Sci-
^ences in Tra^ice^ declares (in the Preface to the fixth Volume
of his Hijiory of InfeBs\\x^ publifhed at Paris) that he has re-
peated all Mr. Tremb ley's Experiments, not only by him-
felf, but with Mr. Jussieu and feveral others of the faid
Academy, and found them fucceed as they had done in Hol-
land, of which he gives a general and fuccind Account.
When firft he faw tv/o compleat Animals forming themfelves
from the Parts of one Polype cut afunder, he knew not, he
fays, how to believe his Eyes ; and he can't yet behold it,
without new Amazement, tho' he has feen it an hundred and
an hundred times. He adds, that the Curious in France (oon
began to try if other Creatures might not be found with the
fame extraordinary Faculty. That Mr. Bonnet foon dif-
cover'd a liendgr Water- Worm about one Inch and half long,
that had the fame Property; and Mr. Lyonett found
another above three Inches long and the Thicknefs of the
treble String of a Violin, which being cut into thirty or forty
Farts afforded the fame Phaenomena,

Mr. Reaumur imagining that fome Sea Productions,
whofe Shape fomewhat refembles this Frefi-Water Polype,
fuch as the Vrtica; marin<£ and Star-Fijh, might have the
like Faculties, engaged Mr. Guettard and Mr Jussieu
to make Variety of Experiments on the Coafts of Poiclu and
No7'mandy, They broke and cut Star-Fijh into feveral Parts,
and had the Pleafure to fee the feveral Parts continue alive,
and their Wounds cicatrize and heal : and tho' they could
not Hay long enough in tlit Country to fee new Parts fhoot
forth inllead of tho fe cut away, Mr. Gerrard de Vil-
iARS has feen the Urtica on the Coafts near Rochelle repro-
duce all the Parts cut off, and the Star-FiJh putting forth
new Radii in the room of thofe they had been deprived of.
When the Fiihermen faw Mr. Jussieu tearing and cutting
cue of thofe Animals in Pieces, they told him, 'twas Labouc
in vain, he could not kill it ; Experience having taught theni
what Men of Learning had never fo much as heard of.
Mr. Reaumur and Mr. Bonnet found alfo fome forts of
Earth- Worms, which being cut in two, each half had all it^
PefiCicncies reproduced after fome Months. Many indeed

dicd^

Animalcules hi Wafers'. 99

frequently on the Coaft of Normandy *.
They arc fcen fticking on the Declivity of
Rocks ; fome red, fome green, and fome
of otlier Colours : where they look like
Muflirooms while fliut and folded up, but
hke Anemonies when they open and dilplay
themfclves. There is no opening them by
Force without dcftroying them ; but on
Preffure they fometimes ejecft feveral young
ones of different Sizes : which feems to prove
them both Male and Female, and alfo to be

viviparous.

died, but as fome fucceeded, the Mifcarriages mud be im-
puted to want of Care, and not to the w^nt of fuch an Abi-
lity in thefe Animals.

It may, perhaps, be expelled of me, to add here fome far-
ther Relation of this extraordinary Creature j as 'tis well known,
by many, that for a Year and half part, great Numbers of
them have been continually under my Examination ; but hav-
ing lately publilhed whatever I can atteft concerning it from
my own Knowledge, under the Title of An EJfay tcixarcis a
"Natural Hi jl or J of theVoi.wz ; (v\ herein I defcribe their dif-
ferent Species, the Places where to feek and how to hnd them,
their wonderful Production and Increafe, the Form, Struc-
ture, and Ufe of their feveral Parts, and the Manner they
catch their Prey; with an Account of their Dijeajcs and Cures,
of their amazing RefroduSiion after being cut in Pieces, of the
beft Methods to perform that Operation, and of the Time
requifite to perfedt the feveral Parts after being divided : and
alfo full Directions how to feed, clean, manage, and prefcrve
them at all Seafonsofthe Year: likewife 2. Cou)-fe of real
Experiinevts^ perform'd by cutting them every Way that can
be eafily contrived ; lliewing the daily Progrcfs of each Part
towards becoming a perfed Po'rpe; the Whole explained
every where by great Numbers of Figures, and intermixt
throughout with V2ix\tly oi Obfernjations and Experiments ;)
I muft refer my Reader to that Effay ; as an Abftrad tiiereof
vould not only over-fwell this Volume, but bkwile prove an
Injury to thofe that have bought the former two Editions.
* Vid. Spe^acle de la Nat, Part II. Dial. -2.

loo Animalcules in Wafers,

viviparous. If you loofen their Hold, carry
them away, and keep them in Water, they
will fix themfelves to the firft convenient
Place they find. When the Sea-Mii/hroom
is about to open, it raifes itfelf, and thrufts
out two little white and ftriped Bodies like
Bladders, round which appears a great Va-
riety of Points or Trunks of different Sizes
and Colours ^ whence fome Naturalifts have
called it the Sea- Anemone, This Opening,
not unlike the blowing of a Flower, has
inclined others to look upon it as a fort of
Plant, or elfe as partaking both of the Ani-
mal and Vegetable Nature. But fince all
thefe little Points or Studs are not Leaves, but
a fort of Snouts or Trunks, through which
this Creature fucks in itsNourifhment, as the
Sea-Urchin and Star-Fijh do thro' their fine
Reeds or Prickles, we can't deny it a Place in
the Rank of Animals -, and efpecially after fo
remarkable a Circumftance (confirmed by
ocular Teilimony) as that of three or four
young ones iffuing from the Parent upon
fqueezing it.

There is a fort o? Star -Fiji:) ^ called by
RoNDELETius, p.t 121. Stella ArborefcenSy
which from a Body fomewhat like the Sea-
Urchin^ fends out five Branches in Form of
a Star : thefe five divide into ten, thofe ten
again into twenty ; the twenty into forty,
the forty into eighty, the eighty into one
hundred and fixty : the one hundred -and

fixty

j^nimalcuks t?i Waters. i o i

fixty into three hundred twenty ; the three
hundred twenty into lix hundred forty; the
fix hundred forty into one thoufand two
hundred eighty ; the one thoufand two hun-
dred eighty into two thoufand five hun-
dred fixty ; the two thoufand five hundred
fixty into five thoufand one hundred twenty ;
the five thoufand one hundred twenty into
ten thoufand two hundred forty ; the ten
thoufmd two hundred forty into twenty
thoufmd four hundred eighty -, the twenty
thoufand four hundred eighty into forty
thoufand nine hundred fixty; and thofe
again into eighty one thoufand nine hundred

twenty. The farther Divifions could not

certainly be traced ; tho' probably, when
the Fifh was alive, they might have been
diftinguifli'd much beyond this Number -}-.
All thefe flender Threads, thro' their whole
Length, have minute Clafpers ififuing from
them, and appear very amazing when exa-
mined by the Mi cr of cope.

To conclude this Chapter. — If the fmall-
eft living Creatures that have been yet dif-
covered are produced in theWaters, in them
we find alfo the largeft and moft monftrous.
NoBird orBeaft comes near the Size of many
Kinds of Fifnes, nor can the Elephant itfelf
be brought in Comparifon with the Whale.

f Vid. Philo/o^b, Tranjail. Numb. l"].

Joan-

J 02 ^Animalcules in Waters,

Joannes Faber Lynceus alTures us,
that in the Year 1624, he faw himfelf a
Whale, that was caft upon the Shore near
Santa Sever a^^ about thirty Miles from Rome^
ninety-one Palms in Length, and fifty in
Thicknefs : its Mouth was fixteen Palms
long and ten high, and being opened and
kept gaping, a Man on Horfeback might
therein find Room enough. Its Tongue was
twenty Palms, that is, about fifteen Foot in
Length. He adds, that four Years before,
another Whale was thrown afhore near the
Ifland of Corjicay not far from the Coafl of
Italy ^ which, being a Female, was found big
with a Cub thirty Foot long, and fifteen
hundred Pounds in Weight. He fays, the
Carnea Pinguedo [Lard or Fat] only of the
Parent Whale, weighed One hundred and
thirty five thoufand Pounds.

Let us now refleft how amazing the Dif-
parity between fuch a Fiih as this, and a
minute Animalcule lefs than the thoufandth
Part of a Grain of Sand in Bignefs ! How
innumerable muft the Kinds of Creatures be,
that form the Progreffions from one Size to
the other ! And how equally wonderful does
the Hand of Providence appear, whether it
adtuates an enormous Mountain of Matter,
©r enlivens an Atom 1

C H A P^

[ 103 ]

CHAP VI.

An 'Examination of the Blood /;/ Anhnahl

WE cannot employ the Microfcope to
any more ufeful Purpofe, than to
view the natural Courfc of the Blood within
its Veffels, or examine the Contexture of it
when extra(5led from them : for the Prefer-
vation or Reftoration of the Health of Man
may be greatly adv^antaged by fuchEnquiries.

By feeing it within the Veffels, we may
judge of the Situation, Dimenfions, Arrange-
ment, and Ramifications of the Arteries and
Veifis through which it pafTes, together with
the general State of the Fluid, the Degree of
Its Impulfe, ProgrefRon, or Motion, and
the Tendency or Direction of its Current
paffing through them.

When taken from the Veffels, w^e can
examine it more minutely, and obferve all
the little Alterations that may happen in the
Mixture, Size, Form, and Quality of the
Particles compofing its more folid or more
fluid Parts.

. I fhall now fhew how the Micro/cope may
be employed in both thefe Ways ^ but think,
proper to premife a fhort Account oftheBIooJ
itfelf, fincc our Knowledge of that will the
better enable us to make a right Judgment
when we come to fee it circulate.

CHAP.

[ I04 I

CHAP. VIT.

Some Account of the Blood, as exammed
by the Microscope.

TJU MAN Blood, and the Blood of Land-
^•^ Animals^ is found by the Microfcope'
to confift oi round red Globules floating in
a tranfparent Water and Serum. Each red
Globule is made up of fix fmaller and more
tranfparent ones : and Mr. Leeuwenhoek
has difcovered, that each of thefe again is
compofed of fix Globules fl:ill more minute
and colourlefs : fo that every common red
Globule is compounded of at leafl: thirty-
fix fmaller ones ^ and perhaps the Divifion

;r

*

may ftill go on much farth(

The fpecific Gravity of thefe Globules is
fomew^hat more than of the Serum wherein
they float, as is fhewn by their fubfiding in
Blood extradied from the Veins and at reft :
They have alfo a confiderable Attradion to
each other, and when brought in Contadl,
cohere fo ftrongly (unlefs foon feparated
again by Motion) as to form a Subftance re-
fembling foft Fiefh.

'Tis not difficult to imagine^ how fix foft
and flexible Globules, eafily compreffible
into any Shape, may compofe one larger
Globule : but to make it the better under-

* /7^. Leeuwen. Arc, Nat, Tom. IV. pag. 12.

flood.

f*^- -lt>^

J-Vi^.J ./i. JO^f.

^Vy. 2f./i.j,.^

ooo o OOOO o o

> o o o o

Poooosooooo

OttOOoOOO

oooooooo

JF/j^ .J£^.yi.^uo

° "o^ 0 ooooooooooouoooooo
5.2^o»<,oooaoooooooooooo

■ .fljtp-o O 0 o o o o o

ooo OOOOOOO"

ooooooooooOooo

vOOO o oooo oooo oooo

ir-i A-oo..ojyoo

J^/^^. r./i.^3Ji

Fcff.I./. / /

^y. JT./ ^

:Fi^. T./i.^3j.

Some Account of the Blood. 105

flood, I fliall borrow two Draughts from
Mr. Leeuwenhoek.

Fig. I. Plate X. fliews one fuch large
Globule, wherein five of the fmaller fort
that compofe it appear in Conta6l, the fixth
lying behind.

Fig. II. fliews, how by their mutual At-
tradtion to, or Preflure againft each other,
they readily unite to form a perfed: round
Body.

It is alfo eafy to conceive, that thefe li?r
Globules, and even the more minute ones?
ftill whereof they are compounded, may
occafionally be feparated, in order to pafs
thro' fuch extreamly minute Veflels as with-
out Separation they cannot poffibly enter ;
and may re-unite when they meet again in
Veflels where they have more Room. And
we are very certain, that fometimes they
cohere, in greater Numbers, and form larger
Mafles than are conliftent with a free and
healthy Circulation.

Mr. Leeuwenhoek and Dr. Jurin af-
ter the moft accurateAdmeafurement, by the
Way defcribed pag. 46th, agreed, that the
Diameter of a common red Globule of hu-
man Blood is equal to the 1^ one thoufand
nine hundred and fortieth Part of theLeno;th
of an Inch. Mr. Leeuwenhoek before

% Vide Philof.ph. Tranfaif. Numb. 1 06.

this

106 Some Actount of the Bloods

this had computed that ^f- twenty five thou-*
fand of them were but equal to a Grain of Sand ^

Suppofing, then, the Blood, in People of
found Health, to confift of Globules of fuch
Size and Compofition as before mentioned,
foft, flexible, and eafily feparable ; it mufh
neceffarily happen, that a confiderable Alte-
ration in any of thefe Particulars will occa-
lion a morbid State. — Should the Globules^
forlnftance, be divided too minutely, and not
readily again cohere ; fhould they become
rigid and unfiexible, either when feparated or
united^ or fhould they coagulate and become
infeparable, bad Confequences muft enfue.

The great Boerhaave fays, that Health
confifls in an equal Motion of the Fluids, and
an equal Refiflance of the Solids. Now the
Fluids move equally when their Force is not
greater in one Part than in another ; and the
Refiflance of the Solids is equal, when they
comprefs the Fluids every where fo equally
that no Senfe of Pain arifes.

But when the Globules of the Blood co-
here in MaiTes too large, and will not eafi-»
ly be fo feparated as to pafs freely thro' the

*f- If the Diameter of one thaufand nine hundred and
forty Blood -Globules be equal to the Length of one Inch;
and if, as Geomctriciajzs demonftrate. Spheres be to each
other as the Cubes of their Diameters, it muft neceffarily
follow, that a Sphere whofe Axis is one Inch in Lengthy
muft be equal to feven thoufand three hundred and one mil-
lions, three hundred and eighty-four thoufand foch Globules.

4 minutefl;

Some Acccwit of the Blood. 107

hiinuteftVeffels, the Force of the Fluid muft
there be greater, and confequently unequal ;
the Refiftance of the Solids muft alfo be
thereby increafed, and rendered likewife un-
equal : whence fome Diftemper muft arife;
If, on the other hand, the Globules are
broken, or feparated into fmallerMaffes than
the natural Standard Size, they will take up
more Room than they did before ; and, be-
ingcrowded too abundantlyinto the capillary
VefTels, will occaiion Diftenfion, Uneafinefs^
and perhaps a partial Stagnation there :whilft,
in the larger Veffels, the Current rolls along
with too great Rapidity, the Force of the
Fluids, and theReliftance of theVeflels are
both rendered unequal, and theBallanee be-
tween the Solids and Fluids is entirely over-
turned. None of the Secretions in this State
can duely be performed, and unlefs fome
means -be found to reftore the Equilibrium,
the Event muft foon be fataL

I believe it will be allowed, that v/herc
One Perfon dies from a Diforder in the con-
taining VefTelSjTwenty mifcarry by fome un-
natural Alteration in the Fluids that pafs
through them: and therefore if we can find
what their natural State is, theMeans where-
by it may be preferved in fuch State, by
what Accidents it may be prejudiced, and
how it may be reftored, our Pains will be
\vell employed.

I In

io8 Some Account of the Blood,

In order to obtain this ufeful Knowledges
it will be neceffary to examine the human
Blood and other Juices, frequently, with the
MicrofcopCy in every Condition, and under
every Diftemper, as well as in a State of
Health : by which we fhall have ocular De-
monftration of its different Appearances in
each State, and of the Changes it undergoes ;
iand byExpcriments of various Mixtures with
it, may poffibly difcover by what means it
can be altered from one Condition to another;
as from a thin and broken to a more firm
and confiftent State, and fo on the contrary.

Would our learned Phyficians, who are
beft able to judge of fuch Matters, be indu-
ced to take this Method into their Pradlice^
it is reafonable to believe, that in a few
Years the Caufes of Difeafes would be better
known, and the Art of Healing brought to a
much greater Certainty than it is at prefent.
An Obfervation of Mr. Leeuwenhoek is
very well worth regarding : he took notice,
that when he was gready diforder'd, the Glo-
bules of his Blood appeared hard and rigid,
but grew fofter and more pliable as his
Health returned : Whence he infers, that in
an healthy Body it is requifite they fliould
be foft and flexible, that they may be capa-
ble of paffing through the capillary Veins
and Arteries, by eafily changing their round
Figures into Ovals, and alfo of re-afliiming
their former Roundnefs when they come in-
to Veffels where they find larger Room.

Some Account of the Blood. 109

Changes are produced in Fluids furprizing-
\y and fuddcnly, as a very few chymicai Ex-
periments will demonflrate : the Bite of Fe^
no /nous Great are s^ and Lioculating for the
SjnallFox^ fliew likewife, how minute a
Proportion of poifonous Matter will conta-
minate the whole Mafs of human Blood j
which can no otherwife be effecfled but by
altering the Solidity, Figure, Size, or Motion
of its component Parts or Globules. And it
is probable, that in many Cafes, it may be
changed from a morbid to a healthy State,
by ways not lefs eafy, could we be fo happy
as to find them out: for we cannot reafon-
ably fuppofe, that the beneficent Author of
Nature has given more certain and ready
Means of doino; MIfchief than of doino-Good,

Many Diflempers might perhaps be cured
by an immediate Admiffion of fome Medi-
cine into the Veins, v/hich elude the Power
of all that can be taken by the Mouth. For
the Stomach, by its Heat, its Adtion, and a
Mixture of its Juices, works fuch an Altera-
tion in things, before they can be admitted
into the Blood, that they are unable to pro-
duce the fame EfFed:s as if they were receiv-
ed into it fimply and unchanged.

Some Trials that have been made already,
may ferve in a great meafure towards con-
firming the above Suppofition. Dr. Fabri-
cius injedled with a Syphon into the Median
Vein of a Soldier's Right Arm, in the Hof-

I 2 pital

iio Some Account of the Blood.

pital at Dantzick *, about two Drams of a
certain Purgative Medicine, which in about
four Hours began to operate, and gave the
Patient five Stools. His Cafe was Venereal,
and in fo terrible a Manner, that there were
Nodes on the Bones of his Arm. But by
this fingle Injediion, and without any other
Medicine, the Protuberances gradually dif-
appeared, and the Difeafe was quite cured.
He like wife injected into the Vein of a mar-
ried Woman, thirty-five Years old, and trou-
bled from her Birth with Epileptic Fits, a
fmall Quantity of a purging Rozin diflblved
in an Anti-Epileptic Spirit : this occafioned
a few gentle Stools 5 after which the Fits
were lefs violent every time than other, and
in a fhort time returned no more at all.

Dr. Smith J, of the fame City, injeded
Alteratives into the Veins of three Patients ;
one was lame with the Gout, another ex-
ceedingly Apople(fl:ic, the third afflidled with
that ftrange Diftemper called the Plica
Tolonica \ and they were all cured by the
faid Injed:ions.

S. FraCassati injefted Aqua Fortis into
the jugular and crural Veins of a Dog, which
4ied immediately. The Blood was found
fixed in the fmaller Veffels, and the larger
Veffels burfl. Whereupon he remarks, that
as an Apoplexy is caufed by a Coagulation of

* Philofoph. Tranfad. Numb. 30. % Ibid. 39.

the

So/?ie Account cf the Blood. 1 1 1

tlie Blood, it may probably be cured by fome

Dijjohcnt injected. Another Dog, in

whofe Veins Oil of Vitriol was injecfled, com-
plained a great while, foamed like Epileptics,
breathed Hiort, and died. His Blood was

fixed and grumous, refembling Soot. Oil

of Tartar was injedied into a third Dog,
who after much bemoaning, appeared fwell'd,
and died. His Blood was not in the leaft
curdled, but thinner and more florid than
common. This proves too great a Sepa-
ration as well as a Coagulation mortal.

Mr. Boyle found, that by putting a little
Aqua Fortisy Oil of Viti'lol^ or Spirit of
Salt into warm Blood, it did not only lofe
its pure Colour and become dirty, but in a
Moment was coagulated; whereas urinous
Spirits abounding in volatile Salts, fuch a^
Spirit of Sal Armoniac^ mingled with it,
did not curdle it, or debafe its Colour, but
made it redder, kept it fluid, and preferved
it a long while from Putrefadllon,

As the Microfcope has informed us of the
StruBure of the Bloody which without its
Help could never have been difcovered, and
as its continual Afliftance is needful to exa-
mine and diftinguifh minutely any Changes
that may be wrought therein, either for the
better or the worfe, by Accident or by Me-
dicine ; I hope this Difcourfe will not be
judg'd too long or foreign to my Subje(5l,

I 3 fiucc

J 12 Q/ ^oiewing the Blood

iince Hints of this Kind may prove highly
beneficial to Mankind, if they (hould be fa
fortunate to fall into the Hands of thofe who
are inclinable to purfue and improye upon
them.

I come now to defcribe the Manner of
bringing the Blood to a Arid: Examination
before the Microfcope^ and ihall offer fuch
Ways as I have myfelf experienced, not
doubting but the Ingenious will contrive
others, as they may find Occafian,

CHAP. VIII.

Of viewing the Blood with the Microfiope,

A K E (with the Tip of a Feather, or
,™ ^ ^oft Hair Pencil) a fmall Drop of
'war7n Blood immediately from the Vein :
fpread it, as thin as poflible, on the cleareft
fingle Ifinglafs placed on a Slider on purpofe^^
and apply it to the firft or fecond Magnifier :
the Globules will then be feen diftlnd:ly, and
a little Pracftice will enable to form a Judg^
ment of any Alteration that may happen in
the Size^ Figure^ Colour^ or Appearance of
them. We may alfo examine the Blood ex-
treamly well, by taking up a little of it in a
very fmall capillary Tube of the thinneft
Glafs, and then placing the Tube before the.

Magnifier.

If

ivlth the Ml cr of cope. 1 1 3

If a Drop of the fame Blood be diluted
with warm Water, and applied in either of
the above Ways, fome of the larger Globules
will appear more afunder, and a great many
of them will be.feen divided into the fmaller
ones which compofe them.

If fome of the fame Blood be mix^ed with
a little warm Milk, fevcral red unbroken
Globules will be {(ttw diflincftly 5 but thofe
that are again feparated into their fmaller
ones with be confounded with the Milk it-
felf, of which the greateft Part is nothing
elfe but Heaps of fuch like-fized minute
Globules. ■ -'"•

If we defire to try by Experiment what
Alteration any Liquor, either poifonous or
medicinal, can produce on the Contexture
of the Blood, the Liquor fhould be blended
with it at the very Inftant of its iffuing from
the Vein : for if the Blood be in the leaft
coagulated before fuch Mixture, no certain
Conclufions can be formed. Putting the
VefTel into which we receive it into a Bafon
of Water a little hotter than the Blood, will
preferve it longer fluid, and make our Ex-
periment by any Mixture v/ith it fucceed the
better. — I would alfo advife, to get your
Inftrument in perfeft Readinefs, by adjuft-
ing the Magnifier before the Vein is opened "3
and likewife to make your Obfervations in k
warm Place, left the Blood become congeal-
ed before you can finifh your Enquirv.

I 4 'la

114 Of viewing the Bkod

In all Enquiries of Confequence, it is bell
to draw the Blood from a large Vein : be-
caufe what we can gain (by the Prick of a
Pin or Needle) from the Finger, or any fuch
Part, iffues from fome extreamly minute ca-
pillary Veffels only, and perhaps is not fp
good a Sample of the Contexture of the
whole Mafso-- — Some Trials on both may
however not be amifs, to difcover v/hat Dif-
ference there is between them.

By mingling with the Blood the leaft imar
ginable Quantity oi xht poifo?ious Juice which.
iffues from theTeeth of a Viper when enrag-
ed, or from any other Animal ^ Vegetable^
or Mineral^ we fhall difcover its immediate
EfFecfl upon the Globules y and by conlider-
ing, that the Alteratioii we obferve is wrought
in it, tho' at reft, wp fhall be able to judge
and calculate what Confequences muft enfue
from fuch a Mixture with the Blood, as it
circulates through the Veins of a living
Creature.

Mr, William Cowper examining a
jBolution oi Opium with the Microfcope^ found
its diffolved Particles in the Shape of fringed
Globules : whence he concludes, that fuch
Particles circulating in the Mafs of Blood;^
may be fo entangled in its Serum, or thicken
it in fuch a Manner, as to retard its Velocity
when over- violent, and render its Motion
fcaim and equal ; whereby all painful Senfa-
4 tions

with the Microfcopc. ii^

tions will be taken off. And from the fame
Principles it is cafy to account for all its
other Effcds, and perceive how too great a
Number of fuch fringed Globules muft caufe
a total Stagnation of the Blood, and confe-
quently kill. Vid. Philof. Tranf Numb. 222.

Spirits, Oils, diffohed Salts, TinBiires,
Ejjences, and all other chymical Preparations
iurnifli us with numberlefs Subjeds of Ex-
periment ; and are certainly capable of pro-
ducing the moft fudden and amazing Ef-
fefe, either good or bad, if injeded into the
Blood-Veffels of living Animals : the Caufes
of which Effeds may in a great Degree be
difcovered and accounted for, by microfco-
pical Obfervations on Mixtures of them with
the Blood w^hen extracted from the Veins.

A little Blood being mixed with about
four Times its Quantity of * Sal Volatile
Oleofim, and viewed through a Microfcope^
there appeared an immediate Separation of
the Globules. In about the eighth Part of
a Minute fome of them were much dimi-
ni(hed, and in a Quarter of a Minute many
of them were much diffolved and entirely
difappeared. Sometimes twenty Globules
were k^w near together, which foon leffen'd
to eighteen, then to fixteen, and became
fewer and fewer till only two or three were
left. Whence it is probable, that Sal Fo-

* Jrcan. Nat. Tom. IV. p. 36.

latilf

J 1 6 Of viewing the Bloody &c.'

latile Oleofum taken with the Food, and fa
carried into the Ladeals and Blood-Veffels,
may retain its Power of preventing fuch Co^f
agulations as would otherwife happen.
„,<5'.The Urine y Saliva ^ Semen ^ Sweaty Fences
Jilviy and all other Animal JuiceSj are like^
wife Objeds for the Microfcope, to be exa-
mined either alone, or mixed with the
afprefaid Liquors : whence much ufefu|
Knowledge may be acquired.

As to Colour in the Blood, a Blacknefs
arifes in it from a Deficiency of Serum^ as
Palenefs does from too great an Abundance
of it : for it will be always found, that when
Globules cohere together in too great Num-
bers they give a black Appearance. When
this therefore is the Cafe, pieans of diluting
fhould be found out, and made ufe of; fince
it is abfolutely requifite to Health, that the
Globules of the Blood fhould float in a due
Quantity of Serum, andbe thereby circulated
freely through the minuteft Veffels, a con-
trary State to which has proved the Death of

thoufands. Mr. Leeuwenhoek tell^

us, that whenever he found his Blood too
deep coloured, his Way wa,s to drink four
Piihes oi Coffee in a Morning, in the Room
of his ufual two -, and fix Difhes of T^ea y^
the Afternoon, inftead of three. He drank
it as. hot as poffible, and went on in this Man-
ner, till he perceived his Blood grow paler, and
confequently its Globules farther feparated.
A OH A P.

C H A P. IX.

The CiRguLATioN of the Blood.

IN order to view the Blood circulating
through its Vejfch^ we mufl: make ufe of
fuch fmall Creatures as by their Tranfpa-
reiicy permit us to look within them, and
lee what pafles there : for, in a Man, or any
of the large Animals, the Skin is fo opake,
that we cannot difcern even the fine Blood-
Veffels themfelves, and much lefs the Cur-
rent that runs along them. Our Informa-
tion, however, will not be greatly different ;
for the whole Animal Creation is eflablifliecj
on one and the fame Plan, and the Circu-
lations in the meanefl living Creature are
carried on through Veffels of a like Structure
(in the general) and are accelerated, or re^
tarded, by the fame Caufes as in the nobleft.
And, in Truth, as to the Circulations of
the Fluids, and the Motions of the Bowels,
the Brain, or any of the internal Parts,
more Knowledge may be gained by infpe61:-
ing Infects and fmall Animals with the Mi-
crofcope^ than by the moft fkilful and curious
Diffed:ions, or anatomical Experiments oa
larger Subjedls. For the Skins of fome of
thefe little Creatures are fo tranfparent, that
we may fee plainly through them the Order
and Difpof^tioi> of the Veffels underneath ;

and

1 1 8 The Circulation of the Blood.

and the Coats of thefe Veffels are, again, of
fuch an amazing Thinnefs and Delicacy of
Contexture, that they are little or no Impe-
diment to our View of the fecret, tho' re-
gular. Operations of Nature, and the Laws
ihe adls by, when undifturbed and quiet ;
whereas our Diffedlions of larger Animals,
while alive, may fhew her at work, indeed,
but in fuch Confufion, by our breaking in
upon her violently, that all her Motions, then,
muft be in great Diforder, and confequently
uncapable of affording any fatisfadtory Infor-
mation as to the Circulations.

In this Sort of Creatures too, after view^-
ing, as long as we think fit, the natural *and
regular Current of the Blood, as it is carried
on in a State of Health ; we may by Pref-
fure, and feveral other Ways, impede, di-
fturb, and divert its Courfe ; and may find
Means, by various Mixtures with it, of in-
ducing a morbid State 3 and at laft, by let-
ting the Creature dye before our Glafs, we
may perceive all the Changes it undergoes,
and what occafions the intermitting, vibrar
ting, trembling Pulfe of expiring People. '

In feveral of thefe little Creatures we can
not only fee the general Courfe of the Blood,
but are able perfectly to diftinguifh the Fi-
ssure and Circumftances of the Globules
whereof it is compounded, and the Altera-
tions they fuffer, when they pafs out of the
larger into the more minute veiTels. For

many

7he Circulation of the Blood. 119

many of the Veflels are fo fmall, that even
iingle Globules cannot pofTibly find a Paffagc
thro' them without being comprelTed into
oval Shapes : and yet thele Veflels are large
in Comparifon of the fineft Veflels of all, to
pafs through u^hich, the Globules muft be
divided and fubdivided into their fmallefl: and
moll minute component Globules.

'Tis amazing to obferve, how careful
Providence has been to prevent the Elood
from coagulating, or cohering in Mafles dan-
gerous to Life, by the very Difpofition of
the Veflels it runs through : which, whether
feparating or uniting, are fo contrived, as to
caufe the Globules to come frequently toge-
ther with a brifk Collifion, or ftriking
againft each other. The A?'teries^ for Ex-
ample, which convey the Blood from the
Heart to the Extremities of the Animal,
and in their Progrefs continually lefl^en their
Diameters, and divide into fmaller Branches
almofl: ad infinitum : in thefe Arteries^ I
fay, at every fuch Divifion, many of the
Globules of the Blood mufl: rufli, with a
confiderable Force, againfl: an Angle direct-
ly in their Way ; whence recoiling back on
thofe immediately behind, they mufl: fl:rike
upon one another, and caufe a kind of
Commotion, ere the Current can divide
readily into the two fmaller Branches. See
Fig. III. Plate X. In the Feins^ which^

OQ

J20 Of viewing the Current

on the contrary, return back the Blood front
the Extremities to the Heart, whofe Dia-
meters enlarge as the Tide rolls along, and
whofe fmall Branches are continually unit-
ing and making larger Veffels, till at laft
all their Streams fall into one 3 here, at.
every Conjun(ftion of two Branches, their
Currents rufli againft each other with Vio-
lence : by which Concuffion unnatural Co-
hefions are broken, or prevented \ and of this
the Microfcope can afford us ocular Demon-*
ftration. Vide Fig. IV,

CHAP. X.

Of viewing the Current and the CiRCU*
LATioN of the Blood.

BY the Current of the Blood, I mean, its
fireaming or pajfing on either from of
towards the Hearty through any Vefet^.
whether it be a Vein or Artery.

By the Circulation I would be underftood
to intend, the Courfe or Current of it, from
the Hearty along the Arteries, to the Extre-
mities of the Body : together with its Return
by the Veins from the EiXtremities back again
towards the Heart.

Both thefe the Microfcope can bring to
View J but the latter is fomewhat more dif-
ficult

-Pa</. !2J.

j'^.jr.^.(24.

and Circulation of the Blood. 13 1

ficult to be afllired of than the former ; for
when the Vcflcls before us are extreamly
fmall, it is not always eafy to diftinguiih
which of them are Veins and which are
Arteries.

The larger Arteries are indeed diflinguifli-
able by a Protrufion of the Blood at each
Contraction of the Heart, then a Stop, and
then a new Protrufion, which may plainly
be feen continually fucceeding one another :
whereas the Current paflTes through the Veins
with an equal and unintermitting Stream.
But in the more fine and extream Branches
of the Arteries this Difference is not perceiv-
able.

The tranfparent Membrane between a
Frog's hind-foot Toes is the Objc6l moft
commonly employed for viewing the Current
and Circulation of the Blood 5 and, in this,
if well expanded, it may be feen fairly and
diftin(5lly, both in the Veins and Arteries, in
the manner reprefented Plate XI. Fig. I.

A. A. two Toes of a Frog's hinder Foot.

B. the thin Membrane between the Toes^
extended.

C.C.C. the Trunks of the Arteries.

D.D. the Trunk of a Vein.

E.E.E. Arteries and Veins in the fine
Membrane, with the Blood-Globules circu-
lating through them.

The

122 Of 'viewing the Current

The Way of applying it to the Microfcopd
was defcribed Page 1 3 3 and therefore needs
not be repeated here.

The Tails or Fins of fmall Fifhes may
likewife be ufed very commodioufly to this
Purpofe, and prefent to view great Num-
bers of Veins and Arteries with the Blood
pafling different Ways through thenii

It Is difficult here in London to meet with
any Fifhes alive and proper for this Infpec-
tion, except Eels ^nd Flounders : either of
thefe will ferve however exceeding well 5

but the fmaller they are the better. Put

your Eel into a Glafs Tube fill'd with Water,
after wiping off its Slime, which would ob-
fcure your Glafs. Then having flopped
both Ends, to prevent the Water*s running
out, apply the Tail or Fin to your Micro-
fcope, and you'll fee the Circulation in a very
agreeable Manner. If you put not Water iii
your Tube, the Sliminefs of the Eel will im-
mediately foul the Glafs and prevent your
Pleafure.

The flat Figure of the Flounder will not
permit us to put it in a Tube as we do the
Eel^ or view it by every Kind of Micro-
fcope : but if a plain Piece of thin Glafs be
placed over the Hole, where Objedts are ap-
plied to the Double Refledling Microfcope,
its Tail may be fpread advantageoufly upon:
the faid Glafs : and by fetting a Book, or

feme-

and Circulation of the Blood, 123

fomctliing clfe of a proper Height to fupport
the Body of the Filli, it will lye in a very
good Pofition for View, and the Circulation
may be {^^\\ diftlncflly.

Eels and Flounders live a long while out
of Water, and are therefore mofi: ufeful for
this Service here at London -, but in the Coun-
try many Sorts of other fmall Fifhes may be
found much more tranfparent.

Mr. Leeuwenhoek informs us *, that
he faw, with great Admiration, in the ut-
mofl: Extremities of a very minute Fifli's
Tail, how the larger x\rteries were there di-
vided into the moft fine or evanefcent ones ;
and that many of the fmalleft Veins, re-
turning from the faid Extremities, met to-
gether at laft in fome larger Vein. There
appeared alfo in fome Veffels, fuch an Agi-
tation of that Blood (which was protruded
from the larger Arteries towards the eva-
nefcent Ones at the very Extremity of the
Tail, and returned afterwards through many
minute Veins into a large One) as hardly can
be conceived. In the larger Arteries he
could perceive a continual new Protrulion,or
Acceleration of the Blood's Courfe received
from the Heart ; but in the fhialler Arteries
the Motion feemed equable without any

• ArcQn. Nat. Tom. IV. Epift. 65,

K fuch

124 Q/" "viewing the Current

fuch repeated Propulfion : and though in the
minuteft Veffels there appeared no Colour,
yet in the larger Vein or Artery, though
near the End of the Tail, the Blood was
plainly red.

We cannot properly call any Veflel an
Artery farther than the Pulfation reaches ;
beyond that, and returning towards the
Heart, it muft be accounted a Vein : for
Veins are only Arteries elongated ; but as
they frequently divide into Branches that
evade Difcovery, it is, perhaps, impoffible
to determine exactly, where the Arteries end
and where the Veins begin.

They do not always, however, branch
out fo extreamly fine before their Inofcula-
tion or Communication with the Veins ; for
the. fame curious Obferver tells us, that on
each Side the little Griftles, which gave a
StifFnefs to the Tail of the Fifh abovemen-
tioned, he could fee a very open Communi-
cation of the Veins and Arteries : the Blood
running towards the Extremities through
Arteries, and returning back again through
Veins that were evidently a Continuation of
thofe Arteries, and of the fame Diameter
with them : And this he faw in thirty-four
different Places, in as many Arteries, and as
many Veins. The Manner whereof, as by
him delineated, is fliewn^ Tab. XL Fig. IL_

A» A,

and Circu/ation of the Blood. "12 5

A. A. rcprcfent two Arteries, one of
which runs on each fide a minute Griflle.

B. B. their open Communix:ation with the
two Veins C. C.

As this wliole Fifli was not half an Inch
in Length, how fmall mufl the Tail thereof
be, in which, notwithftanding, the Circu-
lation of the Blood was vifible in thirty-four
Places, and the Current of it in iixty-eight
Velfels ! and yet thefe VefTels were very far
from being the moft minute of all. How
inconceivable then muft be the Number of
its Circulations in an human Body ! Nor
need we wonder to behold it ifTuing forth
at every Prick of a Pin or Needle. Upon
confidering this, Mr. Leeuwenhoek adds,
that he is fully perfuaded, a thoufand diffe-
rent Circulations of the Blood are continual-
ly carried round in every Part of a Man's
Body that is not larger than the Breadth of
his Fore-finger Nail ^.

