Full text of "Statical essays, containing vegetable staticks, or An account of some statical experiments on the sap in vegetables : being an essay towards a natural history of vegetation (3rd edition, with amendments)"

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STATICAL ESS ATS.-

CONTAINING

VEGETABLE STATICKS;

//f7^ Or, an Account of fome /i tx-r-tfY^' ^

Statical Experiments

ON THE

SAP in VEGETABLES.

BEING

An Essay towards a Natural Hiftory of
Vegetation: Of. Ufe to thofe who
are curious in the Culture and Improve-
ment of Gardening, &c.

ALSO

A Specimen of an Attempt to Analyfe the Air,
by a great Variety of Chymio-Statical
Experiments, which were read at feveral
Meetings before the Royal Society.

VOL. I.

^uideji in bis, in quo non naturae ratio intelligent is appareat ? Tul.de Nat. Deor.
——Etenim Experimentorum longe wajor eft fubtilitasy quam fenfus ipjius .

Itaque eo rem deducimus, ut fenfus tantum de Experimento, Experimentum

de rejitdicet. Fran, de Verul. Inftauratio magna.

By STEPH. BALES, D, D. F. R. S.

Rector of Faringdon^ Hampjhire^ and Minifter
of Teddington, Middle/ex.

The Third Edition, with Amendments.

LONDON:

Printed fo> W. Innys and R. Manby, at the Weft-End of
St. Paul's;' T.Woodward, at the Half-Moon ovcr-againft
. St. Dunfian's Church in Fleet-ftreet ; and J. Pe el e, at Locke's
Hetfti in Amm-Cormi . M . dc c. xxx nil.

2 IE 5 5

Feb. 1 6, 1726-7. Imprimatur.

Isaac Newton, Pr.Reg.Soc,

>r^uAo^A~

T O

His Royal Highness.

GEORGE

Prince of WALES.

May it pleafe Tour fioyal Highnefs,

I Humbly offer the following Expe-
riments to Your Highnefs's Patro-
nage, to proted; them from the
reproaches that the ignorant are apt
A 2 unrea-

DEDICATION.

unreafonably to call on refearches of
this kind, notwithftanding they are
the only folid and rational means
whereby we may ever hope to make
any real advance in the knowledge
of Nature : A knowledge, worthy the
attainment of Princes.

And as Solomon, the greateft and
wifeft of men, difdained not to in-
quire into the nature of Plants, from
the Cedar in Lebanon, to the Hyjfop
that fpringeth out of the wall : So it
will not, I prefume, be an unaccept-
able entertainment to Your Royal
Highnefs, at leaft at Your leifure
hours ; but will rather add to the
pleafure, with which vegetable Na-
ture in her prime verdure charms us :
To fee the fteps fhe takes in her pro-
ductions, and the wonderful power
fhe therein exerts : The admirable

pro-

DEDICATION.

provision fhe has made for them, not
only vigoroufly to draw to great
heights plenty of nouriihment from
the earth ; but alfo more fublimed
and exalted food from the air, that
wonderful fluid, which is of fuch
importance to the life of Vegetables
and Animals ; and which, by infinite
combinations with natural bodies, pro-
duces innumerable furprizing effects,
many inftances of which I have here
(hewn,

The fearching into the works of
Nature, while it delights and inlarges
the mind, and ftrikes us with the
ftrongeft aflurance of the wifdom and
power of the divine Architect, in
framing for us fo beautiful and well-
regulated a world, it does at the fame
time convince us of his conftant bene-
volence and goodnefs towards us.

A 3 That

DEDICATION.

That this great Author of Nature
may ftiower down on Your Royal
Highnefs an abundance of his Blef-
fings, both Spiritual and Temporal,
is the fincere prayer of

Tour Royal Highnefs s
Mojl Obedient,

Humble Servant \

Stephen Hales,

the

THE

PREFACE.

THERE have been, within lefs
than a Century, very great and
ufeful dif cover ies made in the amazingly
beautiful Jlruclure and nature of the
animal economy ; neither have Plants
pajfed unobferved in this inquifitive age,
which has with fuch diligence extended
its inquiries, infome degree, into almofl
every branch of Nature s inexhauflible
fund of wonderful works.

We find in the Philofophical Tranf-
aElions, and in the Hijlory of the Royal
Academy of Sciences, accounts of many
curious Experime?its and Obfervations
made from time to time on Vegetables,
by fever al ingenious and inquifitive Per-
fons : But our country7nan Dr. Grew,
0*fc/ Malpighi, were the firfi, who, tho

A 4 in

ii The Preface.

in very dijlani countries, did nearly at
the fame time, unknown to each other,
engage in a very diligent and thorough
inquiry into the JlruSlure of the vejfels
of Plants ; a province, which till then
had lai?i uncultivated. They have given
us very accurate and faithful accounts
of the flruElure of the parts, which they
carefully traced, from their firft minute
origin, the feminal Plants, to their full
growth and maturity, thro their Roots,
Trunk, Bark, Branches, Gems, Shoots,
JLeaves, Bloffoms and Fruit. In all
which they obferv d an exacl and regular
fymmetry of parts mojl curioufly wrought
in fuch manner, that the great work of
Vegetation might effectually be carried
on, by the uniform co-operation of the
fever al parts, according to the different
offices afftgned them by Nature.

Had they fortuned to have fallen into
this fat teal way of inquiry, perfons of

their

The Preface. iii

their great application andfagacity had
doubtlefs made confiderable advances in
the knowledge of the nature of Plants.
This is the only fur e way to meafure the
fever al quantities ofnourifhment, which
Plants imbibe and perfpire, and thereby
to fee what influence the different fates
of Air have on them. This is the likeliefl
method to find out the Sap's velocity , and
the force with which it is imbibed : As
alfo to ejlimate the great power that
Nature exerts in extending and pufhing
forth her produElions by the expanfion of
the Sap.

About twenty years fince, I made
feveral hcemaflatical Experiments on
Dogs ; and fix years afterwards re-
peated the fame on Horfes and other
Animals, in order to find out the real
force of the blood in the Arteries, fome
of which are mentioned in the third
chapter of this book : At whicb times I

wifhed

iv The Preface.

wiped I could have made the like Ex~
periments, to dif cover the force of the
Sap in Vegetables ; but defpaired of
ever efieEling it, till, about feven years
fince, by mere accident I hit upon it<>
while I was endeavouring by fever always
to flop the bleeding of an old Jlem of a
Vine, which was cut too near the bleed-
ing feaf on, which I feared might kill it:
Having, after other means proved inef-
feSlual, tied a piece of bladder over the
tranfverfe cut of the Stem, I found the
force of the Sap did greatly exte?2d the
bladder ; whence I concluded, that if a
long glafs-tube were fixed there in the
fame mamier, as I had before done to
the Arteries of fever al living Animals,
I fhould thereby obtain the real afc end-
ing force of the Sap in that Stem, which
fucceeded according to my expeSlation :
and hence it is, that I have been irf en-
fib ly led on to make farther a?id far-
ther

The Preface. v

ther refearches by variety of Expert
ments.

As the Art ofPhyfick has of late years
been much improved by a greater know-
ledge of the animal (economy ; fo doubt-
lefs a farther infight into the vegetable
eeconomy mufl needs proportionably im-
prove our skill in Agriculture and Gar-
denings which gives me reafon to hopey
that inquiries of this kind will be accept-
able to many, who are intent upon im-
proving thofe innocent, delightful, and
beneficial Arts : Since they cannot be in-
fenfible, that the moft rational ground
for Succefs in this laudable Purfuit mufl
arifefrom a greater infight into the na-
ture of Plants.

Finding by many Experiments in the

fifth chapter, that the Air is plentifully

infpired by Vegetables, not only at their

roots, but alfo thro feveral pjhrts of their

trunks and branches ; this put ??}e upon

making

vi The Preface.

making a more particular inquiry into
the nature of the Air, and to dif cover ,
if pojfible, wherein its great importance
to the life and fupport of Vegetables
might conftft ; on which account I was
obliged to delay the Publication of the
reft of thefe Experimettts, which were
read two years Jince before the Royal So-
ciety•, till I had made fome progrefs in
this inquiry : An account of which I
have given in the Jixth chapter.