The Tail of a Newt, or Water-Lizardy
applied in a Glafs Tube, after the Manner
direded for the Eel, affords an entertaining
Profpe(ft of the Circulation through Num-
bers of fmall VefTels. But nothing can fliew
it finer, than an exceeding fmall -f- Nevot of

* Leeuwen. Arcan. Nat. Tom. pag. 169.
f Phil. Trarfaa, Numb. 288.

K z this

126 Of viewing the Current

this Water-Kind, which fometimes maybe
found lefs than an Inch long, and fo tranfpa-
rent, that the Blood may be feen running in
all Directions, not only through the Veffels
of the Tail, but throughout the whole Body:
And it is particularly delightful, to behold, in
the little Toes, the Stream thereof running
to the Extremity in one Channel, and return-
ing back again by another. Juft below the
Head are on either Side three Fins, or fome-
what like Fins, which, in fwimming, the
Creature makes ufe of to poife and guide its
Body : each of thefe appears by the Micro-
fcope divided, like Polypody^ into many point-
ed Branches : in any one whereof, as in the
Toes, the Blood is feen coming along an Ar-
tery to the Extremity, and then immedi-
ately returning towards the Heart again,
through a Vein that lies parallel, and almojft
clofe thereto, and with which, its Commu-
nication is very apparent. — As thirty or forty
of thefe Branchings prefent themfelves be-
fore the Eye fometimes at once, with the
Blood diftind:ly circulating in all, they afford
a charming Sight : and they may be viewed
by the third or fourth Magnifier : for the
Globules of 4:lie Blood in Newts are larger
than in any other Creature I have examined,
and are fewer in proportion to the Serum or
Water they float along in. To which I may
alfo add, that the Figure of them^ as they are

carried

a?2d CiracIafio7i of the Blood, 127

carried along the Vcflcls, changes in a moft
furpr hig Manner.

In Spring-time, if a little Fi'ogs Rpawn be
kept Ibmc Days in a Imall Quantity of the
Ditch-Water wherein you found it, you'll
be furniflied with a Number of exceedingly
fmall Tadpoles^ w^hich, when firfl they be-
gin to fwim, are almoft wholly tranfparent :
and if placed before the Microfcope, in a
Tube proportionably fmall, with fome Water
in it, you'll eafily difcern the Heart and its
Pulfition, together with the Blood circulat-
ing in every Part of the Body ; and, particu-
larly, in the Tail, more than fifty VefTels
prefent themfelves at one View.

Thefe Tadpoles become lefs clear every
Hour, and in a Day or two their Skin grows
fo opake, that the Circulation of the Blood
can be feen no longer, unlefs it be in the
Tail, or better ftill in the Fins, at the joiur-
ing on of the Head.

A fmall Miifcle taken carefully from its
Shell, and placed before the Microfcope on
an Ifmglafs, affords a View of many Arteries
and Veins, through which the Circulation
of the Blood may be very clearly ktx\ : and
one great Advantage in this Objedl is, that
it lies always quiet ; whereas moft other
Creatures are difficult to be kept ftill long
enough for Obfervation. The Motion of the

K 3 BI004

128 Of viewing the Current

Blood continues in it fix or feven Hours with
little Alteration : and, by moiftening it now
and then with fait Water, may probably be
continued much longer.

I can alfo affure you, from my own re-
peated Experiments, that if a large Mufcle
be carefully opened, and a Piece of the thirj
tranfparent Membrane eafytobe found there-
in be fnipped off with a Pair of fharp SciiTars,
and applied to the Microfcope, the Blood
will be feen paffing through Numbers of
Veins and Arteries -, and if the Extremity of
the Membrane be viewed, the true Circula-
tion, or the Return of the Blood from the
Arteries through the Veins, will be fhewn in
a delightful and fatisfadory Manner, and
continue for a long Time. There are like-
wife other tranfparent Parts of the Mufcle^
where the Paffage of the Blood is very dif-
cernable : And, as Mufcle s are to be got moft
times of the Year in Londony the Knowledge
hereof will, I hope, oblige the Curious.

We are told by Mr. Leeuwenhoek,
that in the fartheft Joints of the hinder Legs
of little ^ Crabs, he beheld the Blood circu-
late through the Arteries and Veins, with
greater Rapidity than he had ever obferv'd it
in any other Creature ; and, moreover, that
the red Globules thereof were twenty-five

5 Leeuw. Arc. Nat. Tom. IV. Ep. 84. Again Ep. 86.

times

and Circidatio7i of the Blood, 129

times fewer in Proportion to its Serum than
in any other Land or Water-Animal he had
ever before examin'd.

At the proper Time of Year, exceeding;
fmall Crabs may be found, in great Abun-
dance, under Stones and Brick-bats on the
Shore of the River T^hamcs^ when the Tide
is out: and as many of them are no larger
than a little Spider^ it is highly probable fuch
may be tranlparent in many Places of the
Limbs and Body; notwithftanding Mr.
Leeuwenhoek found his, which were an
Inch broad, opake every where but in the
extreameft Joints of the hinder Legs. Per-
haps too, they may appear more tranfparent,
if they are applied to the Mic?'oJcope in a little
Tube filled with Water, than if they are
viewed dry 3 for 'tis obfervable, that many
Objefts require a Tranfparency by being
wetted, in the fame manner as Paper be-
comes clear by being rubbed v/ith Oil.

The Blood may be feen circulating in the
Legs and Tails oi Sh7:'imps^ efpecialiy if view-
ed in Water; but then the Water muft
have a little Salt put thereto, or elfe they
will foon expire. Li Shri??2ps the Blood is
not red ; which has given Occalion to call
them as well as many other Lifeds exa?igueSy
ov bloodlefs : tho' in reality no living Crea-
ture is without Blood; for animal Life con-
fifts in a Circulation of fome Fluid through

K 4 Arter.

l^o Of viewing the Current

Arteries and Veins, and that Fluid, what-
ever Colour it may be of, is properly to be
accounted Blood. In Graf shoppers the Glo-
bules (which may be feen paffing through
the Veffels in their V\^ings) are green, and
yet I am apt to think, no body that vievs^s
them will heiitate to call them, with the
Serum wherein they fwim. Blood.

In the tranfparent Legs and Feet of feve-
ral fmall Spiders^ the Current of the Blood
may plainly be diftinguiilied both in the
Veins and Arteries: alfo in the Legs of very
fmall Pimices or Bugs it is remarkably vilible,
together with an extraordinary Vibration
of the Veffels, which I never have ob-
ferved in any other Creature. In thefe too,
if clear, as they may fometimes be found,
the wonderful Motions of all the internal
Parts will afford an agreeable Entertainment
to the Curious, and may be examin'd as long
and as often as they pleafe. For I have kept
a Bug alive, in a Slider between two Pieces
of limglafs, at leafl fix Weeks together, not-
withftanding it was confined fo clofe as to
be uncapable of flirrlng : and altho' during
that time, it often feem'd dead and motion-
lefs, when I placed it before the Microfcope
a little Warmth would fet the Bowels at
work again, and renew the -Current of the
Blood as briflcly as ever«

and Circulation of the Blood, 131

After many Obfcrvations made by Mr.
Leeuwenhoek on the Blood of Cocks,
Sparrows, Frogs, Trciits, Perch, Cod, Salmon,
&CC, he affirms, that the red Particles in the
Blood of Birds, Fijhes, and Water'AniinalSy
are conftantly *' flat and of an oval Figure,
that is, they are longer than their Breadth,
and appear as in Plate X. Fig. V. The fe-
rous Part of the Blood in Fijhes and Aquatic
Aitimals is alfo greatly more, in Proportion
to the red Particles, than it is in Beajis or
Men, and the Particles themfelves are larger :
fo that, by being bigger, and fwimming far-
ther afunder, they may be feen much better.

Mr. Leeuwenhoek obferved the Blood
circulating in the filmy Wings of a -j- Bat,
and likewife in its Ears, and found the Glo-
bules thereof perfecftly round : Wherefore,
allowing his Affertion, that in Fifhes and
Birds they are alway flat and oval, we need
no longer hefitate how to clafs this odd
Creature 5 but, notwithftanding its flying,
fliall pronounce it to be a Beajl,

He tells us, that Bats can fee as well by
Day as Night: but he fuppofes the Heat
and Drynefs of the Day-Air would fhrivel
up the thin Membranes of their Wings, and
confequently flop the Circulations there:

* Acr. Nat. Tom. I. Part II. p. 51. Again, Tom. IL
Epift. 128. Again, Tom. IV. Epiil. 65.
f Acr, Nat. Tom. IV. Epilt. 67.

whereas

132 Of viewtJig the Current

whereas the cool Dews of the Evening ren-
der them moift and pliable 3 which makes
them chufe that time to come abroad.

In viewing feveral of the Objeds here
mentioned, one fhall often obferve the Blood
pafTmg through Veflels fo minute, that the
Globules of it cannot glide along otherwife
than fingle, and fqueezed into oblong Forms :
yet an hundred of the red Globules of fuch
Blood, if placed clofe to one another in a
Row, would not equal the Length of the
Diameter of a large Grain of Sand -, and
confequently a Million of them exceeds not
a Grain of Sand in Bignefs *.

TheEffefbs of Heat and Cold upon the
Blood are well worth taking notice of: for
as Heat relaxes the Veffels, the Blood finds
more Room to move in, its Gloubles float at
greater Difliances, and it circulates more
freely : whereas Cold fo contracts the Vef-
fels, that the Globules are compreft toge-
ther, and the Blood is impeded, and in fome
Degree coagulated in the minute Capillary
Veins and Arteries of the extream Parts; as
is evident from the Swelling and Blacknefs
of the Hands and Feet when expofed to
fevere Cold.

* Leeuwen. Arc, Nat, Tom. I. Part I. p. 35.

Before

and CircuJ alien of the Blood, 133

Before I clofe this Chapter, I fliall briefly
communicate fome Experiments, I had the
Pleafure of making laft Summer, with my
jnoft ingenious and vakiablc Friend Docflor
Alexander Stuart, Phyfician to her late
Majefty, in order to view the Circulation of the
Blood by the Solar or Camera Obfciira Micro-
fcope, v^'h'ich. has the Advantage of magnifying
Objecfts beyond any other fort of Microfcope :
but muft refer the Curious to a more full
Account thereof laid by this Gentleman be-
fore the Royal Society, and which will be
publifhed in the Philofophical Tra?ifa6fio?is,

I muft firft defcribe a particular Apparatus,
invented by the DoSfor, for examining the
Circulation of the Blood in Frogs, Mice^
Bats J or any Creatures of the like Size. In
this Contrivance the Looking-glafs, Tube,
and convex Lens are juft the fame, and
placed in the Hole of a Window-Shutter in
the fame manner as defcribed Pag. 22. But
here, inftead of ufing Wilson's Yit\\& Pocket
Microfcope, he has got the Belly-Part of a
large Reflecfting one fixed horizontally on a
Pedeftal, at a Height exacflly equal to the
Tube. This ftands on a litde Shelf made
to fupport it ', and to the Snout thereof,
w^hich lies on a Level with the Tube, the
Magnifiers are fcrewed. The Objedl being
extended and faftened with Strings and Pins
on a Frame convenient for the Purpofe, is
applied between the Tube and the Magni-
fier:

134 Of Viewing the Current

iSer : whereby the Sun's Rays refledted from
the Looking-glafs, through the Tube, upon
the Objed;, pafs on through the Magnifier,
and exhibit upon thp Screen an Image of
the Objecfl mpfl prodigioufly enlarged. This
I hope may give fome Idea of our Inftru-
ment : and now I come to the AppUcation.

Our Objedl was a Frog^ whofe Limbs
being extended and faftened on the Frame,
we opened the Skin of the Belly from near
the Anus to the Throat y then giving it a
little Snip fideways both at the Top and
Bottom, by flicking a Fijh-Hook in each
Corner of the Skin, it was eaiily ftretched
out before the Microfcope^ and prefented on
the Screen a moft beautiful Pidiure of the
Veins and Arteries in the Skin, with the
Blood circulating through them. In the
Arteries we could plainly perceive the Blood
flopping, and as it were receding a little, at
each Dilation of the Heart, and then im-
mediately rulhing forwards again at each
Contradlion , whilft in the Veins it rolled
on in a continual Current with inexpreffiblq
Rapidity *.

After confidering this as long as we
thought needful, we opened the Abdomen^
and extending the Mufcles before theili'/^r^-

* When the Arteries were magnified very much, by rea-
moving the Screen to a confiderable DiHance, the alternate
Expanfion and Contradlion of their Sides were very vifible
and remarkable.

fcope^

and Circulation of the Blood, 135

[cope, by the fame Means as we had done
the Skin, we had the Plcafure of viewing
their Structure, which we found to confift
of Bundles of tranfparent Strings or Fibres,
lying parallel to one another, and joined to-
gether by a common Membrane. Thcfe
Strings or Fibres appeared through their
whole Length made up of minute roundifli
Veficles, or, in other Words, fecmed like
Ruflies divided the long Way. We could
not be certain of any Circulation through
the Mufcles, though ibmetimes we imagined
we faw a very flow Motion of fome tranf-
parent Fluid : but the Obje6l growing dry
and rigid, obliged us to leave that Enquiry
to a farther Examination.

We then proceeded to our laft Experi-
ment, which was to draw out gently a Part
of the Frogs Gut, in order to apply the Me-
fentcry to the Mi cr of cope : and herein we
fucceeded fo happily, that I believe the Cir-
culation of the Blood was never before {^tn
in fo diftind: and fine a Manner. No Words
can defcribe the wonderful Scene that was
prefented before our Eyes ! We beheld the
Blood pafling through numberlefs Veflels at
one and the fame Inflant, in fome one Way,
in others the quite contrary. Several of the
Veflels were magnified to above an Inch in
Diameter, and the Globules of the Blood
rolling through them feem*d near as large as
Pepper-Corns 5 whilfl: in many of the mi-

nuteil

1^6 Of viewing the Current^ &c.

nuteft Veflels only iingle Globules were able
to find a Paffage, and that too not without
changing their Figure into that of oblong
Spheroids. We faw here like wife, much
better than we had done before, the Pulfa-
tion and Accelleration of the Blood in the
Arteries, in the Manner before defcribed,
and could clearly diftinguifh two or three
Veflels lying over one another, with Cur-
rents running different Ways. In fliort, it
appeared like a beauteous Landfcape, where
Rivers, Streams, and Rills of running Water
are every where difperled.

During this Examination, we took notice
of a VeflTel extreamly minute, iflliing from
the Side of a larger, and turning backwards
from it in a curve Line. We perceived, at
unequal Intervals, fometimes one, fometimes
two, and fometimes three colourlefs Glo-
bules, dropt or fqueez'd out of the larger
Veflfels into this minute one, and gliding
through it fingly and very flowly -, which
made the DoBor imagine it might be a fe^
cretory DuB. We obferved likewife, that
as the Animal grew languid and near ex-
piring, the Blood in the Arteries would fl:op
on a fudden, feem as it were coagulating,
and then run backwards for fome timej
after which, it would again recover its na-
tural Courfe with a great deal of Rapidity,
-—A due Confideration of thefe Appearances
might poffibly account for the Intermiflions,,
3 StartS;,

^he Pulfation of the Heart, 137

Starts, and Irregularities in the Pullc of Per-
fons near the Point of Death.

C H A P. XL

The Pulfation of the Heart.

THIS wonderful Phaenomenon may be
feen diftindtly in feveral fmalllnfeds,
fome whereof I lliall here mention, with
fliort Direftions how to find it.

Divide a "* Bee^ particularly an Humble--
Bee^ near the Neck : and its Hearty which
is a white pulfing Particle, may be feea
beating brilkly.

The Head of the J Horfe-Fly being cut
off, juft at the fetting on of the Neck, a
little Particle (which is the Heart) will ap-
pear with a Pulfation in it for half an Hour.

The -f* Grafskopper has a green Film or
Plate over its Neck and Shoulders, v/hich
being raifed with a Pin, its Heart may be
feen beating, very orderly, for a long while
together.

Cut off the Head of that little flying Bee-
tle, known to every Child by the Name of
§ Lady-Birdy or Cow-Lady : eredl it per-

* Dr. Power's Micro/cop. Ohfer^v. p. 4. J Ibid. p. 7.
f Ibid. p. 24, §j Ibid. p. 30.

pendicu-

138 7he Pulfation of the Heart.

pendicularly, and you'll fee two fmall black
Eyes, each fet between three white Plates
like polifh'd Ivory, on one fide two fmall
ones, and a large one on the other. Pull
off both the crullaceous and filmy Wings
which cover a tender black Skin, and re-
moving that Skin, the Pulfation of the Heart
may be feen beating vigoroufly for twelve or
fourteen Hours.

The Heart of a * Snail is to be found
exad:ly againft the round Hole near its Neck,
of a white Colour, -f and may be feen beat-
ing a quarter of an Hour after Diffedion.

It may alfo be feen in a Loufe^ as I fhall
fhev/ when I come to defcribe that Crea-
ture ; and I make no doubt the curious and
dilio-ent Enquirer will be able to difcover it
in Multitudes of other little Animals.

The perijlaltic Motion of the Stomach
and Bowels may be feen very diftindly in
Lice^ Gnats, Flies, &c. and a Multitude of
other Infeds.

* Power's Micro fcop. Ohfewat. p. 36.

4- SwAMMERD. Hiji, Generate des Infe^es, p. 77.

CHAP,

[ ^9 ]

c n A p. XII.

Of the mulcular or flcfliy Fibres ^Animals.

THE ;ftyZn' Fibres of the Mufcles (ac-
cording to the Obfervations oi Mo?i^
fieur Muvs) are compofed of other final Icr
Fibres or Fibrils, the Size of a llender Hair ;
five or fix hundred of which Fibrils go to
the making up of one Jiepy Fibre^ whofe
Diameter is no more than the twenty-fourth
part of an Inch. Each of thefe Fibrils is
again compofed of more than three hundred
final 1 tranfparent 'Tubulin fo extreamly flen-
der, that were one of thofe Blood-Globules
(which Mr. Leeuwenhoek fuppofes but
the Millionth Part of a Grain of Sand) di-
vided into twenty-four Parts, even thefe
minute Parts could hardly enter and pafs
through fuch exceedingly fmall Tubes. And
yet, that they do enter and pafs through
them is evident, by the Rednefs of the Flefh
of Animals. We mufi: therefore infer, that
the Tubtili forming a Fibril are really hol-
low : that the Extremities of the Arteries
open into them, and empty there a Part of
their Liquor, which is carried back again by
the Veins to the Heart : and that the Glo-
bules of the Blood, are, for this Purpofc,
divided into Parts inconceivablv fmall. "*

* Vid. Phil. Tranf. Niunb. 339,

L Mr.

140 Of the Mujcular Fibres of Animals,

Mr. Leeuwenhoek fays, each Mufcular
Fibre is compofed of many fmaller Filaments
or Fibrils; which, however minute, he could
plainly diftinguifh to be vafcular : for, if
he cut acrofs their Length, the Light ap^
peared through the Mouths of the Veffels ;
but if he cut them ever fo little obliquely
no Light was to be {tQ,n^, He found alfo,
that each Fibril is invefted with a * minute
Membrane, which is only a Congeries of
Blood- Veffels, conveying Juices and Nou-
riihment thereto, tho' their Finenefs renders
them invilible. It is not, however, to be
imagined, that each Fibril has its peculiar
Membrane : but that all the Membranes to-
gether are like a Net finely fpread, with a
Fibril iffuing through each of its Mefhes.

This Structure of the Fibres he obferved
in the Flefh of an Ox, and of a Whale;
but more plainly" in that of a Whale, the
Beef-Fibres lying more compad: and clofe.
He alfo found that the Fibres of a Moufe
were of the fame Thicknefs as thofe of an
Ox, though thirty thoufand Mice are not
equal to one Ox in Bignefs : whence he
concludes, that the different Size of Ani-
mals is entirely owing to the greater or lefs
Number and Length of the Fibres J.

t Phil. Travf. Numb. 367.
■ '* GoRTER. Medic. Comfend. p. 58, 59. Leeuw. Arc,
Nat, Tom, III. p. 58. { Ibid, p. 61.

Thefc

Of the Miifcidar Fil)rcs of Animals, 14 x

Tlicfe fcjhy Fibres appear, through their
whole Length, encompalTcd with circular
Wrinkles. If a Thread were twifted about
a fine "Needle in a Screw-like Form, with
fpiral Circumvolutions, fo that each Thread
be dillantfrom another the Diameter of the
Needle, it would naturally 'reprefent the
Manner of thefe circular Twiflings. And
this Difpofition is wonderfully contrived for
the ready Dilie?fo?i or CcntraBion of the
Fibres : for as a Cord will be diftended or
contrac^led quicker^ or fioiver^ in proportion
to its Length, the fame muft alfo be the
Cafe in Animal Fibres 3 and, therefore, on
thefe Principles we may calculate how much
more nimbly the Leg of a Moufe can move
than the Leo; of an Ox.

i)

The Method of viewing the Mufcular
Fibres is, to (fut carefully, and with a very
fharp Razor or Penknife, a Slice of dryed
Fleih or Fiih, as thin as poflible. Lay it
on a Piece of Glafs, and moiften it with
warm Water ;- which drying foon away,
will leave the VelTels open and diftinguifh-

able.- It is obfervable that the Fibres of

Fifli are larger than thofe of Flefh.

That the Mufcular Fibres are vafcular, or
made up of little hollow Vellcls, is fuppofed
by Malpighius, Borelli, Gorter, our
own Countryman Mr. Hooke, who fays,

Lr-2 they

.142 Of the Mujcular Fibres of Animals,

they appeared to him like Strings of Pearls ;
and, very lately, by Dr. Alex. Stuart,
in his learned and ingenious Treatife de Mo-
tu Mufcuhrum ; where from fuch a Struc-
ture, and by the Influx of the nervous Fluid,
he accounts, very reafonably, for the elaftic
Force, the Contradlion, the Diftenfion, and
all the,A6lions of the Mufcles *. But as
thefe Gentlemen differ fomewhat in the Fi-
gure of the little Veiicles, fuppofed to make
up the mufcular Fibres, the Curious will do
well to examine, with the Micro/cope^ into
this Matter, as carefully as poffible ; and
that, by contriving all the Ways they can
think of to view the Fibres in living Ani-
mals. For, whatever Form the Veffels may
have when replete with a nervous or other
Fluid, I am afraid, when the Fibres have
been dried, or the Veffels collapfe together
by not being fupplyed with fuch Fluid, the
true Form and Strudlure of them can never
be fully known.

: Our Obfervations, 'tis probable, may be
made with moil Succefs on InfeBs, their
flefliy Fibres, as Mr. Leeuwenhoek tells
lis, being no lefs vifible than thofe of larger
Creaturea : which he found, by -cutting off
and examining the fleihy Parts of the Legs
of "f- FlieS:, Gnats^ A?its^ 6cc. in all which he

* Fii/. GoRTER de Fahrica l^ Motu Mvfculor, Stuart
de Motu Miifc. p. 49. f Arc, Nat, Tom. HI. p. 108.

could

0/ B o N E s. 143

could plainlydiilinguini the circular Wrinkles
or Circumvolutions enconipadlng the Fibres,
as they are picitur'd Plate XL Fig. III.

CHAP. XIII.

Of Bon e s.

UPON examining of Bones with a M/-
crofcope, their fuperficial Part is found
to confift of a great many fmall Veflels, and
fome few of a larger Size : which laft, when
they come to the Surface of the Bone, ap-
pear im^fted with either a Membrane or
bony Subftance perfectly tranfparent. The
Infide of the Bone has a fpongy or cellular
Subftance, confifting of long Particles clofe-
ly united, which are compofed of number-
lefs fmall Veflels, fom.e running length-ways,
and others taking their Courfe towards the
Sides of the bony Particles, which, not-
withflanding their great Number of Aper-
tures, are extreamly hard, and lye fome pa-
rallel, and others perpendicular to theLength
of the Bone.

Mr. Leeuwenhoek difcovered, once, in
a fmall Bit of a Shin-Bone, four or five Vef-
fels, with Apertures large enough for a Silk
to pafs through ; each whereof feemed fur-
nifli'd with a Valve, difpofed in fuch a Man-

L 3 ner

144 (y B o N E s.

ner as to let out vv^hat was contained in the
Veffel, but fuffer nothing to return into it''^\

*^ It may poffibly be conceived by fome,
*^ fays Dr. Grew, that the Bones ^ at leaft
" fome of them, are hard at the firft : as
*' Salts and other cryftallizing Bodies are as
*^ hard upon the very firft Inftant of their
" Shooting, as they are when grown into
" large Cryftals. But it is fo far evident
^' that all the Bones are foft at the firft, that
*^ I am of Opinion, they are originally a
*' Congeries of as true Fibres or fibrous Vef-
'^ fels as any other in the Body ; which by
sc 'Degrees harden into Bones, in like Man-
" ner as the inmoft Veffels of a Plant do in
'^ time harden into Wood. And as in a
" Plant there are fucceffive Additions of
" Rings or Tubes of Wood, made out of
" Veffels : fo in an Animal, it feems plain,
^' that there are Additions fucceflively made
" to the Bones out of the fiiroiis Pa?^ts of
" theMufcles: efpeciallythofewhiteft Fibres
" which run tranfverfely, and make the Sta--
^' men or Warp of every Mufcle. So that,
" as in the Bark of a Plant, part of the Vef-
^^ fels are fucceflively derived outward to the
'^ Rind, and part inward to the Sap, which
" afterwards becomes hard Wood ; fo, in the
" Flefh of an Animal, Part of the white
^' tranfverfe Fibres are fucceffively derived

* Fhilofo^h, franf. Numb. 366.

^^ to

0/ t/je Nerves. 145

to the Skin (of wliich it chiefly confifls)
and Part of them inwardly, making flill
new Pcriojlcunis one after another, as the
old Ones become fo many Additions to
the * Bones."

Whoever would examine the Bones^ mufl:
.^/liave off, with a Iharp Pen-knife, very thin
^ Pieces, lengthways, crofsways, and obhquely,
and that from the Infide, Outfide, and Mid-
dle of the Bone. Apply to the Micro/cope
fome of thefe Shavings dry, and others moi-
ftened with warm Water, and thus the Vef-
fels will be feen in all Diredtions. But the
beft Way of fliewing the bony Strucflure, is,
by putting the Bones in a very clear Fire
till they arc red hot 5 then taking them out
-- carefully, you'll find the bony Cells, though
tender, perfed: and entire: And being now
quite empty, they may be viewed with great
Eafe and Pleafure.

CHAP. XIV.

O/^/y^^N E RV E S.

MR. Leeuwenhoek endeavoured to
dlfcover, by \\\^Mic7'ofcope, the Struc-
Uire of the Nerves^ in the Spinal Marrow

* Grew's Rarities ol Grejham College, p. 6.

L 4 of

146 Of the 'N ERVES.

of an Ox ; and faw, with great Delight, that
minute hollov/ Veffels, of an unconceivable
Finenefs, invefted with their proper Mem-
branes, and running out in Length parallel
to one another, make up their Compofition.
And though fome hundreds of thefe Veffels
go to the Formation of the leaft Nerve that
can poffibly be examined, he did not only
difcern the Cavities of them, which he com-
puted to be three times lefs than their Dia-
meters, but, in fome, perceived the Orifices,
as plainly, as the Holes in a pricked Paper
are to be feen v/hen looked at againft the
Sun. It requires however great Dexterity
and Expedition to make this Examination
with Succefs -, for after a thin Slice of the
Spinal Marrow is placed before the Micro-
Jcope^ in lefs than a Minute's Time it be- ^
comes dry, and the whole Appearance va-
niihps*.

The fame ingenious Enquirer into Nature
examined likewife the Brain of feveral Crea-
tures, fuch as an Indian Hen, a Sheep, an
Ox, a Sparrow, &c. and could there diftin^
guifh Multitudes of Veffels, fo extreamly
fmall, that if a ^ Globule of the Blood (a
Million v/hereof exceed not a Grain of
Sand in Bignefs) were divided into five hun-
dred Farts, thofe Parts would be too large

f Arc. Nat. Tom. III. p. 310, 355, 440.
^ Ibid. Tpm. I. Part 1. p. 30.

Of the Nerves. 147

to pafs into fuch Veflels. He obfervcd far-
ther, X that the Veflels in the Brain of a
Sparrow are not fmallcr than in an Ox ; and
argues from thence, that there really is no
other Difference between the Brain of a large
Animal and that of a fmall one, but only a
greater or fmaller Number of Veflels ; and
that the Globules of the Fluid pafling thro*
them are in both of the fame Size.

Though it does not diredly relate to Mt-
crofcopcs^ I hope I may be excufed for taking
Notice here, that in the Year 171 1, Dodor
Alexander Stuart -f-made a Difcovery,
that the Nerves are not elaftic, contrary
to the Opinion of all preceding ^///'/?(?rj;
and proved it by the following Experiment:
Laying a Piece of Twine, about four
Inches in Length, parallel to the Nerve,
Artery and Vein of thelnfide of the Thigh
in an human Subjedt, and tying thefe to-
gether, above and belov/, as foon as they
were cut out of the Body, and laid on a
Board ; the Artery and Vein were feen to
contradl equally, to the Lofs of a quarter
Part of the Length they had in the Body
^' before Excifion^ but the Nerve continued
*' of the fame Length with the Twine, as
M in the Body."

X Arc. Nat. Tom. I. Part I. p. 38.
t Vid. Stuart's Uciures on Uufcular Motion in the
Year i-";8, p. 3.

^ ' ^ CHAP.

CC
CC
<C
(C
CC
C C
CC
CC

[ h8 ]

C H A P. XV.

Of the Generation of Animals and
Vegetables.

T^^iivocal or fponfaneous Generation^ that
•^-^ is, aProdu6tion of Plants without Seeds,
and of Hving Creatures without any other Pa-
rents but Accident and Putrefadion, how-
ever abfurd it may feem to us, was an Opi-
nion that prevailed, almoft univerfally ; till
Microfcopes overturn'd it, by demonftrating
that all Plants have their Seeds, and all Ani-
mals their Eggs : whence other Plants and
other Animals, exactly of the fame Species,
are perpetually and unalterably produced.

Nothing feems nov/ more contrary to
Reafon, than that Chance and Naftinefi
jfliould give a Being to Uniformity, Regula-
rity, and Beauty : That two fuch unlikely
Principles ihould produce, in diiferentPlaces,
Millions of Vegetables of the fame Kinds,
and alike, exacftly, even in the moft minute
Particularities : or, what is yet more amaz-
ing, that dead corrupting Matter and blind
uncertain Chance iliould create living Ani-
mals, fabricate a Brain, conftitute Nerves
iffuing from it, compofe a Contraft of Muf-
cles, furnifh out Eyes, Lungs, a Heart, a
Stomach, Bowels, and all other Parts ufeful
to fuch Creatures : and that too not after an
awkardj flovenly, variable, undefigning and

unfiniih'd

Of the Generation of Animals ^ Sec, 149

iinfinlfli'd manner ; but with a Contrivance,
Dexterity, Elegance, Perfection and Con-
Aancy beyond the utmoll Power of Art to
imitate. This, however, was the Opinion,
not only of the Ignorant and Illiterate, but
of the moll: learned grave Philofophcrs of pre-
ceding Ages; and would, probably, ftill have
been taught and believed, had not Micro^
[copes difcovered the manner how all thefe
Things are generated, and reftored to God
the Glory of his own amazing Works J.

The Eye, affifted by a good MicrofcopCy
can diftinguiili plainly, in the Semen mafculi^
nurn of Animals, Myriads of Animalcules
alive and vigorous ; though fo exceedingly
minute, that, it is computed, three thou-
fand millions of them are not equal to a
Grain of Sand, whofe Diameter is but the
one hundreth Part of an Inch -f* : And the
fame Inftrument will inform us beyond all
Doubt, that the Farince of Vegetables are
nothing elfe but a Congeries of minute
Granula^ whofe Shapes are conftant and
uniform as the Plants thev are taken from.

\ I would as foon fay, that Rocks and Woods engender
Stags and Elephants, as affirm, that a Piece of Cheele ge-
nerates Mites. Stags are born and live in Vi^oods, and Mites
in Cheefe ; but they both owe their Being to that of other
Animals. Spetl. de la Nat. Eng. Edit. izmo. Vol. II, p. i i ,

f Vid. Keil's Anat. 5th Edit. p. 116,

And

I ro Of the Generation

And as the Seeds of Plants are proved, by
repeated Experiments, to be unprolific, if
the Farince be not permitted to fhed, it has
been fuppofed, that all its Gramila contain
femmal Plants of their own Kind.

The Growth of Animals and Vegetables
feems to be nothing elfe but a gradual Un-
folding and Expanfion of their Veffels, by a
flow and progreffive Infinuation of Fluids
adapted to their Diameters ; until, being
fl:retch'd to the utmoft Bounds appointed
them by Providence at their Formation, they
attain their State of Perfedion, or, in other
Words, arrive at their full Growth.

'Tis thought probable, according to this
Theory, that, in Animals (of the larger and
more perfed Kind at leaft) the Semen of the
Male being received into the Matrix of the
Female, fome of the Animalcules it contains
in fuch Abundance, find an Entrance into
the Ovaria^ and lodge themfelves in fome
of the Ova placed there by Providence as a
proper Nidus for them.

An Ovum becoming thus inhabited by an
Animalcule, gets loofen'd in due Time from
its Ovarium^, and paffes into the Matrix
through one of the Fallopian Tubes. The
Veins and Arteries that faftened it to the
Ovary, and were broken when it dropped
from thence, unite with the Veffels it finds
here, and compofe the Placenta, The Coats
of the Ovum, being fweU'^i and dilated by

cf Animals and Ve get able s» 151

the Juices of the Matrix^ from the other In-
teguments needful to the Prefervation of the
httle Animal ; which receiving continually
a kindly Nouriflimcnt from the fame Juices,
gradually ilretches and enlarges its Dimen-
lions, becoming then quickly vifible with all
the Parts peculiar to its Species, and is called
a Fa:tiis.

In Plants, which are uncapable of re-
moving from Place to Place as Animals can,
it was requifite a Repofitory for their Fari^
nee fhould be near at hand, to prevent its
being loft : And accordingly we find, that
every Flower producing a Farina^ has like-
wife in itfelf a proper tjterus for the Recep-
tion of it : Where the Ova thereby impreg-
nated, are expanded by the Juices of the Pa-
rent Plant to a certain Form and Bulk, and
then becoming what we call ripe Seeds, they
fall to the Earth, which is the natural Ma-
trix for them.

According to the above Suppofition, a ripe
Seed falling to the Earth, is in the Condition
of the Ovum of an Animal getting loofe
from its Ovary, and failing into the Uterus :
And, to go on with the Analogy, the Juices
of the Earth fwell and expand the VefTels of
the Seed, as the Juices of the Uterus do
thofe of the Ovum, till the feminal Leaves
unfold, and perform the Office of a Place?ita
to the Infant included Plant ; which im-
bibing fuitable and fufficient Moifture, gra-
dually

1^2 * Of the Animalcules

dually extends its Parts, fixes its own Root,
flioots above the Ground, and may be fald
to be born.

As Difcoveries made by the Micrcfcope^
of infinite Numbers oi Animalcules in the
Semen Mafciilinum of all living Creatures,
and likewife of a Regularity and Conftancy
in the Farina of each Species of Vegetables,
analogous to the faid Animalcules in the Ani-
mal Semen^ have been the principal Means
of convincing us that all Things are pro-
duced by Parents of their own Kind, accord-
ing to the eternal and unalterable Laws efta-
biifhed at their firft Creation ; I hope this
ihort Account of Generation, before my en-
tering upon thofe Subjects, will not be judged
improper.

CHAP. XVI.

Of the Animalcules in Semine

Masculino.

T the Beginning of the Year 1 678, Mr.
Nicholas Hartsoeker, of Rot-
derdam^ declared in a Treatife of Dioptrics^
by him^then publifh'd, that it was twenty
Years fmce he firft be^an to examine the
Semen Mafculimim of feveral living Crea-
tures by the Help of Microfcopes : that, as

far

in Seminc Mafculino. 155

far as he knew, he was the firfl Perfon who
had ever done (o ; that he had found in fuch
Setnen infinite Numbers oi Aiiimalcules^ moft
exceedingly minute, almoft in the Shape of
Tadpoles or young Frogs ; and that he had
made this Difcovery known to the World
in the 30th of the Ephetnerides Eruditorum^
printed ^t Paris in the fame Year 1678.

Mr. Leeuwenhoek, in the 113th of
his Epiftles, {dd.ttd January 1678) is very
angry at this Claim -, and aiTerts, that he
himfelf firft difcovered the Ajiimalcules in
Semijie 5 and fent an Account thereof to the
Royal Society in November 1677, as he
proves by the Philofophical T^ranfadlioriSy
publiilied in Dece?nber ibjy, and in Janu^
ary and Feby^iiary 1678: nay, he farther
affirms, that Letters had pafTed between him
and Mr. Oldenburg on this Subjed: in
1674. This Difpute concerns us no farther
than as it fhews about what Time the Exift-
ence of thefe Animalcules was firft difcover-
ed, which fome of my curious Readers may
perhaps be incjuifitive to know.

The general Appearance or Figure of the
A?2imalcules in the Se?nen Mafculinum of
different Kinds of living Creatures is very
much the fame : that is, the Bodies of them
all feem of an oblong oval Form, with long
tapering flender Tails iffuing therefrom; and
as b)^ this Shape they fomewhat refemble

'Tadpoles^

154 0/ ^^^ Animalcules

^adpoleSy they have frequently been called
by that Name ; tho' the Tails of them, in
Proportion to their Bodies, are much longer
than the Tails of 'Tadpoles are : and it is ob-
fervable, that the Animalcules in the Semen
of Fifhes have Tails much longer and flen-
derer than the Tails of thofe in other Ani-
mals, infomuch that the Extremity of them
is not to be difcerned without the beft Glaffes
and the utmoft Attention : their Bodies are
alfo much fmaller.

The general Appearance of them as above
defcribed, is {hewn Plate XII. Fig. I.

In the Spring Seafon, at the Time that
Frogs engender, upon opening the Tefticles
of a Male, and applying fome of the Jemtnal
Matter before the Microfcope, Multitudes
of Animalcules appeared therein, about * one
thoufandth Part of the Thicknefs of the Hair
of a Man s Head, as nearly as could be com-
puted : whence it foUoWs, that a thoufand
Millions of them would be but equal to a
Globe whofe Diameter is the Thicknefs of
the Hair of a Man's Head. And there feem-
ed to be ten thoufand of them at leaft for
each one of the Female Ova.

The Shape of them is given in the fame
Plate, Fig. II.

* LtEuwEN. Jrcan, Nat. Tom. I, Part I. p. 51.

Upou

r^/.i./,.jfi^

A ' ^

mm

yMt^-f^^^^

J'y.ir.n.j.So

ffl. J.

c-

y

JF^j. TJ^.^i y^^

I^y.rT/.yi ^(^^

-Fajr.J./i. JS^

F^.jr.^.ut,^

^

/;/ Semine Mafculino.

^s

tJpon viewing the Mi/t or Semen Mafcu^
Ihiiun of a living CoJ-fifli with a Micro^
/^d?/>^',fuch Numbers oi Animalcules v^\\}^ long
Tails were found therein, that at leaft ten
thoufand of them were fuppofed to exift in
the Quantity of a Grain of Sand. Whence
Mr. Leeuwenhoek argues, that the Milt
of that fingleCod-Fifh contained mor^ living
Animalcules than there are People alive
upon the Face of the whole Earth at one and
the fame Time : ^ for he computes, that
one hundred Grains of Sand make the Dia-
meter of an Inch; wherefore in a cubic Inch
there will be a Million of fuch Sands. And
as he found the Milt of the Cod-Fifh to be
about fifteen cubic Inches, it mnft contain
fifteen Millions of Quantities as big as a
Grain of Sand . Now if each of thefe Quan-
tities contain ten thoufand Animalcules^ there
mufl: be in the whole one hundred and fifty
thoufand Millions*

Then, to find out, in a probable manner,
the Number of People living upon the whole
Earth at one Time 3 he reckons, that in a
great Circle there are five thoufand four
hundred Dutch fquareMIles^ whence he cal-
culates the Surface of the Earth to contain
nine Millions, two hundred feventy-fixThou-

t Arc. Nat. Tom. I. Par. II. p. 9.

M fand

156 Of the Animalcules

fand, two hundred and eighteen fuch fquare
Miles : and fuppofing one Third of the
Whole, or three Millions, ninety-two Thou-
fand and feventy-two Miles to be dry Land 5
and of this, tvv^o Thirds, or two Millions,
iixty-one Thoufand, three Hundred and
eighty-two Miles to be inhabited : and fup-
pofing farther, that Holland and Weji-Frief-
land are twenty-two Miles long and i^^^xi
broad, which make one hundred and fifty.-^
four fquare Miles 5 the habitable Part of the
World is thirteen Thoufand three Hundred
and Eighty-five times the Bignefs of Holland
and WeJi'FrieJla?id.

Now, if the People in thefe two Provinces
be fuppofed a Million, and if all the other
inhabited Parts of the World were as po-
pulous as thefe, (which is highly impro-
bable) there would be thirteen thoufand
three hundred and eighty- five Millions of
' People on the Face of the whole Earth : but
the Milt of thisCod-Fiih contained one hun-
nred and fifty thoufand Millions of AnimaU
r^/fc, which is ten times more than the Num-
ber of all Mankind.

The Number of thefe Animalcules may be
computed another Way : for the ingenious
Author of SpeBacle de la Nature fays'*, that

Vid. ^(£i, de la Nat. Eng. i.zmo. Edit, Vol. I. p- 231.

thtee

i?i Seminc Mafculino. 1^7

three curious People counted, with all the
Care they were able, as mauy of the Eggs
or Row of a female Cod-Fifli as weighed a
Dram, and agreed pretty well in the Num-
ber, which they wrote down. They then
weighed the whole Mafs, and fetting down
eight times the Sum of one Dram for every
Ounce, which contains eight Drams : all the
Sums together produced a Total of nine
Millions three hundred and thirty-four thou-
fand Eggs, -f-

Now fuppofing (as Mr. Leeuwenhoek
does of the Sanen Mafcidimim of Frogs) that
there are ten thoufand An'unalcules in the
Milt for each One of the Female Ova in the
Row, it will follow, that iince the Female
Row is found to have nine Millions three
hundred thirty-fourthoufandEggs,the whole
Milt of the Male may be reckoned to con-
tain ninety-three thoufand four hundred and
forty Millions of ^7/>^2^/(:z//^5 : w^hich, tho'
greatly fhort of the firft Calculation, is al-
moft feven times as many as the whole hu-
man Species.

To find the comparative Size of thefe
Animalcules, Mr. Leeuwenhoek placed a

■f Four Millions and ninety-fix thoufand Eggs were com
puted in the Row of £ Crab, each of which received its Nou"'
rifhment by a Rope from the Crab\ Body. Vid. Arc. Nat.
Tom. 1. Par. II. p. 240.

M 2 Hair

1 5^ ^f ^^^ Animalcules

* Hair of his Head near them, which Hair
through his Microfcope appeared an Inch in
Breadth ; and he was fatisfied that at leafl:
fixty fuch Animalcules could eafily lye within
that Diameter 5 whence, their Bodies being
fpherical, it muft follow, that two hundred
and fixteen thoufand of them are but equal
to a Globe whofe Diameter is no more than
the Breadth of fuch an Hair.

He obferved, that when the Water where-
with he had diluted the Semen of a Cod-
Fifh was exhaled, the little Bodies of the
Animalcules burft in Pieces, which did not
happen to thofe in the Se?nen of a Ram :
which he imputes to the greater Firmnefs
and Coniiftency of the latter, as the Flefh of
a Land- Animal is more compacfl than that
of a Fifh. He like wife takes Notice, that
the Tails of thofe in Fiihes are fo extreamly
{lender, that he could never be certain of
his feeing the very Tips or Extremities of
them.

In the Milt of a Jack, at leaft -f- ten
thoufand Animalcules were difcernable, in a
Quantity not bigger than a Grain of Sand,
exad:ly, in Appearance, like thofe of the Cod-
Fifh ; and upon putting J four times as
much Water to it, they were perceived to
become ftronger and brilker, and to fwim

* Phil, Tranf, Numb 270. f Jrc. Nat. Tom. I.

Par. II, p. 2. J Phil. tranfa6l. Numb. 270,

as

/;/ Scmine Mafculino. 159

as if in Purfuit of Prey, with greater Velo-
city ; tho' (being viewed in a capillary Tube)
their whole Courfe was no longer than the
Diameter of a Hair.

If you would view the Animalcules in
the Milt or foft Row of Fifl:ies, fqueeze out
a little of it, and putting the Quantity 6f
a Pin's Head upon a fmgle Ifinglafs, dilute it
with Rain or River Water, till the little Crea-
tures have fufficient Room to fwim about
freely, and {hew themfelves to advantage ;
which they can by no means do unlefs it
be made very thin. Or, after you have
mixed fome Water with it, apply it to the
Microfcope in one of your fmalleft capillary
Tubes 3 which Way Mr. Leeuwenhoek
informs us, he found the moft ufeful for the
Examination of the Sc??2en of different Crea-
tures. [N. B. - The Eggs in the Row, and
Animalcules in the Milt of Fhhes of one
Year old, are as large as in thofe of the fame
Species of twenty Years old. j

Upon opening the Se?ni?2al V-eJjels of a
Cock, fqueezing out a fmall Drop of the &-
men^ and viewing it with a Microfcope^ Le-
gions oi Animalcules appeared therein, fwim-
ming in Crowds together, and croffing one

f ^rr. iV^/. Tom. III. p. 188.

M 3 another

i6o Of the Animalcules

another with as much Brifknefs and Vigour
as if the Cock had been but newly dead, tho'
it Was killed the Day before : And by feve-
ral Trials on the Semen of other Cocks it has
been found, that the Animalcules therein
v/ill live many Hours in a CapillarjrGlafs
Tube.— —To a flight Obferver they feem in
the Form of Eels ; but if the greateft Mag-
nifiers be ufed with due Attention, they will
be found fhaped as Fig. III. Plate XII. — -
Their Size is fo extreamly minute, that a
4- Million of them are fuppofed not to
exceed the Bignefs of a Grain of Sand, and
their Tails cannot be difcerned without much
Diiiiculty, being ten thoufand times more
flender than the Hair of a Man's Hand*

A little of the Seminal Matter taken from
the Tefticle of a Dog, abounded with Ani^
malcules, J a Million whereof would hardly
equal a large Grain of Sand : and after fome
of this Matter had been kept (tv^n Days
in a Glafs Tube, feveral of the Animalctiles
remained alive and vigorous. [Their Form
is fliewn Fig. IV.]— The rejiicles of a
Plare, tho' four Days dead, were alfo ex-
ceedingly full of Animalcules like thofe in
Dogs, fwimming in a clear Liquor, but
without Motion.

•f Arc. Nat, Tom. ir. Par. IT. p. 369.
J Arc, Nat. Tom. I. Pay. II. p. 160.

Killing

i?i Scmine Mafculino. i6i

Killing a Female Rabbet immediately af-
ter the Coitus, and opening the Uterus there-
of, innumerable Aiiimakules were found in
a fmall Drop, taken from the Mouth of the
Fallopia?i I'ube^ where it opens into the Ma-
trix : but none were difcerned in the Uterus
itfelf, or farther along the Tube. They
had long Tails, and for the moft part * fix
tranfparent Globules appeared on the Body
of each, as in Fig. V. i : tho' fome had only
one Globule at the End of the Body, and
another in the Tail, as Fig. V. 2.

Examining a Drop of Semen taken from
the Teflicles of a Ram, it abounded with
Animalcules in as great Numbers as the fe-
minal Matter of other Creatures ; but with
this extraordinary -^ Singularity, that Multi-
tudes of them fvvam the fame Way together,

and

* Jrc. Nat. Tom. I. Par. II. p 160.

-f- Mr. Leeuvvenhoek opened the Uterus of an Ewe,
which about feventeen Days before hsd been coupled with
a Ram, and in one of the Cornea obferved a little ;W//^
Jiejpy Subjianccy wherein no Shape could bediftinguifhed. He
put this in a Glafs Tube the Thicknefs of a Quill, fiiPd with
Oyl of Turpentine, and apply'd it to his Micro/cope, s but could
make nothing of it in that Manner. Wherefore he took it
from the Tube, and extending it very gently out of the round
Figure in which it lay, he perceived extreamly plain the
Formation of all the Vertebrae, with the Blood-Veilels and
I^amifications paffing over them, and in two Places could fee
the Spinal Marrow. He could alfo diftinguilh not only the
Head, but alfo the Mouth, Brain, and Eyes the Eignefs of
two Grains of Sand, and plear as Cryftal : He faw likewife

M 4 the

1 62 O/^ /& Animalcules

and feemed to have the Inclination of Sheep,
to follow their Leader and move in Flocks,
Mr Leeuwenhoek fays, he found fo
much Pleafure in obferving this, that he
called in fome Neighbours to fliare it with
him.

Their Form was that of Fig. VT.

A Buck being killed in Rutting-time, the
J Vafa Defere72tia were found turgid with a
milky Fluid, a Drop whereof, when applied
to the Mi cr of cope J appeared full oi AniinaU
ciiles moving very brilkly. The greateft
Difnculty was to lay them properly before
the Micro/cope : for when the Matter is too
thick, nothing can be fcen but a confufed
Motion, and when fpread thin it dries away
immediately ; but by diluting it with warm
Wat^r, juft enough to change its Colour,
they were feen diftindtly.

The human Semen has likewife been view-r
ed by the Micro/cope^ and found no lefs

the Ribs and Inteftines : though the whole Creature was no
larger than the eighth Part of Fea. — After this he opened
the Uterus of another Ewe, but three Days from the Coitus ;
and fearching the Liquor coming from it very diligently with
a Magnifying Glafs, obferved a little Particle the Size of a
Orain of Sand j which examining with an excellent Micro-
/cope, he v/ith great Pleafure found to be an exceeding minute
Lamb lying round in its Integuments, and could plainly
difcern its Mouth and Eyes. Vid. Arc. Nat. Tom. I. Par. II .
pag. i6ij, and T73.

X Vid. PhiL Traf!f, |^umb. ^^4,

plentifully

in Semine Mafcullno. 163

plentifully flocked with Life than that of
other Animals : for more than ten thoufand
living Creatures were feen, by Mr. Leeu-
WENHOEKj moving in no larger a Quantity
of the fluid Part thereof that the Bignefs of
a Grain of Sand -, and in the thicker Part
they were fo throng'd together, that they
could not move for one another. Their Size
was fmaller than the red Globules of the
Blood, and even lefs than the millionth Part
of a Grain of -f* Sand. The Bodies of them
are roundifh, fomewhat flat before, but
ending fliarp behind, with Tails exceedingly
tranfparent, five or fix times longer, and
about five times more flender than their Bo^
dies. They move themfelves along by the
violent Agitation of their Tails, in various
Bendings, after the Manner that Eels or Ser-
pents fwim : and, fometimes, their Tails
are moved thus eight or ten times in getting
forwards the Diameter of a Hair.

Their Shape and Form is fhewn Fig. VII.

It is wonderful to confider the Minutenefs
of thefe little Animals, and particularly the
amazing Slendernefs of their Tails : which
muft, notwithftanding, be furniili'd with as
many Joints as the Tails of larger Creatures,
fince they are able to move them with great

f Jrcan, Nat, Tom. II. Part II. p. 61, 69, 286.

Argility :

164 of the Animalcules

Agility : and, befides, every one of thefe
Joints mufl: be provided v^ith its proper Muf-
cles, Nerves, Arteries and Veins ; and alfo
with Fluids circulating thro' them, and fup-
plying them vi^ith Nourifhment, Strength,
and Motion. In ihort, the Mind lofes itfelf
in contemplating a Minutenefs beyond all
human Conception ; tho' Reafon tell us, it
certainly muft be. I remember Dr. Pov^er
has a fine Paflage to this Purpofe in the Pre-
face to his Experiments. " It has often
feem'd to me (fays he) an ordinary Pro-
bability, and fomething more than Fancy,
(how paradoxical foever the Conjecture
may feem) to think, that the leaft Bodies
we are able to fee with our naked Eyes,
are but middle Proportionals^ as it were,
betwixt the Greatefi and the Smalleji Bo-
dies in Nature ; which two Extremes lye
equally beyond the Reach of human Sen-

fation. For, as on one fide they are but

narrow Souls, and not worthy the Name
of Philofophers^ that think any Body can
be too great y of too njaji in its Dimenfions :
" fo like wife are they as inapprehenfive,
^' and of the fame Litter with the
^^ former, that, on the other fide, think the
" Particles of Matter may be too little^ or
" that Nature is ftinted at an Atom, and
" mufi: have z No?t ultra oi her Subdivi-
" fiOAS."

As

<c
<c
((
cc
cc
ce
cc
<c
cc
cc
cc
cc

/;; Semine Mafculino. 165

As the Animalcules in tlic Semm Mafcidi-
niim of different Creatures arc not much un-
like in Shape, it is alfo obfcrvablc, that they
do not differ in * Bignefs according to the
Sizes of the Creatures they are taken from ;
but feem, in this Refped:, analogous to the
Seeds of Trees and Plants, whofe Size bears
very little Proportion to the Bignefs of the
Trees and Plants producing them. The
Seed of an Apple, for Inllance, is fome
thoufands of Times fmaller than a Cocoa-
Nut, tho' the Trees they grow ow have not
that Difproportion : And the Seeds of To-
bacco (whereof a thoufand -^ weigh not
above a fingle Grain) are lefs beyond Com-
parifon than many kinds of other Seeds whofe
Plants are not near fo large as Tobacco is.
Hence it comes to pafs, that Animalcules
may be difcovered in theSeme?! of the fmallefl
Birds, Quadrupeds andFiflies, nay, and even
in Infects too. For Mr. Leeuwenhoek
aiTures us, he found a white Matter he had
fometimes fqueezed from the hinder Parts of
male X Spiders, about the Bignefs of a Grain
of Sand, to be indeed their Semen^ by difco-
vering therein prodigious Multitudes oi Ani~
malcules^ which continued living above five
Hours, but were fo extreamly minute, that
he fuppofes a thoufand Millions of them

* Arc, 'Nat. Tom. IV. pag. 30. f Dr. Power's Ex-
perlm, pag. 30, J Phihfoph. Tran/a^, Numb 279.

would

1 66 O/* Animalcules

would not equal the Size of aGrain of Millet.
He found them likewife in the Semen of the
^ Dormoufe, in ^ Oyfters, in " Silkworms, in
the ^ Labella minima^ or fmall Dragon-Fly,
in the common *" Fly, in the male ^ Flea, in
^ Gnats, and in feveral other Infeds : and,
without doubt, a curious Enquirer will be
able to difcover them in abundance of Sub-
jed:s yet unexamined j for Nature is uni-
form in all her Works, and there is good
Reafon to believe that they certainly exift in
all the animal Part of the Creation.

Amongft the many Species of Aitimalcules
obferved in Waters and Infufions, there are
^ none found refembling thofe in Semine :
but the Animalcules in the Semen of all Sorts
of Creatures hitherto examined have a com-
mon and general Likenefs to one another ;
with this Particularity, that they appear in
continual Motion, without the leafi: Reft ox
Intermiflion, provided the Fluid be fufRcient
for them to fwim about in.-

Many People have imagined, that living
Creatures might alfo be found in the other
cinima] 'Juices : but after the ftridleft and
moft careful Examination, it appearsc ertain.

» Jrc. Nat. Tom. I. Par. II. p. 27. ^ Ibid. Tom. II.
Par. I. p. 144. c Ibid. Par. II. p. 422. '^ Ibid. Tom. IV.
p. 19. ^ Ibid. * Ibid. p. 20. 8 Ibid. p. 22. ^ ibid-
Tom. III. p. 294.

I that

J'a^ id?-

i'lyJ^.fJSy

y/aU-n

^ujr.JiM.iiS^S^g

^^JT/i. S.IS

I'yX /t3.U.

J^i^. ^If.fvSJLSL

i?i the Teeth. 167

that nothing with the leaft Token of Life
is to be difcovered by the beft Glaffcs, either
in the Blood, Spittle, Urine, Gall, Chyle,
or any of the Hu??wurs, except the Semen
only.

CHAP. XVII.

Of Animalcules in the Teeth.

T Hough no Animalcules can be found in.
the Saliva or Spittle, great Numbers,
of different Kinds, may be difcover'd in the
whitip Matter flicking between the Teeth :
if it be picked out with a Pin or Needle,
mixt with a little Rain- Water and Spittle
without Bubbles, and applied before the Mi-
crofcope. And fometimes they are fo incre-
dibly numerous, and fo full of Motion, that
the whole Mafs appears alive.

+ The largeft fort (fliewn Plate XIII.
Fig. I. Numb. I.) move along very fwiftly
in the Spittle or Water -, of thefe there are

. but few.

The fecond fort are more numerous, and
have a Motion peculiar to themfelves, as re-
prefented Numb. 2.

X Vide Jrc. Nat, Tom. IV. p. 40- Agai"» Tom. IV.

1 68 Of Animalcules in the Teeth.

The third fort are roundifli, and fo mi-
nute, that a Grain of coarfe Sand would
equal a Million of them in Bignefs : they
move fo fwiftly, and in fuch Multitudes,
that they feem like Swarms of Gnats or
Flies, and the exad: Shape of them is not
eafy to be diftinguifhed.

Some or all of thefe three kinds may be

found, pretty conftantly, in the Matter taken

from between the Teeth of Men, Women,

or Children -, efpecially from betweeil the

Grinders, even though they wafh their Teeth

continually, and clean them with the utmoft

Care : but from the Teeth of People that are

morecarelefs, the faid Matter affords another

Sort of Animalcules, in the Shape of Eels

or Worms, as pidlured Numb. 4. Thefe

move themfelves backwards, or forwards,

with great Bendings of the Body 5 and force

their Way through the minuter Animalcules

every where around them, with the fame

Eafe as a large Butterfly would break through

a Swarm of Gnats. There are likewife, in

this Matter from the Teeth, other Sorts of

Animalcules^ whofe Motions are fo extreamly

languid, that v/ithout long Attention they

cannot be diftinguifhed to be alive.

Obfervation, They all dye if Vinegar be
applied to them. ; v/hence it feems reafonable
to conclude, that waihing the Teeth and
Gums with Vinegar may be a Means of pre-
ferving them from thefe minute Creatures.

CHAP,

[ i69 ]

C H A P XVIII.

Of the Itch.

Tri E Micro/cope has difcovered, what
without it could fcarce have been ima-
tyuied, that the Diftemper we call the Itch^
is owin«^ to little Infers under the Ciiticula,
whofe continual Bitings caufe an ouzing of
Serum from the Cutis, and produce thofe
Puftules orwatry Bladders whereby this Dif-
eafe is known. This was found out by
Dr. BoNONio, ■* who obferving that itchy
People frequently pull out of their fcabby
Skin little Bladders of Water, with the Point
of a Pin, and crack them on their Nails like
Fleas, he determined to examine what thefe
Bladders might really be. Wherefore pick-
ing out with a fine Needle a little Puftule
from a Place fcabbed over, and where there
was a fevere Itching, he fqueezed a thin
Matter from it, and perceived a very fmall
white Globule fcarcely difcernable, which,
applying to the Microfcope, he found to be
a very 77ii?iute AnijnaU in Shape refembling a
Tortoife, of a whitiih Colour, but darker on
the Back than elfewhere, w^ith fome long
and thick Hairs iffuing from it, very nimble
in its Motion, having fix Legs, a fharp Head,

Philofoph. Iranf. Numb. 283.

and

170 Of the I T c fci.

and two little Horns ; being in Shape as re~
prefented by the two Pictures, Fig. II. a. b.
Plate XIII.

This Experiment was repeated on Itchy
Perfons of all Ages, Sexes and Complexions,
and at all Seafons of the Year, and he con-
ftantly found the fame Animalcules in moil
of the watry Puftules : and though by rea-^
fon of their Minutenefs and Colour (which
is the fame as the Skin) it is difScult to dif-
cern thefe Creatures on the Surface of the
Body, yet he fometimes faw them upon the
Joint of the Fingers in the little Furrows of
the Cuticulay where they firft begin to enter
with their iharp Heads, gnawing and work-
ing in their Bodies, till they are got quite
under the Cuficula, where they burrow from
Place to Place, caufe a troublefome and grie-^
vous Itching, and force the infedcd Perfon
to fcratch, which only ferves to increafe the
Malady ; for, by breaking the little Puftules
and fome fmall Blood- Veffels, Scabs, crufty
Sores, and fuch like foul Symptoms enfue :
whilft thefe mifchievous Animalcules efcape
the Nails by their Minutenefs^ and difperlc
themfelves the farther.

Frequently obferving thefe Animalcules y
he perceived one of them drop a little oblong
white Egg, almoft tranfparent, from the
hinder Part of its Body : and afterwards he
faw many of the fame Sort of Eggs -, which
proves them generated like other Creatures

from

Of their c\il 171

from a Male and Female, though he was
never able to diftinguifli the Sex of any he
examined.

The Figure of the Egg is fliewil c.

We may hence account how this Dirtem-
per comes to be fo very catching, fince thcfe
Animalcules^ by fimple Contadt, can eafily
pafs from one Perfon to another, having not
only a fwift Motion, but clinging to every
thing they touch, and crawling as well upon
the Surface of the Body as under the out-
ward Skin • and a few being once lodged,
tliey multiply apace by the Eggs they lay.
The Infection may alfo be propagated in a
like manner by Sheets, Towels, Handker-
chiefs^ or Gloves, ufed by itchy People ;
iince thefe Anijjialcules may eafily be har-
boured in fuch things, and will live out of
the Body two or three Days.

The Difcovery of thefe Animalcules fliews
the Reafon likewife why this Diflemper is
never to be cured by internal Medicines :
but requires lixivial Wafhes, Baths, or Oint-
ments, made up with SaltSy Sulphurs^ Vi^
triols^ Mercuf-yy Precipitate^ Sublnjiate^ or
fuch kinds of penetrating and corroding Re-
medies as can powerfully kill thefe Vermin
in the Skin. And if, fometimes, we find
the Difeafe returns upon us, in a little while
after we fuppofed it quite cured by Undlion,
it is no great Wonder ; fince, tho' the Oint-

N ment

ij2, Of Scales on

ment may deftroy all the living Animalcules^
it may not probably kill their Young Ones
in the Eggs, laid in Nells in the Skin ;
which, coming to hatch, may renew the
Diftemper. For this Reafon, it is advifeablc
to continue the Anointing for fome Days>
even after the Cure feems perfedt.

CHAP XIX.

Of Scales on the Human Skin.

TH E Cuticula^ Scarf 'Skin^ or outward
Covering of the Body, is remarkable
for its Scales and for its Pores,

Its Scales are a Difcovery of the Micro^
fcope 5 for being fo minute that ^ two hun-
"dred of them may be covered with a Grain
of Sand, they could never be difcerned by
the naked Eye. They are placed as on,
Fifhes, *f three deep ^ /. e, each Scale is fo
far covered by two others, that only a third
Fart thereof appears : which lying over one
another, may be the Caufe v/hy the Skin of
the Body appears J white ; for about the
Mouth and Lips, where they only juft meet
together, and do not fold over, the Blood-

* Vid. Jrc. Nat. Tom. I. Par. IL p. 208. Again,
Tom. IV. p. 46. t Ibid. p. 4.7. % '^^i^' P« S ^ • ^ ,

■ Veffels

the Human Skin.' '\y\

VclTels arc {q,z\\ through, and the Parts look
red. The perfpirahlc Matter is luppofed to
ifTue between thele Scales (which lye over
the Pores or excretory Veffels through which
the watery and oily Humours perfpire) and
may find Vent in an hundred Places round
the Edges of each Scale *: fo that if a Grain
of Sand can cover two hundred Scales, it
will be able to cover twenty thoufand Places
where Perfpiration may iffue forth.

A Piece of Skin taken from between the
Fingers, from the Forehead, Neck, Arms,
or any other foft Part of the Body, which is
not hairy, ferves beft to Ihew the Scales ; for
where the Skin is callous, they are glewed
as it were together.

They are generally of five Sides, as in the
Picfture, Fig. IK. a.

Their Difpofition on the Skin is fliewn
Fig. III. b.

If they are fcraped off with a Penknife,
put into a Drop of Water, and fo applied to
the Micrcfcope, they will be feen to o-ood
Advantage.

Arcan. Nat. Tom. IV. p. 4S.

N 2 CHAP.

[ 174 3
CHAR XX.

7he Pores of the Skin.^

EVERY Part of the human Skin is full
of excretory DuBs or Pores, which emit
fuperfluous Humours^ continually, from the
Mafs of the circulating Fluid.

In order to view the Pores, cut a Slice of
the upper Skin with a fharp Razor as thin
as poffible : then immediately cut a fecond
Slice from the fame Place, which apply to
the Microfcope, and in a Piece not larger
than a % Grain of Sand can cover > innumera-
ble Pores WAX be perceived, as plainly as little
Holes pricked by a fine Needle may be
difcerned if it be held up againft the Sun*
The Scales of the outer Skin prevent any
diftin(fl View of the Pores, unlefs they are
fcraped away with a Penknife, or cut off in
the above Manner ; but if a Piece of the
Skin between the Fingers, or in the Palms
of the Hands, be fo prepared, and then ex-
amined, theLight will be feen very pleafantly
through the Pores

Mr. Leeuwenhoek endeavours to give
fome flight Notion of the incredible Num-

{ Jrcan, Nat, Tom. 11. p 409, 412.

ber

7he Pores of the Skin.' *i7j^

ber of Pores in a human Body. He -f fun-
pofes there are one hundred and twenty fuch
Pores in a Line one tenth of an Inch long ;
however, to keep within Compafs, he reckons
only one hundred. An Inch in Length will
then contain a thoufand in a Row, and a
Foot twelve thoufand. According to this
Computation, a Foot fquare muft have in
it an hundred and forty-four Millions : and
fuppofing the Superficies of a middle-fized
Man to be fourteen Feet fquare, there will
be in his Skin two thoufand and fixtecn Mi-
lions of Pores.

To acquire fome clearer Idea ftill of this
prodigious Number of Pores by our Con-
ception of Time, let us reckon with *
Mersennus, that each Hour confifts of
fixty Minutes, and each Minute of fixty
Seconds, or fixty Pulfations of an Artery :
in one Hour there will then be three thou-
fand and fix hundred Pulfes; in twenty-four
Hours eighty-fix thoufand and four hundred ;
and in a Year thirty-one Millions five hun-
dred and thirty-fix thoufand. But there
are about fixty-four times as many Pores
in the Surface of a Man's Skin, and there-
fore he mufl: live fixty-four Years, ere he
will have a Pulfation for every Pore in his
Skin.

^ Jrcan, Nat. Tom, III. p. 413.
* Ibid. p. 413.

N 3 Dr.

176 ^T/S^ Pores of the Skin.

Dr. Nathaniel Grew obferves, that
the * Pores through which we perfpire are
more particularly remarkable in the Hands
and Feet ; for if the Hand be well wafhed
with Soap, and examined with but an indif-
ferent Glafs, in the Palm, or upon the Ends
and firft Joints of the Thumb and Fingers,
innumerable little Ridges parallel to each
other, of equal Bignefs and Diftance will be
found. Upon which Ridges the Pores may-
be perceived by a very good Eye, lying in
Rows, even without a Glafs : but, viewed
throup-h a good Glafs, every Pore feems like
a little Fountain, with the Sweat ftanding
therein as clear as Rock- Water y and, if
wiped away, it will be found immediately to
fpring up again.

When we confider the Multitude of Ori-
fices all over the Skin, it is reafonable to
imagine, that minute Animals, as Fleas,
Lice, Gnats, &c, do not with their flender
Inftruments make new Perforations, but
rather tliruft or infinuate them into the Vef-
fels of the Skin, and fuck out the Blood, or
v/hat other Humour is their proper Aliments

Fhilo/opb^ Tranfa£tions, Numb. 159^

CHAP.

[ '77 ]
CHAP. XXf.

0/ the h ou s E.

THE Loi/fe has fo tranfparcnt a Shell
or Skin, that we are able to difcover
more of what pafles within its Body, than
in mofl other living Creatures ; which ren-
ders it a delightful Objed for the Micro-
fcope.

It has naturally three -f Divlfions, "viz.
The Head, the Breaft, and the Belly or Tail-
part. — In the Head appear two fine black
Eyes, with a Horn that has five Joints, and
is furrounded with Hairs, ftanding before
each Eye -, from the End of the Nofe or
Snout there is a pointed projecting Part, ferv-
ing for a Sheath or Cafe to a Sucker, or
Piercer, which the Creature thrufts into the
Skin, to draw out the Blood or Humours it
feeds on, as it hath no Mouth that opens.
This Piecer or Sucker is judged to be "*■
kvca hundred times flenderer than a Hair ;
is contained in another Cafe within the firft,
and can be thruft out or drawn in at Plea-
fure.

The Breaft is marked very prettily in the
Middle, the Skin thereof tranfparent, and

f Fid. SwAMMERDAM Hift. Gcncr. dcs Inlefles, p. 174.
* Vid. Jrc. Nat. Tom II. p. 74.

N 4 full

j^B Of theL ov SI.,

full of little Pits. From the under Part of
it proceed fix Legs, each having five Joints,
their Skin refembling Shagreen, except to-
wards the Ends, where it appears finoother.
Each Leg terminates in tv^o hooked Clav^s
pf unequal Length and Size, which it ufes
as we 'vvould a Thumb and middle Finger.
There are -f- Hairs between thefe Claws, as
well as over all the Legs.

On the Back of the Tail-part we may dif-
cern fome * Ring-like Divifions, abundance
of Hairs, and a fort of Marks that look like
the Strokes of a Rod on one that has been
whipt. The Skin of the Belly feems like
Shagreen, and towards the lower End is
clear and full of little Pits ; at the Extremity
of the Tail are two little femi-circular Parts,
covered all over with Hairs, which ferve to
conceal the Anus.

When the Loufe moves its Legs, the Mo-
tion of the Mufcles (which all unite in an
oblong dark Spot in the Middle of its Breaft)
may be dijftinguiflied perfecflly : and fo may
the Motion of the Mufcles in the Head
be, when it moves its H^orns. The Motion
of the Mufcles is alfo vifible in the feveral
Articulations of the Legs. We may like-
wife fee the various Ramifications of the

"I" Fide SWAMMERD. p. IJ^.

f Vide Philof-.ph. Iran/. Numb, I02<

Vein

ifi?

0/tbeLovsz, ■^' 179

Veins and Arteries (which are white) with
the Puhe regularly beating in the Arteries.
But the moft furprizing of all is the periftal-
tic Motion of the Inteftines, continued from
the Stomach along all the Guts down to the
Anus.

If a Loufe, when very hungry, be placed
on the Back of the Hand, it will thruft its
Sucker into the Skin, and the Blood may
be ken paffing in a fine Stream to the Fore-
Part of the Head ; where falling into a
roundifh Cavity, it paiTes again, in a like
Stream, to another circular Receptacle in the
Middle of the Head -, from thence through
a fmaller Veffel to the Breaft ; and then to
a Gut that reaches to the hinder Part of
the Body, where in a Curve it turns a little

upwards. In the Breaft and Gut the

Blood is without Intermiffion moved with
great Force, efpecially in the Gut , and that
with fuch a ftrong Propulfion downwards, and
fuch a Contraction of the Gut as is amazing :
which continual and ftrong Aftion of the
Stomach and Bowels upon the Food of this
Creature, to further its Digeftion, is worthy
to be confidered.— — In the upper Part of
the crooked afcending Gut juft mentioned,
the propelled Blood ftands ftill, and feems
to undergo a Separation : fome of it be-
coming clear and waterifli, v/hile certain

little

i8o OfthelaOVSE.

little black Particles pafs downwards to the
Anus -f*.

If a Loufe be placed on its Back *, two
bloody darkifh Spots appear ; the larger in
the middle of the Body, and the leffer to-
wards the Tail. In the larger Spot a white
Film or Bladder contrails and dilates up-
wards and downwards from the Head to-
wards the Tail ; the Pulfe of which is fol-
lowed by a Pulfe of the dark bloody Spot,
in or over which the white Bladder feems to
lye. This Motion of Syftole and Diaftole,
is feen belt when the Loiife grows weak.
The white pulling Bladder feems to be the
Heart, for on pricking it the Lotife inftantly
dies. In a large Loufe the Pulfation may be
feen in the Back, but the white Film not
without turning the Belly upwards. The
lower darkiih Spot Dr. Harvey conjedlur'd
to be the Excrements in the Guts. -

Lice are not Hermaphrodites^ as has er-
roneoufly been imagined, but Male and
Female. Mr. Leeuwenhoek difcovered
that the Males have % Stings in their Tails,
but the Females none : and fuppofes the
fmarting Pain they fometimes givearifes from
their Stinging, when made uneafy by Pref-

t Vid. Philofoph, Tranfacl. Numb. 1 02.
* Vid. Dr. Power's Obferv. 9.
% Arc. Nat, Tom. II. p. -jj.

4 fure

Of the L ov s-E, i8i

fure or otherwife ; fince, if roughly handled>
they may be feen to thruft out their Stings ;
and as he felt little Pain or Uneafinefs frona
the Sucker or Piercer, tho' feven or eip-ht
were feeding on his Hand at once. The
Females lay Eggs or Nits, whence yoii/ig
Lice come forth, perfe(5l in all their Mem-
bers, and undergo no farther Change but
an Increafe of Size.

Mr. Leeuwenhoek being delirous to
learn the Proportion and Time of their In-
creafe, put two '^Females into a black Stock-
ing, which he wore both Night and Day;
and found that in fix Days one of them had
laid fifty Eggs, and upon diired:ing it faw as
many more in the Ovary -, whence he con-
cludes, that in twelve Days it would have
laid an hundred Eggs. Thefe Eggs hatch-
ing in fix Days (which he found to be their
natural Time) would probably produce fifty
Males and as many Females : and thefe Fe-
males coming to full Growth in eighteen
Days, might each of them be fuppofed, af-
ter twelve Days more, to lay alfo an hundred
Eggs ; which Eggs in fix Days farther (the
Time required to hatch them) might pro-
duce a younger Brood of five thoufand -j-.
So that, in eight Weeks, a Loufe may fee
five thoufand of its own Defcendants ; an

♦ Arc. Nat, Tom. I. p. 78.

Increafe

I §2 Of the ho vseI

Increafe hardly credible, were it not proved

by Experience.

A Lottfe may be differed eafily in a fmall
Drop of Water, upon a Slip of Glafs that
can be applied to the Micro/cope -, but with-
out Water the Parts are very difficult to di-
vide, and when feparated fhrivel and dry up
immediately. Thus, five or fix Eggs of a
full Size and ready to be laid may be found
in the Ovary of a Female, with fixty or
feventy of different Sizes, but all much more
minute, as the Eggs are in the Ovary of a
Hen. In the Male the Penis is rernarkable,
and alfo the Teftes, whereof it has a
double Pair ; the Sting likewife defcrves a
curious Examination. Thefe Creatures avoid
the Light as much as poffible, and are im-
patient of Cold. The Females, if failing,
appear very white, and even after feeding
feem lefs red than the Males, the Blood not
appearing fo plainly through their Veffels,
from the Multitude of their Eggs.

The Picture of the conunon Loiife is given
Plate XIII. Fig. IV.

Its Piercer or Sucker is fhewn by a.

The Sting of the Male by b.

There's another Kind of Loufe, found
about uncleanly People, which from its
Shape is called the Crab-Loufe, The Ver-
min adhering to and feeding on the Bo-
dies of different Animals, though much un-

Of the Louse* 1S3

like in Form and Size, are alfo commonly
called Lice. Of thelc there arc numberlefs
Species, feveral whereof we are obliged to
SeigniorKEDi for giving us the Drawings of,
at the End of his Treatifc (ie Ge?ieratione In-
feBorum^ whence Mr. Alb in has taken
them into his Book of Spiders : but few of
thefe have been fufficiently examined by the
Microfcope, and there are great Variety of
other Kinds that are yet quite unknown.