JVhere it appears by many chymio-
ftatical Experiment s, that there is dif-
fufed thro all natural mutually attraEl-
ing bodies \ a large proportion of parti-
cles ^ which ^ as the firft great Author of
this important difcoveryy Sir Ifaac
Newton, obferves, are capable of being
thrown off from denfe bodies by heat or
fermentation into a vigoroufly elaftick
and perma?/iently repelling ft ate ; and
alfo of returning by fermentation, and

fome-

The Preface, vii

fometimes without it, into denfe bodies :
It is by this amphibious property of the
Air, that the main and principal ope-
rations of Nature are carried on ; for
a mafs of mutually attraSling particles y
without being blended with a due pro-
portion of elaflick repelling ones, would,
in many cafes, foon coalefce into ajlug-
gifh lump. It is by thefe properties of
the particles of matter ', that he fo Ives
the principal Phenomena of Nature.
And Dr. Freind has from the fame
principles given a very ingenious Ratio-
nale of the chief operations in Chymiflry.
It is therefore of importance to have
thefe very operative properties of natu-
ral bodies further afcertained by more
Experiments and Obfervatio?ts : And it
is with fatisfa&ion, that we fee them
more and more confirmed to us, by every
farther inquiry we make, as the follow-
ing Experiments will plainly prove, by

Jhewing

viii The Preface.

Jhewing how great the power of the at-
traEiio?i of acid fulphureous particles
inujl be at fo?ne little diflance from the
point of contaEi) to be able mojl readily
tofubdue and fix elajlick aereal parti-
cles y which repel with a force fuperior
to vafil incumbent prejfures : Which
particles we find are thereby changed
from a ftrongly repelling^ to as firongly
an attraSling Jlate : And that elafii-
city is no immutable property of air,
is further evident from thefe Experi-
ments ; becaufe it were impojfible for
fuch great quantities of it to be confined
in the fubfiances of Animals and Vege-
tables, in an elafiickfiate, without rend-
ing their confiituent parts with a vafl
explofion.

I have been careful in making, and

faithful in relating the refult of thefe

Experiments ; and wijh I could be as

happy in drawing the proper inferences

from

The Preface. ix

from them. However I may falljhort
at jirji fetting out in this flatical way
of inquiring into the nature of Plants^
yet there is good reafon to believe^ that
conjiderable advances in the knowledge
of their nature may, in procefs of time^
be 7nade by refearches of this kind.

And I hope the publication of this
Specimen of what I have hitherto done,
will put others upon the fa7ne purfuits>
there beings in fo large a fields and
among fuch an innwnerable variety of
fubje&S) abundant room for many heads
and hands to be employed in the work :
For the wonderful and fecret operations
of Nature are fo involved and intricate y
fo far out of the reach of our fenfes^ as
they prefent themf elves to us in their na-
tural order j that it is impojfible for the
moft fagacious and penetrating Genius
to pry into themy unlefs he will be at the
paws of analyfmg Nature by a numerous

and

x The Preface.

and regular feries of Experiments^ which
are the only Jolid fowtdation whence we
may reafonably expeEl to make any ad-
vance in the real knowledge of the ?iature
cf things.

I muft not omit here publiekly to ac-
htowledge^ that I have in fever al refpeEls
been much obliged to my late ingenious
and learned neighbour and friend 'Robert
Mather, of the Inner-Temple, Efq^for
his afftflance herein.

Whereas fome complain, that they do not under-
fland the fignification of thofe fhort figns or
characters, which are here made ufeof in many
of the calculations, and which are ufual in
Algebra ; this mark -f- fignifies more, or to be
added to. Thus page 18, line 4, 6 ounces -j- 240
grains, is as much as to fay, 6 ounces more by,
or to be added to 240 grains. And in line 16,
of the fame page, this mark x or crofs figni-
fies multiplied by •, the two fhort parallel lines
fignify equal to ; thus 1820 x 4= 7280 : 1, is
as much as to fay, 1820 multiplied by 4 equal to
7280 is to 1.

THE

CONTENTS.

CHAP. I.

Experiments, Jhewing the quantities of
moijiure imbibed and perfpired by Plants
and 'Trees. Page 4

CHAP. II.

Experiments, whereby to find out the force
with which Trees imbibe moijiure. 84

CHAP. III.

Experiments, Jhewing the force of the fap in
the Vine in the bleeding feajon. 108

CHAP. IV.

Experiments, Jhewing the ready lateral motion
of the Sap, and confequently, the lateral
communication of the Sap-ve'ffels. The free
pajfage of it, from the fmall Branches to-
wards the Stem, as well as from the Stem
to the Branches, with an account of Jbme
Experiments, relating to the Circulation,
or Non-circulation of the Sap. 3 28

a CHAP,

The Contents.

CHAP. V.

Experiments, whereby to prove, that a con*

Jiderable quantity of air is infpired by

Plants, 155

CHAP. VI.

A Specimen of an attempt to analyfe the Air
by chymio-ftatical Experiments^ which Jhew
in how great a proportion Air is wrought
i?ito the compojition of Animal^ Vegetable,
and Mineral Sub/lances : And withal, how
readily it refumes its elajlick State, when
in the dijfolution of thofe Sub/lances it is
dif engaged from them. i6z

CHAP. VII,

Of Vegetation. 318

The Conclujiou. 35?

A Table where to find each Experiment,

Experiment

Page

Experiment

Page

38.

118

39*

126

40.

128

41.

131

42.

43-

134

44.

137

45* 46-

138

47.

155

io.

48.

156

II.

49>5°>5*-

1*73

12.

52, 53. 54.

175

13* I4>

55> 56-

176

I5>

57-

if?

16,

58, 59-

178

17.

60, 6i, 62.

179

18.

63, 64-

180

19.

65, 66,

181

20.

67, 68, 69, 70.

182

21.

71,72.

i«3

22.

73> 74.

184

33.

75-

it;

24.

76.

188

25.

77.

189

26,

Exper. on Calc.

} i93

27.

Human.

28,29,

78, 79.

199

30.

80,81.

202

3*.

JOI

82.

203

3*.

102

83.

204

33>

103

84.

205

34.

108

85, 86.

206

35.

87.

207

112

88,89.

209

?7-

IJ5

9°> 91-

217
Expe-

A Table where to find each Experiment.

Experiment

Page

Experiment

Page

92-

219

1 10.

244

93-

220

III.

248

94.

221

IL2.

252

95.

222

H3-

253

96,97.

224

114.

2 55

98.

225

**5-

263

9g.

226

116.

264

100.

227

117.

273

101.

228

•118.

281

102.

229

119.

288

103.

230

120.

299

104.

23I

121.

3C4

105, 106.

232

122.

329

107.

236

123.

33i

108.

238

124.

344

109.

• 239

A Table

where to

find each Figure.

Figure

Page

Figure

Page

I, 2.

24.

132

3> 4, 5-

25, 26.

134

27, 28,

29, 30

IS2

7> 8> 9-

5°

3^32-

160

10, u> 12.

33. 34-

168

i3> 14.

35* 36>

37-

210

15, 16, 17, i

S. 1 12

3s. 39-

266

19.

1*5

40,4^

42,43,

44. 346

20, 21.

45, 46.

350

22, 23.

J3°

THE

INTRODUCTION.

TH E farther refearches we make in-
to this admirable fcene of things*
the more beauty and harmony we
fee in them : And the ftronger and clearer
convi&icns they give us, of the being, power
and wifdom of the divine Architect, who
has made all things to concur with a won-
derful conformity, in carrying on, by va-
rious and innumerable combinations of mat-
ter, fuch a circulation of caufes and efFe&s,
as was neceffary to the great ends of na-
ture.

And fince wc are allured that the all-wife
Creator has obferved the moil exadl propor-
tions, of number , weight and meafure, in
the make of all things ; the mbft likely way
therefore, to get any infight into the na-
ture of thofe parts" of the creation, whicl}
come within our obfervation, muft in all
reafon be to number, weigh and meafure-
And we have much encouragement to pur-

B fu*

2 Vegetable Staticks.

fue this method, of fcarching into the nature
of things, from the great fuccefs that has
attended any attempts of this kind.

Thus, in relation to thofe Planets which
revolve about our Sun, the great Philofo-
pher of our age has, by numbering and
meafuring, difcovered the exact proportions
that are obferved in their periodical revo-
lutions and diflances from their common
centres of motion and gravity : And that
God has not only comprehended the dujl
of the earth in a meafurey and 'weighed the
mountains in fcales, and the hills in a ba-
lance^ Ifai. xl. j 2. but thathealfo holds the
vaft revolving Globes, of this our folar Sy-
ftem, moft exactly poifed on their common
centre of gravity.