Evenlnfeds are infefted with Vermin that
feed on them and torment them. A Sort o£
Beetle known by the Name of the Lotijy
Beetle^ is remarkable for Numbers of little
Creatures that run about it nimbly from
Place to Place, but will not be fhaken oft.
Some other Beetles have Lice alfo, but of
different Kinds.

The Ear^ivig is troubled frequently with
minute Infedls, efpecially jufl under the fet-
ting on its Head. They are white and fl:iin-
ing like Mites, but much fmaller : they are
round-backed, flat-bellied, and have long
Legs, particularly the two foremoft. The
fame has not been obferved on any other
Animal.

S?mi/s of all Kinds, but chiefly the large
ones without Shells, have many little Infedls,
extreamly nlm.ble, that live and feed upon
them.

Numbers of little ;W Lice, with a very
fmall Head, and in Shape refembling a Tor-

toife.

1 84 Of t^e Lots s"^,

toife, are often to be feen about the Legs of
Spiders. Whilft the Spider Hves, they ehng
clofely to it, but if it dies they leave it.

WhitifhLice are frequently to be difcover-
ed running very nimbly on Humble-Bees : I
have feen them frequently on Ants : many
Kinds are difcoverable on Fiflies : Kircher
fays he has found Lice on Fleas; and, pro-
bably very few^ Creatures are free from them.

As fome may be defirous to know w^hat
Kinds oi Lice^ Seignior Redi has ob-
ferved and given Drawings of, the following
Lift is inferted to fatisfy their Curiofity. Lice
found on the Hawk, three Sorts : on the
large Pigeon, the Turtle-Dove, the Hen^
the Starling, the Crane. On the Moor-Hen
three Sorts, On the Magpie, the Heron^
the leffer Heron, the Swan, the Turkifli
Duck, the Sea-Mew, the fmaller Swan : on
the wild Goofe two Sorts : on the Teal, the
Kaftrel, the Peacock, the White Peacock^
the Capon, the Crow, the White Starling :
on Sweet-meats and Drugs : on Men, two
SortSy viz, the common Loufe and the Crah-^
Loufe : on the Goat, the Camel, the -f* Afs^
the African Ram, the African Hen ; on the
Stag two Sorts, and on the J Tiger.

CHAR

* Redi calls the Vermin on Beails tediculi ot Licei thofe
on Birds Pulices or Fleas. He fays every Kind of Bird has
its particular Sort o^ Fleas, different from thofe of other Birds :
That all when firfl hatched are white, but gradually acquire
a Colour like the Feath€i-s they live among: yet remain

tranfparen&

[ i85 1
CHAP. XXII.

Of the WooD-LousE.

There's a little Animal, in Shape and
Colour like a Loufe, that runs fwiftly
by Starts or Stops, and is commonly found
on the Leaves and Covers of Books, or a-
mongft rotten Wood : 'tis called a Wood--
Loiife, or Wood-Mite^ and is know^n almoft
to every Body, The Eyes of this Creature
are of a golden Colour, and can be drawn in
or thruft out at Pleafure ^ the Periftaltic
Motion of the Bowels appears in it diftinft-
ly, and what is ilill more wonderful, a
Motion of the Brain is feen,

I take this to be the Animal Mr. Der-
HAM calls the Pedicuhis Pidfatorius^ or
Death-Watch (in FhiL Tranf. Numb. 291.)
where he fays, the Pedicidus Pidfaforius^
and the Scarahceia Sojiicephaliis are the only
two Infecfls that make regular clicking Noifes
like the Beat of a Pocket- Watch.

tranfparent enough for a good Micro/cope to difcover the Mo-
tions of their Intellines : That the Crare has a white Sort,
marked as it were with Arabic Charaders : and that their '
Size is not proportion'd to the Eirds they breed upon, for the
little Black-bird has Fleas as large as the Snvan.

■\ Aristotle in his Hijiory of A?nmols, and Pliny, on
his Authority, afierts, that JJfes and Sheep are free fromV'er-
min : but Redi proves they are both miflaken as to the Jfi}
and as to Sheej), every shepherd Boy is able to confute them,

X The Loi'.fe of a Lion refenibles that of the Tiger in Shape,
but is larger, and of a brighter red. Vid.R£Di Experitfi,
circa Generat. hife^. p. 312, & feq.

CHAP.

[ i86 i
C H A P. XXIIL

O/* M I T E S.

lY Mites are commonly underftood ther
minute Creatures found in great Abun^
dance in Cheefe that is decaying. To the
naked Eye they appear Uke moving Particles
of Duft ; but the Micro/cope difcovers them
to be Animals, perfed: in all their Members,
having as regular a Figure, and performing
all the neceflary Offices of Life, in as orderly
a Manner, as Creatures that exceed them
many millions of times in Bulk.

They are cruftaceous ^ Animals, and ufu-
allytranfparent. The principal Parts of them
are, the Head, the Neck, and Body. The
Head is fmall in Proportion to the Body,
with a fharp Snout, and a Mouth that opens
and fhuts like a Mole's. They have two
little Eyes, and are extreamly quick-fightedj
for if you touch them once with a Pin or
other Inftrument, you'll perceive how readi-
ly they avoid a fecond Touch. Some have
fix Legs, and others eight > which proves
them of different Sorts, tho' in every refpec^
befidcs they appear alike. Each Leg has fix
Joints, furrounded with Hairs, and two little

*■ Vid. Power's Obferv, Hook's Microgr. p. 214.

Claws

0/ M I T E S. 1

Cl:\\vs at the Extremity thereof, which caa
calily take up any thing. The hinder Part
of the Botly is pkimp and bulky, and ends
in an oval Form, .with a few exceeding long
Hairs illuing therefrom. Other Parts of the
Body and Head are alfo thinly befet with
lonz Hairs.

Thefe Creatures are Male and Female.
The Female lays Eggs ; whence (as in Lice
and Spiders) the young ones Iffue forth with
all their Members perfe6t, though moft ex-
ceedingly minute: but, notwithftanding their
Shape does not alter, they caft their Skins
feveral times before they attain their full
Growth.

They may be kept alive many Months
between two concave Glaffes, and applied to
the Microfcope at Pleafure, and by often
looking at them many curious Particulars
will be difcover'd. They may thus frequent-
ly be feen * in Coifu, conjoined Tail to Tail;
for though the Penis of the Male be in the
Middle of the Belly, it turns backwards like
that of the Rhi?iGceros, The Coitus is per-
formed with an incredibly fwift Motion,
Their Eggs, in warm Weather, hatch in
twelve or fourteen Days -, but in Winter-
time and cold Weather not under feveral

» Vid. Arc. Nat. Tom. IV. p. 360.

O . Weeks

i88 0/* Mites.

Weeks. 'Tis not uncommon to fee the
young Ones ftruggling to get clear of the
Egg-ihell, which fometimes they are a Day
about.

The Diameter of a M/^'^'s Egg feems equal
to the * Diameter of the Hair of a Man s
Head; and fix hundred fuch Hairs are about
equal to the Length of an Inch. Suppofing,
then a Pigeon'^ Egg is three quarters of an
Inch in Diameter : four hundred and fifty
Diameters of a Mites Egg are but equal to
the Diameter of the Egg oi^. Pigeon : and,
confequentlvj if their Figures be alike, we
mult conclude that ninety-one Millions, an
hundred and twenty Thoufand Eggs of a
Mite are not larger than one Pigeons Egg.

Mites are moft voracious Animals 5 for
they devour not only Cheefe, but likewife
all Sorts of dryed Fifh orFlelh, dryed Fruits,
Grain of all Sorts, and almoit every thing
beiiQcs that has a certain Degree of Moifture
without being over-w^et : nay, they may of-
ten be obferved preying upon one another.
la eating they thrufi: one Jaw forwards and
the other backwards alternately, whereby
they appear to grind their Food ; and after
they have done feeding they feem to munch
and chew thcGud.

*■ Phihfoph. ^rmfaci. Numb. 333. & 284.

Thefe

Cy Mites; 189

Thcle :ire the Vermin that find a Way in-
to the Cabinets of the Curious, and eat up
their fine Butterjiici and other choice hifeclsy
leaving nothing in tlieir Head but Dull and
Ruins. The bed Method of preventing this,
is, to keep the Drawers or Boxes continually
fupply'd with Camphire^ whofe hot and dry
Effluvia penetrate, flirivel up, and deftroy
the tender Bodies of thcfc little mifchievous
Plunderers.

It muft however be remembered, that

there are fcveral Species of Mites, which

differ in fome Particulars, thouo-h their eene-

ral Figure and the Nature of them be the

fame. For Inftance, the * Mites in Malt-

Duft and Oatmeal-Duft are nimbler that

Checfe-MiteSy and have more and lonp-er

... . '^

Hairs. The Mites amongft Figs refemble

Scarabs, have two Feelers at the Snout, and
two very long Horns over them, with three
Legs only on each Side, and are more flug-
gifli than thofe in Malt. Mr. Leeuwen-
HOEK obferved fome Mites on Fio:s to have
longer Hairs than he had feen on any other
Sorts ; and upon Examination found thofe
Hairs were fpicated, or had other little Hairs
ifliiing from their Sides : whence he ima-
gined they might be jointed at the little Di-
flance where thefe Hairs come forth. He

Vide Power's Ohfer'v, p. lo.

O 2 had

jgo Cy Mites.

had alfo feen the like Hairs on other Mkes^
tho' very' feldom. Mr. Hook defcribes a
Sort of thefe Animals, which he terms -f-
wandering Mites^ as being to be found in
every Place almoft where they can get
Food.

Happening, fome Years ago, to look into
an empty white Gallipot, I fancy'd it was
dufty ', but, on a nearer View, perceiving
the Particles to move, I examined them by
the MicrofcopCy and difcovered what I had
taken for Duft to be Swarms of thefe wan-
dering Mites, which were tempted and
brought thither by the Smell of fome Ca-
viere, that had been in the Gallipot a few
Days before.

The Mite is exceedingly tenacious of Life 5
I have kept them in my Glaffes Months to-
gether, even without Food -, and Mr. Leeu-
WENHOEK fays, one he ftuck upon a Pin
before his Micro/cope % lived in that Condi-
tion eleven Weeks.

The Pidure of the Mite is fhewn Plate
XIII. Fig. V.

One of its Eggs appears juft by, at a.

-[• Hook's Microgr. p. 205.

% Arc. Nat, Tom. IV. pag. 363,

CHAP,

[ 191 ]

CHAP. XXIV.

Of the Flea.

THIS well-known little Creature is co-
vered all over with black hard (lielly
Scales, Plates, or Divifions, curioufly jointed,
and folded over one another, in fuch a Man-
ner, as to comply with all the nimble Mo-
tions and Acftivity of the Animal. The Scales
are curioufly pojifliedj and befet about the
Edges with long Spikes, in the moft beauti-
ful and regular Order poflible. Its Neck is
finely arch'd, and much refembles the Form
of a Lobfter's Tail. The Head is very ex-
traordinary -y for from the Snout Part there-
of proceed its two Fore-Legs, and between
them lies the Piercer or Sucker w^herewith it
penetrates the Skin of other living Creatures
and draws out its Food. It has two large
beautiful black Eyes, and a Pair of little
Horns or Feelers. Four other Legs are join'd
on at the Breaft, fo that it has fix in all -,
which, when it leaps, fold fhort one with-
in another, and exerting their Spring all at
the fame Inflant, carry the Creature to a fur-
prizing Diftance. The Legs have many
Joints, are very hairy, and terminate in two
long fharp hooked Claws, as may be feeii
Fig. VL Plate Xm.

O X The

192 Of the Flea,

The Fkd% Piercer or Sucker is lodged be-
tween its Fore-Legs, and includes a Couple
of Darts or Lancets, which, after the Piercer
has made an "* Entrance, are probably thruft
farther into the Flefh, to make the Blood
flow from the adjacent Parts, that it may be
fucked up 3 and feems to occaiion that round
red Spot, with a Hole in the Center of it,
w^hich we commonly call a Flea-Bite. This
Piercer, its Sheath opening fideways, and
the two Lancets within it are very difficult to
be itcn^ -f* unlefs the two Fore-Legs, be-
tween which they are ufually folded in and
concealed from View, be cut off clofe to the
Head : for a Flea rarely puts out his Piercer
except at the Time of feeding, but on the
contrary keeps it clofely folded inwards : the
beft Way therefore of coming at it is, by
cutting off the Head firft, and then the
Fore-Legs ; fince in the Agonies of Death,
it may eafily be managed, and brought be^
fore the Micro/cope,

Fleas are Male and Female, and lay Eggs
as well as Lice and Mites-, but are extream-
ly different in all the Progrefs of their Lives
befides,paffing through the fame Changes ex-
adly as the Silk%vG?in does. They depoiite their
Eggs at the Roots of the Hair of Cats, Dogs,

* Vid. Jrc. Nat. dcua. Tom. IV. p. 22.
-j- Ibid, p. 332, FhiL Iravfcti, Namb, 249,

•and

Of the Flea. 193

jfnd other Animals, flicking them faft there-
to by a kind of glutinous Moiflure. When
the Eggs hatch, not perfecft Flcas^ but little
Worms or Maggots, whofe Bodies have Ic-
veral annular Divilions thinly covered with
long Hairs, come out of them, and feed on
the Juices of the Animal, v/hereto they clofe-
ly adhere -j^. Thefe Maggots are very briflc
and nimble, but if touched, or under any
Fear, roll themfelves up on a fudden in a
round Figure, and continue motionlefs for
fome Times after which they flowly open
themfelves and crawl away, as Caterpillars
do, with a lively and fwift Motion.

When the Time of their Change ap-
proaches, they conceal themfelves as much
as poffible -, eat nothing, lie quiet, and feem
as if dying: but if viewed with t\it Micro-
fcope^ will be found, with the Silk or Web
that comes out of their Mouth, weaving a
Covering or Bag round them, whofe Infide
is as white as Paper, though without it al-
ways appears foil'd with Dirt. In this Bag
they put on the Cbryfalis or Aurelia Form,
and become Milk-white : but two or three
Days before they break from this Prifon,
their Colour darkens, they acquire Firm^
nefs and Strength, and as foon as they ilTuc
from the Bag are perfe^ Fleas ^^ and able tQ
leap away.

f ?hih TranCja. Namb. 249,

o 4 It

/

194 Of the "F J. "E, aI

It has been difcover'd, by putting the
Eggs of Fleas in a fmall Glafs Tube, and
keeping it conftantly warm in one's Bofom,
that, in the Midft of Summer, they hatch
in four Days: then, feeding the Maggots
with dead Fhes, which they fuck greedily,
in eleven Days they come to the full Perfec-
tion of their reptile State: when the Maggot
fpins its Bag, and in four Days more changes
into a Chry falls ^ after lying in which Con-
dition nine Days, it becomes a perfedf Flea.
It IS then immediately capable of Coition,
and in three or four Days lays Eggs. So
that in -f* twenty-eight Days a Flea may
come from the Egg itfelf, and propagate its
Kind ; and their vafl Increafe will not feem
fo great a Wonder, if we confider, that
from March to December there may be {twtn
or eight Generations of them. After having,
laid their Eggs they foon die, as all Creatures
do that undergo fuch like Changes.

By keeping Fleas in a Glafs Tube corked
at both Ends, but fo as to admit frefh Air,
their feveral Actions may be obferved, and
particularly their Way of coupling, which is
performed Tail to Tail, the Female (which
is much the larger) ftanding over the Male,
They will alfo be feen to lay their Eggs, not
all at once, but ten or twelve in a Pay for

f Vid. Jrc. AWo Tom, IV. p. 325.

' feveral

Of theVh'E.x. 19^

feveralDays fiicceflively ; which Eggs hatch
in the lame Order.

A Dillcdion of tlic Flea may be cffecfled
after the flime Method as that of the Loufe^
that is, in Water : the * Stomach and
Bowels, with their periftaltic Motion may
plainly be dilHnguilhed, and alfo the -f-Teftes
and Penis, together with Veins and Arteries
minute beyond Conception. Leeuwen-
HOEK affirms, that he has likewife difcover'd
innumerable Animalcules fhaped like Ser-
pents in the Semen majciilinum of a Flea,

Two Things in this Creature deferve our
Confideration, to wit, its furprizing Agility,
and its prodigious Strength, whereby it is
enabled to leap above an hundred times its
own Length : as has been proved by Expe-
riments. What vigorous Mufcles ! and how
weak and fluggifli, in Proportion to its own
Bulk, is the Horfe, the Camel, or the Ele-
phant, if compared with this puny Infecft !

A Flea's Egg is fliewn Plate XIII. Fig.

yi. I.

The TVorm ox Maggot proceeding from it.
Fig. VI. 2.

♦ Vid. Aj-c. Nat. Tom. IV. p. 20.

CHAP.

t ^96 ]

CHAP. XXV.

O/' S P I D E R S.

VERY Body is fo well acquainted with
___ the general Form of a Spider^ even
without the Affiftance of a Microfoope^ that
I fhall fpend no Time in the Defcription of
it : but proceed to give an Account of fom<=*
Tarticulars in this Animal, which are difco-
verable only by that Inftrument.

As a Fly (the Spiders, natural Prey) is
extreamly cautious and nimble, and comes
ufually from above, it was neceffary the
Spider fhould be furniihed with a quick
Sight, and an Ability of looking upwards,
forwards, and fidev/ays at the fame time :
and the Micro/cope fhews, that the Num-
ber, Structure, and Difpoiition of its Eyes
are wonderfully adapted to ferve all thefe
Purpofes.

Moft Spiders have eight * Eyes : two on
the top of the Head or Body (for there is
no Divifion betv^/'een them, a Spider having
no Neck) that look diredly upwards -, two
others in Front, a little below thefe, to dif-
cover all that paffes forwards : and on each
fide a couple more, one whereof points fide-

f N. B. Spidsr^s Eyes are not pearled.

ways

Of Spiders. 197

ways forward, and the other fideways back-
wards : fo tlrat it can fee almofl quite round
it. All Kinds of them have not indeed a
like Number of Eyes, for we find ten in
fome, in others only eight, fix, or four • and
in the Field, Long-Legs, or Shepherd-Spider^
no more than two. But whatever the
Number be, they are immoveable and tranf-
parent j are litaatcd in a moft curious Man-
ner, and delerve the ftricfteft Examination.
The beft Way of viewing them is, to cut off
the Legs and Tail, and bring only the Head-
part before the Microfcopc.

All Spiders have eight Legs, which they
employ in walking, and two Arms or fhorter
Legs near the Mouth, that aflift in taking
their Prey. They appear thickly befet with
Hair, have each fix Joints, and end with
two hooked Clav/s, ferrated, or having Teeth
hke a Saw on their Infide, whereby they
cling faft to any thing ; and at a little Di-
llance from thefe Claws a fort of Spur ftands
out, without any Teeth at all. See Fig. VIL
Plate XIIL

But the dreadful Weapons wherewith the
Spider feizes and kills its Prey are a Pair of
fharp crooked Claws or Forceps, (by fome,
tho' very improperly, called Stings) in the
Fore-part of its Head. The Scolopefidra^
or Indian MillepeSy and feveral other Li-
fefts have Weapons of the like Form, and

ferving

19^ Of Spiders.

ierving to the fame Purpofe. Thefe CIaw«
or Pincers ftand horizontally -, and are, when
not made ufe of, concealed in two Cafes
contrived for their Reception : into which
they fold like a Clafp-knife, and there lye
between two Rov^^s of Teeth, that are like-
wife employ'd to hold fafl: its Prey. This
Apparatus is better fhewn than defcribed :
See Fig. VIII.

Mr. Leeuwenhoek informs us, ^ that
each of thefe Claws or Pincers has a fmall
Aperture or Slit near its Point, as in a Viper's
Tooth : through which he fuppofes a poi-
fonous Juice is injedled into the Wound it
makes, occafioning Death to Flies and other
Infers. But Dr. Mead, in his moft excel-
lent E/fay on Poifons^ believes this to be a
great Miftake : having not been able to dif-
cern any Exit or Opening, though he view'd
thefe Parts feveral times with a very good
Mi cr of cope. And he was the more confirmed
in this Opinion, by examining a Claw of the
great American Spida% defcribed by Piso,
and called Nhamdu^ given him by Mr. Pe-
TivER : which being about fifty times big-
ger than that of any European Spider, if
there had been any Slit in it, he doubted
not his Glafs would have difcover d it -, but
yet he found it to be quite folid. Befides^

f Vid. Jrc, Nat. Tom. IV. Par„ IL p. '3,\g,

" after

O/' S P 1 D E R S. 199

^' after repeated Trials he plainly faw that
" nothing dropped out of the Claws, which
" were always dry, while the Spider bit, but
" that a fliort white Probofcis was at the
" fame time thrufl out of the Mouth, which
•' inftilled a Liquor into the Wound." And
he farther obferves, *' that the Quantity of
*' Liquor emitted by our common Spiders
" when they kill their Prey, is vifibly fo
" great, and the wounding Weapons fo mi-
" nute, that they could contain but a very
" inconfiderable Portion thereof, if it were
*' to be difcharged that way."

Spiders frequently caft their Skins, which
may be found in Cobwebs, perfecftly dry and
tranfparcnt ; and from fuch Skins, the For-
ceps or Claws (for they are always ilied with
the Skin) may ealier be feparated, and exa-
mined with more Exadnefs than in a living
Spider : for they commonly appear fpread
out fairly to view, and, by their Tranfpa-
rency every minute Part is feen with much
Diftindnefs. But neither this Way, nor
any other, have I been ever able to difcern
the Aperture Mr. Leeuwenhoek fpeaks
of.

The Contexture of the Webs of Spiders^
and their Manner of Weaving them, are far-
ther Difcovcries of the Microfcope ; for that
•informs us, that the Spider has five little

Teat-.

200 Of Spiders.

Teats or Nipples near the Extremity of the-
Tail, whence a gummy Liquor proceeds^
which adheres to any thing it is preffed againft,
and being drawn out, hardens inftantly in
the Air, and becomes a String or Thread,
ftrong enough to bear five or iix times the
Weight of the Spider ?> Body. This Thread
is compofed of feveral finer ones that are
drawn out feparately, but unite together two
or three Hairs Breadth diftant from the Bo-
dy of the Spider. The Threads are finer or
coarfer according to the Bignefs of the Spider
that fpins them. Mr. Leeuwenhoek com-
putes that an hundred of the fineft Threads
of 2i full-grown Spider are not equal to the
Diameter of the Hair of his Beard ^ and,
confequently^ if the Threads and the Hair
be round, ten thoufand fuch Threads are
not bigger than fuch an Hair. He calcu-
lates farther, that when youjig Spiders firft
begin to fpin, four hundred of them are
not larger than one that is full-grown j and^
therefore, the Thread of fuch a little Spi^
der is fmaller by four hundred times than
the Thread of a full-grown One : allowing
which, four Millions of a young Spide?^'^
Threads are not fo big as the fingle Hair of
a Man's Beard. ■^"

* Phil, Tranf, Numb. 272,

0/^SrjDER$. 201

The Eggs oi (on^t Spiders arc very plcafant
Objedls, being round at one End and flattifh
at the other, with a Deprefllon in the Center
of the flattilh End, and a yellowifli Circle
round it. Their Colour is a blewilh White
like counterfeited Pearl ; and when they
hatch, the little Spiders come out pcrfed:ly
formed, and run about very nimbly. The
Female depofits her Eggs, to the Number
of five or fix hundred, in a Bag ftrongly
compofed of her own Web, which £he ei-
ther carries under her Belly and guards with
the greateft Care, or elfe hides in feme fafe
Recefs. As foon as the Eggs are hatched,
the minute Spiders appear very agreeably in
the Microfcope,

It has been before obferved, that the Cur-
rent of the Blood may be feen in the Legs
and Body of this Creature ; and the judi-
cious Obferver will difcover many other
Wonders in the DiiTedtion and Examination
of its feveral Parts, which it w^ould be tire-
fome for me to dwell on here. I cannot,
however, conclude this Plead, without point-
ing out two or three Kinds of Spiders as
particularly worth Notice.

There is a little lukite Field Spider with
fliort Legs, found plentifully among new
Hay, v/hofe Body appears like white Am-
ber, with black Knobs, out of each where-

3 ^f

202 O/* Spiders,

of grow Prickles like Whin-Pricks. Some
have fix, fome eight Eyes, that may be di-
Itinftly feen, quick and lively : each Eye has
a Violet-blew Pupil, clear and admirable,
furrounded by a pale yellow Circle.*

The wandering or -f* hunting Spider y who
fpins no Web, but runs and leaps by Fits,
has two Tufts of Feathers fixt to its Fore-
Paws, which well deferve being placed be-
fore the Microfcope : the Variety and Beauty
of Colouring all over this little Creature af-
ford likewife a moft delightful View.

J The Long-Legs^ Fields or Shepherd-
Spider is a moft wonderful Creature : It has
two Fore-Claws at a great Diftance from
the Head, tip'd with Black like a Crab's,
that open and jfhut in the Manner of a Scor-
pion's, and are Saw-like, or indented, on

the Infide. ^Cut all the Legs from this

Spider^ and place it before the Microfcope^
and you'll dlfcover, that the Protuberance
on the top of the Back is furnifh'd with two
fine Jet-black Eyes.

The little red Spider that creeps on the
Barks of Trees fhould aifo not be neglefted,

* Dr. Power's Micro/cop. Ohfernj. p. 13.

f Hook's Mkrog. pag. 200. % Ibid. p. 14.

[ 203 ]

CHAP. XXVI.

Of the Gnat.

THE Produdion of this Creature is from
an Egg^ depofited by its Parent upon
the Waters, which firft becomes a Wo?^m or
Maggoty then a very odd aquatic Animal^
(defcribed pag. 88.) and afterwards a Gnat.
The particular Beauties of it cannot poffi-
blybe difcovered without thtMicroJcope-, but
by the Affiflance of that Inftrument, it ap-
pears to be adorned by Nature in a more
extraordinary Manner than mofl: other living
Creatures are. Its Tail-Part is covered over
with Feathers, moft exquifitely difpofed in
Rows : of different Colours, but yet perfed:-
ly tranfparent. The § Ereaft (which is cru-
ftaceous) is bedecked with little ftiif Hairs
or Briftles, inftead of Feathers ; and from
thence fix hairy Legs proceed, with fix Joints
to each, and at the End two little Claws.
The Feet are all over feather 'd in a Manner
refemblino: the Scales of Fifhes, with abun-
dance of little black Hairs amonsift them,
appearing flubborn like Hogs Briftles. Its
Wings are encompaffed v/ith a Furbelow of
long Feathers : and the Veins or Ribs that

5 SWAMMERD, HiJi^Geverale des Infedts^ p. Io8.

P . ^^ fsrve

204 Of the Ol^ AT,

ferve to ftrengthen them are alfo either fea^
thered or fcaled. Between thefe Ribs an ex-
ceeding thin tranfparent Membrane is ex-
tended, full of little black fharp-pointed
Hairs, that are ranged every where with the
utmoft Regularity. But as there are ^ dif-
ferent Sorts of Gnats, their Wings are alfo
very different, fome having a Border of long
Feathers, others of {hort ones, and others
none at all : the Rib^-work of the Wings,
•likewife, in fome is feather'd, in fome fcaled^
^nd in fome befet with Prickles.

But the mofl wonderful Part of this Crea-
ture is its Head : as it contains the Horns,
the Sting or Sucker, and the Eyes. The
Horns of the briijh-hornd or Male Gnat are
a moft charming Object : it has two Pair,
one whereof is furrounded, at little Diftances,
with long Hairs ilTuing out circularly : each
Circle leilening more than other as it ftands
nearer the Extremity of the Horns : and the
whole, together, exadlly reprefenting the Fi-
gure of the Plant called Equifetiim or Horfe-
'l^aiL The other Pair are longer and much
thicker than the foregoing, and hairy from
End to End. In the great-belly d or Female
Gnat^ the iirft Pair of Horns, though of the

J Mr. Derham oblerved near forty difFerent Species of
Gnats about the Place where he lived, which was V^mhijler
ill EJfex. Vide FhjfiCO-T^heoh^)\ p. 378.

fame

Of tht' Gnat. 20^

fame Figure as the Male's, has Hairs not
near fo long, and the Iccond Pair is fhortcr
than the firft by at lead three Parts in four.

The Fiercer^ Sti?:g, or Sucker is a Cafe
cover'd with long Scales, that lies concealed
under the * Gnat\ Throat, when not made
ufe of. The Side opens, and four Darts are
thrufl: out thence, occafionally ; one where-
of (minute as it is) ferves for a Sheath to
the other three. The Sides of them are ex-
treamly fharp, and they are barbed or in-
dented towards the Point, whofe Finenefs is
inexpreffible, and fcarcely to be difcerned by
the greateft Magnifier. When thefe Darts
are thruft into the Fleih of Animals, either
fucceffively, or in Conjund:ion, the Blood
and Humours of the adjacent Parts muft
flow to and caufe a Tumour about the
Wound, whofe little Orifice being clof^d up
by the Compreilion of the external Air, can
aiford them no Outlet. When a Gjmt finds
any tender juicy Fruits, or Liquors, fhe fucks
up what fhe likes, through the outer Cafe,
without ufing the Darts at all : but if it is
Flefh, that refills her Eiforts, fhe ftings very
feverely, then fheaths her Weapons in their
Scabbard, and through them fucks up the
Juices Ihe finds there. The Pain they caufe

* - ' " , - ■».■.■»

* Vid. Hiji. cf Nat. Eng. i2mo Edit. Vol. I. p. 124.

P 2 is

2o6 Of the Gnat.'

is only while they are entering, and continues
not when the Gnat is fucking : nor is its
Stinging out of Revenge, but from mere Ne-
ceflity, to obtain a proper Suftenance.

The Gnath four Darts are ihewn Plate
XIII. Fig. IX. a, b, c, d.

A Gnafs Eyes, which form the greateft
Part of its Head, are pearled, or compofed
of many Rows of little femcircular Protube-
rances ranged with the utmoft Exaftitude.
What thefe Protuberances are, and the Pur-
pofes whereto they ferve, will be explained
when we come to treat of the Eyes of In-
fers,

The Motion of the Inteftines may be feen
in the tranfparent Parts of this Animal, and
upon Diffe<flion many curious Difcoveries
may be made. Mr. Leeuwenhoek fays
he found in the * Semen of the Male num-
berlefs Animalcules fmaller than thofe in
Fleas, and in the Female a furprizing Quan-
tity of Eggs. And, indeed, the Spawn of
this Infed: is amazingly great, in proportion
to its Size, beijig feen floating on the Waters
(though always faftened to fomethingto pre-
vent its fwimming away) fometimes above
an Inch in Length, and half a quarter in Dia-
meter y the Eggs (each of which has a little

*. Leeuwen. Jrcan. Nat. Tom.IV. p. 22.

black

0/ /Z;^ Ox-Fly, or Gad-Bee. 107

black Speck) being placed in cxadt Order,
and kept together by a fort of Gelly or glevvy
Matter, which the minute Maggots, when
hatched, carry down with thcni to the Bot-
tom, and thereby cement together the fmall
Particles of Earth or Sand that form their
Cells or Cafes.

CHAP. XXVII.
Of the Ox-Fly, or Gad-Bee,

ANOTHER Creature that undergoes a
like Change, is the Ox-Fly, Dun-fly^
or Gad-Bee, an Infedt very troublefome to
Cows and Horfes.

This, like the Gnat, has a long Probofcis,
with a fliarp Dart or Darts fheathed therein.
The Ufe of thefe Darts is to penetrate the
Flefh of Animals, and feed on their Blood :
whereas the Probofcis can only ferve to fuck
the Juices, Honies, or Dews, from Fruits,
Flowers, or the Leaves of Plants : and Pro-
vidence feems to have kindly furniflied it
with this twofold Inftrument, that if one
Sort of Provifion fails, it may be able to fub-
lill on the other. It is worth Enquiry whe-
ther hice. Fleas, Hoiife-Biigs, &:c. are not
alfo provided for the fame Purpofe.

P 7 The

2o8 Of the Ox-Fly, or Gad-Bee.

The Eggs of this Infedl are depofited in
the Waters, and produce an extraordinary
Kind of little Worm or Maggot, the Extre-
mity of whofeTail is incircled with moveable
Hairs, which being expanded on the Sur-
face of the Water, enable it to float along,
f as in Plate VII. Fig. XIII. a. When it
would defcend towards the Bottom, thefe
Hairs are made to approach each other in an
oval Form, and inclofe a little Bubble of Air;
by means whereof it is able to rife again :
and if this Bubble efcapes, as fometimes it
will, the Infedl immediately fqueezes out of
its own Body another like Bubble to fupply
the Place thereof. The Maggoty as defcend-
ing, is iliewn Fig. XIII. b. Its Snout has
three Divifions, whence three little pointed
Bodies are thruft out, in continual Motion,
like the Tongues of Serpents.

Thefe Maggots are frequently to be met
with in Water taken from the Surface of
Ditches. The Motion of their Inteflines are
perfedly lingular and diftinguifhable, and
they are Obj efts well deferving our particular
Obfervation.

f Y'li. SwAMMZRD. H{J},Generak des InfeSleSy p. 14S.

C f I A P.

[ -09 ]
CHAP. XXVIII.

Of the Stings of Insects.

THE jl.mrp and penetrating hijlruments
wherewith the Tails of Bees, Wafps,
Hornets, Ants, and fome other Infe6ls are
armed, I diflinguiili by the Name oi Stings :
being Weapons given them by Nature to
defend themfelves and offend their Enemies -,
whereas the Trunk or Prohofcis which Gnats,
Fleas, Lice, and many other Kinds carry in
their Mouth, though it maybe equally fharp,
is not intended as an Inftrument of Revenge,
but for procuring and fucking in their Food;
and therefore, when fuch Creatures bite or
fting us, as we term it, we muft not ima-
gine they do fo out of Anger, but from Ne-
ceffity. Squeeze or ftrike a Bee or Wafp,
it inftantly puts forth its Sting, but no Pro-
vocation can urge a Gnat or Flea to bite :
on the contrary, when difturbed or hurt they
draw in their Probofcis inftead of thru fting
it out, and never make ufe of it but when
they think themfelves perfeftly fafe and
quiet. There is befides, this farther Diffe-
rence : a Sti?ig inje^s a venomous Liquor
into the Wound it makes, but a Prohofcis
fuck's or draijos out the Blood and Humours
from it.

P 4 As

$IG W ^ Bee'j Sting.

As the Strudture and Contrivance of moft
Stings are nearly alike, by defcribing one, the
reft will be underftood : I ihall, therefore,
give a brief Account of the Sting of a Bee^
as difcovered by the Microfcope, .

CHAP XXIX.

Of a B E eV Sting.

^'T"^HE Sting of a Bee is a horny Sheath
^ or Scabbard that includes two bearded
Parts. This Sheath ends in a fharp Point ;
near the Extremity whereof a Slit openS;^
through which, at theTirne of flinging, two
^earded Darts are protruded beyond the En4
of the Sheath ; one whereof being a little
longer than the other, fixes its Beard firft \
but the other inftantly following, they pene-
trate, alternately, deeper and deeper, taking
hold of the Flefh with their Hooks, till the
whole Sting becomes buried in the V/ound ;
and then a venomous Juice is injeCled, thro*'
the fame Sheath, from a little Bag at the
Root of the Sting, which occafions an acute
Pain, and a Swelling of the Part, continuing
ibmetimes feveral Days. This is beft pre-
vented, by enlarging the Wound immediately
to give it fomfj Difcharge,

The

Of a Bee's Sting. 21 1

^ The two Darts lye within the Sting as in
Plate XIII. Fig. X. .7.
When thruft out they appear as in Fig. X. /5.

Mr. Derham fays, he counted, in the
Sti?ig of a JV^fp, eight Beards on the Side of
each Dart, fome what like the Beards of Fifh-
Flooks, and I have obferved the fame Num-
ber in that of a Bee, When thefe Beards are
flruck deep in the Flefh, if the wounded
Perfon ftarts before the Bee can difengage
them, {he leaves her Sting behind flicking
in the Wound : but if he has Patience to
ftand quiet, till {he brings the Hooks clofe
down to the Side of the Darts, {he withdraws
her Weapon and the Wound becomes much
lefs painful. A Wafp is not fo liable as a
Bee to leave its Sting behind, the Beards of
it being rather fhorter, and the Animal
flronger and more nimble.^

To viev/ the Sti?tg of a Bee by the Mi-
crofcope^ cut off the End of its Tail, and
then touching it with a Pin or Needle, it
will thruft out the Sting and Darts, which
may be fnipt off with a Pair of Sciffars and
kept for Obfervation. Alfo if you catch a
Bee in a Leather Glove, its Sting will be

* ^^'^^'Di^UhuCiPhy/.ThcoI, p. 241. Spca, ck la Nat.
Pial. VI.

left

212 Of the Sting of a Scorpi6n.'

left therein, being unable to difengage it»
Hooks from Leather : and when it is quite
dead, which it will not be till after feveral
Hours, you may by Care and Gentlenefs
extract it with its Darts and Hooks. By
fqueezing the Tail, pulling out the Sting,
and preffing it at the Bottom, you may like-
wife force up the Darts ; but without fome
Pracftice this will be a little difficult.

The Bag containing the Poifonous Juice
may eafily be found at the Bottom of the
Sting and examin'd, being commonly pul-
led out with it : and, by letting the Bee
ftrike it% Sting u^on fome hard Body, enough
of the faid Juice may be obtained to put upon
a Slip of Glafs, in order to view the Salts^
floating therein at firft, and afterwards flioot-
ing into Cryftals.

CHAP. XXX,

Of the Sting of a Scorpion,

OWfar the Sting of a Scorpion Is of a
like Stru(fl;ure with that of a Bee I ne-
ver had the Opportunity of examining, as
none of them are brought alive to England %
but the Curious that go abroad to hot Coun-
tries, where they are produced, would do
well to obferve, particularly, whether a Dart

or

Of the Sting of a Scorpion. 213

or Darts are not Hicathed in the horny Sting
at the Extremity of their Tall.

The Opinions of Authors are very diffe-
rent as to this Creature's having or not hav-
ing any Opening in its Sti'/ig, through which
a Poifon illues into the Wound it makes.
Galen fiiys, there is none : Pliny, Ter-
TULLiAN, Elian, Aldrovand and Others
aflert, on the contrary, that there is. But I
think this Matter is fet in the trueft Light
hy Seignior Kedj, that dihgent Naturahft,
who took the Pains to examine Sco?^pio?2s
brought from Tunis, from Egypt, and
from Italy, in order to difcover this Aper-
ture, with two of the beft Micro/copes in
the Mufceiim of the Gra?id Duke of Tus-
cany, one whereof was made at Rome,
and the other in England : but, though
thefe Glaffes were excellent, he was unable
to difcern the leaft Perforation. However,
not fatisfied with only viewing them, he en-
deavoured, by Preffure, to fqueeze from the
Cavity of the Sting any Liquor it might con-
tain ; but he found it fo hard and horny,
that Squeezing could have no Effe6t. He,
moreover, caufed a Scorpion to ftrike on a
Plate of Iron, but no Moifture appeared
thereon ; fo that he began to conclude Ga-
len's Opinion right 3 when he difcovered,
accidentally, an exceeding fmall and almoll
invifible Drop of white Liquor upon the
3 ^ting'.

214 Of the Sting of a Scorpion.
Sting ^ -J which convinced him that Eli Ail'
fays true, where he afferts, that the Perfo-
ration in a Scorpions Sting is fmall beyond
the Poffibihty of being feen. And fuch a
Drop he frequently faw afterwards, in the
Progrefs of his Experiments, on the Stings
of feveral Scorpions^ at the Time of their
Striking : which Drop entering the Wound,
produced the moft fatal EfFe6ls» \

What a virulent and furprizing Poifon
m.uft: this be ! that, in fo very minute a Quan-
tity, can contaminate the whole Mafs of the
Fluids, and bring on fudden Death, not only
in Man and other fmaller Creatures, but
even in Lions, Camels and Elephants, as we
are affured it will ! How fubtle, how pene-
trating, how divifible, muft the component
Particles of this little Speck of Venom be !
and how ftrong a Proof it affords, that the
greatefl: Changes imaginable maybe wrought
in the human Body, by the Admixture of
different Liquors with the Blood even in the
fmailefl Quantities !

* Vid. Redi de Gener. InfeSi. p. 127.

f Mr. Leeuwenhojek difcovered an Opening on eack
Side of the Sting for the Emiffion of this Poifon ; which he
fuppofes is not difcharged till the Sting is buried in the Wound,
'Si^. Arc, Nat. Tom. 11. p. 167.

CHAP.

[215 ]

CHAP. XIII.
Of the Poison of a Viper.

THE Mifchief done by the ^//>f;*,orany
other Serpent, is not effected by means
of a Sting, (for what is darted out of its
Mouth, and by the Vulgar fuppofed a Sting,
is nothing but the Tongue of the Animal,
and perfcdly harmlefs :) but its Teeth are
the dreadful Weapons wherein the Poifon
lies, and its Bite is all we need to fear.

Dr. Mead, in his moil valuable Effay on
the Poifo?i of the Viper ^ b.as defcribed thefe
Teeth and their Poifon fo much better than
it is poffible for me to do, that I fliall beg
Leave to borrow the chief I have to fay from
him.

The poifonous Fa?2gs or great Teeth are
crooked and bent : they are hollow from
the Root a confiderable Way up, not to the
very Point, (which is folid and fliarp to pe-
netrate the better) but to within a little Di-
fl-anceof it: as may be feenbyfplittingaTooth
through the Middle. This Cavity ends in a
vifible S'it refemblins; a Nip or Cut of a Pen.
See Plate XIII. Fig. XI. The Poifon is
eje(5led through this Slit from a Bag at the
Root ol the Teeth, into which it is difcharg'd
by a Dufl juft behind the Orbit of the Eye,

from

2i6 Of the Poison of a Viper.

from a conglomerated Gland that feparates it
from the Blood.

The venomous Juice of the Viper may be
got by enraging it till it bites on fomething
folid. This Juice the Dodor put carefully
on a Glafs Plate, and examined it by the Mi-
crofcope. Upon the firfl; fight he could dif-
cover nothing but a Parcel of fmall Salts
nimbly floating in the Liquor : but in a very
ihort Time the Appearance was changed,
and thofe faline Particles v^ere now ihot out
as it were into Cryftals of an incredible
Tenuity or Sharpnefs, with fomething like
Knots, here and there, from which they
feemed to proceed : fo that the whole Tex-
ture did in a manner reprefent a Spider's
Web, though infinitely finer and more mi-
nute ', and yet withal, fo rigid were thefe
pellucid Spicula or Darts, that they remained
unaltered upon his Glafs for feveral Months.
And, by conndering the necefl^ary Efl:ed:s of
fuch Spicula in the Blood, this learned Phy-
fician accounts very reafonably for all the
Symptoms ufually fucceeding the Bite of this

Animal.

Galen fays, the Mountebanks of his Time
ufed, Vvdth fome kind of Pafte, to flop the
Perforations in the Teeth of Fipers, whereby
they kept in the Venom ; and then v/ould
fufFer themfelves to be bit, pretending their
Antidotes prevented any ill EiFefts.

CHAP.

[217 ]

CHAP. XXXII.

Of the Snail.

THE * S/ii?// has four Eyes, at the End
of optic Nerves, fheathed in her Horns,
which Ihe can draw in, or thruft out, turn,
or diredl, as flie finds moft convenient.

When the Horns are out, cut off nimbly
the Extremity of one of them, and, placing
it before the Microfcope^ you may difcover
the black Spot at the End to be really a
Semi globular Eye.

The DilTecftion of this Animal is very cu-
rious ; for the Microfcope does not only fliew
the Heart, beating, juft againft a round Hole
near the Neck, which feems the Place of
Refpiration ; but alfo the Liver, Spleen,
Stomach, Veins, Arteries, Guts, Mouth and
Teeth. The Guts are green, from the Crea-
ture's eating Herbs, and branched all over
with fine capillary white Veins. The Mouth
is like a Hare's or Rabbet's, with four or fix
'Needle-Teeth refembling thofe of Leeches^
and of a Subftance like Horn.

Snails are all Hen?iaph?'odites^ having
both Sexes united in each Individual. They
lay their Eggs with great Care in the Earthy

* Vide Power's Obfew. p. ;8. Lister Exerc* Anatom,
CachL ipa, d, la Nature, Dial. XI.

and

2i8 Of the S^ Alt:

and the Young Ones come out, when hatch*
ed, with Shells compleatly formed, and of a
Minutenefs proportionable to their own Size*
Thefe little Shells enlarge, as the Snails ad-
vance in Growth, by the Addition of new
Circles^ of which Circles they always conti-
nue to be the Center.

Cutting off a Snail's Head, a little Stone
appears, ^ .which from its diuretic Quality is
of fingular Service in gravelly Diforders. Im-
mediately under this Sto?ie the beating Heart
is feen, with its Auricles, which are mem-
branous ; all of a white Colour, as are alfo
the Veffels iffuing therefrom. This little
Stone feems intended to ferve inftead of a
Breall-Bone, which mofl: other Creatures
have.

It is very remarkable that Snails difcharge
their Excrements at an Opening in the Neck,
that they breathe there, and that both their
Male and Female Parts of Generation are
fituated near the fame Place. The Male
' Part is very long, and in fhape refembles the
Penis of a Whale.

f Fid, SwAMMERDAM, Hiji. Gencr. des InfeSis, p. 77.

iL- XX A xp

[ 219 ]

CHAP. XXXIII.

Of the common Fly.

THE common F/>' is adorned with Beau-
ties not to be conceived without aM/-
crofcope. It is ftudded from Head to Tail
with Silver and Black, and its Body is all
over befet with Bridles pointing towards the
Tail. The Head of it contains two large
Eyes, encircled with Borders of Silver Hairs;
a wide Mouth, with an hairy Trunk or In-
ftrument to take in its Food : a Pair of fhort
Horns, feveral ftiff black Briftles, and many
'other Particulars difcoverable by the Micro^
fcope"^. Its Trunk confifts of two Parts, fold-
ing over one another, and fheathed in the
Mouth. The Extremity thereof is fharp
like a Knife, for the Separation of any thing.
The two Parts can alfo be formed, occafion-
ally, into a Pair of Lips for taking up pro-
per Quantities of Food, and by the F/y's
fucking in the Air, they become a kind of
Pump, to draw up the Juices of Fruits or
'other Liquors.

Some Flies are much lighter coloured and
more tranfparent than others, and in fuch
.the Motion of the Guts may be feen very

^^eSfade de la Nat, Dial. VII.

220 Of the common Fly.

diftindly, Avorking from the Stomach to-
wards the Anus 3 and alfo the Motion of
the Lungs, contrading and dilating them-
felves alternately. Upon opening a Fly^
iiumberlefs Veins niay likewife be difcovered,
difperfed over the Surface of its Inteftines :
for the Veins being blackifh, and the Inte-
ftines white, they are plainly vifible by the
Microfcope, though two hundred thoufand
times flenderer than the Hair of a Man's
Beard. According to Mr. J Leeuwenhoek,
the Diameter of four hundred and fifty fuch
minute Veins were about equal to the Dia-
-meter of a fmgle Hair of his Beard ; and
confequently, two hundred thoufand of them
put together would be about the Bignefs of
fuch an Hair.

In moil kind of FHes^ the Female is
furniihed with a moveable Tube at the End
of her Tail, by extending of which fhe
.can convey her Eggs into convenient Holes
and Pveceptacles, either in Flefh or fuch
other Matters as may afford the Young Ones
.proper Nourifhment. From the Eggs come
forth minute Worms or Maggots, which
after feeding for a while, in a voracious Man-
ner, arriving at their full Growth, become
transformed into little brown Aurelias 3

X Jrc. Nat. Tom, II, p. 77.

whence.

Of the We EVIL J '221

whence, after fomc time longer, they ilTue
pcrfcLt lilies.

It would be cndlefs to enumerate the dif-
ferent Sorts of ¥Ucs^ which may continually
be met with in the Meadows, Woods and
Gardens ; and impofiiblc to defcribe their
various Plumes and Decorations, furpaffing
all the Magnificence and Luxury of Drefs
in the Courts of the greateft Princes. Every
curious Obferver will find them out himfelf,
and, with Amazement and Adoration, Hft
up his Eyes from the Q-eature to the
Creator.

C H A P. XXXIV.

Of the Weevil, cr Corn-Beetle.

rHE Weevil and the JVof are two kinds
of fmall Infedts that do abundance of
Mifchief to many Sorts of Grain, by eat-
ing into them and devouring all their Sub-
ftance.

The Weevil is fomewhat bigger than a
large Loufe, of the Scarab kind, with . two
pretty, jointed, tufted Horns, and a Trunk
or Piercer projecfting from the Fore-part of
its Head. At the End of the Trunk (v/hich
is very long in Proportion to its Body) are a
fort of Forceps or iharp Teeth, wherewith
it gnaws its Way into the Heart of the

0^2 Grain,

222 Of the W E E V I L."

Grain, either to feek its Food or depofit its
Eggs there.

By keeping thefe Creatures in Glafs
Tubes, with fome few Grains of Wheat,
their Copulation has been difcovered, and
likewife their Manner of Generation, which
is thus.—-)- The Female perforates a Grain
of Wheat, and therein depofits a fingle ob-
long Egg, or two Eggs at moft, (a Grain of
Wheat being unable to maintain above one or
two of the young Brood when hatch'd) and
this ihe does to five or fix Grains every Day
for feveral Days together. Thefe Eggs, not
above the Size of a Grain of Sand, in about
feven Days produce an odd fort of white Mag-
goty which wriggles its Body pretty much,
but is fcarce able to move from Place to Place,
as indeed it ha3 no occafion, being happily
lodged by its Parent where it has Food
enough . This Maggot turn s into an Aureliay
which in about fourteen Days comes out a
ferfeB WeeviL

As many People are unacquainted with
the Weevil^ aPidure of it is given PlateXIIL
Fig. XII.

Weevils when In the Egg, or ,not come
to their perfed: State, are often devoured by
Mites.

\ T/^^Leeuwen. Epift. de fexto Augujii 1687. ad Reg,
Societ.

CHAP,

r 223 ]

C II A p. XXXV.
Of the W o L r.

TH E Wolf is a little white Worm or
Maggot that infefts Granaries and Corn-
chambers, and unlefs proper Care be taken,

will do unfpeakable Damage. 1 call it a

Worm or Maggoty becaufe under that Form
it docs the Mifchief, though in its perfed:
State it is really a fmall Moth^ whofe Wings
are white, fpotted with black Spots.

This little Maggot has fix Legs ; and, as
it creeps along, there iflues from its Mouth
an exceeding fine Thread or Web, by which
it faftens itfelf to every thing it touches, fo
that it cannot fall. Its Mouth is armed with
a pair of reddifli Forceps or biting Inftru-^
ments, wherewith It gnaws its Way, not only
into Wheat and other Grain, but perforates
even wooden Beams, Boxes, Books, and
almoft any thing it meets with.

Towards the End of Summer, this per-
nicious Vermin (in Corn-chambers infefted
with them) may be izt'ii crawling up the
Walls in great Numbers, in fearch of pro-
j>er Places where they may abide in Safety
during their Continuance in their Aurelia
State : for when the Time of undergoing a
Change into that State approaches, they for-

CL3 fake

224 Of ^^^ Wolf.

fake their Food, and the little Cells they had
formed of hollowed Grains of Corn, clotted
together by means of the Web coming from
their Mouths, and v/ander about till they
find fome Wooden Beam, or other Body to
their Mind, into which they gnaw Holes
with their iliarp Fangs, capable of conceal-
ing them : and there, enveloping themfelves
in a Covering of their own Spinning, foon
become metamorphofed into dark-coloured
Aurelias. -f*

Thefe Aurelias continue all the Winter
unad;ive and harmlefs : but about April or
May^ as the Weather grows warm, they
are transformed a -new, and come forth
Moths of the Kind above defcribed. They
may then be ic^n in great Numbers taking
little Flights, or creeping along the Walls y
and, as they eat nothing in their Fly-ftate,
are at that Time not mifchievous. But they
foon copulate and lay Eggs ( fhaped Hke
Hen's Eggs, but not larger than a Grain of
Sand) each Fem^ale fixty or feventy, which,
by means of a Tube at the End of her Tail,
fhe thrufts or iniinuatesintothelittleWrinkles,
Hollows, or Crevices of the Corn 5 where,
in about fixteen Days they hatch, and then
the Plame bedns ; for the minutp Worms
or Maggots immediately perforate the Grain

^ Vid. Leeuv/eh. Experiment. ^S ContempL'E^'\?i. 71.

thev

of the Wolf. 225

they were hatched upon, cat out the very
Heart of it, and with their l^^cbs cement
other Grains thereto, which they likcwife
fcoop out and devour, leaving nothing but
Hulks, and Duft, and fuch a quantity of
their Dung, as (hews them to be more vo-
racious Infcc^ls than the JVerjil.

The watchful Obferver has two Opportu-
nities of deftroying this Vermin, if they hap-
pen to be got among his Corn. One is, when
thev foriake their Food and afcend theWalls,
which they will fometimes almoft cover :
the other, when they appear in the Moth
State, At both thefe Times they may be
crulhed to Death asiainfl the Walls in ^rreat
Numbers by clapping Sacks upon them.
But they may ftill be exterminated more
effecfbually, if clofing up all the Doors and
Windows, the Corn-Chamber be filled with
the Fumes oi Brimjlone by leaving it burning
on a Pan of Charcoal, without giving it any
Vent for twenty-four Hours. Great Cau-
tion, however, muft be ufed, to open the
Windows and Doors, and let all the Fumes
be entirely gone, before any body enters the
Place afterwards, for Fear of Suffocation,
The Fumes of Sulphur are in no wife hurt-
ful to the Corn, or give it any Taile.

The Pidure of the JVoIf'm its Reptile
State, (when it goes by that Name) is fliexyn
plate XIII. Fig. XIII. a.

CL4 Its

226 Of the pearled Eyes ^"Infedls.

Its Appearance when transformed into a
Moth is feen Fig. XIII. b.

Old Corn is lefs fubjedl to thefe devouring
Jnfe6ls than Corn that is new ; for its Skin
being more hard and dry, it is much more
difficult for the little Maggots when iirft
hatch'd to penetrate.*

CHAP. XXXVI.

Of the pearled Eyes of ^ Insects.

^ I "^HE Eyes of hife^s are amazing Pieces
j^ of Mechanifm, whofe Structure and
Difpoiition, without the x-^ffi fiance of the
Micrcfcope^ would for ever have been un-
known to us. — —Beetles^ Dragon-flies^ BeeSy
Waffs, AntSy common Flies, Butterflies, and
many other Infects have two Crefcents, or
immoveable Caps, compofing the greateft
Part of the Head, and containing a prodi-
gious Number of little He?nifpheres or round
Frotuberances, placed with the utmoft Re-
gularity and Exacftnefs in Lines croffing each
other, and refembling Lattice- Work. Thefe

* J call this Infe£l the Wolf from the Latin Name Lupus ;
given, J fuppole, for its Voraciourntls.

f Vide Spcaacle de la "Nature, Dial. VIII. Hook's
yjcrog. p. to >. Leeuw. Arc. Nat. Tom. II. Part. II. p. 41.
A£,ain, p. 424. Derham's Fhyf. ^Ibeol. p. 364.

are

Of the pearled Eyes of Infers. 227

are*a Colledlion of £)r5, fo perfedlly fmooth
and polilhed, that like fo many Mirrors they
refle(ft the Images of all outward Obje<!^s.
One may fee the Figure of a Candle multi-
plied almoft to Infinity on their Surfaces,
ihifting its Beams into each Eye, according to
the Motion given it by the Obferver's Hands ;
and as other Creatures are obliged to turn
their Eyes to Objefts, this Sort have fome
or other of their Eyes always ready direcfted
towards Objedts, on whatever fide they pre-
fent themfelves. In fliort, all thefe little
Hemifpheres are 7'eal Eyes^ having in the
middle of each a minute tranfparent Le?is and
Pupils through which Objedls appear topfy-
turvy as through a convex Glafs : This be-
comes alfo a fmall Tekfcope when there is a
jufl focal Diftance between it and the Le?i5
of the Microfcope, It is alfo reafonable to
believe, that every Lens has a diftinft Branch
of the Optic Nerves adminiftring to it : and
yet, that Objedls are not multiplied, or ap-
pear otherwife than fingle, any more than
they do to us, who fee not an Objedt double
though we have two Eyes.

Every Man almoft that has feen a Micro-
fcope has been entertained w^ith a View of
thefe 7ninute Eyes, and yet very few perhaps
have well confider'd either the Nature or
the Number of them. Mr. Hook com-
puted fourteen thoufand Hemifpheres in the
2 tw^o

2 2S Of the pearled Eyes g/'Infeds.

two Eyes of a DronCy viz, feven thoufand
in each Eye. Mr. Leeuwenhoek reckoned
fix thoufand two hundred thirty-fix in a
Silk-Worm % two Eyes, when in its Fly-fi:ate ;
three thoufand one hundred eighty- one in
each Eye of a Betth : and eight thoufand
in the two Eyes of a cmnmon Fly, The
Libella, Adder-Bolt^ or Dragon-Flyy is the
nioft remarkable of all the Infecfts we know
for its large and fine pearled Eyes ; which
even with a common Reading Glafs appear
like the Skin we call Shagreen. Mr. Leeu-
wenhoek reckons in each Eye of this
Creature, twelve thoufand fi ve hundred forty-
four LenfeSy or, in both, twenty-five thou-
fand eighty-eight 5 placed in an hexangular
Poiition, each Lens having fix others round
it ; which is alfo the Order mofl: common in
other Eyes. He likewife obferved in the
Center of each Lens a minute tranfparent
Spot, brighter than the refi:, and fuppofed to
be the Pupil through which the Rays of
Light are tranfmitted upon the Retina, This
Spot had three Circles furrounding it, and
feemed io.'^tn times lefs than the Diameter
of the whole Lens, We fee here, in each
of thefe exceedingly minute lenticular Sur-
facesy as much Accuracy in the Figure and
Polifh, and as much Contrivance and Beauty
as in the Eye of a Whale or an Elephant :
and how delicate, how exquifitely delicate
muft the Filaments of the Retina be w^hich

ferve

Of the pearled Eyes cf Infecfls. 229

ferve to each of thefe, fince the wliole Pic-
ture of Obje(fl:s painted thereon, muft be
Millions of times lefs than the Images of
them pictured on the human Eye !

If we cut off the Eye of a Dragon Fly^
of a Drone^ or of a common Ffyy and with
a Pencil and fome clean Water wafli out
all the Veffels, thofe Veflels may be exa-
min'd by the Microfcope^ and the Numbers
of them will appear wonderful and furpriz-
ing ; and then if the outward Covering be
dryed carefully, fo as not to fhrink, it will
be rightly prepared for making Experiments
with the Microfcope : and, upon viewing it,
we {hall perfectly diftinguilh the numerous
Protuberances or Hemifpheres^ divided frorn
one another, with a fmall Light iffuing be-
tween them, and fix Sides to each. Mr.
Leeuwenhoek having prepared an Eye
in this Manner, placed it a little farther
from his Microfcope than when he would
examine an Objed: : fo as to leave a right and
tXTidi focal Dijiance between it and the Lem
of \\\'i Microfcope ', and then, looking thro'
both,- in the Manner of a T^elefcope^ at the
Steeple of a Church, which was two hun-
dred ninety and nine Feet high, and {^vcn
hundred fifty Feet from the Place where he
flood, he could plainly fee, thro' every little
Lem^ the whole Steeple, inverted, tho' not lar-
ger than the Point of a fime Needle: and then

direi^-

27,0 Of the Antennae, Feelers,

direffing his View to a neighbouring Houfe,
-he faw, through abundance of the Httle He-
ffiifphereSj not only the Front of the Houfe,
but hkewife the Doors and Windows 3 and
was able to difcern diftindlly w^hether the
Windows were fhut or open.

There canbe no doubtj'that Lice^ MifeSy
and multitudes of other Animalcules^ much
fmaller ftill than they, have Eyes contrived
and faihion'd, to difcern Objeds fome thou-
fands of times lefs than themfelves : for fo
the minute Particles they feed on, and many
other Things neceffary for them to diftin-
guifli and know perfectly, muft certainly
be. — What a Power then of magnifying are
fuch Eyes endued with ! and what extraor-
dinary Difcoveries might be made, were it
poiTible to obtain Glaffes through which we
could fee as they do 1

CHAP. XXXVII.

')j the Antennae, Feelers, or Horns of

Insects.

""^ HE Horns oilnfeBs have been thought
by many defigned only to clean their
Eyes, by wiping off any Duft that may fall
thereon : but as we conftantly obferve them

perforin--

c?r riorns oflnfcAs. 251

performing that Office with their Fore-legs,
'tis certain their Horns mull: be intended for
fome other Purpofc. And fince they are
perpetually feeling before them with their
Antenna as they walk along,* Mr. Derham
very reafonably imagines them abfolutely
neceflary to fearch and find out their Way.
For as their Eyes are immoveable, fo that
no Time is required for their turning them
to Objefts, there is no neceffity that the
Retifia^ or Optic NervCy fliould, occafionally,
be brought nearer to, or removed farther
from the Cotviea^ as it is in other Animals;
which would require Time: but their Cornea
and Optic Nerve being always at one and
the fame Diftance, and fitted only to fee di-
ftant Objects : they would be infenfible of,
and apt to run their Heads againft Bodies
very near them, were they not aflifted by
their Feelers,

And that this, rather than wiping theEves^
is the chief Ufe of the Feelers, is farther
manifeft from the Antennce of the Flejh^
Fly, and many other Infefts, which are
fliort and ftrait, and uncapable of beino- bent
down to, or extended over the Eyes : as aUb
from others enormoufly long, fuch as thofe
of the Capricorni or Goat Chafers, the
Cadew Fly, and divers others both Beelks
and Flies,

* \)^Tiiihn"& Phyftco-ThecL p. 3^!;,

Th

e

232 Of the Wings of Infeds.

The lamellated Antenncje of fome, tlie
clavellated of others, the Topknots or Tufts
like Dandelion Seeds, the branched, the fea-
thered, and divers other Forms of Horns of
the Beetle^ Butterfly^ Moth, Gnat^ and many
Kindsbelide, are furprizingly beautiful when
viewed through a Microjcope, And, in fome,
thefe Antennce diftinguifh the Sexes ; for in
the Gnat-kind all thofe with Tufts, Feathers,
or Bruih-Horns (of which there are great
Varieties) are Males : thofe with iliort fingle-
ihafted Horns are Females,

CHAP. XXXVIII.

Of the Wings (p/' Insects.

"^ H E R E is fuch infinite Variety in the
Contexture, Formation, Difpofition
and Ornaments of the Wings of LifeBs^ ac-
cording to their different Wants and Ways of
Life, that nothing but a curious Obfervation
can make us have any true Conception of it.
Some Wings are filmy, as thofe of Dragon--
Flies : others are ftuck over with fhort Bri-
ftles, as in Flefi-Flies 5 fome are Films co-
vered with fliort Feathers, like the Tiles of a
Houfe, as in Butterflies and Moths ; others
have divided Wings^ as the grey and white

Of the Wings ^/Tnfefts. 233

feathered Moth, The Wings of many Sorts
of Gnats are adorned with Rows of Feathers
along their Ridges, and Borders of Feathers
round their Edge. Some, again, have Hairs,
and others Hooks, placed with the greatefl
Regularity and Order. Ail of the Scarab
Kind have Elytra^ or Cafes^ into which their
Wings are folded and prefervcd until they
want to employ them. Some of thefe Cafes
reach almoft to the Extremity of the Tail,
as in molt Kinds of Beetles -, and others are
very ihort, as in the Earwig, Many of
them are like wife extreamly beautiful when
brought before the Microfcope.

All thefe Kinds of Wings have certain
bony Parts or Ribs, that give them Strength,
along the Sides of which run large Blood-
Veffels, branching out into numberlefsDivi-
fions, and conveying Nourishment to the in-
termediate Parts : for though no Circulation
can be difcerned in them, it being probably
extreamly flow, we can fcarce doubt that
there muft be continually a Supply of Juices
to the Quills, Hairs, or Briftles, wherewith
they are armed or ornamented.

As to Motion, Wings that are filmy move
faflier than thofe covered with Feathers. Mr.
Hook obferves, that in the Wings of fome
minute Flies there are many Hundreds, if
not Thoufands of Vibrations in a Second,
and fuppofes them the fwifteft Vibrations in

the

234 Q/' ^^^ Wings of Infedls.

the World : whence he reflects very ingeni-
oufly, on the Quicknefs of the Animal Spi-
rits, that ferve to fupply this Motion.

Thofe converfant in Microfcopes need not
be informed, that the beautiful Colours on
the Wings of Butterflies and Moths are ow-
ing to elegant minute Feathers ending in
^illsy and placed with great Exaftnefs in
orderly Rows ; as, when rubbed off, the
Holes they come from fhew : but few, it
may be, have much obferved the great Va-
riety of their Make, not only in Moths and
Butterflies of different Sorts, but even in
thofe taken from different Parts of the fame
Wing 'y infomuch that it is pretty difficult to
find any two of them exaftly alike.

Rub thefe Feathers gently off, with the
End of your Finger, or Pen-knife; and,
breathing upon a fingle Talc in one of your
SliderSy apply it to the Feathers, which feem
only like a fine Dufl, and they will imme-
diately adhere to it : then placing it before
the Mi cr of cope, if they are not perfed, or
lye not to your Mind, wipe them off, and
put on others in the fame Manner, till yoii
get thofe you like: then cover them with
another Talc, and faflen It down with a
Wire, that you may preferve them for future
Examination. Look at them with the /fo'ri
or fourth, then with the fecond, and at lali
with xhQ great eji Magnifier.

The

Of the Ballances or Poilcs ij/'Infefts. 235

The Wing of a Midge is a moft curious
OhJe(il, and lb indeed is every Part of that
minute Infedl. Tlic Wing of the Httle Plume
Moth is compofed of feveral diftincft Qmlls,
hkc thofe of Birds. There arc alfo Wings
folded up in the Httle Cafes on the Backs of
Earwigs very pretty to examine. But no
more need be faid of Wings, fince every
body muft be fenfible the great Variety of
them is an endlefs Subjedl of Enquiry and
Admiration.

CHAP XXXIX.

Of the Ballances or PoifyS of Infeds.

•

MOST Infefts having but two Wings,
are provided with a little Ball or
Bladder under each, fet at the Top of a llen-
derFoot-ftalkj which is moveable every Way
at Pleafure. With thefe they ballance them-
felves in Flight as a Rope-Dancer does with
his Pole leaded at each End ; and if one of
them be cutoff, the Creature flies for a while^
very awkardly, as if over-heavy on one Side,
and falls at laft to the Ground. ' Thefe Blad-
ders, being hollow, may ferve likewife to pro-
duce the Noife many Sort of Flies make, t>y
ftriking their Wings againfl them, and be a
gleans of finding out one another. In fonie

R * Creatures

■^36 Of the Scales of Fiilies.

Creatures they ftand alone, but the whole
Fly-Tribe have little Covers or Shields under
which the y lye and move. Infedls that have
four Wings ballance themfelves with the two
leffer Ones, and, as they want not, have none
of thefe little Poifes. The Micro/cope may
probably find out ftill farther Beauties, Con-
trivances and Ufes for them than have been
yet difcovered.

C H A P. XL.

Of the Scales ^Fishes.

TH E Scales^ or out fide Coverings of
F'ljhes are formed with furprizing
Beauty and Regularity ^ and in different
Kinds of them, exhibit an endlefs Variety in
Figure and Contexture. Some are longifh,
fome round, fome triangular, fome fquare,
^nd fome or other of all Shapes we can well
imagine. Some, again, are armed with fharp
Prickles, as thofe of the Pf^r^i?, Soal^ &cc^
Others have fmooth Edges, as of the Cod-
Fijhy Carp^ Tench^ &c. There is likewife a
great Variety even in the fame Fifh ; for the
Scales taken from the Belly, the Back, the
Sides, the Head, and all the other Parts, are
very different from one another. And, in-
deed^ for Variety, Beauty, Regularity, and the

Order

Of the Scales of Fifhes. 237

Order of their Arranciement, the Scales of
Fiihes bear a near Relcmblance to tlic Fea-
thers on the Bodies and Wings of Moths and
Butterflies.

Thefe Scales are not fuppofed to be flied
every Year -f-, nor during the whole Life of
the Fifli ; but to have an annual Addition
of a new Scale^ growing over and extending
every Way beyond the Edges of the former,
in proportion to the Fifli's Growth ; fome-
what in the fame Manner as the Wood of
Trees enlarges yearly by the Addition of a
new Circle next the Bark. And as the Age
of a Tree maybe known by the Number of
Ringlets its Trunk is made up of, fo in Fiflies
the Number of Plates compoiing their Scales
denote to us their Age. It is alfo probable,
that as there is a Time of Year when Trees
ceafe to grow, or have any farther Addition
to their Bulk, the fame thing happens to
the Scales in Fifhes ; and that, afterwards,
at another Time of Year, a new Addition,
Increafe, or Growth begins. Somewhat
like this in Birds and Beafls their Feathers
and Hairs demonftrate.

Mr. Leeuwenhoek took fom.e Scales
from an extraordinary large Carp^ forty-two
Inches and a half long, and thirty-three and
a Quarter in the Round, Ryjiland Meafure,

t Vid. Leeuwen. Epift. Phyfiol. £///?. 24 Maii 17 16.

R 2 which

238 Of the Scales ^Flilies.

which were as broad as a Dollar. Thefe he
macerated in warm Water to make them
cut the eafier : and then cutting obliquely
through one of them, beginning with the
firft-formed and very little Scale in the Cen-
ter, he, by his Micro/cope^ plainly diftin-
guiflied forty Lamella or Scales^ glewed as it
were over one another; whence he concluded
that the Fifh was forty Years of Age. *f-

It has generally been imagined that an
jEf/has got no Scales ', but if its Slime be
wiped clean avv^ay, and the Skin be examined
by a Microfcope., it will be found covered
with exceeding fmall Scales^ ranged in a
very orderly and pretty Manner : and I be-
lieve few Filhes, unlefs fuch as have Shells^
are to be found without Scales.

The Way of preparing Scales, is to take
them oft carefully with a Fair of Nippers,
wafh them very clean, and place them in a
fmooth Paper, between the Leaves of a
Book, to make them dry flat, and prevent
their (hrivelling up. Then place them be-
tween your Talcs in Sliders, and keep them
for Examination.

The Snake^ the Viper, the Slew-Worm^
the Lizard, the Eft, &c, afford a farther
Variety of Scales.

f Jrcan. Nat, Tom. III. p. 2! 4.

CHAP.

[ =39 ]

t

C H A P. XLI.

Of /^d? O Y S T E R.

IN the clear Liquor of an Oyjler many
little round living Animalcules have been
found, whofe Bodies being conjoin'd formed
fpherical Figures, with Tails, not changing
their Place but by finking towards the Bot-
tom, as being heavier than the Fluid: Thefe
were iz^n fometimes feparating, and prefent-
ly afterwards coming together and joining
themfelves again. In other Oyflers A7iimaU
ciiles of the fame kind were found, not con-
joined, but fwimming by one another, whence '
theyfeemed in a more perfed: State, and were
fuppofed by Mr. Leeuwenhoek to be the
Aniynalcules in the Rov) or Semen of the
Oyfter, %

A Female Oyjlci" being opened, incredible
Multitudes of minute F^mbryo-Oyjlers covered
with little Shells perfedly tranfparent were
plainly feen therein, fwimming along flow-
ly: in another they were found of a brownifh
Colour without any apparent Life or Mo-
tion, Monfieur Joblot kept the Water
running from Oyjiers three Days, and it ap-
peared full of young Oyjiers that fwam about

X Arc. Ntit. Tom, ll. Par. I. p. 52. Again, p. 145.

R 3 nimbly,

240 Of the Oyster.

nimbly, and increafed in Bignefs daily. A
Mixture of Wine, or the very Vapour of
Vinegar, killed them.

In the Month of Augujl Oyfters are fup-
pofed to breed, becaufe young Ones are then
found in them. Mr. Leeuwenhoek
opened an Oyjftef on the fourth of Augufi,
and took out of it a prodigious Number of
minute Oyjlers^ all alive, and fwimming
brifkly in the Liquor, by the Means of cer-
tain exceeding fmall Organs extending a little
Way beyond their Shells, v^hich he calls their
Beards. In thefe little Oyfters he could di-
ftinguiih the joining of the Shells : and per-
ceive fome that v^ere dead, with their Shells
gaping, and as like large Oyfters in Form, as-
one Egg is like another.

As for the Size of thefe Embryo-OyfterSy
he computes, that one hundred and twenty
of them in a Row would extend an Inch j
and, confequently, that a globular Body
whofe Diameter is an Inch, would, if they
were alfo round, be equal to one Million
feven hundred and twenty-eight thoufand of
them. ^ He reckons three or four thou-
fand are in one Oyfter, and found many of
the EmbryO'Oyfters among the Beards, fome
fattened thereto by flender Filaments, and

* Vid. Jrc. Nat, Tom. IV. p. 51^.

Others

Of the Light 071 Oyfters. 241

others lying loofe. He likewife found other
Animalcules in theLiquor, five hundred times
fmallcr than Emhryo-Oyjlers,

CHAP. XLII.

Of the Light 07i Oysters.

IT is not very uncommon to fee on the
Shells of Oyfters, when in the Dark, a
finrmig Matter^ or blensjijh Lights like the
Flame of Brimftone, which flicks to the
Fingers when touched, and continues fhining
or giving Light a confiderable time, though
without any fenfible Heat J. Monf. Auxaut
obferved this JJrMtig Matter with a Micro-
fcope, and difcovered it to confift of three
Sorts oi Animalcules, The iirfl whitifh,
having twenty-four or twenty-five Legs on
each Side, forked ; a black Speck on one
Part of the Head ; the Back like an Eel
with the Skin ftrip'd off. The fecond Sort
red, refembling the common Glcw-ivormy
with Folds on its Back, but Legs like the
former, a Nofe like a Dog's, and one Eye
in the Head. The third Sort fpeckled, a
Head like a Scal^ with manyTufts of whitifh
Hairs on the Sides thereof. He faw alfo
fome much larger, and greyifh, having a

+ Vid. Phil, tranf. Numb. 12.

R 4 grea^

242 OfH^eMvscfE,

great Head, two Horns like a Snail's, and
fix or eight whitifli Feet : but thefe fhined
not.

As the Bodies of Lobfters and fome other
Kinds of Fifhes, tainted Flefh, rotten Wood,
and other Subftances are fometimes found to
fhine, with a Light refembling the foregoing,
may it not probably proceed from the fame
Caufe, VIZ. from Animalcules ? Some have
alfo fuppofed, that the Ignis Fatuus, Will-
in-a-Wifp^ or Jack-a-Lanthorn, is nothing
elfe but a Swarm of minute flying Infedts,
that emit Light around them in the manner
Glow-worms do : and indeed the Motions,
and feveral other Circumftances of this Sort
of Fire (if I may fo term it) feem favour-
able to fuch Opinion.

The Curious will judge it proper to exa-
mine this Matter carefully, and to them it is
fubmitted.

CHAP. XLIII.

Of the Mu s c L e;

I Have obferv'd already, in the 127th Page
of this Treatife, that a Mufcle is a moft
delightful Objed for the Micro/cope y and
that hi the tranfparent Membrane, which
immediately appears on opening of the Shell,

the

Of the Muscle. 243

the Blood may be feen circuhiting through
an amaziiv^ Number of VeiU'ls, even in the
fmalleft Particle of it that can be applied for
Examination.