And if we reflect: upon the difcoveries
that have been made in the animal oecono-
my, we fhall find that the moft confider-
able and rational accounts of it have been
chiefly owing to the ftatical examination
of their fluids, viz. by inquiring what quan-
tity of fluids, and folids diflblved into fluids,
the animal daily takes in for its fupport
and nouriihment : And with what force,
and different rapidities, thofe fluids are car-
ried

Vegetable Stathks. 3

ried about in their proper channels, accord-
ing to the different fecretions that are to
be made from them : And in what pro-
portion the recrementitious fluid is convey-
ed away, to make room for frefh fupplies;
and what portion of this recrement nature
allots to be carried off, by the feveral kinds
of emunctories, and excretory dufts.

And fince in vegetables, their growth, and
the prefervation of their vegetable life, is
promoted and maintained, as in animals,
by the very plentiful and regular motion
of their fluids, which are the vehicles or-
dained by nature, to carry proper nutriment
to every part ; it is therefore reafonable to
hope, that in them alio, by the fame me-
thod of inquiry, considerable difcoveries
may in time be made, there being, in many
refpedls, a great analogy between plants and
animals.

B 2 CHAP

4 Vegetable Staticks.

CHAP. I.

Experiments, jhewing the quantities imbibed
and perfpired by Plants and Trees.

Experiment I.

JUL Y 3. 1724. in order to find out the
quantity imbibed and perfpired by the
Sun-flower, I took a garden-pot (Fig. 1.)
with a large Sun-flower, a, 3 feet-}-| high,
which was purpofely planted in it when
young; it was of the large annual kind.

I covered the pot with a plate of thin
milled lead, and cemented all the joints fill,
fo as no vapour could pafs, but only air, thro'
a fmall glafs tube d, nine inches long, which
was fixed purpofely near the ftcm of the
plant, to make a free communication with
the outward air, and that under the leaden
plate.

I cemented alfo another fhort glafs tube
g into the plate, two inches long, and one
inch in diameter. Thro' this tube I watered
the plant, and then flopped it up with a
cork ; I flopped up alfo the holes /, /, at the
bottom of the pot with corks.

I weighed

Vegetable Static fa. 5

I weighed this pot and plant morning
and evening, for fifteen feveral days, from
July 3. to Aug. 8. after which I cut off the
plant clofe to the leaden plate, and then
covered the ftump well with cement ; and
upon weighing found there perfpired thro*
the unglazed porous pot two ounces every
twelve hours day ; which being allowed in
the daily weighing of the plant and pot, I
found the greateft perfpiration of twelve
hours in a very warm dry day, to be one
pound fourteen ounces; the middle rate of
perfpiration one pound four ounces. The
perfpiration of a dry warm night, without
any fenfible dew, was about three ounces 5
but when any fenfible, tho' fmall dew, then
the perfpiration was nothing; and when a
large dew, or fome little rain in the night,
the plant and pot was increafed in weight
two or three ounces. N. B. The weights
I made ufe of were Avoirdupoife weights.

I cut off all the leaves of this plant, and
laid them in five feveral parcels, according
to their feveral fizes ; and then meafured
the furface of a leaf of each parcel, by lay-
ing over it a large lattice made with threads,
io which the little fquares were \ of an inch
B ^ each*

6 Vegetable Staticks.

each 5 by numbring of which I had the iur-
face of the leaves in fquare inches, which
multiplied by the number of the leaves in
the correfponding parcels, gave me the area
of all the leaves; by which means I found
the furface of the whole plant, above ground,
to be equal to 5616 fquare inches, or 39
fquare feet.

I dug up another Sun-flower, nearly of
the fame fize, which had eight main roots,
reaching fifteen inches deep and fideways
from the flem : It had befides a very thick
bufh of lateral roots, from the eight main
roots, which extended every way in a he-
mifphere, about nine inches from the flem
and main roots.

In order to get an eftimate of the length
of all the roots, I took one of the main roots,
with its laterals, and meafured and weighed
them ; and then weighed the other feven
roots, with their laterals ; by which means
I found the fum of the length of all the
roots, to be no lefs than 1448 feet.

And fuppofing the periphery of thefe
roots, at a medium, to be 0.13 1 of an inch,
then their furface will be 2276 fquare
inches, or 15. 8 fquare feet; that is equal

Vegetable Stoticks. 7

to 0.4. of the furface of the plant above
ground.

If, as above, twenty ounces of water, at
a medium, perfpired in twelve hours day,
(/. e.) thirty-four cubicle inches of water, (a
cubick inch of water weighing 254 grains)
then the thirty-four cubick inches divided
by the furface of all the roots, is = 2286
fquare inches ; (/. e.) -~js is = -~j; this gives
the depth of water imbibed by the whole
furface of the roots, viz ^ part of an
inch.

And the furface of the plan: above ground
being 5616 fquare inches, by which divide-
ing the 34 cubick inches, viz. v|i6,3= 1T7*
this gives the depth perfpired by the whole
furface of the plant above ground, viz. 7^7.
part of an inch.

Hence, the velocity with which water
enters the furface of the roots to fupply the
expence of perfpiration, is to the velocity,
with which their fap perfpires, as 165 : 6jy
or as FTT : ,^-j, or nearly as 5 : 2.

The area of the tranfverfe cut of the mid-
dle of the ftem is a fquare inch ; therefore
the areas, on the furface of the leaves, the
roots and ftem, are 5616, 2276. 1,

B4 The

8 Vegetable Statich.

The velocities, in the furfaceof the leaves,
roots, and tranfverfe cut of the ftem, are
gained by a reciprocal proportion of the
furfaces.

*g ^leaves — 5616
3= 2276

Now, their perfpiring 34 cubick inches in
twelve hours day, there muft fo much pafs
thro' the ftem in that time; and the velo-
city would be at the rate of 34 inches in
twelve hours, if the ftem were quite hollow.

In order therefore to find out the quan-
tity of folid matter in the ftem, July 2jth at
7. a. m. I cut up even with the ground a
Sun-flower; it weighed 3 pounds; in thirty
days it was very dry, and had wafted in all
2 pounds* 4 ounces ; that is | of its whole
weight: So here is a fourth part left for
folid parts in the ftem, (by throwing a piece
of green Sun-flower ftem into water, I found
it very near of the fame fpecifick gravity
with water) which filling up fo muchofthe
ftem, the velocity of the fap muft be increas-
ed proportionably, viz. $ part more, (by

reafon

Vegetable Staticks. 9

reafon of the reciprocal proportion) that 34
cubick inches may pafs the ftem in twelve
hours ; whence its velocity in the ftem will
be 45 | inches in twelve hours, fuppofing
there be no circulation, nor return of the
lap downwards.

If there be added to 34, (which is theleaft
velocity) -j of it = 1 1 -j, this gives the greateft
velocity, viz. 45-j. The fpaces being as 3 : 4.
the velocities will be 4 : 3 :: 454-: 34.

But if we fuppofe the pores in the fiirfacc
of the leaves to bear the fame proportion,
as the area of the fap-veffels in the ftem do
to the area of the ftem; then the velocity,
both in the leaves, root and ftem, will be
increafed in the fame proportion.

A pretty exaft account having been taken,
of the weight, iize, and furface of this
plant, and of the quantities it has imbibed
and perfpired, it may not be improper here,
to enter into a comparifon, of what is taken
in and perfpired by a human body, and this
plant.

The weight of a well-fized man is equal
to 160 pounds: The weight of the Sun-
flower is 3 pounds ; fo their weights are to
cash other as 160:3, or as 53: 1.

The

io Vegetable Statu ks.

The lurface of fiich human body is equal
to 15 fquare feet, or 2160 fquare inches.

The furface of the Sun-flower is 5616
fquare inches 5 fo its furface is, to the furface
of a human body, as 26 : 10.

The quantity perfpired by a man in twenty-
four hours is about 3 1 ounces, as Dr. Keill
found. Vid. Medic. Stai.Britan. p. 14.

The quantity perfpired by the plant, in
the fame time, is 22 ounces, allowing two
ounces for the perfpiration of the beginning
and ending of the night in July, viz. after
evening, and before morning weighing, juft
before and after night.

So the perfpiration of a man to the Sun-
flower is as 141 : 100.

Abating the fix ounces of the thirty-one
ounces, to be carried off by refpiration from
the lungs in the twenty-four hours ; ( which
I have found by certain experiment to be fo
much, if not more ) the twenty-five ounces
multiplied by 43 8> the number of grains
in an ounce Avoirdupois, the producl: is
10950 grains; which divided by 254, the
number of grains in a cubick inch of water,
gives 43 cubick inches perfpired by a man :
which divided by the furface of his body,

viz.