Mr. Leeuwenhoek, in feveral that he
difleftcd, difcovered Numbers of Tijggs or
Rmbryo-Mufclcs in the Ovcwium^ appearing
as plainly as if he had k^n them with the
naked Eye, lying with their fharp Ends
faftened to the Strings orVcffels whereby
they receive Nouriflmient. Thefe minute
Eggs or E??jb?jo-Mufcles^ are, in due Time,
laid or placed by the Parent, in a very re-
gular and clofe Order, on the Outfide of the
Shell : where, by Meahs of a glewy Mat-
ter, they adhere very faft, and continually
increafe in Size and Strength, till becoming
perfeft Mufcles, they fall off and fliift for
themfelves, leaving the Holes where they
were placed behind them. This, abundance
of Mufcle-Shclls viewed by the Micro/cope
can fhew. Sometimes two or three thoufand
of thefe Eggs adhere to the Shell of oneMuf-
cle ; but 'tis not certain they v/ere all fixed
there by the Mufcle itfelf, for they frequently
place their Eggs on one another's Shells.
The fringed Edge of the Mufcle, which
Mr. Leeuwenhoek calls the Beard, has
in every the minuteft Part of it fuch a
Variety of Motions, as is unconceivable : for
being compofed of longiih Fibres, each Fibre
has on both Sides a vaft many movins: Par-
'^ tides,

244 0/ ^^^ M u s c t E.

tides, which one would almoft imagine to
be Animalcules, -f-

The Threads or Strings, which we term
the Beard, are compofed of a Glew which
the Mufcle applies by the Help of its Trunk
to fome fixed Body, and draws out as a Spi-
der does its Web, thereby faftening itfelf,
that it may not be wafhed away. If Mufcles
be put into Salt and Water, we may have
the Pleafure of feeing them perform this
Work, and faften themfelves to the Sides or
Bottom of the VelTel we place them in.

Cockles, Scallops, Limpets, Periwinkles,
and Abundance of other Shell-Fifh, are Ob-
jed:s that have as yet been very flightly exa-
mined by the Micro/cope y and, therefore,
the ferious Enquirer into Nature's fecret Ope-
ration^ may here be certain of difcovering
Beauties which at prefent he can have no
Conception of.

•\ Philof. Tranfaa. Numb. 336. Arc. Nat, Tom. II.
p. 19. &c. Tom. IV. p. 423, &c.

CHAP.

[ 245 ]
CHAP. XLIV.

Of H A 1 K S.

TH E Hah's of Animals are very diffe-
rent in their Appearance before the
MicrofcopCy and can furnifh out a great Va-
riety of pleafing Obfervations. Malpighi
difcovered them to be tubular, that is, com-
pofed of a Number of extreamly minute
Tubes or Pipes, in his Examination of a
Horfe*s Main and Tail, and in the Briftles
of a Boar. Thefe Tubes were moft diftin-
guifhable near the End of the Hairs, where
they appeared more open : and he fometimes
could reckon above twenty of them. In the
Hedge-hog's Prickles, which are of the Na-
ture of Hairs, he perceived thefe Tubes very
plainly, together with elegant medullary
Valves and Cells.

There are alfo in the Hairs of many Ani-
mals, in fome tranfverfe, in others fpiral
Lines, fomewhat of a darker Colour, run-
ning from Bottom to Top in a very pretty
Manner. A ^ Moufe's Hairs are of this
Sort, they appear as it were in Joints like
the Back-bone, are not fmooth but jagged
on the Sides, and terminate in the fharpeft
Point imaginable. Hairs taken from a

f Vid. Arcan. Nat, Tom. III. p. 47.

Moufe's

246 O/" Hairs.

Moufe's Belly are lead opake, and fitteft for
the Microfcope.

The Hairs of Men, Horfes, Sheep,
Hogs, &c, are compofed of fmall, long, tu-
bular Fibres or fmaller Hairs, encompafled
with a Rind or Bark , from which Strudlure
a Split Hair appears like a Stick fhivered with
beating. They have Roots of different
Shapes in different Animals, become length-
ened by Propulfion, and are thicker to-
wards the Middle than at either End.

Hairs of Indian Deer are perforated from
Side to Side : our Englifi ones feem covered
with a kind of fcaly Bark. The WhifKcrs
of a Cat, cut tranfverfly, have fomewhat in
the Middle like the Pith of Elder. * The
Quills of Porcupines or Hedge-hogs have
alfo a whitifh Pith in a ftar-like Form : and
a human Hair cut in the fame Manner fliews
a Variety of Veffels in very regular Figures.

Hairs taken from the Plead, the Eye-
brows, the Noftrils, the Beard, the Hand,
and other Parts of the Body, appear unlike,
as well in the Roots as in the Hairs them-
felves, and vary as Plants do of the fame
GenuSy but of different Species.

Hook's Microg. p= 157..

CHAP,

[ 247 ]

CHAP. XLV.

Of the Farina of Flowers.

THE Farina-, or mealy Powder, found
on the little pendant Tops of almoft
every Flower, is fomewhat fo analogous to
the Sevien of Animals, that it deferves the
ftri^left and moft' attentive Examination.

This Pov/der, whofe Colour is different in
Flowers of different Kinds, was imagined,
by former Ages, to be a meer excrementi-
tious and unneceffary Part of the Plant : but
the Micro/cope here alfo has made furprizing
Difcoveries, by fhewing, that all the minute
Grains of this Powder are regular, uniform
and beautiful little Bodies, conftantly of the
fame Figure and Size in Plants of the fame
Species, but in different Kinds of Plants as
different as the Plants themfelves.

It was impoffible to obferve this Order
and Configuration of the Fariiii^, without
concluding, that Providence, which never
ads in vain, muff intend a nobler Ufe for
Bodies fo regularly formed, than to be diffi-
pated by the Winds and loft. This Relledion
drew on farther Examination ; and farther
Examination, by the Help of the fame In-
ftrument, foon difcovered, that this Powder
is produced and preferved with the utmoft

Care,

248 Of the Farina 5/* Flowers.
Care, in Veffels wonderfully contrived to
open and difcharge it when it becomes ma-
ture : that there is likewife a Pijiil^ Seed^
Veffely or Uterus in the Center of the Flower,
ready to receive the minute Grains of this
Powder, as they either fall of themfelves,
or are blown out of their little Cells. And
Experience, founded on numberlefs Experi-
ments, proves, that on this depends entirely
the Fertility of the Seed : for if the Farina-
Vejfels be cut away before they open and
ihed their Powder, the Seed becomes barren
and unprodudlive.

This Farina is therefore iudp:ed to be the
Male Seed of Plants, and every little Grain
of its Powder may poffibly contain in it a
minute Plant of the Species whereto it be-
longs. ^It is wonderful to obferve the va-
rious Contrivances Nature employs to pre-
vent this Powder from being unprofitably
difperfed, and to affift its Entrance into the
proper Pijlil^ Seed-Fejfel or Uterus prepared
for it. The Tulips for injftance, which ftands
upright, has its Pijiil fhorter than the Fari-
na-VeJfels^ that the Powder may fall dired:ly
on it: but in the Martagon, which turns
downwards, the Fijlil is longer than the faid
VefTelSj and fwells out at its Extremity, to
catch the Farina hanging over it, as it
flieds.

A Mind

Of the Farina <?/ Flower. 249

A Mind inquifitivc into Nature's hidden
Beauties, will find inexpreffible Delight in
examining and confulering the endlefs Va-
riety difcoverable in the Farince of number-
lefs vegetable Species. In that of the Mal-
low, each little Grain appears to be an opake
Ball with Prickles iffuing from it on every
Side. The Sun-Flower Farina feems com-
pofed of flat circular minute Bodies, fharp-
pointed round the Edges \ the middle of
them appears tranfparent, and exhibits fome
Refemblance of the Flower it proceeds from.
The Powder of the Tulip is exactly fliaped
like the Seeds of the Cucumbers and Melons.
TheKzr/W of the Poppy appears likePearl-
Barley, with a Furrow, as in that, reaching
from End to End. That of the Lilly is a
great deal Hke the Tulip.

ril not anticipate the Pleafure of the Cu-
rious, or take up their Time in defcribing
more of the Farince^ which every Flower
they come at prefents to their Examination;
but advife them not to neglecfl the Veflels
that contain it, for they will find Beauties in
them alfo fufiicient to reward their Pains.

Gather your Farina in the mid ft of a
Sun-{hiny dry Day, when all the Dew is off;
be careful not to fqueeze or prefs it, but
iliake or elfe gently brufh it off with a foft
Hair Pencil upon a Piece of clean white Pa-
per.

250 Of the Farina of Flowers.

per. Then take a fmgle Talc or Ifinglafs
between your Nippers, and breatliing on it,
apply it inftantly to the FarijiUy which the
Moifture of your Breath will make adhere to
it. If too great a Quantity of Powder feems
flicking to your Ifinglafs, gently blow off a
little 3 if there be not enough, breath on it
again, and touch the Fai'ina with it as be-
fore. Then put your Glafs into the Hole of
a Slider, and apply it to the Microfcope to
fee if the little Grains are fpread according to
your liking, and v/hen you find they are,
cover them cautioufly with another Talc,,
which fallen down w:ith a brafs Wire j but
let not the Glafles prefs hard upon the Fa-
rina^ for that will deftroy its true Figure^
and reprefent it different from what it is,

A Collecflion of the moft remarkable
FarirKZ thus preferved muft be a lafting
Entertainment to thofe who ftudy Na-
ture : to fuch I alfo recommend a diligent
Examination of the little Cells that con-
tain the Farina^ and likewife of the Pijiih
or Uteri and other Parts of Generation in
Flow^ers. Let them only begin with the
Arch-Anp-el, or blind Nettle with a white
Flower, or even with the common Mallow,
and they will difcover Beauties, impoffible to
be defcribed. And as every other Flower
has Organs for the fame Purpofe, though of
a different Form and Structure, here are

Wonders

Of Seeds. 251

Wonders in ahuiidance for the MicTofcope to
difcovcr, and happy tlie Man who can find
moll Leilure to explore thtfe Worlds as yet
unknown !

I {hall add only one Obfervatlon more be-
fore I leave this Head, which is, that as
the Aninuilcules \x\ Scmine differ not in Big-
ncfs according to the Size of thofe Animals
whence the Semen comes : fo the minute
Grains compoling the Farina of Vegetables
are not bigger or lefs in Proportion to the
Size of the Plants producing them, but are
often the dired: contrary; as we find by the
Farina of the little creeping Mallow, the
Globules of which are larger than thofe of
the lofty gigantick Sun-flower.

CHAP. XL VI.

Of Seeds

EACH Seed includes a Plant : that Plant, again.
Has other Seeds, which other Plants co-ntain :
Thofe other Plants have all their Seeds ; and, Thofe,
More Plants, again, fucceflively inclofe.

Thus, ev*ry fingle Berry that we find,
Has, really, in itfelf whole Forefts of its Kind.
Empire and Wealth one Acorn may difpenfe.
By Fleets to fail a thoufand A^es hence :
Each jVIyrtle-Seed includes a thoufand Groves.
Wbere future Bards may warble forth their Loves.

S So

252 0/* S E E D S.

So Adam Loins contain'd his large Poflerity,

All People that have been, and all that e*er ihall be.

Amazing Thought ! what Mortal can conceive

Such wond'rous Smallnefs ! -Yet we muft believe

WhatReafon tells : for Reafon's piercing Eye
Difcerns thofe Truths our Senfes can't defcry.

I hope to be excufed for borrowing the
Lines above from a little Poem of my own,
called the Vfiiverfe^ publiflied fome Years
ago \ as. they contain a Suppofition, which,
however chimerical it may appear at firft,
will, if duely confider'd, be found, perhaps
'hot only poffible, but even highly probable.
Malpighi, Leeuwenhoek, Hooke,
Grew, and feveral others bear Witnefs, that
the Microfcope has difcovered minute Plants
not only in the larger Seeds, fuch as the
Walnut, Chefnut, Acorn, Beechnut, Seed
of the Lime, Cotton-Seeds, Peafe, &c. but
alfo in the fmaller of Radifh, Hemp, Cher-
vil, Scurvy-grafs, Muftard, and multitudes
of other Seeds. About two Years ago, I
likewife had the Honour to prefent the Dif-
fedlion of a Seed of the Grame7i tremu-
luni:, or trembling Grafs^ with an Account
thereof to the Royal Society^ wherein a per-
fect Plant appeared, with its Root, fending
forth two Branches, from each of which fe-
veral Leaves or Blades of Grafs proceeded.
Thus far our Sight, affiiled by xh^Micf'ofcope^
- is able to difcover : and as that Inftrument

convinces

0/ S E E D S. 253

convinces us, that Nature in her Operations
is in no wile confined to our Conceptions of
Bignefs, but afts as freely in the minute Fa-
brick of a Mite, as in the Bulky Compafs of
a Whale or Elephant : nay, that fhe rather
feenis to wanton in her Skill, by giving a
greater Number of Limbs, and more nu-
merous Ornaments to the minute Creatures
than to the larger ones. When thefe Things,
I fay, are feen, and refledted on, it is eafy to
conceive the reft.

Moft Kinds of Seeds muft be prepared, In
order to difcover the minute Plants they con-
tain, by fteeping them in warm Water till
their Coats can be feparated and their femi-
nal Leaves opened without Laceration : tho'
fome new Sorts may better be diffedled dry.
But Seeds, even without any Preparation, are
exceeding pretty Objefts, and afford infinite
Varieties of Figure, Colour and Decoration.

The Seeds of Strawberries rife out of the
Pulp of the Fruit, and appear themfelves hke
Strawberries when viewed.

Poppy Seeds (and what we call Maw-
Seeds, which come from Germany, and are
produced by a Kind of Poppy) in Shape re-
femble little Kidneys, but have Furrows or
Ridges on their Surfaces curiouily difpofed
with regular Sides and Angles. From thefe
Seeds a Duft may be (haken, that books a-
greeable enough when brought before the

S 2 Micro-

254 ^f Seeds.

Microfcope 5 having nearly the fame Appear-
ance as the Surfaces of the Seeds, with the
Advantage of being tranfparent. This Duft
is really the fine Membranes that lay betv^een
the Seeds; w^hich by the PrefTure of the
Seeds againit them., have received Marks
correfponding to the Ridges or Furrows on
the Seeds themfelves.

■ ' Seeds of the leffer Moonwort, of Tobacco,
Lettice, Thyme, Chervil, Parfley, and a thou-
fand others, afford a delightful Entertainment.
. The Ancients imagined the capillary Plants
and many other Kinds to produce no Seeds
at all, and their Miftake could never have
been re6tiiied by the naked Eye : but the
Microfcope has difcovered, that all the feve-
ral Species of Fern, Hearts-Tongue, Maiden-
Hair, &c. are fo far from being barren in
this Refpeci:, that they are amazingly fruit-
ful : that the Seed^Veffels are on the Backs
of the Leaves, and that the Duft which flies
off when v/e meddle with them, is nothing
but their minute Seeds. Thefe Seed-Veffels
appear to the naked Eye like a black or
brown Scurf on the Backfide of the Leaf ;
but, when viev/ed by the il^/^r^c?^^, refem-
ble little circular Tubes, divided into many
Cells containinp- Seeds. When the Seed is
^ ripe, the Veffels fly open with a Spring, and
fpirt the Seeds out on every Side, in the
Form of Duft : and if at that Seafon fome
of the Leaves are put in a Paper Cone, and

that

Of S EEDS, 255

that be held to the Ear, the Seed- V'effels may
be heard to buril with a conliderablc Noile.
Some of thefe minute Veflels contain at leafl
an hundred Seeds, inviliblc to the naked Eye.

Itwould be tedious to enumerate the Beau-
ties of Seeds, fince every tranfient Obferver
muft be fenfible of their great Variety : but
I beHeve I fliall be excufed, if I take Notice
of the Powder or Seed of the Fujigus Puhe-
rukntus or Puff-Ball, which, when crufli'd,
feems to the naked Eye like a Smoke or
Vapour ; but when examined by one of the
greateft Magnifiers (for elfe it cannot be di-
llinguiflied) it appears to be infinite Num-
bers of httle Globules, of an Orange Colour,
fomewhat tranfparent, whofe Axis is not
^bove the fiftieth Part of the Diameter of a
Hair : fo that a Cube of a Hair's Breadth
Diameter would be equal to an hundred and
twenty-five thoufand of them. This was the
Powder of a Fungus bigger than two Fifts ;
but in another Sort the Size of a fmall Apple,
the Globules were of a darker Colour, and
had each a little Stalk or Tail ^, Thefe are,
evidently, fo many ??imute Puff-Balls, fur-
nifhed with Stalks or Tails to penetrate eafily
into the Ground : and the Mifchief they dp

• Vide Philofoph. Travfaa. Numb. 284. and Derham's
Phvf» ^heolog. pag. 418.

S 3 the

256 . Of Leaves.

the Eyes is probably owing to their fharp
Stalks that prick and wound them. *

CHAP. XLVII.

Of Leaves.

f j "^HE Leaves of Trees or Plants are full
J^ of innumerable Veins and Ramifica-
tions, that convey the perfpirable Juices tq
the Pores, for their Difcharge. Whether or
no there be any Circulation in them is ftill a
Matter of Doubt 3 but as their Juices, when
let out, immediately break, coagulate, and
become a ftifF Jelly, it feems probable there
may be fome Circulation which prevents the
fame Effedl in the Veffels. The fudden
fhrinking, clofing, and opening of Flowers,
the railing and finking the Heads of Poppies,
&c, the vermicular Motions of the Veins of
Plants when expofed to the Air, feem alfo io
imply fome what like Senfation. The Mi"
crofcope may perhaps be of fervice to difcover
much more on thefeSubjed:s thanwe yet know.

* A Puff-B all h&m% burll near the Eyes of a Eoy of twelve
Vears old, by an unlucky Play-fellow, and the Duft thereof
flying into them, occafioned fuch Swelling, Inflammation,
and mtenfe Pain, with a continual Difcharge of Water, that
jie could not open them for feveral Days ; and did not reco-
ver his Sight in lefs than a Fortnight, tho' all the Remedies
that could be thought on were applied. Vide Joh. Muys
f rax. chiru'r. ration, Oblerv. I. ; .

" ■■ ■ Mr.

0/ Leaves. 257

Mr. Lekuweniioek tearing to Pieces a
Leaf of the Species of Box called Pah;:a
Cerc?'isy that he might examine it the better,
computed one Side of it to be furniflied with
and hundred feventy-tvvothoufand and ninety
Pores ; and as the other Side muft have as
many, the whole Number of Pores in a fingle
Leaf of i^(?A' will be three hundred forty-four
thoufand one hundred and eighty.

The Leaves oi Rue feem full of Holes like
a Honey-comb ; all the Kinds of St. Johiis
Wort appear likewife ftuck full of Pin-Hole^
to the naked Eye ; but the Microfcope fliews,
that the Places where thofe Holes feem to
be, are really covered with an exceeding
thin and white Membrane.

The Backfide of the Heib Mercury \ooVz
as if rough-caft with Silver, and the Ribs full
of white round tranfparent Balls, like num-
berlefs Grapes, faftenedbyilender Footrt:alks»

A Sage L^^/ appears like Rug or Shag,
full of Knots taflel'd with filver Thrums, and
^mbelliflied with fine round cryftal Beads or
Pendants, faftened by little Footftalks.

The Backfide of a Kofe Leaf^ but efpe-
qially of Sweet Briaf\ looks diaper'd with
Silver. "^

Every Body knows that the Leaves of
Stingifig Nettles are thick fet with fliarp

* Dr. Power's Micro/cop. Ohfer^jat.

S 4 Prickles,

25^ ^f L^ A V E S.

Prickles, that penetrate the Skin v^^hen
touched, and occafion Pain, Heat, and Swel-
ling : which Symptoms were imagined, for-
merly, to enfue from the Prickles being left
in the V/ounds they make. But the Micro-
fcope difcovers fomething much more won-
derful in this common Vegetable, and fhews
that its Prickles are formed and a6l in the
fame Manner as the Stings of living Animals.
For every one of them is found to be a rigid
hollow Body, terminating in the moft acute
Point imaginable, with an Opening near its
End. * At the Bottom of this Cavity lies
a minute Veffel or Bag, containing a limpid
Liquor, which, upon the leaft touching of
the Prickle, is fquirted through the little Out-
let ; and, if it enters the Skin, produces the
Michiefs before-mentioned by the Pungency
of its Salts. Hence it come to pafs, that
when the Leaves of Nettles are confiderably
dried by the Heat of the Sun, they fting but
very little : w^hereas fuch as are green and
juicy produce violent Pain and Inflammation »
But the quite contrary to this w^ould happen,
if the Sym^ptoms. w^ere only owing to the
Breaking of the Prickles in the Flefli : fince,
when dry, they mull be more brittle, as well
as more rigid, than when they abound with
Juice.

* Hook's Mkrogr.i^^ i±z. Arc, Nat, Tom. I. Par. III.

^.ere.

Of Salts In 'GerieraL 259

^icrCy Are there any Valves in the Vef-
fels of Vegetables, as in thofe of Animals,
to let the Juices pafs, but hinder their Re-
turn ?

C H A P. XL VIII.

Of Salts i?i General,

IT is I think agreed, that all Bodies have
their Salts -, from whofe different Confi-
gurations and Impreffions many wonderful
Changes areeffecftedbothinSoHds and Fluids,
in things animate and inanimate. Saline
Particles ftiiking upon the Nerves of Ani-
mals excite the Senfations of Tafte and Smell;
and as their Forms and Degrees of Impulfe
are almoft infinitely diverfified, the Senfi-
bility of Pain or Pleafure arifing therefrom
muft be varied almoft infinitely, according
to the greater or lefs Delicacy of the Organs
they ftrike upon. — It is therefore of great
Confequence to difcover what we can about
them.

The Microfcope fhews, that Vinegar owes
its Pungency to Multitudes of floating ob-
long quadrangular Salts, each of which, ta-
pering from its Middle, has two exquifitely

fliarp

26o- Of S A L T ^ in General,

fharp Ends. Thefe Salts being inexpreflibly
minute, can hardly be difcoveredj unlefs a
Drop or two of Vinegar be expofed for fome
Hours to the Air, that the more watry Part
may evaporate, before we attempt to view
them.

Their Shape appears, Plate XIV. Fig. I.

If Crabs Eyes are infufed in Vinegary
after the EfFervefcence is over, the Shapes of
the Saks will be found quite altered -, their
fharp Points feem broken off, and they ap-
pear in different fquare-Hke Forms, as at
Fig. II.

In Wines of feveral Kinds the Salts are
jdiftinguiiliable, of various Figures, many of
jthem refembling thofe in Vinegar^ but with
Ends much more obtufe : fome are fliaped
like a Boat, fome like a Spindle, others like a
Weaver's Shuttle, and others fquare : ther^
are alfo infinite Varieties of other Forms.

The Salts of Sugar candy'd are fhewn
Fig. III.

Vegetable Salts are to be extradled by
burning the Wood, Stalks, or Leaves of any
Tree, or Plant ; throwing the Aflies intp
Water j then filtering, and fetting the Li-
quor; to cryflallize in a cold Place. Their
Oils alfo, when examined, prefent abundance
pf Salts,

The Salts of Minerals or Metals are to be
come at, by quenching them, when red hot,
in V/ater, then filtering, evaporating, and
cryftallizing. Prettjf

y. Jr. '.

/ /</. /.^.2t>0.

-tu/. 2f^/>. 20}.

I'ly. Jl./>. 2dc.

J^u/. K/?. aOj.

I

4

/

luj.m.

vjf.p.26^

3- 4.

^.

J'

\m^^

6

Tl^.IX.^.26^.

^l^.JC./K 2dj, Fit/. . \ /.

^^

:s

f^.iei-

Fi^.-r.^.26'o.

-F/^.JJ^f>.a6j.

^JLa. jT.tf. 260.

GD

luf.Tir.

Iu7.M./>.

/'^aiz^lP.\

-F^. K/,. a6j. I-^_ FT.;r.2/,j.

vjr.p.2f4.

■^

^^■7'zir./,.,oj.

J- b.

m

r/p

J I

"y ^MT^

a;

'i^.JL.^.2()^,

K,. XT.

.XI. ^.2

Of Salts /;/ General. 261

Pretty Salts for Obfervation are, Pot-Afh,
Ejiglijl) and RuJJiafi : Salt of Wormwood,
Stacchariim Sat urn i^ Salt of Tartar, Salt Ar-
moniac, Salt of Hartfliorn, Salt of Amber,
Sic. They fliould be examined firft in their
dry or cryftallized State, and afterwards dif-
folved in a very fmall Qantity of fome tranf^i-
parent Fluid.

The Salts found in all Bodies when fepa-
rated by Fire, feera as fo many Pegs or
Nails *, penetrating their Pores, and faflen-
ins: their Parts toeether : but as Pep^s or
Nails when too large or too numerous,
ferve only to fplit or rend afunder 5 Salts^ by
the fame Means, oftentimes break, feparate,
and dilTolve, inftead of joining and making
fafl. They indeed are meerly Inftruments,
and can no more adl upon or force them-
felves into Bodies, thanNails can without the
Stroke of a Hammer y but they are either
driven on by the Preffure of other Bodies, or
by the Spring of the Air impelling them.
As Salts enter the Pores of all Bodies, Water
infinuates between the Particles of Salt : fe-
parates, or diiTolves, and fuftains them in irs
InterfUces, till by being in a State of Reft
they precipitate, and form themfelves into
Maffes. By this diffolving Power, Water

* Vid. ^taach de la Nat. Dial. XXVI.

becomes

262 Of Salts in Mineral Waters.

becomes the Vehicle of Salts^ and conveys
them into the Pores of Bodies, where it
leaves them to execute their proper Office.

Moft forts oi Anirnal znA. Vegetable Salts
are hkewife, probably, diiTolved by the
Juices of the Stomach, before they enter the
Blood, or they would occafion great Mif-
chiefs : and the Difficulty of diffolving fome
mineral Salts^ or breaking of their Points in
the fame Manner, may be the Reafon of
their dreadful Effefe.

CHAP. XLIX.

Of Salts i7i Mineral Waters,

^PIE Mi or of cope may be of lingular Ser-
^ vice to determine, by ocular Exami-
nation, what Kinds of Salts our medicinal
Springs are charged with ^ whence to form
a- Judgment in what Cafes their Waters may
be drank to Advantage.

The four Kinds oi f off le Salts ^ befl known,
are, according to Dr. -f- Lister, Vitriol^
Almn^ Salt-petrey and Sea-Salt : whereto
he adds a fifth, lefs known, though more

f Vide Lister de Fontibus Medicatis Anglise,

common

Of Salts /;/ Mineral Waters, 26^

common thiin any, 'viz, Calcarioiis Salt, or
Nitre,

Green Vitriol \s produced- from the Iron
Pyrites, When mature and perfedt, its Cry-
ftals are always pointed at each End, and
confift often Planes with unequal Sides: that
is, the four middle Planes are Pentagons, and
each of the fliarp Ends is made up of three
triangular Planes, as Plate XIV. Fig. 4.

AluNi burnt, diffolv'd in Water, and ftrain-^
ed, affords Cryftals whofe Top and Bottom
are two fexangular Planes, the Sides round
which appear compofed of three Planes that
are likewife fexangular, and three double
quadrangular ones, placed alternately. So
that every perfed" Cryftal confifts of eleven
Planes, "viz, five fexangular, and fix qua-
drangular. Fig, V-.

The Water of our Inland Salt-Sprifigs af-*
fords Cryftals of an exact cubical Form, one
Side or Plane whereof feems to have a par-
ticular Clearnefs in the Middle, as if fome
Deficiency were in that Place -, but the other
five Sides are white and folid. See Fig. VI.

Sal Gem, difiTolved, ihoots into the like
cubic Cryftals.

Sea-Water boiled to Drynefs, and its Salt
diflblved again in a little Spring Water, gives
Cryftals alfo that are cubical, but remarka-
bly, different from thofe laft defcribed : for
in the Cryflals of Sea Salt, all the Angles of
the Cube are feemingly cut off, and the

Corner^

264 Of Salts in Mineral Waten,
Corners left triangular : (See Fig. XL XL)
whereas the Salts of our Inland Spiings
have all their Corners fharp and perfeft, as
Fig. VL

Nitre^ or Salt^Pefre^ throws itfelf into
long flender fexangular Cryftals, whofe Sides
are Parallelograms. One End conftantly
terminates either in a pyramid-like Point, or
elfe in a fharp Edge, according to the. Pofi-
tion of the Sides of two unequal Planes.
The other End is always rough, and appears

as

if broken. FiK^Ylh VIL

o

The moft general, tho' leaft noted of all
the fqffile Salts among us, is a kind of Wall
or calcarious Nitre^ or Lime-Salt^ which
may be colleded from the Mortar of ancient
Walls 5 and is, as Dr. Lister fuppofes,
what a great. Part of the Earth and Moun-
tains confift of :|:. Its Cryftals are flender and
long, the Sides of them four unequal Paral-
lelograms : their Point at one End is formed
of two Planes with triangular Sides > the
other End terminates in two quandrangular

J We are well alTured, that in France^ it is the common
Pradlice, for thofe who have the Superintendency of the
King's Salt'Petre Works, to amafs vaft Quantities of the
Mortar and Rubbifli taken horn old Buildings : whence, by-
proper Management, they extra<5l abundance of this caUaricus
Nitre. And when they have got all they can from it, by
letting it lie together for fome Years, it becomes impregnated
anew, and affords almoil as much as it did at firft.

Planes :

Of Salts in Mi?ieral JFatcrs, 265

Planes : though both Eixls are fcldom to be

found unbroken Of this Salt fome is feen

with five Sides, and all the other "V'^arieties
may be found in it which are fliewn Fig.
VIII. I. 2. 3. 4. 5. 6. 7.

Unripe, or imperfe(^l: Vitriol^ is a white
Salt, whofe Cryllals are Cubick Rhom-
boides : as Fig* IX.

The Cryftals of our Inland S^alt- Springs^
not yet arrived at Maturity and PerfecSion,
are formed like Fig, X.

The Particles of each of thefe particular
Salts^ either in falling one upon another, or
uniting on one common Bafe, form them-
felves into Maffes, which are invariable, and
always of the fame regular Figure : but it is
beft to examine them in the fmalleft Mafles,
their Shape being there moft perfedl and
diftindl.

C H A P. . L.

Mifcellajieotis Discoveries and
Observations.

IT has been urged by fome in behalf of
fpontaneous Generation, that Worms are
found in the human Bowels, of a Fieure

o

ktn no where elfe > and therefore that they
muft be generated there, fpontaneouflv, bv
the Slime and Heat of the inteflines : for if
they proceed from Parents of their own Kind
3 without

^266 MifceUaneOtis Difccveries,

without the Body, and get into it by Acci-
dent, either in the Egg or any other State,
where are thofe Parents found ? — This feems
a very ftrong Objeftion j but the Microfcope^
I beUeve, can enable us to anfwer it.

Worms found in the human Body are of
three Kinds, viz. the Afcarides^ or little
(Idort Jlender Maggots^ fo nearly refembling
a Sort frequently met with in warm moift
Places, under rotten Wood, &c, that they

' may reafonably be fuppofed the fame. — The
^eretes^ rotundi^ or long round Worms ^ which

. are evidently the Species of Earth-worms
found commonly in Dunghills and Hot-
Beds ; whofe Degree of Warmth is pretty
equal to that of the human Bowels. And
the Lati^ Fafcice^ Tape-Worms^ or Joint-
worms^ which are broa#, flat, full of Joints,
and fometimes of a monftrous Length, ex-
tending many Yards along the Inteflines. —
This is the Animal faid to be found no where
elfe ; but the Mi or of cope has very happily
difcovered Worms of the fame Figure ex-
actly, and differing in Size only, in the In-
teflines of Eels J fo fixt as not to be removed
without great Difficulty, but contracting and
dilating themfelves very agreeably *. They
are of an incredible Length in comparifon of
their Breadth, and when contraded become

* Jrcan, Nai, Tom. IV. p. 367,

fix-

and Objetvatiom] 26 J

fix times broader than when extended. There
^re Tape-Wornn like wife in the Bowels of a
Tiirbiit^ tho' Ihorter than thofe in Eels^ and
with a Head not quite the fame. They are
fixed to the Guts by a kind of Hooks which
they have in their Mouths, and are not to
be got off, but by holding the Tail with one
Hand, and feparating the Head from the
Inteftines with a Needle.

Having found thefe Woryns in the In--
teftines of Fipes^ let us now confider hdw
they could get there. And, 'tis probable, they
are naturally Water-Animals, whofe Eggs
orYoung Ones getting into the Stomach with
the Water or the Food, become hatched or
nourifhed there. In the fame Manner they
may alfo be introduced into the Stomach of
other Animals : and their Difference of Size
in one or the other, may arife from the dif-
ferent Degrees of Heat, and the Kinds of
Nourifliment they meet with. — — Three
other Sorts of Wo7-ms are alfo found in the
Inteftines oi Eels, Carp are likewife fubjecft
to Worms which make them very lean, and

fo is the 'Trout. There are two Sorts of

white Worms in the Whiting \ and the Mi-
crofcope may difcover them perhaps in every
other Kind of Fiih -, nor can we wonder at
it, when we refledl how liable Fiflies muft
be to fwallow the Eggs or Young Ones of
whatever Infefts are Inhabitants of the Waters.

T 2. There

268 ^Mifcellaneoui Difcov cries

2. There are frequently, In thtLi'vers of
Sheep, Animalcules jQhaped like the Seed of a
Gourd, or rather like a fmall thin Myrtler-
Leaf with a , very fhort Foot-ftalk. Theij:
Colour is whitifh, but nurnberlefs branching
Veffels or minute Canals of a greenifh Yel-
low are difperfed every where about them i
and a round Hole or Mouth appears near the
Stalk End. Thefe Creatures are found often
in the GalUBladder^ and in every- Part of
\kvt Liver 'y where, forming themfelves little
Cells, they abide in a Liquor that is feem-
ingly Blood mixt with Gall. -f-

3 . In the He ad J of ^ ^tags^ Worms or
Maggots are moft commonly to be met with,
lodged in a Cavity under the Tongue, near
the Vertebrce where the Head joins on to
the Neck. Their Shape is partly Cylindrical,
being flat underneath, but rounded on the
upper Side : in Colour white, with many
femi-annular Rings befet with darkifh Hairs.
On the Head are a Couple of exceeding fmall
white Horns, which are thruft out or drawn
in like a Snail's ; and under them two mi-
nute Claws, black, hard and iliarp, exciting
much Itching, and thereby great Uneafinefs.

f Vide Redi de Generate Infedl, p. (3u2.
* Ibid. p. 307.

They

and Oifervafions. 269

They move along by fixing thefe Claws, and

then dragging up their Bodies to them. The

End where their Excrements are difchareed

1 • • •

has a little Opening, with two black Spots

refembling a Half-Moon * Twenty or thirty

are ufually found in one Head, of the Siz^

of very large Maggots.

4. Like to the foregoing, cfpecially to-*
wards the Tail, but fmaller, lefs vigorous,
and not fo hairy, are certain Maggots found-
in the * Heads of Sheep. Their white Bo-
dies are marked acrofs with blackLines (par-»
ticularly the largeft of them :) and two black
Spots at the x^nus, which form a Half-Moon^
in the Worms of Deer, compofe in thefe a
compleat Circle. They abide m.oft common-
ly in a hollow Part of the Os Fro?itis^ near
the Infertion of the Horns, but are fome-
times found even in the Noftrils, and in the
Cavities round the Roots of the Horns.
Sometimes too they get higher up i?:!:o the
Head, and make the Sheep run mad. They
are lefs numerous than thofe in Deer, being
feldom more than ten or fifteen.

5. Early in the Spring Seafon, we fhall
frequently find flicking to Pales of Wood,
efpecially very old ones, and fometimes to
Walls of Brick or Stone, a fort oi little Worm

* Vide Red I de Generat. Infect, p 309-

T 2 or

%jo Mifcellaneom Dif cover ies

or Maggos^ inclofed in a Cafe about the Big-'
nefs of a fmall Barley-Corn. If this Cafe be
viewed with the Micro/cope , it appears co-
ver'd all over with a mofh delicate fort of
Mofs, intermixed with fine Sand or Earth. At
the fliarpeft End there's a little Hole through
which the Excrements are difcharged, and
at the other a larger Opening, where the
Creature puts out its Head, and faftens itfelf
to the Pales or Wall. The included Ani-
mal is all black, about two Lines of an Inch
long, and three quarters of a Line broad.
Its Body has feveral Ringlets folding over one
another. Its Head is large, flat and poliih'd,
refembling Tortoife-fhell, with fome Hairs
iffuing from it ; and near thereto on each
Side are three Legs. The Mouth is large,
and in continual Motion, and from it pro-
ceeds a flender Thread or Web : the Eyes
are black and round. This is a pretty Ob-
je(5l, and changes I believe to fome fort of
minute Fly, tho' I have not had an Oppor-
tunity of making the Experiment.

6. Nothing is more common, in the Be-
ginning of Summ^er, than to fee the Leaves
of Peaches, Nedarines, and Cherries curled
up and blighted : which Leaves on Exami-
nation are found covered with little * InfeBsy

* Monf. Dela Hire calls thefe Pucerons, or little Fleas,
and inftances them as Infefts that come from ^walking to flyhig^
without paffing through the Aurelia State : which they do by-
only calling off their Skins, as a little Obfervat ion will fnew.

fome

a?id OhfervatloJisl 271

fome blackilli, others green ; fomc winged,
and others without Wings. Thele Creatures
bring forth their Young alive and perfc(5t,
and if their Bodies he opened, feveral perfed:
Embryos will be feen therein. — It remains a
Doubt, whence, and by what means, thefe
Infed:s are convey'd upon the young Iprout-
ing Leaves, which, at the fame Time, are al-
ways covered with a glutinous and honey-like
Moifture: but we may hope, diligent Obfer-
vations will difcover this Secret to us. Trees
in this Condition are vifited by Multitudes of
Ants ; which hurt not the Trees, as fome
erroneoufly conjedlure, but do them Service,
by devouring this Vermin that infclls them.