Vegetable Staticks. 1 1

viz. 2160 fquare inches, the quotient is near-
ly y_ part of a cubick inch perfpired off a
fquare inch in twenty-four hours. Therefore
in equal furfaces, and equal times, the man
perfpires f0, the plant 7£T, or as 50 : 15.

Which excefs in the man is occafioned
by the very different degrees of heat in each:
For the heat of the plant cannot be greater
than the heat of the circumambient air,
which heat in Summer is from 25 to 35 de-
grees above the freezing point, {vide Exp.
20.) but the heat of the warmeft external
parts of a man's body is 54 fuch degrees,
and the heat of the blood 64 degrees;
which is nearly equal to water heated to
fuch a degree as a man can well bear to hold
his hand in, ffirring it about 5 which heat is
fufficient to make a plentiful evaporation.

£>u. Since then the perfpirations of equal
areas in a man and a Sun-flower, are to each
other as 165 : 50, or as 3 JL : 1 ; andfincethp
degrees of heat areas 2 : 1, muff not thefum
or quantity of the areas of the pores lying
in equal furfaces, in the man and Sun-flower,
be as 1 2. : 1 ? for it feems that the quantities
of the evaporated fluid will be as the degrees
of heat, and the fum of the areas of the pores,
taken together. Dr.

12 Vegetable Staticks.

Dr. Keill, by eftimating the quantities of
the feveral evacuations of his body, found
that he eat and drank every 24 hours, 4
pounds 10 ounces.

The Sun-flower imbibed and perfpired in
the fame time 22 ounces 5 fo the man's food,
to that of the plant, is as 74 ounces to 22
ounces, or as 7:2.

But compared bulk for bulk, the plant im-
bibes 17 times more frefti food than the man:
For deducing 5 ounces, which Dr. Keill al-
lows for the faces ahi, there will remain 4
pounds 5 ounces of frefh liquor, which en-
ters a mans veins; and an equal quantity
paffes off every 24 hours. Then it will be
found, that 17 times more new fluid enters
the fap-veffels of the plant, and paffes off in
24 hours, than there enters the veins of a
man, and paffes off in the fame time.

And fince, compared bulk for bulk, the
plant perfpires feventeen times more than
the man, it was therefore very neceffary, by
giving it an extenfive furface, to make a large
provifion for a plentiful perfpiration in the
plant, which has no other way of dis-
charging fuperfluities 5 whereas there is pro-
vifion made in man, to carry off above

half

Vegetable Staticks. 13

half of what he takes in, by other eva-
cuations.

For fince neither the furface of his body
was extenfive enough to caufe fufficient ex-
halation, nor the additional wreak, arifing
from the heat of his blood, could carry off
above half the fluid which was neceflary to
be difcharged every 24 hours; there was a
neceffity of providing the kidneys, to per-
colate the other half through.

And whereas it is found, that 17 times
more enters, bulk for bulk, into the fap-vef-
fels of the plant, than into the veins of a man,
and goes off in 24 hours: One reafon of
this greater plenty of frefh fluid in the vege-
table than the animal body, may be, becaufe
the fluid which is filtrated thro' the roots im-
mediately from the earth, is not near fo full
freighted with nutritive particles as the chyle
which enters the lacteals of animals 5 which
defect it was neceffary to fupply by the en-
trance of a much greater quantity of fluid.

And the motion of the fap is thereby much
accelerated, which in the heartlefs vegetable
would otherwife be very flow; it having
probably only a progreffive, and not a circu-
lating motion, as in animals.

Since

14 Vegetable Staticks.

Since then a plentiful perfpiration is
found fo neceffary for the health of a plant
or tree, 'tis probable that many of their dis-
tempers are owing to a ftoppage of this per-
fpiration, by inclement air.

The perfpiration in men is often flopped
to a fatal degree ; not only by the inclemen-
cy of the air, but by intemperance, and vio-
lent heats and colds. But the more tempe-
rate vegetables perfpiration can be flopped
only by inclement air -, unlefs by an un-
kindly foil, or want of genial moifture, it is
depriv'd of proper or fufficient nourishment.
As Dr. Keill obferv'd in himfelf a con-
fiderable latitude of degrees of healthy per-
fpiration, from a pound and a half to 3 pounds ;
I have alfo obferved a healthy latitude of
perfpiration in this Sun-flower, from 16 to
28 ounces, in twelve hours day. The more
it was watered, the more plentifully it per-
fpired, (ceteris paribus ) and with fcanty
watering the perfpiration much abated.

Experiment II.

From July 3d. to Aug. 3d. I weighed
for nine feveral mornings and evenings a

middle-

Vegetable Staticks. 1 5

middle- fized Cabbage plants which grew in
a garden pot, and was prepared with a leaden
cover, as the Sun-flower, Exper. ijl. Its
greater! perfpiration in twelve hours day
was 1 pound 9 ounces; its middle perfpira-
tion 1 pound 3 ounces, = 32.7 cubick inches*
Its furface 2736 fquare inches, or 19 fquare
feet. Whence dividing the 32 cubick inches
by 2736 fquare inches, it will be found
that a little more than the— of an inch
depth perfpires off its furface in twelve hours
day.

The area of the middle of the Cabbage
flem is -ff|- of a fquare inch ; hence the ve-
locity of the fap in the ftem is, to the ve-
locity of the perfpiring fap on the furface
of the leaves, as 2736 : |££ : : 4268 : 1 .

for i!36Ji_LL6 68. But if an allow-

ioo T

ance is to be made for the folid parts of the

flem, (by which the paffage is narrowed) the

velocity will be proportionally increafed.

The length of all its roots 470 feet, their

periphery at a medium ~T of an inch, hence

their area will be 256 fquare inches nearly;

which being fo frnall in proportion to the

area of the leaves, the fap muft go with

above

\6 Vegetable Staticks.

above ten times the velocity through the
furfdce of the roots, that it does thro* the
furface of the leaves.

And fetling the roots, at a medium, at 12
inches long, they muft occupy a hemifphere
of earth two feet diameter, that is, 2.r cu-
bick feet of earth.

By comparing the furfaces of the roots of
plants, with the furface of the fame plant
above ground, we fee the neceifity of cut-
ting off many branches from a tranfplanted
tree: For if 256 fquare inches of root in
furface was neceffary to maintain this Cab-
bage in a healthy natural ftate: fuppofe, upon
digging it up, in order to tranfplant, half the
roots be cut off, ( which is the cafe of moft
young tranfplanted trees) then it's plain, that
but half the ufual nourifliment can be car-
ried up through the roots on that account ;
and a very much lefs proportion on account
of the fmall hemifphere of earth, the new
planted fhortened roots occupy ; and on ac-
count of the loofe pofition of the new turn-
ed earth, which touches the roots at firft
but in few points. This (as well as experi-
ence) ftrongly evinces the great neccffity of

well watering new plantations.

Which.

Vegetable Stathks* \f

Which yet muft be done with caution, for
the skilful and ingenious Mr. Philip Miller
F. R. S. Gardener of the Botanick garden at
Cbelfea, in his very ufeful Gardeners Dicti-
onary, fays, <c As to the watering of all new*
<c planted trees, I mould advile it to be done
" with great moderation, nothing being
<c more injurious to them than over-water-
<c ing of them. Vide Planting!' And I ob-
served, that the dwarf pear-tree, whofe root
was fet in water, in Exper. 7. decreafed very-
much daily in the quantity imbibed ; viz. be-
caufe the fap-veffels of the roots, like
thofe of the cut off boughs, in the fame
Experiment, were fo faturated and clogged
with moifture, by ftanding in water, that
more of it could not be drawn up to fup*,
port the leaves*

Experiment IIL

From July 28. to Aug. 25. 1 weighed for
twelve feveral mornings and evenings, a
thriving Vine growing in a pot ; I was fur-
niflied with this and other trees, from his
Majefty's garden at Hampton-court , by the

C favour

18 Vegetable Statich.

favour of the eminent Mr. Wife. This
vine was prepared with a cover, as the Sun-
flower was. Its greateft perfpiration in 12
hours day, was 6 Ounces + 240 grains; its
middle perfpiration 5 ounces -\- 240 grains
— 10 g~ cubick inches.