7. The Ant itfelf is an Objecfl well worth
our Notice, being a Creature of a very fm-
gular Strudure. The Head large, adorned
with two pretty Horns, each having twelve
Joints. Its Eyes are protuberant and pearl-
ed : it has Jaws faw-like or indented,- with
{t\^^ little Teeth that exacftly tally, opening
fide-ways, and able to gape very wide afun-
der ; by the help whereof it is often feen
grafping and tranfporting Bodies of three or
four times its own Bulk and Werght. It is
naturally divided into the Head, the Breaft,
and the Belly or Tail : each of thefe Parts
joining to the other by a very (lender Liga-
ment. From the Breaft-Part, three Legs
come forth on either Side. The Tail is armed

T 7 vv'ith

272 ^ Mifcellaneom Difcoveries

with a Sting, which the Animal ufes only
when provoked ; but then a poifonous Li?-
quor is conveyed by it into the Wound, oc^
cafioning Pain and Swelling. The whole
Body is cafed over v\^ith a fort of Armour, fo
hard, as fcarce to be penetrated by a Lancet,
and thick fet v/ith fhining whitifli Briftles,
The Legs, &c. are alfo covered with Hairs,
but much fmaller and of a darker Colour.

Upon opening an Ant-HilU we ihall fee
them carrying in their Mouths and fecuring
with great Solicitude fm.all whitifh Bodies,
ufually caird their Eggs. Thefe, hov/ever,
are not Eggs, but Ants in their Aurelia State y
each encompafs'd with an Integument of its
own fpinning. We might have conje6lur'd
this from their Largenefs in Proportion to a
perfecl Ant -, but the Micro/cope fully proves
it, by difcovering to us their real Eggs^ of
an oblong oval Figure, about the Size of a
Grain of Sand * : ninety whereof would not
extend the Length of an Inch, nor an hun-
dred and feventy be equal in Bignefs to one
of thefe Aurelia inclofed in its Cafe. Thefe
minute Eggs produce Maggots^ which after
a Time fpin themfelves Coverings, become
Aurelias^ and then Ants, The Parents Af-
fedlion for their Young in the Aurelia State
is fo ftrong, that when Danger threatens,
they inftantly run away with them, and v/ill

* Vide L^EuwEN, Epiii ad Reg. Soc, 9 Sep. 1687.

fooner

and Obfey-vatiojjs, 273

fooner die than leave them. There are fe-
veral Sorts oi Ants differing both in Size and
Colour; and towards the End of Summer
many of them are feen having four Wings.
Thefe, Swammerdam fays, are Males. -f-

The French Academy has publifli'd a curi-
ous Account oi Ants^ whence I fliall abftrad:
fome few Particulars. Every A?it\ Nefl
(it tells us) has a ftrait Hole leading into it,
about the Dep:h of half an Inch 3 which,
afterwards, runs Hoping downwards to the
publick Magazine, where the Grains they
colied: are ftored up : and this is a different
Place from that where they reft and eat.
— — Their Corn being kept under Ground,
would flioot and grow, did they not prevent
it by biting out the Germen or Bud before
they lay it up : but this they conftantly do ;
for if their Corn be examined, no Bud will
be found therein, nor if fowed in j:he Earth,
will it ever vegetate. Was it, however, to
lye continually in the Ground, the Moifture
would occafion it to fwell and rot, and make
it unfit for Food. But thefe Inconveniencies
they find means to remedy by their Vigilance

and Labour in the following Manner.

They gather very fmall Particles of dry
Earth, which they bring out of their Holes

-}- Vid. SwAMMJBRD. Bijl. Generate da Infixes y p. 183.

T 4 every

274 Mifcellaneotis Dijtoveries

every Sunfhiny Day, and place them in the
Heat. Every one of them brings in her
Mouth a Particle of this Earth, lays it by
the Hole, and then goes to fetch another i
fo that in a Quarter of an Hour a vafl Num-
ber of fuch fmall Particles of dryed Earth
are heaped round the Hole. Their Corn is
laid upon this Earth when under Ground,
and covered v^lth the fame. When thefe
Particles of Earth are brought out, they fetch
out their Corn iikevi^ife, and place it round
this Earth J making tw^o heaps about the
Hole, one of dry Particles oi Earth, and
the other of Grains of Corn. Laft of all,
they fetch out the Remainder of their dry
Earth whereon the Corn was laid. They
never go about this Work unlefs the Weather
be clear, and the Sun very hot : but when
both are favourable they perform it almoft
every Day.

The Author of this Account had found a
Neft of A72fs m a Box of Earth ftanding
out from a Window two Stories high ;
whence they made Excuriions both upwards
to the Top of the Houfe, where fome Corn
lay in a Garret ; and dov/nwards into a Gar-
den, which the Window overlook'd. The
Situation of this Neft obliged them to go up
or down a great way before they could pof-
fibly meet with any thing ; but he found,
iiotwithftanding, that none of them ever re-
turned emptyj but every one brought a Gr^in

, " of

cmd Obfcrvations. 275

of Wheat, Rye, or Oats, a fmall Seed, or
even a Particle of dry Earth, if nothing elle
could be got. Some travelled to the farther
End of the Garden, and, with prodigious
Labour, brought heavy Loads from thence.
It required four Hours, as he learned by fre-
quent Obfervation, to carry a pretty large
Grain or Seed from the Middle of the Garden
to the Neft : and he computed therefrom,
that an Aiit works as hard as a Man who
iliould carry a heavy Load twelve Miles a Day.
The Pains thefe Ants took, to carry Grains
of Corn up a Wall to the fecond Story,
climbing all the Way with their Heads down-
ward, muft be exceedino; areat. Their
Wearinefs was Ihewn, by their frequent Stops
at the moft convenient Places ; and fome ap-
peared fo fatigued and fpent they could not
reach their Journey's End : in which Cafe,
'twas common to fee the ftronoeft Aiits.
which had carried home their Load, come
down again and help them. Sometimes
thev were fo unfortunate to fall down \tith
their Burdens v/hen juft in Sight of Home :
but when this happened, they feldom loft
their Corn, but carried it up again. — He faw
one, he fays, of the Jhmlleft Ants carrying
a larg-e Grain of Wheat with incredible
Pains. When (ht came to the Box where
the Nefl was, {he and her Load together
tum.bled back to the Ground. Going down
to look for her, he found flie had recover'd

4 the

2 76 Mifcelhmmws I)ifcoveries

the Grain, an-d was ready to climb up again.
Th^ fame Misfortune befell -her three times;
but ilie never let go her Hold, nor wa^s dif-
couraged 5 till at laft, her Strength failing,
fhe was forced to Hop, and another Ant
affifted her to carry home her Load to the
publick Stock.

How wonderful is the Sagacity of thefe
Infedls ! How commendable their Care, Di-
ligence and Labour ! How generous their
Affiilance of one another for the Service of
the Community ! How noble their publick
Virtue, which is never neglected for the Sake
of private Intereft ! In all thefe Things they

deferve our Notice and Imitation. A con-

temxplative Mind will naturally turn its
Thoughts from the Condition and Govern-
_ ment of Ant-Hills to that of Nations ; and
refled:, that Juperiour Beings may poffibly
confider Human Kind and all their Solici-
tudes and Toils, Pride, Vanity, and i\mbi-
tion, with no more Regard than we do the
Concerns of thefe little Creatures.

8. Among Pinks, Rofes, and Sun-flowers,
there's to be found, almoil: conftantly, a
little y long^ imnbkBifeB fmaller than a Loufe,
fometimes creeping, and fometimes leaping.
It appears in the Micro/cope bodied like a
Wafp, with fix or {tvcn annular Divifions :
it has two fair long black and yellow Wings;
two Horns, each rifing from a knobbed

Root 3

und Objirvations. 277

Root ; two black Eyes, and fix Legs. 'Tis
fo tender, the leafl Touch kills it, but a very
pretty Objed:.

9. A Utfle Infeui is conftantly found in
the Froth (or Cuckow-Spit as fome call it)
that hangs on the Leaves of Rofemary, La-
vender, &c. It creeps firft, then leaps, and
at laft flies. It has fix Feet, with two
blackilli Claws at the End of each ; a long
Probofcis to fuck up its Food, two Horns,
and a Pair of darkifli red pearled Eyes. The
Tail ends in a Stump, but by its annular
Divifions can be thruft out or drawn in at
Pleafure.

10. There's a pretty yellow InfeB on Sy-
camore Leaves, with fix Legs, running very
nimbly. The Eyes are red, prominent and
pearled ; the Horns are flit, and forked at
the Ends. At firfl: it has no Wings, but
near the Shoulders are two little Protube-
rances, whence two long Wings come forth,
when it turns into a Fly or Locufl:. It is
hairy towards the Tail.

1 1 . A fmall white oblong InfeS fticks to
the Ribs on the Backfides of Rofe-Tree
Leaves, towards the End of Summer, which
turns into a little yellow Locuft that (kips
about the fame Tree, In both States it is a
pr£tty Objeft.

12, There

278 Mifcellaneous Difcovertes

12. There is alfo 2. grcQuitti Grafshopper
or Locujl^ on Goofeberry-Leaves, Sweet-
Bryar, and Golden Moufe-Ear, in April
and May^ with four Legs, two black Eyes,
a Pair of curious Horns, and many other
Beauties. '

13. In the Water of Ditches there are
frequently Numbers of Water -Spiders^ not
larger than a Grain of Sand ; they are very
voracious, hunting about continually for
Prey : and may be feen by the Mi cr of cope
catching and devouring other minute Ani-
malcules. Some have eight, fome ten Legs,
and Antemice]6mX.^^ like Equifetum orHorfe-
Tail.

14. Likev/ife in ftanding Waters v/e may
often meet with flender Eels or Worms^ about
the third of an Inch, and fometimes more,
in Length. They are full of Joints from
End to End at large Diftancesfrom one
another, have a iliarp Head like an EeU a
large Mouth, and two fine black Eyes. Thc/
Tail terminates in a Tuft of Hairs of a very
curious Strudlure , the Motions of the In-
teftines are feen diftind:ly, and the whole
Animal is a delightful Objed. The Blood-
red Jointed Worm^ very common in ftagnant
Waters, is alfo well deferving our Obferva-
tion.

I r. The

iand Ohfer'oafions, 279

15. The Crajie-FIy, called by Aldro-
%AND Culcx maxifnus, by Swammerdam
Tipula tiTveftris^ and by tjfie common People
Father -long-Legs^ affords, in every Part of
it, agreeable Subjedls of Examination : But
the Feet are more particularly furprizing ;
for upon diflediing them, in a Drop of
Water, the flefliy Fibres contract and diftend,
in a manner not to be imagined without fee-
ing it, and continue their Motions three or
four Minutes. Mr. Leeuwenhoek found
it conftantly in the Feet of this Creature,
but not in thofe of any other Infed:. "* The^
Inteftines are alfo very curious, confifting of
numberlefs Veflels and Organs, which may
be feen as plainly by the Microfcope, as the
Bowels of larger Animals can by the naked
Eye. -j- The Tails both of the Male and
Female are of an extraordinary Strucfture :
that of the Female ends in a fharp Point,
wherewith £[:ie perforates the Ground, and
depofitcs her Eggs under the Grafs, in Mea-
dows.

16. The Midtipes, or Scolope7id7'a, has a
very long flender Body : its Mouth is armed
with a Pair of fharp Forceps, and in hot
Countries (where they are of a large Size)

• Vid. y/rr. Nat. Tom. III. p. 119. f Torn. IV. p. 351.

its

aSo Mifeelianeous Difio'^ries

% Bite is venomous 5 but our fmaller Ones
feem not mifchievous. One I examined had
fifty-four Joints, and from every Joint a Leg
iiTued on each Side, w^hich, v^ith two others
at the End of the Tail larger than the reft,
made in all one hundred and ten. When
the Creatures move along, thefe Legs follow
one another very regularly, making' a pretty-
kind of Undulation, not to be defcribed,
and. giving the Body a fwifter ProgreffioEt
than one would expecft, where fo many Feet
take fo many fhort Steps, in turn, one afterf
another. There are feveral Sorts of thefe
infeidls, different in Shape j and in Number
of Legs, which the Curious will be pleafed
to examine. ^

' tj. There's an extraordinary Sort or-
Caterpillar y of a middle Size, having four
Tufts of yellowifh white Hair, like little
Bruflies, of an equal Height, {landing up-
right on its Back : below thefe, from each
Side, iiTues a Bunch of dark-colour'd Hairs
of different Lengths, the Extremities of
which are black. Tw^o more Bunches of
the fame Form rife from the Head like
Horns, and another ftill from the Top of
the. Tail. Every Hair in thefe Bunches,

* Leuwenhoek fays, the Indian Millepes has eig.ht
Eyes like tjie Spider, J^ere, Have ^r.glift: Ones fo tooi

when

C7id Ohfer'vatiom. 281

when viewed through the Microfcopc^ re-
fembles a Pcacock\ Feather, and is a de-
lightful Objc(ft. The Inquifitive will find
abundance more Wonders in this ama-zing
Creature, and indeed in moft Sorts of Catcr^
pillai

irs\

18. The S/ik'fForm h a Creature, every
Part whereof, either in the l^P^Grm or F/y^
Statey deferves our particular Attention :
but as. both Malpighi and Leeuwen-
HoEK have examined it with great Skillj
and publifhed their Obfervations with ana-
tomical explanatory Drawings, I fhali refe^
the Curious to them, and to their own En-
quiries ; only advifing fuch as fhall engage
in a farther Examination, not to neglecfl: the
Ski?is thefe Animals caft off three times
before they begin to fpin : for the Eyes,
Mouth, Teeth, Ornaments of the Head,
and many other Parts maybe difcerned better
in the cajl-off Skins than in the real Ani-
mal. A due Obfervation of the Changes

of this Creature, from the Caterpillar to the
Nymph, Aurelia, or Chyfalis, and thence
to the Moth or Buttei-jly • State, will give a
general Notion of the Changes ^Caterpil-
lars undergo, though fome little Differences
may be in the Manner. Swam mer dam
fays, the Butterfly, by a judicious Exami-
nation, may be traced and difcerned under

each

I

282 Mifcellaneous Dif cover ies

each of thefe Forms, which are only di£*
ferent Coverings or Drefles for it.

19. The Tail of the Male Silk-Worm be-
ing fqueezed. Animalcules were found in the
Semen * four times as long as broad : their
Backs thicker than theirBellies, like the Shape
of a Trout. Their Length was fuppofed to
be about half the Diameter of a Hair.-- — -•
This I experienced myfelf, on the 8th Day
oi Auguji^ in this prefent Year 1742, when
taking a Male Silk-Worm^ that was juft then
come forth in its MothS fate ^ and giving its
Tail feveral little gentle Squeezes, in about
a Minute's Time, a fmall Drop of a browniih
white Liquor was fquirted brifkly from it on
a Talc I held to receive it : and diluting, this
with a little Water warmed in my Mouth
for that Purpbfe, I was very much furprized
and pleafed to obferve the numberlefs Ani--
malcules it contained, fwimming about, alive
and vigorous.——

N. B, Whoever would make this Experi-
ment, mtufl: do it, before the M?//' has been
coupled with the Female ; for nothing is to
be got from it afterwards, as I have found
by feveral. Trials.

20. The Probofcis oi 2. Butter fiy^ which,
winds round in a fpiral Form, like the Spring

* Vid. Leeuwen. Arc. Nat, Tom. I. Par, II, p. 422.

of

of a Watch, fcrves both for Mouth and
Tongue, by entering into the Hollows of
Flowers, and extrading their Dews and
Juices. — The Shape and Structure of it will
be found very furprizing.

2 1 . The Legs and Feet of LifeBs are won-
derful in their Strudure and Contrivance,

•according to their different Circumftances
and Neceffities of Life, and afford a pleafing
Variety of Objedls. It is pretty to obferve,
not only the Iharp hooked Claws, but alfo
the fkinny Palms of fome Flies, &c. which
enable them to walk on Glafs and other
fmooth Surfaces, even with their Bodies
hanging downwards, by means of the Pref-
fure of the Atmofphere ; others again have a
fort of Spunges, which preferve their Claws
from being broken or blunted by ftriking
againft hardBodies, as the Claws of Cats, &c^
are, by foft fleihy Protuberances at the Bot-
toms of their Feet.

22. The Nymph of the Clothes-Moth, which
(from being often found fcudding among
Books and Papers) Mr. Hook calls the fil-
ver-Goloured Book-worm, is covered with
thin tranfparent Scales, from whofe Sur-
faces a multiplicity of Refledlions of Light
make the Animal appear in Colour like a
fine Pearl. It has fix Legs, runs by Starts
and Stops, and has three Horns at the Ex-

U tremitv

284 Mifcellaneotis Difcoveries

tremity of the Tail. As this Defcription 1^
fufficient to make it known, I fhall leave
the Curious to examine its Beauties, and not
anticipate their Pleafure. Vide Hookas Mi--
crog, p. 208.

23. On the Leaves of Orange-Trees, Fig-
Trees, Willovi^s, and many other Trees and
Plants, there are various Kinds oii^iinute In--

feBs^ as yet but little known, inclofed in
Tubercles or Swellings*

24. The Eggs of InjeBs are remarkable
for their different Figure and Colour, and
for the particular Regularity and Exadtnefs
wherewith they are frequently placed. We
ihall fometimes find a fort cemented round
a Twig of the Sloe-Tree or Damfon-Tree,
as if faften'd there by Art, and ranged meer-
iy for the Sake of Beauty. The Variety of
them is inconceivable, and to be fought for
as well in the Waters as elfewhere j as thofe
will be convinced who will take the Pains
to examine in the Spring, the Water-CreiTes,
Brook-lime, and other Water-PIants, on the
Back of whofe Leaves infinite Numbers of
mmute Eggs may frequently be difeovered,
appearing to the naked Eye only as a SlimCa

25. In Cellars, on the Corks of Bottles,
there are three or four Sorts of very furpriz-
ing Infed:s.

26. The

and Ohfervatiohs* 28c

lb. I'he hums of a Fro^^ blown up and
dry'd, will aiiill us to difcover the true
Structure of that Bowel.

27. Ccchineal, v/Iiich comes from A^e'-uj
Spain y and is fo vahiaMe for its Ufe in dying
Scarkt, Criinfon^ and F.-rpk^ has been af*
ferted, by fome, to be a Seed or Grain, and,
by others, an InfccTt ; but the Mtcrofccpe de-
termines thefe Difpiites, by fhev/ing plainly,
after jfteeping it in Water twenty-four Hours,
an oval Body, Scales, Legs, and a oointed
Trunk : in iliort, the whole refembles our
Cow-Lady. Many Eges may be difcovered
upon opening their Bodies 5 and if you burn
them, let their Afhes ftand two or three
Days in Water, then filter and evaporate,
their Salts may be diftindlly feen.

20. The Feathers of Birds afford Variety
of Beauty, and differ greatly from one ano-
ther, not only in their general Colour and
Form, but in the Structure of each particu-
lar Part ; as as every Body muft be fenfible,
who examines thofc of the Oftrich, the Pea-
cock, the Eagle, the Swan, the Parrot, the
Owl, and all the numerous Species of Birds.
Their Quills too deferve our Attention ; and
our Obfervations on them will be affifled by
reading the 36i:h Obfervation in Mr. Hook's
Micrography^ j>. 168. and alfo Mr. Leeu-

U 2 wenhoek's

:^86 Mifcellaneous Dif cover les

wenhoek's Experiments^ in the 4th Tome
of his Writings, p. 323.

29. Mojfes of all Kinds are agreeable Ob-
jects, and appear, by the Microfcope^ to be _
as perfecft in their Leaves, Flowers and Seeds,
as the largeft Plants or Trees. Thofe, par-
ticularly, that grow on the Rocks and Coafts
of the Sea, exhibit amazing Beauties.

30. Spunge h reckoned 2. Tlajit- Animal^
and appears compofed of minute Veffels re-
fembling Veins apd Arteries^

3 1 . Decayed Fruits, moift Wood, damp
Leather, ftale Bread, and abundance of other
Things, contrad; what v/e call Mouldinefs ;
which the Micro/cope difcovers to be nothing
elfe but innumerable ??ii?iiite PlantSy bearing
Leaves, Flowers and Seeds, and increafing in
a manner almoft incredible : for in a very
fev/ Hours the Seeds fpring up, arrive at full
Maturity, and bring forth Seed themfelves ;
fo that a Day produces feveral Generations of
them. There are many Sorts of thefe micro-
fcQpical PlantSj very different in Size and

Appearance : Some of the Mufhrcom Kind,
Others refembiing Bulruflies, and Others
again bearing vafl Quantities and great Varie-
ties of Fruit. Other Kinds are likewife found,
in great Abundance on the Surface of Li-
quors, when tliey are what v/e term Moihery.

32. The

and Obfcrvations. 287

32. T\\Q Air 'Vv dels, Sap-Vejfcls, and Pores
of Wood are wonderful in their Figure,
Number, and Difpofition : as plainly appears
by IhavinfT off the thinnell Slices pollible,
lengthwifc, crofbvvife, and obliquely, and
bringing them to view. Fir and Cork are
the readieft for this Purpofe : but all other
Kinds of Wood, tho* with fomewhat more
Trouble, may be render'd fit to be examin-
ed. In a Piece of Cork, no longer than

the eighteenth Part of an Inch, fixty Cells
were number 'd in a Row -, whence it fol-
lows, that one thoufand and eighty are in
'the Length of an Inch : one Million an hun-
dred fixty and fix thoufand four hundred in
an Inch fquare ; and in a Cubic Inch one
thoufand two hundred fifty-nine Millions,
feven hundred and twelve thoufand. J

In the Pith of Trees and Plants, cut (o as
to become tranfparent, the Veflels may be
difcerned difiiindly. The Pores of Wood
may likewife be feen advantageoufly in Char-
coal and Small'CoaL

3 3 . There are many Sorts of Sajzd ; fome
gathered on the Sea Shore, or, on the Shores
of Rivers, and others found within Land.
The Grains of each Sort dijfFer much in Size,

J Hook's Microg. p. 114.

U \ Form,

2 88 Mifcellaneom Difcoveries

Form, and Colour : fome are opake, other:S
tranfparent : fome have rough Surfaces, and
others are quite fniooth/^ Thefe Varieties
are very agreeable to examine by the Micro--
Jcope^ which fliews, in fome of the fliining
Kinds, Grains having all Numbers of Sides
and Angles, arid fo finely poliflied, that no
Diamond is more exquifite^y beautiful. On
others grotefque Figures, or R.eprefcntation8
of Landfcapes, Buildings, Plants, and Ani*
pi.als, at once furprize and pleafc.

34. In order \.o examine Diamonds -f- with
ihe greater Exaclnefs, Mr. Leeuwenhoek
broke a fmall one between two Hammers,
and placing the Pieces before his Microfcope^
in the Sun-(hine, he faw m.any fparkling
Flames ifilie from them, with a continual
Corrufcation, in fame, like a faint Lightning.
Then viewing them in the Shade, he obferv-
ed, among other pretty Appearances, a litde
Flame that feeined to dart from each Particle
'of the Diamond : and it was a glorious Sight
to behold Multitudes of fparkling Flames,
pioft of a bright Fire-Colour, and others
greenifli, flaflimg faintly and like Lightning
at a Diftance.-— In other Pieces of the Dia-*

* YiAQPhilofophicalTranfaaions, Numb. -289. Hook's
Microp-. p. 80

f Vide Phihfoph. franfaB. Numb, 374.

mQn^

and Obfet'vations. 289

niond tlie Lamellce or Layf^rs compofing it
were very plainly to be diftinguiflied.

35. In ftriking Fire with a Flint and Steel,
little Piirtlcles of Steel are flruck off, and
melted into Globules by the Collilion s as
will be evident upon making the Experiment
over a Sheet of white Paper, and viewing
what falls into it through the Microfcope.
Mr. Hook firft made the Trial, and found
that a black Particle, no bigger than a Pin's
Point, appeared like a Ball of poliihed Steel,
and ftrongly refleded the Image of the
Window near which he examined it. X ^^
is alfo entertaining enough to feparate the
melted Iron Particles from the Particles of
Stone, which fometimes are vitrified ; by
means of a Knife that has been touched by
a Loadftone.

36. Kind Nature has fupply'd the Seeds of
Dandelion, Thiftles, and m.any other Plants
with a Do'ivn, that ferves inftead of Wings
to convey them to diftant Places. The Y'l-
gures offuchZ)(5iiy/7, in different Plants, are
very different when looked at through Glaf-
fes : fome appearing plain and fmooth, others
rough and thorny, and others again with
little Hooks or Clafpers to catch hold of any

X Hooit's Microgr. p. 25, 44* 4^' , .

U 4 tl"^!!^

s-

igo Mifcellaneous Difcoveries

thing. Peaches, Quinces, and fome other
Fruits have like wife a foft Down, which is
worth examining, as Vvrell as the Hairs on
many forts of Leaves, Fruits and Seeds.

37. There is a very fine Down or Hair
called Cow age y or Cow-It ch^ growing on a
fort of hairy Kidney-Bean that comes from
the Eafi-hidies. The Pods, about three
Inches long, refernble a French Bean, and
are covered with this Down or Hair, which
is very ftifF for its Bignefs, caufes Pain and
Inflammation if rubbed on any Part, and
Vs^hen viewed by a Microfcope appears like
Multitudes of Needles.

A fort of curling Morns ^ rifing out of the
Middfe of fome Carnations and Pinks, are
exceeding pretty Objects.

38. The Flakes oi falling Snow are various
in their Configurations, and extreamly beau-
tiful, if examined before they melt : which
may eafily be done by making the Experi-
ment in the open freezing Air. Descartes,
Dr. Grew, Mr. Hook, Mr. Morton, Dr.
Langwith, and others, have given us feve-
ral of their different Star-like Forms : and
Dr.STocKE, oi Zealand y have lately commu-
nicated to thtRoyal Society fome new Figures
unobferved before.

The Configuration of theParticles of Dew
may perhaps be likewife well worth obferv-
ing, ' Plu^

iind Obfcrvations. 291

Plumous Alum, Talcs of different Kinds,
Afbellos, Marcafites, and all Sorts of Mine-
rals and Foffils, afford a Variety of agreeable
and curious Objects.

iEthiops Mineral, Calomel, Mercurius dul-
cis, and all other Mercurial Powders, are
^ound, when examined by the Alicrofcope,
to be full of minute Globules of crude and
unaltered Mercury.

Common Salt diffblved in Water exhibits
infinite Numbers of quadrangular Bodies.

Toads, Frogs, and Newts, are * killed by
rubbing Salt upon their Backs : Snakes,
Vipers, Rattle - Snakes, &c, by drawing-
thro' their Skin with a Needle a Thread dio-
ped in Oil of Tobacco ^ and Mercury is a
mortal Poifon to Ants,

It would be an endlefs Tafk to point out
half the Objedls fit to be examined by this
ufeful and entertaining Inftrument, which
fupplies us as it were with Eyes, infiniicly
more penetrating than our own ; and difco-
vers Wonders to us which we ffiould be un-
able to conceive without it. The foregoing
are a few only among thofe that are m.oll
curious j but every Creature, every Plant,
and Fruit, and Flower, every Drop of Wa-

* HQQm'i Microgr. p. 144.

ter,

2^2 Art and Nature

ter, and every Particle of Matter, if carefully
examined, will afford us new Inftrudtion and
Delight.

CHAP LI.

T^he Works of Art and Nature
compared together and confiderd.

E F O R E this Treatife is concluded,
it will not perhaps be thought unpro-
fitable, to examine fome of the fineft and
moll exquifite Performances of human Art,
and compare them with the Produdions of
Nature; as fuch a comparifon muft tend
towards humbling the Self-conceit and Pride
of Man, by giving him a more reafonable
and modeil Opinion of himfeif ; and at the
fame time may in fome Degree conduce to-
wards improving his imperfed Conceptions
of the Supreme Creator.

Upon examining the Edge of a very keen
Razor by the Micro/cope^ it appeared as
broad as the Back of a pretty thick Knife ^
rough, uneven, full of Notches and Fur-
rows, and fo far from any thing like Sharp-
nefs, that an Inftrument as blunt as this
feemed to be, would not ferve even to cleave
Wood, -f

f Hood's Micrcgr,

compared and confidered, 293

An eycccdlng fmall Needle being alfo ex-
amined, the Point thereof appeared above a
Qijartcr :)f an Inch in Breadth • not round,
or fiat, but irre^^ular, and unequal \ and
the Surface, though cxtrcanily fmooth and
bright to the naked Eye, fccmed iwW of
RuggcJneis, Holes and Scratches. In fliort,
it refenibled i;n Iron Bar out of a Smith's
Forge. ^"

But the Sting of a 5^5' viewed through the
fame Inflrumcnt, fliewed every where a Fo-
il (h moft amazingly beautiful, without the
lead Flaw, Blcmilli, or Inequality ; and end.-
ed in a Point too fine to be difcei aed : yet
this is only the Cafe, or Sheath, of Inftru^
ments much more exquifite contained there-
in, as before defcribed, Page 210.

A fmall Piece of exceeding fine i^g-w^ ap-
peared, from the large Diftances and Holes
between its Threads, fomewhat like a Hur-
dle or Lattice, and the Threads themfelves
feemed coarfer than the Yarn wherewith
Ropes are made for Anchors.

Some Brujfeh Lace, v/orth five Pounds a
Yard, looked as if it were made of a thick,
rough, uneven Hair-Line, intwifted, faften-
ed, or clotted together in a very awkard and
unartful Manner.

* Philof. Travf. Numb. 324. Sfca. de la Nat, Englifh
j|&4it. i2mo. Vol, I. pag. S.

But,

294 •^^'^ ^^^^ Nature

But a Silkworrris Web being examined,
appeared perfed:ly fmooth and (hining, every
where equal, and as much finer than any
Thread the bell: Spinfter in the World can
make, as the fmalleft Twine is finer than
the thickeft Cable. A Pod of this Silk being
wound off, was found to contain nine hun-
dred and thirty Yards : but it is proper to
take Notice, that as two Threads are glewed
together by the Worm through its whole
Length, it makes really double the above
Number, or one thoufand eight hundred
and fixty Yards : which being weighed with
the utmoft Exacfbnefs, were found no hea-
vier than two Grains and a half.* What an
exquifite Finenefs is here ! and yet, this is
nothing when compared with the Web of a
fmall Spider, (fee Page 200) or even with
the Silk that iffued from the Mouth of this
very Worm, when but newly hatched from
the Egg.

The fmalleft Dot, Hittle^ or Point, that
can be made with a Pen, appears, when
viewed by the Micro/cope^ a vaft irregular
Spot, rough, jagged, and uneven all about
its Edges, and far enough from being truly
round. The fineft and mmntt^ Writing y
fuch as the Lord's Prayer in the Compafs
of a filver Penny, or other fuch like curious

* Ibid. p. 50.

Per-

compared and confidered^ 295

Performance, done by the mofi: able Mafter,
feems, when brought to Examination, as
iliapelels, uncouth and barbarous, as if writ-
ten in Rioiic Chara5lcrs, But the Httle Specks
on the Wings or Bodies of Moths, Beetles,
Flies, and other Infedis, are found, when
magnified, to be moft accurately circular :
and all the other Lines and Marks about
them, appear regularly and finely drawn, to
the utmoft Pofiibility of Exaftnefs.

Dr. Power fays, he faw a golden Chain

at Tredescant's, of three hundred Links,

not more than an Inch in Length, fattened

to, and pulled away by a Flea. And I

myfelf have feen very lately, near Durha??i-

Yard in the Strafid^ and have examined with

my Microfcope^ a Chaife (made by one

Mr. BovERiCK, a Watch-maker) having

four Wheels, with all the proper Apparatus

belonging to them, turning readily on their

Axles : together with a Man fitting in the

Chaife ; all formed of Ivory, and drawn along

by a Flea without any feeming Difficulty. I

wei2:hed it with the p:reatcil Care I was able,

and found the Chaife, Man, and Flea, were

barely equal to a fingle Grain. I weighed

alfo at the fame Time and Place, a Brafs

Chain made by the fame Hand, about two

Inches long, containing two hundred Links,

with a Hook at one End, and a Padlock and

Key

tg6 Art and Natttre

Key at the other ; and found it lefs than

the third Part of a Grain, -f-

We are told, that one Oswald Ne-^
tiNGER I made a Cup of a Pepper-Corn^
which held twelve hundred other little Cups,
all turned in Ivory, each of them being gilt
on the Edges, and jftanding upon a Foot :
and that, fo far from being crouded or want^
ing Room, the Pepper-Corn could have held
four hundred more.

Thefe are fome of the niceft, moft curious
and furprizing Works of Art j but let us
examine any of them with a good Micro*^
fcope^ and we fliall immediately be convinced,
that the utmoft Power of Art is only a Con^
cealment of Deformity, an Impolition upon
our Want of Sight -, and that our Ad miration
of it arifes from our Ignorance of what it
really is.

This valuable Difcoverer of Truth will
prove the moll boafted Performances of Art
to be as ill-fhaped, rugged, and uneven, as

f I have feen fmce ray writing the above, (made by the
fame Artiil) a Quadrille Table with a Drawer in it, an
Eating Table, a Side-board Table, a Looking-Glafs, twelve
Chairs with Skeleton Backs, two Dozen of Plates^ fix Dilhes,
a Dozen Knives, and as many Forks, twelve Spoons, two
Salts, a Frame and Caftors, together with a Gentleman,
Lady, and Footman, all contained in a Cherry Stone, and
not filling much more than half of it.

X Ephem. German, Tom. L Addend, ad Oblerv. 15.

if

ccniparcd and Ccnfidcred, 297

if they were hewn with an Ax, or ftruck
out with a Mallet and Chiflel. It will fliew
Bungling, Inequality, and Imperfedion in
every Part, and that the whole is difpropor-
tionate and monftrous. Our fineft Miniature
Paintings appear before this Inftrument as
meer Dawbings, plaifter'd on with a Trowel,
and entirely void of Beauty, either in the
Drawing, or the Colouring. Our mod
fhining Varnifhes, our fmootheft Poliihings
will be found to be meer Roughnefs, full
of Gaps and Flaws.

Thus fink ihtWorks of Art when we be -
come enabled to fee what they really are ! —
But, on the contrary, the nearer we examine,
the plainer we diftinguifh^ the more we can
difcover of the Works of Nature^ even in
the leaft and meaneft of her Productions,
the more fenfible we muft be made of the
Wifdom, Power and Greatnefs of their Au-
thor.— Let us apply the Microfcope where
we will, nothing is to be found but Beauty
and Perfection. View we the numberlefs
Species of InfeCts that fwim, creep, or fly
around us, what Proportion, Exadtnefs,
Uniformity and Symmetry fhall wc perceive
in all their Organs ! what a Profufion of
Colouring ! Azure, Green, and Vermilion,
Gold, Silver, Pearls, Rubies and Diamonds,
Fringe and Embroidery on their Bodies,
Wings, Heads, and every other Part ! How

rich

Art and Nature

rich the Glow ! how high the Finifhirig !
how inimitable the Polifh we every where
behold ' Search we yet farther, and exa-
mine the Animalcules y many forts whereof
it would be impoffible for an human Eye
unaffiftedtodifcern^ thofe breathing Atoms,
fo fmall they are almoft all Workmanihip !
In them too we ihall difcover the fame Or-.
gans of Body, Multiplicity of Parts, Variety
of Motions, Diverfity of Figures , and par-
ticular Ways of Living, as in the larger Ani-
mals.— How amazingly curious muft the
Internal Strudlure of thefe Creatures be ! The
Heart, the Stomach, the Entrails, and the
Brain ! How minute and fine the Bones^;
Joints, Mufcles and Tendons ! How exqui-
litely delicate beyond all Conception the Ar-
teries, Veins, and Nerves ! What Multitudes
of Vellels and Circulations muft be contain'd
within this narrow Compafs ! And yet, all
have fufficient Room to perform their diffe-
rent Offices, and neither impede nor inter-
fere with one another.

The fame Order, Regularity and Beauty
will appear likewife among Vegetables if
brought to Examination. Every Stalk, Bud,
Flower, or Seed, difplays a Figure, a Pro-
portion, a Harmony beyond the Reach of
Art. There's not a Weed, not a Mofs,
whofe every Leaf does not ihew a Multipli-
city of VelTels and Pores difpofed moft curi-
oully for the Conveyance of Juices to fup-

port

compared and confidered» 299

port and nourifli it, and which is not adorn'd
with innumerable Graces to embclliili it.

The mufl ^^xi^di Works of Art \it\x^y li
Meannefs, a Poverty, an Inability in the
Workman ; but thofe of Nature plainly
prove, the Hand that formed them was ab-
Iblute Mafter of the Materials it wroucrht
upon, and had Tools exadlly fuitable to its
Defign. Every Hair, Feather, or Scale,
even of the mcaneft Infc6t, appears round-
ed, polifhed, and finidi'd to the highefl
Pitch; and Ihews the abundant Riches, Mu-
liificencc, and Skill of its Makers

But fome may pofiibly enquire, to what
Purpofe Providence has beftowed luch an.
Expence of Beauty on Creatures fo infignifi-
cant : and then cry out. What is all this to

us? My Reply is, that the Beauty and

Elegance which adorn them, are evident and
convincing Proofs of their not being fo infig-
nificant as we prefumptuoully fuppofe they
are : for, fuch Beauty mufl: be given them,
either for their own Sake, that thev them-
felves may be delighted with it; or elfe, for
Ours, that we may obferve, in them, the
amazing Power andGoodnefs of the Creator.
If the former be the Cafe, we muft allow
them to be of Confequence 'in the Account
of their Maker, and therefore deferve our
Regard ; and if the latter, it is really our
t)uty to take notice of and admire them. But

X for

goo Some reafonahle Reflexions on

for whatever Reafon God has been pleafed
to beftow Exiftence on them, and to clothe
them with Beauty, what he has judged wor-
thy himfelf to create, is not, fuxely, below
us to examine and confider. The fame
Hand that formed the Whale, the Elephant,
and the Lion, has likewife made the Loufe,
the Gnat, and the Flea.

CHAP Lll.

Some reafonahle Refledlions on Difcoveries
made by the Microfcope.