The fur face of its leaves was 1820 fquare
inches, or 12 fquare feet +92 fquare
inches; whence dividing g\ cubick inches,
by the area of the leaves, it is found that
-^j part of an inch in depth, perfpires off in
12 hours day.

The area of a tranfverfe cut of its ftem,
was equal to 4- of a fquare inch: hence the
fap's velocity here, to its velocity on the fur-
face of the leaves, w7 ill be as 1820 x 4 =
7280 : 1. Then the real velocity of the fap's
motion in the ftem is = 7^f =38 inches
in twelve hours.

This is lbppoiing the ftem to be a hollow
tube: but by drying a large vine-branch, (m
the chimney corner) which I cut off in the
bleeding feaibn, I found the folid parts were
•f of the ftem ; hence the cavity thro* which
the fap paflte, being fo much narrowed, its
velocity will be 4 times as great, viz. 152

inches in 12 hours.

But

Vegetable Statich. 19

But it is further to be confidered, that if
the lap moves in the form of vapour, and
not of water, being thereby rarefied, its ve-
locity will be increafed in a direct propor-
tion of the fpaces, which the fame quan-
tity of water and vapour would occupy 5
And if the vapour is fuppofcd to occupy 10
times the fpace which it did, when in the
form of water, then it muft move ten times
fafler; fo that the fame quantity or weight
of each may pafs in the fame time, thro*
the fame bore or tube : And fuch allow-
ance ought to be made in all thefe calcu-
lations concerning the motion of the fap in
vegetables.

Experiment IV.

From July 29. to Aug. 25. I weighed
for 12 feveral mornings and evenings, a pa-
radife flock Apple-tree, which grew in a
garden por, covered with lead, as the Sun-
flower : it had not a bufhy head full of
leaves, but thin fpread, being in all but 163
leaves, whofe furface was equal to 1589
fquare inches, or 1 1 fquare feet + 5 fquare
inches,

C 2 The

io Vegetable Staticks.

The greateil quantity it perfpired in 12
hours day, was 1 1 ounces, its middle quan-
tity 9 ounces, or 15 \ cubick inches.

The 15- cubick inches perfpired, divided
by the furface 1589 fquajre inches, gives the
depth perfpired off the furface in 12 hours
day, viz. -—r of an inch.

The area of a tranfverfe cut of its fiem, \ of
an inch fquare, whence the fap's velocity
here, will be to its velocity on the furface
of the leaves, as 1589 x 4 = 6356:1.

Experiment V.

From Jit ly 28. to Aug. 25. I weighed for
10 feveral mornings and evenings a very
thriving Limon-tree, which grew in a gar-
den pot, and was covered as above: Its great-
eft perfpiration in 12 hours day was 8 ounces,
its middle perfpiration 6 ounces, equal to
ic-J cubick inches, In the night it perfpired
fometimes half an ounce, fometimes nothing,
and fometimes increafed 1 or 2 ounces in
weight, by large dew or rain.

The furface of its leaves was 2557
fquare inches; or 17 fquare feet ~p 109
fquare inches; diyiding then the 10 cubick
inches perfpired by this furface, gives the

depth

So the feveral fore-
going perfpirations
in equal areas are,

Vegetable Statkh.
depth perfpired in 12 hours day, viz. T|j
of an inch.

-~T in the vine in 12
hours day.

jo- in a man, in a day
and a night.
T£T in a fun -flower,
in a day and night.
jo in a cabbage, in 1 %
hours day.

T£- in an apple- tree,
in 12 hours day.
-j^ in a limon-tree,
in 12 hours day.
The area of the tranfverfe cut of the Hem
of this Limon-tree was — 1 44 of a
fquare inch ; hence the fap's velocity here,
will be to its velocity on the furface of the

leaves, as 1768: 1 for2*57 x IOO= 17- 7
J 144

This is fuppofing the whole ftem to be a hol-
low tube; but the velocity will be increafed
both in the ftem and in the leaves, in propor-
tion as the paffagc of the fap is narrowed by
the folid parts.

By comparing the very different degrees
of perfpiration, in thefe 5 plants and trees*

C 3 we

2 1 Vegetable Staticks.

we may obferve, that the Limon-tree, which
is an ever-green, perfpires much lefs than the
Sun-flower, or than the Vine or the Apple-
tree, whofe leaves fall off in the winter;
and as they perfpire lefs, fo are they the
better able to furvive the winter's cold,
becaufe they want proportionably but a very
fmall fupply of frcuh nourifhment to fup-
port them ; like the exangueous tribe of
animals, fiogs, toads, tortoifes, ferpents,
infecls, &c. which as they perfpire little,
fo do they live the whole winter without
food. And this I find hold true in 12
other different forts of ever-greens, on which
I have made Experiments.

The above- mention'd Mr. Miller made
the like Experiments in the Botanick-gar-
den at Cbelfea, on a Plantain-tree, an Aloe,
and a Paradife Apple-tree; which he weigh-
ed morning, noon, and night, for feveral
fuccefiive days. I ihall here infert the di-
aries of them, as he communicated them to
mc, that the influence of the different tem-
peratures of the air, on the perfpiration of
thtfe plants, may the better be feen.

The pots which he made ufe of were
glazed, and had no holes in their bottoms as

garden

Vegetable Staticks. 25

garden pots ufually have 3 fo that all the
moifture, which was wanting in them upon
weighing, muft neceflarily be imbibed by
the roots of thofe plants, and thence per-
fpired off thro' their leaves.

A Diary of the perfpiration of the Mufa Ar-
bor, or Plantain-tree of the Weft-Indies.
The whole furface oj the plant was 14
fquare feet^ 8 + \ inches. The different
degrees of heat of the air are here noted
by the degrees above the freezing point in
my Thermometer, defcritid in Exper. 20.

1726 Weigh
at 6

May.

*7
18

20
21

22
23

Morn,
pd. ou

38 S
37 ij

37 4

36 14
36 10

36 14
36* 6

Weight
at 12
Noon,
pd. ou.
38 o

37 Si*?

37 *

36 12

37 o

3* rt

48
So

3*1

Weight
at 6
Even.

pd. ou.

37 H

37 3i

37 °

36 n
36 15-

36 n£

This evening T2 ounces of water were poured
removed from the ftove into a cool room, where
Sun, the windows being North-weft.

M B. This plant
flood in a ftove, with a
fmall fire in it $ the af-
pedt of the ftove was
South- eaft.

A hot clear day. Thi
morning he obferve
large drops of water a
the extremity of ever
leaf, and we may obferve
that it perfpires very
much this day,
J An extreme hot clear
day.

Moderately hot, but clear.
This morn. 12, ounces of
water poured into the
pot. Mixture of Sun and
Clouds.

Much thunder, fome rain
and hail at a diftance.
A gloomy day, but no
rain.

into the potj and it was
it had a free air, but no

Calm

Vegetable Statich.

jyii

Weight

ac 6

at 6

May

Morn.

Noon.

Even.

pd. OU.

pd.

pJ. ou.

•

27 OO

*rt

36 irf

*fi

Calm cloudy weather.

37 00

!4i

36 13

A pretty clear day.

36 12

1 1

36' 10

24 1

A hot day.

36 IC-7

i6i

36 6

l/i

A very hot day.

36 6~

iii

S^ 3z

Some rain and cloudy.
At this time, the under
leaves of the plant be-
gan to witherand decay ;
^nd the top leaf" to un-
fold, and fpread abroad j
butthey are obferved ne-
ver to grow bigger, af-

"June.

36 2
36 |£

20
T9

3<5

36 1

36 0

tei they arefully opened.
A temperate day.
Temperate weather not^
very clear.

ur ■*

35"

'rf

3T «3l

Some rain. The whole
plant begins to change
colour, and appear fickly,

$* «*

I9i

35"

11 2

35- 11

irj

He then removed the
plant imp the ftove again
in order to recover it j
but it continued to fade,
and in 2 or 5 days died.

3f 10

284

3>"

3f »i

A cool and cloudy dav.

35- co

** Si

34 M

1 9 1 A warm day : and the

whole plant decayed.

We may obferve from this diary, that
this plant, when in the ftove, ufually per-
fpired more in fix hours before noon than
in fix hours after noon ; and that it perfpired
much lefs in the night, than in the day time :
And fometimes increafed in weight in the
night, by imbibing the moifture of the
ambient air j and that both in the ftove and

Vegetable Statich. 25

in the cool room. Upon making an eftimate
of the quantity perfpired off a fquare inch of
this plant, in 1 2 hours day, it comes but to
TyT of a cubick inch, on the 18 th day of
May, when by far its greateft perfpiration was $
for on feveral other days it was much lefs.

A Diary of the Aloe Africana Caulefcens
foliis fpinofis, maculis ab utraque parte al-
bicantibus not at is, Commelini Hort. Amjl.
commonly called the Carolina Aloe. 7/
was a large plant of its kind. It food
in a glafs-cafey which had a South afpeSi
without a fire.

1726/weight

Weight

1 at 6 |

at 1 2 | q

at 6

May.

Morn. ! 3

Noon. J 2

Night

pd. ou.1 '

4.1 6 if

41 2^36

-M 3

3oi

+ i 1728^

40 14 j2.i£

4.0 1 2

<J.O I2jl6£

40 10 '31

40 8i;29A

40 Q-I27

40 6\ 30

40 ^28

40 6

40 rf

40 4

*7i

41 10

ft* H

..,

This evening promif-
ingfome rain, he fet the
pot out to receive a little j
and then wiping the
leaden furnace of the pot
dry, he fet it into the
glafs-cafe again.

Now the pot broke,
and hindered any fur-
ther obfervations.

We may obferve, that tms Aloe increafed
in weight moll nights, and perfpired moil in
the morning. A Diary

26 Vegetable Statkks.

A Diary of a fmall Parad ife- Apple, with one
Upright ft em 4 feet high; and two fmall
lateral branches about 8 inches long. This
plant food under a cover of wood, which
was open on all fides.

iji6

May
18

J9
20
2.1

16
*7

36 12

16 7

3« 3^

36 OO

IS 4

J 4

18$

i8£

l*i

7^28

37 3

36 14.

36 ioj

3<* T

36 1

IS *3

34 6i

3 +

IS Sh^

37 1 !*o I

36 13^19 The leaves very dry,
36 9 J20iand become fpeckled for
a, 120 jwant of dew.
2 J.' x 2I.I Then he removed the
^ .'plant into the ftove, to
try what efFedt that
would have on its per-
fpiration.

At this time the leaves
were withered with the
heat, and hung down
as if they would fall off".
At this time feveral
of the leaves began to
fall off.

All the leaves fallen
off, except a few fmall
ones, at the extremities
of the branches which
had put out, fince the
plant was in the ftove.
The earth it ftood in
was very moift all the
time.

IS 00

3°

In OBober 1J25. Mr. Miller took up an
African Briony-root, which when cleared
from the mould, weighed eight ounces i-j
he laid it on a fhelf in the ftove, where it
remained till rfie March following; when
upon weighing he found it had loft of its

weight.

Vegetable Staticks. 27

weight. In April it fhot out 4 branches,
two of which were £| feet long, the other
two were one of them 14 inches, the other
9 inches, in length : Thefe all produced
fair large leaves. It had loft i| ounce in
weight, and in three weeks more it loft
2\ ounces more, and was much withered.

Experiment VI.

Spear-mint being a plant that thrives mod
kindly in water, ( in order the more ac-
curatelv to obferve what water it would
imbibe and perfpire by night and day, in
wet or dry weather ) I cemented at r a plant
of it m. into the inverted fyphon ryxb
( Fig. 2.) The fyphon was \ inch diam. at b9
but larger at r.

I filled it full of water, the plant imbibed
the water fo as to make it fall in the
day (in March) near an inch and half from
b to t, and in the night £ inch from t to i :
but one night, when it was fo cold, as to
make the Thermometer fink to the freezing
point, then the mint imbibed nothing, but
hung down its head; as did alfo the young
beans in the garden, their fap being great-

1 8 Vegetable Stattcks.

ly condenfed by cold. In a rainy day the
mint imbibed very little.

I purfued this Experiment no farther, Dr.
Woodward having long fince, from feveral
curious experiments and obfervations, given
an account in the Philofophical Tranfaftions,
of the plentiful perfpirations of this plant.

Experiment VIL

In Augufl, I dug up a large dwarf Pear-
tree, which weighed 71 pounds 8 ounces;
I fet its root in a known quantity of wa-
ter -y it imbibed 15 pounds of water in ten
hours day, and perfpired at the fame time
15 pounds 8 ounces.

In July and Augujl I cut off feveral
branches of Apple-trees, Pear, Cherry, and
Apricot-trees, two of a fort ; they were of
feveral fizes from 3 to 6 feet long, with pro-
portional lateral branches ; and the tranfverfe
cut of the largeft part of their ftems was
about an inch diameter.

I ftripped the leaves off of one bough of

each fort, and then fet their ftems in fepa-

rate glaffes, pouring in known quantities of

water.

The

Vegetable Stathh. tp

The boughs with leaves on them im-
bibed fome 15 ounces, fome 20 ounces
25 or 30 ounces in 12 hours day, more or
lefs, in proportion to the quantity of leaves
they had ; and when I weighed them at night,
they were lighter than in the morning.

While thofe without leaves imbibed but
one ounce, and were heavier in the even-
ing than in the morning, they having per-
fpired little.

The quantity imbibed by thofe with leaves
decreafed very much every day, the fap-
veffels being probably fhrunk at the tranf-
verfe cut, and too much faturate with wa-
ter, to let any more pafs ; fo that ufually in
4 or 5 days the leaves faded and withered
much.

I repeated the fame Experiment with Elm-
branches, Oak, Ofier, Willow, Sallow,
Afpen, Curran, Goosberry, and Philbert
branches; but none of thefe imbibed fo
much as the foregoing, and feveral forts of
ever-greens very much lefs.

Experiment VIII.
Angufi 15. I cut off a large Rujet-pipin,
with two inches item, and its 12 adjoining

leaves;

30 Vegetable Staticks.

leaves ; I fet the ftem in a little phial of wa-
ter : it imbibed and perfpired in three days
|- of an ounce.

At the fame time I cut off from the fame
tree another bearing twig of the fame length,
with 12 leaves on it, but no apple; it im-
bibed in the fame three days near | of an
ounce.

About the fame time I fet in a phial of
water a fhort ftem of the fame tree, with
two large Apples on it without leaves; they
imbibed near \ ounce in two days.

So in this Experiment, the apple and the
leaves imbibe -f- of an ounce; the leaves
alone near -f , but the two large apples im-
bibed and perfpired but \ part fo much as the
12 leaves; tlien one apple imbibed the ~ part
of what was imbibed by the 12 leaves; there-
fore two leaves imbibe and perfpire as much
as one apple; whence their perfpirations
feem to be proportionable to their furfaces -,
the furface of the apple being nearly equal
to the fum of the upper and under furfaces
of the two leaves.

Whence it is probable, that the ufe of
thefe leaves ( which are placed, juft where
the fruit joins to the tree) is to bring nou-

rimment
4

Vegetable Stattch. 31

rifhment to the fruit. And accordingly I
obferve, that the leaves, next adjoining to
bloffoms, are, in the fpring, very much ex-
panded, when the other leaves, on barren
{hoots, are but beginning to (hoot: And
that all peach leaves are pretty large before
the bloffom goes off: And that in apples
and pears the leaves are one third or half
grown before the bloffom blows : So
provident is nature in making timely pro-
vifion for the nourifliing the yet embryo
fruit.

Experiment IX.

July 15. I cut off two thriving Hop-vines
near the ground, in a thick fhady part of
the garden, the pole ftill ftanding; I ftrip-
ped the leaves off one of thefe vines, and fet
both their ftems in known quantities of
water, in little bottles 5 that with leaves
imbibed in 12 hours day 4 ounces, and that
without leaves \ of an ounce.

I took another hop-pole with its vines
on it, and carried it out of the hop-ground,
into a free open expofurej thefe imbibed
and perfpired as much more as the former

\i Vegetable Staticks.

in the hop- ground: Which is doubtlefs
the reafon why the hop-vines on the out-
fides of gardens, where mod expofed to the
air, are fhort and poor, in comparifon of
thofe in the middle of the ground ; rciz. be-
caufe being much dried, their fibres harden
fooner, and therefore they cannot grow fo
kindly as thofe in the middle of the ground j
which by (hade are always kept moifter, and
more duftile.

Now there being iooo hills in an acre
of hop-ground, and each hill having three
poles, and each pole three vines, the num-
ber of vines will be 9000 -, each of which
imbibing 4 ounces, the fum of all the ounces,
imbibed in an acre in 12 hours day, will
be 36000 ounces, = 15768000 grains =
62047 cubick inches or 202 ale gallons; which
divided by 6272640, the number of fquare
inches in an acre, it will be found, that the
quantity of liquor perfpired by all the hop-
vines, will be equal to an area of liquor,
as broad as an acre, and -—- part of an inch
deep, befides what evaporated from the
earth.