•HE Ufe of the Microfcope will natu-
rally lead a thinking Mind to a Confi-
deration oiMatter^ as fafhion'd into different
Figures and Sizes, whether Animate or Ina-
nimate : It will raife our Refledlions from a
Mite to a Whale, from a Grain of Sand to
the Globe whereon we live, thence to the
Sun and Planets ; and, perhaps, onv/ards ftill
to the fixt Stars and the revolving Orbs they
enlighten, where we fhall be loft amongft
Suns and Worlds in the Immenfity and Mag-
nificence of Nature.

Our Ideas of Matter, Space, and Dura-
tion are meerly comparative, taken from
Ourfelves and Things around us, and limited
to certain Bounds ^ beyond which, if we
endeavour to extend them, they become very
indiftinft. The Beginnings and Endings,

excelTive

t)ifcO'Verics made hy the Mlfcroicope. 30 1

exceffive Greatnefs or cxceffive Littlencfs of
Things, are to us all Perplexity and Confu-
fion.

" Let a Man try to conceive the diffe-
rent Bulk of an Animal which is twenty,
from another which is an hundred times
lefs than a Mite ; or to compare, in his
Thoughts, the Length of aThoufand Dia*
meters of the Earth with that of a Million,
and he will quickly find that he has no
different Meafures in his Mind adjufted
to fuch extraordinaryDegrees of Grandeur
or Minutenefs. The Underftanding, in^
deed, opens an infinite Space on every fide
of us ^ but the Imagination, after a few
faint Efforts, is immediately at a Stand,
and finds itfelf fwallowed up in the Im-
menfity of the Void that furrounds it.
Our Reafon can purfue a Particle of Mat-
ter through an infinite Variety of Divifi^
ons, but the Fancy foon lofes Sight of it,
and feels in it felf a kind of Chafm, that
wants to be filled with Matter of a more
fenfible Bulk. We can neither widen,
nor contrad: the Faculty to the Dimenfi-
ons of either Extream. The Objecft is too
big for our Capacity, when we would com-
prehend the Circumference of a World ^
and dv/indles to Nothing, w^hen we en-^
deavour after the Idea of an Atom *."

* Spe^ator, Numb. 420.

X 2 The

302 Some reajbnabk Refle5fio?ts on

The minute Size of microfcopical Ani-
malcules, and the little Space they occupy,
when compared with ourfelves and the Room
we fill, may poffibly increafe our Pride and
Folly, and make us imagine ourfelves of
mighty confequence in the Creation. But
if we carry our Thoughts upwards, and
compare the Body of a Man to the Bulk of
a Mountain, that Mountain to the whole
Earth, the Earth to the Circle it defcribes
round the Sun, that Circle to the Sphere of
the fixt Stars, the Sphere of the iixt Stars to
the Circuit of the whole Creation, and the
whole Creation itfelf to the infinite Space
that is every where diffufed about it, we
fhall find ourfelves fink to nothing.—-
<c ^ Were the Sun with all its planetary
*' Worlds utterly extinguished and annihi-
" lated, they would no more be mifi^ed in
" the Grand Univerfe than a Grain of Sand
*^ upon the Sea-fhore : the Space they pof-
" fefs is fo exceeding little, in comparifon
^^ of the Whole, that it would fcarce make
" a Blank in the Creation. The Chafm
would be almoft imperceptible to an Eye
that could take in the whole Compafs of
Nature, and pafs from one End of the
" Creation to the other." What then is

f Vide Spe^ator, Numb. 565.

the

Difcoveries made by the Microfcopc. 303

the miglitieft Monarch that ever lived !
What is the whole Race of Man !

A IVIite upon a Cheefe is as large and
conliderable, in Proportion, as a Man upon
the Earth : the little Infeds feeding on the
Leaves of Peach-Trees and Cherry-Trces,
are no ill Reprefentation of Oxen grafing in
large Paflures : and the minute Animalcules
in a Drop of Water, fwim about with as
much Freedom as Whales do in the Ocean :

All have equal Room in Proportion to

their own Bulk.

The Term or Duration of Life, in different
Creatures, is likewife comparatively long or
Ihort, according to the Number, Quicknefs,
or Slownefs of Ideas, prefenting themfelves
fuccefiively to the Mind. For, when the
Ideas fucceed one another fwiftly, and many
of them are crouded into a narrow Com-
pafs, the Time, however fhort it may be,
will feem long in Proportion to the Num-
ber of Ideas paffing through it : on the con-
trary, when the Ideas are but few, and fol-
low one another very flowly, a long Time
will appear iliort, in Proportion to their flow
SuccefTion, and the Smallnefs of their Num-
ber.

'' It is evident, fiys Mr. Lock, to any
" one who will but obferve what pafTes in
" his own Mind, that there is a Train of
[^ Ideas, which conftantly fucceed one an-

X 3 *' other

304 Some reafomble Ke flections, on

other in his Underftanding, as long as he
is awake. Reflection on thefe Appear-
ances of feveral Ideas one after another in
our Minds, is what we call Duration,
For whilft we are thinking, or whilft we
receive fucceffively feveral Ideas in our
Minds, we know that we do exift : and
fo we call the Exiftence, or the Conti-^
nuation or Exiftence of ourfelves, or any
thing elfe commenfurate to the Succeffion
of any Ideas in our Minds, the Duration
of ourfelves, or any fuch other Thing
co-exifting with our Thinking ^."

From thefe Principles it is manifeft, that
one Day may appear as a thoufand Years,
and a thoufand Years but as one Day : by
which means, the Lives of all Creatures, for
aught we know, may feem to themfelves
nearly of the fame Duration. It is at leaft
probable, that fomething like this may re-
ally be the Cafe as to the Inhabitants of this
our Earth : for as the fame Fundlions or
Offices of Life, mz, to be born, feek pro-
per Suftenance^ increafe in Bulk, arrive at
full Maturity, propagate the Kind, and die,
are equally performed by all ^ they who
perform them in a few Months, Days, or

, * Vide LqcK on Human Vnderjianding^ Chap. XIVc

Hours,

Difcoverics viadc by the Microfcope. 305

Hours *, may be fiippofed, from the Num-
ber and Iwift Succeflion of Ideas fuited to all
thefc Purpofcs, to live as long, according to

* SwAMMERDAM hns publifh'd, in Lq--w Dutch, a curious
Account of what he calls the Efbemerov: a Fly which, he
tells us, lives but five Hours. This Infedis found about all
the Mouths of the Rhine ; and, according to his Drawings
and Defcriptions, feems to be a Species foniewhat between
0\ir May-F/y (bred from the Cadcio-ii'orm) and the Lihella or
Dragon-Tly. It has four Wings, two whereof are Ihorter than
the other j a Pair of fmall Korns, fix Legs, and two VQxy long
firait Hairs iifuing from the Tail. They are feen, he fays,
flying near the Surface of the Water, about Midfummer, for
three fucceeding Days, but no longer in one Seafon. They
cat nothing; and their only Bufmefs is to generate, and drop
their Eggs upon the Water : which Eggs, finking t6 the Bot-
tom, produce a Kind oi Worms or Maggots, that foon hollow
themfelves Cavities in the Clay, where they abide tr.ree
Years ; growing each Year about an Inch in Length. When
the Worm is come to its full Growth, it rifes to the Surface,
about fix o'clock in an Evening: lays its Eggs, and dies
about ten o'Clock the fame Night.

I am furprlzed that Swammerdam fhould fay, the Life
of this Creature is no more than five Hours, when his own
Account plainly proves that it really lives three Years : for
it is certainly as much alive in the Worrn- State, as when af-
terwards it becomes a Fly. Truth fhould be every Body's

Purfuit, and for the Sake thereof I have endeavoured to clear
up the general Millake as to this Fly, which is frequently
produced, upon Swammerdam's Authority, as the mod
remarkable Inibnce we know of the Shortnefs of Life. — But
tho' this Infetfl happens to live much longer than was ima-
gined, I make no doubt, there are fome among the number-
lefs Species of Beings, whofe natural Lives are as Ihort as this
was fuppofed to be : fuch too are moll: likely to be found
amongft the very minute Kinds. For as thofe £xc££dhigf7nall
Plants, invifible to the naked Ey, which compofe what we
call Mouhiinefs, fpring up, bear Fruit, and dye in a few
Hours : we may reafonably fuppofe, the Lives of fome ex ■
cecdingly fmall Anunals to be of as fliort a Duration.

X 4 their'

3^6 Some reafonable Rejleciions on

their own thinking, as other Creatures d'o,
where the fame Train of Ideas proceed mor^
ilowly, and take up many Years.

As the Microfcope difcovers almoft every
Drop of "Water, every Blade of Grafs, every
Leaf, Flower, and Grain fwarming with lur
habitants ^ all of which enjoy not only Life
but Happinefs -, a thinking Mind can fcarce
forbear confidering that Part of the Scale of
Beings which defcends, from himfelf, to the
lov/eft of ail fenfitive Creatures, and may
confequently be brought under his Exami-
nation. " Amongft thefe, fome are raifed
fo little above dead Matter, that it is difficult
to determine v/hether they live or no: others
but one Step higher, have no other Senfe be-
fides Feeling and Tafte : fome again, have
the additional one of Hearing : others of
Sm.ell, and others of Sight, j

It is wonderful to obferve, by what a gra-
dual Progreffion the V/orld of Life advances
through a prodigious Variety of Species, be-
fore a Creature is formed that is com.pleat in
all its Senfes : and, even amongft thefe, there
is fuch a different Degree of Perfeftion in
the Senfes which one Animal enjoys be-
yond what appears in another, that tho' the
Senfe in different Animals be diftinguiflied

% Vide SpedatQi'y Numb. 5 1 9.

Di ft orj erics 711 a dc by //jt'MIcrofcopc. 307

by the iaine common Denomination, itfeems
almoil of a diilercnt Nature. If, after this,
we look into the feveral inward Pcrfedtions
of Cunning and Sagacity, or what we eene-
rally call Inllind:, we find them rifing in the
fame Manner, imperceptibly, one above an-
other, and receiving additional Improvements
according to the Species in which they are
implanted.

This Progrefs in Nature is fo very gradual,
that the whole Chafm, from a Plant to a
Man, is filled up wnth divers Kinds of Crea-
tures, rifing one over another by fuch a gent-
tle and eafy Afcent, that the little Tranfitions
and Deviations from one Species to another
are almofl infenfible. And the intermediate
Space is fo well hufbanded and managed,
that there is fcarce a Degree of Perception
which does not appear in fome one Part of
the World of Life. Since then the Scale of
Being advances by fuch regular Steps fo high
as Man, we may by Parity of Reafon fup-
pofe, that it flill proceeds gradually upwards
thro' numberlefs Orders of Beings of a fupe-
rior Nature to him : as there is an infinitely
greater Space and Room for difi-erent Degrees
of Perfection between the Supreme Being
and Man, than between Man and the mofl
defpicable Infedl/'

Mr. Lock's Thoughts upon this Subjed:
arc very curious ; «' That there fl^ould, fays

" he,,

L

3o8 Some reafonable RefieBhm on

hc) be more Species of intelligent Creatures
" above us, than there are of fenfible and
material below us, is probable to me, from
hence, that in all the vifible and corporeal
World, v/e fee no Chafm, no Gaps. All
quite down from us, the Defcent is by
eafySteps and a continuedSeries of Things,
that in each Remove differ very little one
" from the other. There are Fiflies that
^^ have Wings, and are not Strangers to the
*^ airy Region : and there are fome Birds that
" are Inhabitants of the Water, whofe Blood
" is as cold as Fifh's, and their Flefh fo hke
'^ in Tafte, that the Scrupulous are allowed
" them on Fifh-Days. There are Animals
*'* fo near a-kin to Birds and Beafls, that
they are in the Middle between both.
Amphibious Animals link the Terreftrial
and Aquatic together : Seals live at Sea
and at Land, and Porpoifes have the warm
" Blood and Entrails of a Hog : not to
" mention what is confidently reported of
*^ Mermaids or Sea-Men. — There are fome
•"* Brutes that feem to have as much Know-
ledge and Reafon as fome that are called
Men ; and the Animal and Vegetable
Kingdoms are fo nearly joined, that if
you will take the loweft of one and the
higheft of the other, three will fcarce be
perceived any great Difference between
y them. And fo on till we come to the

"loweft

it

ec

€C

It

Si
€C

cc
<c

JDifcoveries made hy the Microfcope. 309

lowed and the mod inorganical Parts of
Matter, we (liall lind every where that
the leveral Species are hnked together, and
differ but in ahnolt inlenfible Degrees.
And when we confider the infinite Power
and Wifdom of the Maker, we have Rea-
fon to think, that it is fuitable to the
magnificent Harmony of the Univerfe, and
the great Defign and infinite Goodnefs of
the Architect, that the Species of Creatures
ihould aho, by gentle Degrees, afcend up-
wards from us towards his infinite Perfec-
tion i as we fee they gradually defcend
from us downwards. Which if it be pro-
bable, we have Reafon then to be perfua-
ded, that there are far more Species of
Creatures above us than there are beneath:
we being in Degree of Perfection much
more remote from the infinite Being of
God, than we are from the loweft State
of Being, or that which approaches near-
eft to Nothing."

Every Creature is confined to a certain
Meafure of Space, and its Obfervation ftinted
to a certain Number of Obj efts : but fome
move and a6t in a Sphere of a wider Cir-
cumference than that of others, according
as they rife above one another in the Scale
of Exiftence. This Earth is the Spot ap-
pointed for Man to d\Yell and act upon : he

ftand^

3 1 o Some reafonahle ReJIeSlions on

flands foremoft of all the Creatures here, and
links together Intelligences and Brutes. The
Sphere of his bodily Acftion is limited, con-
fined, and narrow: but that of his Mind is
vaft, and extenfive beyond the Bounds of
Matter. Formed for the Enjoyment of in-
telledlual Pleafures, his Happinefs arifes from
his Knowledge; and his Knowledge increafes
in Proportion as he difcovers and conteni-
plates the Variety, Order, Beauty, and Per-
fed:ion of the Works of Nature : whatever,
therefore, can affift him in extending his Ob-
fervations, is to be valued, as in the fame
Degree conducive to his Happinefs.

What we know at prefent, even of Things
the moft near and familiar to us, is fo little
in Comparifon of what we know not, that
there remains a boundlefs Scope for our En-
quiries and Difcoveries ; and every Step we
take, ferves to enlarge our Capacities, and
gives us ftill more noble and juft Ideas of
the Power, Wifdom, and Goodnefs of the
Deity.

The Univerfe is fo full of Wonders, that
perhaps Eternity alone can be fufficient to
furvey and admire them all : perhaps, too,
this delightfuljEmploymentmay be one great
Part of the Felicity of the BlefTed. — When
the Soul ihall become divefted of Fleih, the
Pleafures of Senfe can be no more : and if^

Id i [cover ies made by the MIcrofcope. 311

by a continued Habit, any Longings after
them fliall hang about it, fuchLongingsmuft
create a proportionable Degree of Wretched-
nefs, as they can never polhbly be gratified.
But if its principal Delight has been in the
Contemplation of the Beauties of the Crea-
tion, and the Adoration of their Almighty
Author, it foars, when difembodied, into
the celeftial Regions, duely prepared for the
full Enjoyment of intelleftual Happinefs.

To Thee, eternal felf-exifting Creator
of the Universe ! whofe Will is Nature's
Law ! Omnifcientj Omniprefent, All-Boun-
tiful and Gracious ! To Thee be paid, by
all thy Creatures, Thankfgiving and Ado-
ration, till time fliall be no more !

INDEX.

INDEX.

A.

ANEMONE (Sea) or Mufirootn,
Animal

Jnimakules in Fluids,

how produced ' —

not if covered »
forts in Pepper- Water — .
how killed by different Mixtures
forts in Hay- Water ■

•— fome Univerfal ■'.■

Eel-like Kinds — —

in Vinegar ■

_-how affeded by Heat and Cold — —

■ in Paile * — >

in Rain and other Waters
caufe the Colours of Waters

an extraordinary
Page 99

68

— ibid,
— ' 69

— 72

76

— ibid,

.79

ibid,

80

81

278

84

83»

obferv'd in feveral Infufions by Monf Job lot 87
why not always the fame •— — -— — ibid^
at the Roots of Duck- Weed
in Leaden Pipes and Gutters

two forts in Ditches defcribed
a very extraordinary Kind

■ its Young how produced ■

. as defcribed by Mr. Leewwenhoek —
by Mr. Euffon

by one at Geneva
Refleftions thereon

'AnimakuJes in the Teeth

how to deflroy
in itchy Puftules

in the Light of Oyfters ^

'AnlmalcuUi m^ Semine MafcuUno, how to view — 58,

when firll difcover'd < •

their general Appearance —

their Numbers computed — — 149»
their wonderful Minutenefs — — —
jRefledions on their Size *

91

ibid.

93

94.
ibidt
ibid,

96

97

lOI

167
1 68
169
241
159

ibid,
163

165

AnmaUuUi

INDEX.

Jhifnahulcs in Semine Mafculino of a Frog — — p. i ^^

of a Cod Filh . . i ^ 5

of a Pike __ . . grg

of a Cock . i ■■ I r(^

of a Dog • • 160

of a Hare . . ibiJ,

of a Rabbet - — 161

of a Ram ■ jUd,

of a Man — — ■ . 165

of a Spider ■ i6r

of a Dormoufe . ■ 166

of an Oyfter — .^. 166, 239

of the Mufcle Fifh 243

of a Silkworm ■■ .. 166, 2&2

of a Dragon Fly i^ i ^S

of a common Fly — — ._ /^,-^^

of a Flea — — — ,-^;V.

of a Gnat — — ■ 206
Fide Infeas.

Animalcules in none of the Animal Juices but only the

Semen — — ■ » 166

Animals (living) to examine — ■ ^4, ^7

how admirable their Strudlure . 298

^«/j defcribed 1 ■ .. 271

their Eggs and Aureliae — ., 272

their Sagacity, Forecaft, and Indullry — 275

Reflexions thereon -.— . .n , , . 276
Antenna of Infefts : vide Horns.

Area, or Portion of an Obje6l feen — , ^g

Art compared with Nature — . 292, 297, 299

Arteries and Veins ^ how diftinguifhed — i 2a

Author % Defign in Writing : vid. Introduft. and > ^i

B.

Balances of Infefls — . —
their Ufe

Bat (Obfervations on it) .

Beauty^ why bellowed on Infedls, lSc» ^— —

Bee, vide Sting,

Bignefsy meerly comparative • • —

Shod (Circulation of) to view — 59,

Examination of by the Microfcope —
Account of as fo examined —
Strudlure and Corapofuion of Globules
Size of the Globules -— — -

INDEX.

,^/<?!74 how eafily diforderM ■ p. j^-^

Mixtures with it in the Veins, their EfFefts i id

^- — -when extrafted . no, 114

its Colour whence 1 - n ■ 1 ■ 116
Vide Circulation,

Bhodlefs Animals y a Miftake .^ « 1 • 1 29

Boajis (ridieulous ones) as to Microfcopes • • 64

BoneSi their Structure , i — — 145

foft at iirft ■ ■ — — 144

Manner of viewing them ■ * 145

J5oo/l /F^rw (or Clothes Moth) — ■ 282

j^oAT for preferving opake Obj efts — . _- 61

Brufi^ or Hair-Pencil, its Ufe -— -■ • 1 1

Bug, a curious Objedt .n— ■ -^ 1 30

Butt erf y, its Probofcis ■ ■ ■ -^ ■ 282

C.

Camera Ohfcura Microfcope » ■■ ''• "'''■ 7.t

Cautions in viewing Objeds *— ■ — ■ ■ 62

Q"// to confine living Objefls — -■ — ■ i^

C&/2i« of Gold, its Finenefs ■ • 295

ofBrafs ■ . ihid.

Circulation of the Blood to view ■■ » . ■ 117, 120

between a Frog's Toes ,— «. — -, 1 2 1

in an Eel ■ ■ 122

in a Flounder ■ — — ■ ibid.

in a Fifh's Tail ■ — 123.

how numerous in a Human Body — * 1 2^

in a Newt — — — ^ — • • 1 26

in a Tadpole — — — » 127

in a Mufcle Fifh ■ ■ ihid.

in the Legs of Crabs ■ 1 2S

in Shrimps — -»——__ 12^

in the Legs of Spiders ■■ — — . i jq

in Punices or Bugs ■ " ■ ibid,

in a Bat > 131

in a Frog by the Solar Microfcope, very curious 1 34
its Appearance near the Time of Death — 136

Cochineal ex2.mm^d •= • 285

Colle£iion of tranfparent Objefts to make ■ • 56

of opake Objedls ■ — 60

proper Cafe for them — — ■ 6 1

Colours of Objeds how to judge of ' ^^y 63

C3«f to intercept the Rays of Light, its Ufe 18, 55

C(7ri, its numerous Pores — — > j ;; ' ' ■ 287

Corn Beetle f vid, JVee-vU.

Coifjagef

I N D E X.

t^onuage, or Cow-itch, what ■ ■ ■ ■ . p. 290

Crane- Fly J very wonderful - — 279

Cubct why confiderM a3 if inagnify'd 31, 35

Cir^j, I 200 in a Pcppcr-Corn ■» ■ > 296

D.

De^w recommended to be examined i — — 290

/)/rtmoWi examined by the Microfcopc — — — 288

Do//^A- Rcfleding Microfcope defcribcd . 16

/)fi'zu;; of Thilties, ^c. .... , . 289

Dr/7ai;/;/^r of Objedls to take ■ ■ 24, 48

Duckivcedy Itrangc Animalcules at its Roots •■ ui

/)«v^/'///-//V//t7- full of Animalcules 81;

^yi^gi the Appearance of the Blood then 136

i?^rai;;|- (Lice on) — 1S3

Wings of ' ' 23c

Eely Way to examine it ■ »-"■ \2t

its Scales > ■ 238

-t^/-//^^ Kinds of Animalcules ■ ►s, 278

in Vinegar • 79

Experiments on them «»« ■ • • ^o

in Parte . 81

Way to preferve and examine — — 82

their Appearance by the Solar Microfcope ibid.

^^C-f of Infeifls — 284

'Elephant compared with a Mite : vid. htrodudion.

Ephemeron described 305

Miftake about it redified . iiid.

F.

Farina of Flowers defcribed •' ■ . 247

its Ufe and what it is — — 149, 248

its Beauties • 249

Way to preferve and examine it ■■ 250

its VefTsh curious — — ilfid.

Obfervations on it ■ 151, 2^1

Feathers, delightful Objeds " 2S5

Feelers of Infccls ; vide Horns.

Fibres (mufcular or ilefljy) their Appearance 13J, (41

their Structure 139

in an Ox, Whale, and Moufe ' 1 40

Way of viewing them ■ • 141

in a Crane Fly, very curious ■ 279

Fi^t ^Dvv to place in a Glals Tube ■ i 3

y ' F:jh,

I N D , E X.

?//^-Pan ™ *— - p. 19

Flea defcribed — — 191

Manner of Change from the Egg ' ', .,<' 193

■"its Coitus — — — . •— — 194.

Diffeaionof — " — -;- — — 195

its furprifing Strength and Agility — — ibid.

Fluids y how to prepare and examine — ^ — — 58

/'/y defcribed — — ■ •— — — — 219

its Trunk ■ ■■■ ■■ « i^id.

Diffedlion of ' ■ 220

Manner of Produ6lion ■ — — il^id.

Focus, what ■ — — ^ 4

Forceps, or Plyers, their Ufe — — — — 10

Frog, how to place in a Glafs Tube — — — 13

Apparatus for viewing the Circulation in it 133

Mefentery thereof a curious Objeft — — 135

its Lungs — — — ' — — 285

G. -

Gad-Bee: vide Ox-Ffy — — »- — — 207

G^/z£r^/zc« equivocal, contrary to Reafon — — 148

Manner of — — ■ — — ' — 150

analogous between Animals and Vegetables 151

Glafs fiat, its Effed —- — — - — — 3

convex, its EfFe6l — — — — — 4> 6

its magnifying Power expliained — — 33

how to find its magnifying Power — — ' — 34.

concave, its EiFeft — — — — ""5

G/i^/5 Slips of different Colours, their Ufe — — 60

G/^^J muft be fuited to the Objefts — — — 53

Glafs-Tube, its Ufe . ii, 19

Globules of the Blood how formed — - — • 103

their Size — -- — lor, 13^

their Appearance in Sicknefs ■ 108

in Fifties and aquatic Animals — — 131

how affedled by Heat and Cold ihid.

Vide Circulation.

Globule, or Drop of Glafs, its Inconvenience ■ 6

not ufed by Mr. Leew^wenhoek — — .,— — 7

Gnat, it Manner of Prod uftion 68, 88, 207

Defcription of it 203

its Form in the Water ' ■ ^^

its Wings and Hotns •■ ■ 20^5

iis Piercer defcribed — — — - ' 204

its Spawn ■ • 2®"

Grain of Sand how to be undcrltood as a Meafure 4'

G7-0<VJth

INDEX.

Gro'u;/>& of Animals and Vegetables, what p. 150

H.

Hairs of different Creatures 245

their Strudlurc — ■ ■ ibid,.

their Variety • ■ • 246

of a Caterpillar, very beautiful 280

Hay -Water to make ■ ■ 7^

when ready for Examination — ii>id,

the Animalcules therein ibid.

Health t wherein it confiils 106, 116

how impair'd ■ -.— . 105

how probably it may be reftor'd — — io9

Contrivance of Providence to preferve it -— 119

H?^r/ (Pulfation of) I37

in a Bee

^i;!/^, I — ^ ibid.

a Gralshopper
a Lady- bird
in a Snail
in a Loufe
Hor7js of Infects, their Ufe

-their different Beauty

I.

Ignis Fat mis — — ■ 242

Infujions of Vegetables produce Animalcules ■ 76

obferv'd by Monf Johlot 87

why produftive, a Suppofition ^ — 86

why not always the fame ■ 87

Infe^Sy how to diifed ' 60

•fitteft to ihevv the Circulation and internal Motion •

117, 142

in the Li'- ers of Sheep ~-. . 268

in the Heads of Sheep 269

in the Heads of Deer 268

on Pales and Walls — ' 270

on Leaves • ■ ■ 271

among Pinks, Rofes, l^c. ■ 276

in Cuckow-fpit ^

on Sycamore Leaves > — — 277

on the Ribs of Rofe Leaves J

on Goofeberry Leaves ■ •— ' ■ ■' 278

Legs and Feet examined — -^ • 253

on Orange, Fig, and Willow Leaves — 284.

I N D ^ X.

Infers, their Eggs beautiful ^

^-— — on Corks of Bottles \ ' ' P- 284

In^, a Diftemper occafion'd by Animalcules 160

defcribed ».

how cured

17Q
171

Jurin (Dr.) his Way of meafuring Obje^s « ^ At;

L.

Lac^ (fine BrufTels) examined ^-^ , 202

I-^^^i?77 Pipes or Gutters, Animalcules there defcribed ■ 92

L2a<ves, whether have any Circulation ' 296

their Pores how numerous , 21:7

of Rue -) ^'

St. John's Wort I

Mercury v, . ihid,

vSage t

Rofe and Sweet Briar J

Fern — " * 254

Stinging Nettle (very wonderful) -= — - 258

like the Stings of Animals " ihid.

tsns^ what • 2

Leen'vjenhoek (VJr.) the Structure of his Microfcopes S

Liherkhun (Dr.) his folar and opake Microfcopes ■ 21

Lifey in what Manner long or fhort 303, 305

its Progreffion in diiferent Creatures — 306

Light muH be fuited to the Objedl 55

its different EfFe(^ 54

of a Candle bell: for fome Things ■ 55

of the Sun, not eligible -,,.-,— ^«, ihid.

Zc^w/^ (common) defcribed 177

its Manner of Feeding »■ 179

a Sting in the Male — -*■ ■ ■ • 1 8o

its Increafe how numerous ' 1 8 1

Way to diflea it ' -r— 182

(Crab) — — ■ ihid.

a general Name for the Verniin of Creatures 183, 1 84
on theBeeetle'

Earwig

Snail

Spider

Humble-Bee \

Flea \

( Kinds of) pidurM by Seignior Redi — ihid.

Wood Loufe — — 185

• ■ Magnify ifJg

183

184

INDEX.

M.

M(tgnifyin^ Power of Glaflcs in tlic Single Microfcope, p. 52

explained ■■■ , ^^

how to find and calculate — — 34

Table oF 36

in the Solar Microfcope ■ — — 38

in the Double Microfcope — — 39

Maiij his proper Employment. Vid. htroduHion.

his Capacity for Knowledge 3 1 o

whence his eternal Happincfs mcy poflibly arifc 3 1 1

"Matter y Confidcrations thereon 300

our Ideas of it imperfefl 1 301

Mercury unalter'd infeveral Mercurial Medicines 291

Microfcope what -^ i

by whom and when invented 3

Single • i 2, 7

Double .. -__ ih'id.

their different EfFeds and Advantages 2, 7, 49

Leewwenhoek'i, its Strudlure -— — 8

Wilfon% Single Pocket 9

with a Speculum 14

Standard for its Glaffes propofed 37

Double Rtficding ■ 1 6

Solar ^ or Carrier a Obfcura -■■■ 22

its Advantages 2 5

for opake Objeds 27

Standard for its Glaffes propofed 38

its Advantages — 27, 30

how to ufe it ibid,

ufeful alfo for tranfparent Obje£ls ibid.

wherein it can properly afilll us • 49

why fometimes negledled 51

how ierviceable in the Praftice of Phyfick 1 07

il/.'«;//^z?^i of Animals, is'c. wonderful: \\d..Introd. 163, 298

Reflexions on it - 302

Mefentery oi 2i Frog, extreamly curious ■ 135

il///^/ defcribcd 186

their Coit and Time of Hatcliing 188

tlicir Eggs ibid,

compared with a Pigeon's ■ • ibid.

their Voracioufnefs and Manner of Eating ibid,

how to deftroy ' 89

Sorts of dcfcribed ibid.

wandering ■ 190

vcrv tenacious of Life ■■ > ibid.

Mofcs,

IN D E X,

il^^/, exceedingly beautifal Qbjeds ■ ■ p. 286

Motion feen by Microfcopes, how to be regarded •— 6j'
MouldineJ's, feveral Species of minute Plants — 247

MW///ifj or Scolopendra, very curious • 279

Mufcles of the Abdomen of a Frog 1 35

Mujck-fip a fine Objed — - 1 28, 242

its Eggs and Embryo,- Mufcles 243

how numerous . ■ ■' ihid.

the Beard, its Ufe : " ' 244

iViy/arA Operations amazing « 253

: ;- the Per fedlion of, exemplified — « 29S

compared with the Works of Art 292, 297

the Study of them Man's nobleft Employment :

vid. Introdutt. and — — 300

Needle^ its Point examined 293

Isewis, their Struaiiie and Appearance — 146

notelailic * ■ ■ — - — 147

Mw^, a fine Objed — — iz6

Globules of its Blood larger than inmoftAnimals/^zV.

how to kill ' — — — 291

O.

OlieBs^ how feen through a Single Microfcope — 2

"^ how through a Double one ihid.

how through a Flat Glafs -— . 3

how through a Convex — 4

appearlarge to fhort-figh ted People — 5

their real Size to find ■ 40, 158

yiv. Lceunvenhoek'^sWdCf — — • 41

Mr. Hook''& Way ~ 45

Dr. Jurins Way — — — — ibid.

Dr. Martins Way - — - — 47

Dr. Smith's Way «—— ■ . 48

' Area or Portion of — « ibid.

Kinds proper for the Microfcope — 50

what not proper ■ ' 49

Diredions how to examine 52

to be view'd in every Light 54

theirShadow only feenby theSolarMicrofcope5 5

' how to prepare and apply 56

to make a Collection of 56, 60

Cautions in rhe viewing of -— — — 62

INDEX.

O/^ People, their Manner of Sight — _ pr

Of>ake Oh]ct\s (Microfcopc for) vid. Micro/cope.

to prcperc and prcfcrve . 60

Opium, how it a(5ls on the lilood . ni

Ox -Fly dcfcribcd . , 226

its Manner of Produdion 207

Oyfters, Animalcules in their Liquor . 239

in tlieir Semen 1

Embryos \ ~ '^'^•

their Size and Number ■ 2^0

Light on them 241

P.

PaJ?e full of minute Eels — - . gi

way to preferve them -_ . « /^y^^

People^ old, or fhort-fighted, their Cafe — . a

Pepper -Wateiy vid. Animalcules.

Pm/^j/^/f Motion vifible 13S, 179, 195, 219

Poifes of Infefts, vid. Balances.

Polype y a wonderful Animalcule fo called

Pores of the Skin . ■■

Way to view them

how numerous ■

of Wood, their Numbers —
Pucerons 1

Pulfe beating, vide Heart.

R.

Pain-WRteTt its Animalcules ■ ■ g*

Razor, its Edge examined ■ ■ zg^

S.

Sal Volatile oleofmn, its FiFecls on the Blood 1 1 1;

Salts to prepare and examine ■ .—— rg

their general EfFeds m . 259

in Vinegar ibid.

how changed by Crabs Eves ■ 260

in Wines, Vegetables, and Metals ibid.

Sorts to be ex ami n'd . . 261

their good and ill Efreds ibid.

(Sorts of) in Mineral Waters ■ 262

of Vitriol ■ . 263

unripe — ■ 265

Salt:

N D E Xi

\

ibid.

Salts •>'" ■■ — - — of Alum

from Salt Springs

Sal Gem y. ;i4iii. \._^ p^ 26^

from Sea -Water
Niter

Calcarious Niter • — 264

Sand (Grain of) how underftood as a Meafure — — 41

Sauds fine Objefts for the Microfcope ■ 288

-SW^ of Beings confider'd — — ;. ►- 307

5f«/a on the Humati Skin • 172

howntimerdiis . 173

Way to view them - ibid.

ofFilhes -- — — 237

fhew their Age ■■ — 238

how to prepare — _ ibid,
Scohpendra, vide Mu/tipes.
Scorpion, vide Sting.

Seeds not proportioned to the Size of their Plants 1 65

include minute Plants .. ■ 252

of the Gramen tremulum ■ "■ ibid,

to prepare • ■ 2| 3
of Strawberries } ^__^

Poppy S

Fern ■■ —- ~ — - 254

PufFBall — ~ — 255

—how hurtful to the Eyes — - 256

Semen Mafculinum, vide Animalcules.

Serpents (minute) ■ ■ » 7S

Shaife, Sec. drawn by a Flea — _ 295

Sl>eep (Worms in) vide Infers .

Sight f its Difference how occafion'd -=— 4. '^

common Standard of — — — — - ■"" " 33

Silk.Worm ■ 281

Semen thereof examined — 282

Length and Finenefs of its Silk ■ ^294

Sliders what ■ — 1 9

their great Ufe — — ■ 5^

to prepare a Set of properly *— ^ 57

Snail f a curious Animal — — — 2 1 7

Manner of Produdion and Growth — 2 1 8

Stone found therein — - »^'^*

Sno'uo, its Configuration curious —. 290

Solar or Camera obfcura Microfcope : vide Microfcope,

Spider, its Eyes — — - '9^

Spider^

INDEX.

'Spt4p, its Weapons ■ «■ ■■ — — \ jr.' i'^7

poifunous Liquor how inllilled . ion

Web how fine — — ■ 200

Kggs ^ — 201

White Field , ^^^

Huiuing 1 :

Shepherd > Spider ■■ ■> t u'/ OJ vn-*^— 202
• Ked ) .V.o'i-...

: Water Spider — — .;:T>rtJ— .^ 278

Stags, Worms in their Heads ' ', >qj ■-{ _ ' 268

Star-Fijh > m • ■ ,' . ■ A\y

or Sfel/a arherefceus, fending forth many thoufand

Branches .i ,.i ,. ,0^,

Steel (Particles of) melted by flriking Fire .in >■ 289

StifTg, how diftin^ui(hed ._«^ * . ■ 200

of a Bee oefcribed — • 210, 293

Way to view it ■ ■ ■ ■ . .^ 2 1 1

its poifonous Juice — — 212

of a Scorpion defcribed -— ^-^y^^

its poifonous Juice ■ .-...^ 21%

furprizing Effe£l of ■ - 214

Sunjhinej a bad Light for Objeds ■ . re

Table of the Powers of fingle Glafles - 25

Tittle made with a Pen examin'd » 204.

Tranfparency how fometimes acquired — — 1 2q

Truth only to be fought for ■ ■ 5^

r^^^ (Glafs) its Ufe x j

(capillary) its great Ufe •■ ■ rg

V.

Vegetables (Infufion of) produce Animalcules 70, 76, 86, 87

Veins i formed to preferve Health ■ ■ 1 i j q
Vinegar (Animalcules therein) vide Animalcules,

its Salts examin'd 259

^/^fr, its Teeth and Poifon — — ' 215

W.

Water ^ full of Life : vide Animalcules. 90

Weenjily or Corn -Beetle defcribed — 221

its Manner of ProdufUon — — 222

Whale, its prodigious Size — i o i

WkecL

I N D E X.

Wheei'Worh in tlie Heads of fome Animalcules
'. WilfoiC^ Pocket- Microfcope : vide Micro/cope
.Wings of Infefts ■■ *

their Variety ■ —

their Motion ■

their fine Feathers «

Way to view them ■ •' ■

Wolf defcribed —

" ' its Increafe *■ — ■

Way to deftroy

Wood, its Air-Vcffcls, Sap-Vcffels, Pores, Sifr .

-^W-Loufe -■' .

Worms in Human Bowels /

their Kinds >" ' '■..}> •—

how probably introduced

in Fiihes ' ' ■—

Blood-red, jointed *--*—

p. 91

232

ibid,

ibid.
223
224.
225
287
185
265
266

ibid,
267
278

FINIS.

COLUMBIA UNIVERSITY LIBRARIES

This book is due on the date indicated below, or at the
expiration of a definite period after the date of borrowing,
as provided by the rules of the Library or by special ar-
rangement with the Librarian in charge.

DATE BORROWED DATE DUE

DATE BORROWED

DATE DUE

!

1

C28(1 140)M100