And this quantity of moifture in a kind-
ly ftate of the air is daily carried off, in

a fuffi-

Vegetable Staticks. 3}

a fufficient quantity, to keep the hops in
a healthy (late $ but in a rainy moift ftate
of air, without a due mixture of dry wea-
ther, too much moifture hovers about the
hops, fo as to hinder iri a good meafure the
kindly perfpiration of the leaves, whereby
the flagnating fap corrupts, and breeds mol-
dy fen, which often fpoils vaft quantises of
flourishing hop-grounds. This was the cafe
in the year 1723, when 10 or 14 days al-
moft, continual rains fell, about the latter
half of July, after four months dry weather;
upon which the moft flouriming and pro-
mifing hops were all infected with mold or
fen, in their leaves and fruit, while the then
poor and unpromifing hops efcaped, and pro-
duced plenty ; becaufe they being fmall, did
hot perfpire fo great a quantity as the others;
nor did they confine the perfpired vapour, io
much as the large thriving vines did, in their
fhady thickets.

This rain on the then warm earth made
the grafs moot out as faft as if it were in a
hot-bed ; and the apples grew fo precipi-
tately, that they were of a very flamy conlli-
tution, fo as to rot more remarkably than
had ever been remembred.

D The

34 Vegetable Statkks.

The planters obferve, that when a mold or
fen has once feized any part of the ground, it
foon runs over the whole; and that the grafs,
and other herbs under the hops, are infected
with it.

Probably becaufe the fmall feeds of this
quick growing mold, which foon come to
maturity, are blown over the whole ground:
Which fpreading of the feed may be the
reafon why fome grounds are infected with
fen for feveral years fucceffively ; viz. from
the feeds of the laft year's fen: Might it not
then be advifeable to burn the fenny hop-
vines as foon as the hops are picked, in hopes
thereby to deftroy fome of the feed of the
mold ?

u Mr. Aujlin of Canterbury obferves fen
" to be more fatal to thofe grounds that
fl are low and iheltered, than to the high
" and open grounds; to thofe that are fhelv-
M ing to the North, than to the (helving
" to the South ; to the middle of grounds,
" than to the outrides; to the dry and
11 gentle grounds, than to the moift and ftifF
" grounds. This was very apparent through -
cc out the Plantations, where the land had
tJ the fame workmanfhip and help beflowed

" upon

Vegetable Statich. 35

€c upon it, and was wrought at the fame
lc time j but if in either of thefe cafes there
" was a difference, it had a different effed: ;
" and the low and gentle grounds, that lay
" neglected* were then feen tefs diftempered
" than the open and moift, that were care*
" fully managed and looked after.

" The honey dews are obferved to come
<c about the i ith of June, which by the mid-
<c die of July turn the leaves black, and make
« them ftink."

I have in July (the feafon for fire-blafts*
as the planters call them) feen the vines in
the middle of a hop-ground all fcorehed
up, almoft from one end of a large ground
to the other, when a hot gleam of Sun*
ihine has come immediately after a fhower
of rain ; at which time the vapours are of-
ten feen with the naked eye, but efpecially
with reflecting Telefcopes, to afcend to
plentifully, as to make a clear and diftind:
objedt become immediately very dim and
tremulous. Nor was there any dry gravelly
vein in the ground, along the courfe of this
fcorch. It was therefore probably owing
to the much greater quantity of torch-
ing vapours in the middle than outlides of

D 2 the

$6 Vegetable Staticks.

the ground ; and that being a denfer me-
dium, it was much hotter than a more rare
medium.

And perhaps, the great volume of amend-
ing vapour might make the Sun-beams con-
verge a little toward the middle of the ground,
that being a denfer medium, and thereby
increafe the heat considerably ; for I obferv-
ed, that the courfe of the fcorched hops
was in a line at right angles, to the Sun-
beams about eleven o' clock, at which time
the hot gleam was: The hop-ground was
in a valley which run from South-weft to
North-eaft: And, to the beftof my remem-
brance, there was then but little wind, and
that in the courfe of the fcorch ; but had
there been" fome . other gentle wind, either
North or South, 'tis not improbable but
that the North wind gently blowing the
volume of rinng wreak on the South fide
of the ground, that fide might have been
moft fcorched, and fo vice verfd.

As to particular fire-blafts, which fcorch
here and there a few hop-vines, or one or
two branches of a tree, without damaging
the next adjoining; what Jljlronomers ob-
ferve, may 'hint to us a no very improbable

caufe

Vegetable Staticks. 37

caufe of it; viz. they frequently obferve
(efpecially with the reflecting Telefcopes )
fmall feparate portions of pellucid vapors
floating in the air; which tho' not vifible to
the naked eye, are yet confiderably denfer
than the circumambient air : And vapors of
fuch a degree of denfity may very proba-
bly, either acquire fuch a fcalding heat from
the Sun, as will fcorch what plants they
touch, efpecially the more tender : an effect
which the gardeners about London have too
often found to their coft, when they have
incautioufly put bell-glafTes- over their col-
lyflowers early in a frofty morning, before
the dew was evaporated off them; which
dew being raifed by the Sun's warmth, and
confined within the glafs, did there form a
denfe tranfparent fcalding vapor, which burnt
and killed the plants. Or perhaps, the up-
per or lower furface of thefe tranfparent fe-
parate flying volumes of vapors may, among
the many forms they revolve into, fometimes
approach fo near to a hemifphere, or hemi-
cylinder, as thereby to make the Sun-beams
converge enough, often to fcorch the more
tender plants they fhall fall on : And fome-
times alfo, parts of the more hardy plants

D 3 and

1 8 fegetabh Statkh.

and trees, in proportion to the greater or Iefs
convergence of the Sun's rays.

The learned Boerhaave^ in his Theory of
CkeTniftry, Dr. Shaw's Edition, p. 245. ob-
ferves, " That thofe white clouds which ap-
cc pear in fummer-time, are, as it were, fo
11 many mirrors, and occafion exceffive heat.
}x Thefe cloudy mirrors are fometimes round,
" fometimes concave, polygonous, &c. When
cc the face of heaven is covered with fuch
" white clouds, the Sun mining among
C{ them, muft of neceffity produce a vehe-
Ct ment heat; fincemany of his rays, which
cc would otherwife, perhaps, never touch
" our earth, are hereby reflected to us 5 thus*
ci if the Sun be on one fide, and the clouds
tc on the oppofue one, they will be perfect
ci burning-glaiTe'S.

u I have fometimes (continues he) ob-
ct fcrved a kind of hollow clouds, full of
cx hail and fnow, during the continuance
Ci of which the heat was extreme; fince by
iC fuch condenfation they wrere enabled to
<c reflect: much more ftrongly. After this
cc came a fharp cold, and then the clouds
<c difcharged their hail in great quantity;
:< to which fucceeded a moderate warmth.

" Frozen

Vegetable Staticks. 39

" Frozen concave clouds therefore, by their
" great reflections, produce a vigorous heat,
" and the fame, when refolved, exceflive
« cold/*

Whence we fee that blafts may be occa-
fioned by the reflections of the clouds, as
well as by the above mentioned refraction of
denfe tranfparent vapors.

July 21. I obferved that at that feafon
the top of the Sunflower being tender, and
the flower near beginning to blow, if
the Sun rife clear, the flower faces towards
the Eaft ; and the Sun continuing to fhine,
at noon it faces to the South ; and at fix in
the evening to the Weft: And this not by
turning round with the Sun, but by nuta-
tion; the caufe of which is, that the fide of
the ftem next the Sun perfpiring molt, it
fhrinks, and this plant perfpires much.

I have obferved the fame in the tops of
Jerufalem-artichokes, and of garden- beanss
in very hot Sun-fhine.

Experiment X.

July 27. I fixed an Apple-branch, my 3
feet long, \ inch diameter, full of leaves,
D 4 and

40 Vegetable Staticks.

and lateral {hoots to the tube /, 7 feet
long, JL of an inch diameter, {Fig. 3.) I fil-
led the tube with water, and then immerfed
the whole branch as far as over the lower
end of the tube, into the veflel uu full of
water.

The water fubfided 6 inches the firft two
hours, (being the firft filling of the fap-vef-
fels) and 6 inches the following night, 4
inches the next day ; and 2 + ^ the following
night.

The third day in the morning I took the
branch out of the water, and hung it, with
the tube affixed to it, in the open air; it im-
bibed this day 27 +~ inches in 12 hours

This experiment fhews the great power
of perfpiration; fince, when the branch was
immerfed in the veflel of water, the 7 feet
column of water in the tube, above the fur-
face of the water, could drive very little
thro' the leaves, till the branch was expofed
to the open air.

This alfo proves, that the perfpiring mat-
ter of trees is rather actuated by warmth,
and 10 exhaled, than protruded by the force
of the lap upwards.

And

Vegetable Statich. 41

And this holds true in animals, for the
perfpiration in them is not always greateft in
the greateft force of the blood ; but then often
leaft of all, as in fevers.

I have fixed many other branches in the
fame manner to long tubes, without immerf-
ing them in water ; which tubes, being filled
with water, I could fee precifely, by the
defcent of the water in the tube /, how faft
it perfpired off, and how very little perfpired
in a rainy day, or when there were no leaves
on the branches.

Experiment XI.

Aug. 17. At 1 1 a : m, I cemented to
the tube ab (Fig. 4.) 9 feet long, and \ inch
diameter, an Apple-branch d> 5 feet long, £
inch diameter 5 I poured water into the tube,
\vhich it imbibed plentifully, at the rate of
3 feet length of the tube in an hour. At
1 o' clock I cut off the branch at c, 13 inches
below the glafs tube. To the bottom of
the remaining ftem I tied a glafs ciftern zy
covered with ox-gut, to keep any of the
water which dropped from the ftem cb, from
evaporating. At the fame time I fet the

branch

4& Vegetable Staticks.

branch d r, which I had cut off in a known
quantity of water, in the veffel x (Fig. 5.).
The branch in the veffel x imbibed 18 ounces
of water in 18 hours day and 12 hours night;
in which time only 6 ounces of water had
paffed thro' the (tern c by (Fig. 4.) which had
a column of water 7 feet high, prefling upon
it all the time.

This again fhews the great power of per-
fpiration; to draw thrice as much water,
in the fame time, through the long (lender
parts of the branch r, (Fig. 5.) as was preffed
thro' a larger (lem cb (Fig. 4.) of the fame
branch; but 13 inches long, with 7 feet
preffure of water upon it, in the tube a b.

I tried in the fame manner another Ap-
ple-branch, which in 8 hours day imbibed
20 ounces, while only 8 ounces paffed thro'
the item <rZ>, (Fig. 4.) which had the column
of water on it.

The fame I tried with a quince branch,
which in 4 hours day imbibed 2 ounces'-f-i.,
while but.*, ounce paffed thro' the (lem cb
(Fig. 4.) which had 9 feet weight of water
prelfmg on it.

Xcie, All thefe (under this experiment
11.) were made the firft day> before the

(lem

Vegetable Staticks. 45

ftem could be any thing faturate with water,
or the fap-veflels fhrunk fo as to hinder its
paffage.

Experiment XII.

I cut off from a dwarf Apple-tree e w the
top of the branch /, (Ffg. 6.) which was an
inch diameter, and fixed to the ftem /, the
glafs tube lb: then I poured warer into the
tube, which the branch would imbibe, at
fuch a rate as to drink down 2 or 3 pints in
a day, efpecially if I fucked with my mouth
at the top of the tube /5, fo as that a few air-
bubbles were drawn out of the ftem /-, then
jthe water was imbibed fo faft, that if I im-
mediately fcrewed on the mercurial gage,
mryz, the mercury would be drawn up
to r, 12 inches higher than in the other
leg.

At another time I poured into the tube /,
fixed to a golded Renate-tree, a quart of
high rectified fpirit of wine camphorated,
which quantity the ftem imbibed in 3 hours
fpace ; this killed one half of the tree : this
I did to try if I could give a flavour of cam-
phire to the apples which were in great

plenty

44 Vegetable Statkks.

plenty on the branch. I could not perceive

any alteration in the tafte of the apples, tho'

they hung feveral weeks after; but the fmell

of the camphire was very ftrong in the ftalks

of the leaves, and in every part of the dead

branch.

I made the fame experiment on a vine,
with ftrongly-fcented orange -flower- water;
the event was the fame, it did not penetrate
into the grapes, but very fenfibly into the
wood and ftalks of the leaves.

I repeated the fame experiment on two
diftant branches of a large Catharine pear-
tree, with ftrong decoctions of Saffafrafs, and
of Elder-flowers, about 30 days before the
pears were ripe ; but I could not perceive any
tafte of the decoctions in the pears.

Tho' in all thefe cafes the fap-veffels of
the ftem were ftrongly impregnated with a
good quantity of thefe liquors; yet the capil-
lary fap-veflels near the fruit were fo fine,
that they changed the texture of, and aflimi-
lated to their own fubftance, thofe high-tafted
and perfumed liquors; in the fame manner
as grafts and buds change the very different
fap of the ftock to that of their own fpecifick
nature.

This

46 Vegetable Staticks.

it did not rife at all in the tube, tho' the
top of the ftem was wet: I then filled the
tube with water, but it paffed freely into the
veflel x.

Experiment XV.

Sept. 10. 2+ jl feet from the ground, I
cut off the top of a half ftandard Duke Cherry-
tree againft a wall, and cemented on it the
neck of a Florence flask fy (Fig. 8.) and
to that flask neck a narrow tube g, five feet
long, in order to catch any moifture that
fhould arife out of the trunk y , but none
arofe in four hours, except a little vapor that
was on the flask's neck.

I then dug up the tree by the roots, and
fet the root in water, with the glaffes affixed
to the top of the ftem j after feveral hours
nothing rofe but a little dew, which hung
on the infide off, yet it is certain by many
of the foregoing experiments, that if the
top and leaves of this tree had been on,
many ounces of water would in this time
have palled thro' the trunk, and been eva-
porated thro' the leaves.

I have

Vegetable Statlch. 4?

I have tried the fame experiment with
feveral vine branches cut off, and fet in Water
thus, but no water rofe into/.

Thefe three laft experiments all (hew, that
tho' the capillary fap-veffels imbibe moifture
plentifully; yet they have little power to
protrude it farther, without the affiftance of
the perfpiring leaves, which do greatly pro-
mote its progrefs.

Experiment XVI.

In order to try whether any fap rofe in
the winter, I took in January feveral par-
cels of Filberd-fuckers, Vine-branches, green
Jeflamine-branches, Philarea and Laurel-
branches, with their leaves on them -, and dip-
ped their tranfverfe cuts in melted cement, to
prevent any moifture's evaporating thro' the
wounds ; I tied them in feparate bundles, and
weighed them.

The Filberd-fuckers decreafed in 8 days,
(fome part of which were very wet, but the
laft 3 or 4 days drying winds) the nth part
of their whole weight.

The Vine-cuttings in the fame time the

rt Part-

The

48 Vegetable Statich.

The JelTamine in the fame time the £ part.

The Philarea decreafed the \ part in five
days.

The Laurel the ^part in 5 days, and more.

Here is a confiderable daily wafte of fap,
which muft therefore neceffarily be fupplied
from the root; whence ins plain, that fome
fap rifes all the winter, to fupply this con-
tinual wafte, tho' in much lefs quantity than
in fummer.

Hence we fee good reafon why the Ilex
and the Cedar of Libanus (which were graft-
ed the firft on an Englijh Oak, the other on the
Larix) were verdant all the winter, notwith-
standing the Oak and Larix leaves were de-
cayed and fallen off; for tho', when the win-
ter came on, there did not fap enough rife
to maintain the Oak and Larix leaves, yet by
this prefent experiment we fee, that fome
fap is continually rifing all the winter ; arid
by experiment the 5th on the Limon-tree,
and by feveral other the like experiments, on
many forts of ever-greens, we find that they
perfpiring little, live and thrive with little
nourishment; the Ilex and Cedar might
well therefore continue green all the win-
ter, notwithstanding the leaves of the trees

they

Vegetable Stattch. 49

they were grafted on fell off. See the late
curious and induftrious Mr. Fairchild's ac-
count of thefe graftings in Mr. Millers
Gardeners Didi.ionary ; vide Sap.

Experiment XVII.

Having by many evident proofs in the
foregoing experiments feen the great quan-
tities of liquor that were imbibed and per-
fpired by trees, I was dcfirous to try if I
could get any of this perfpiring matter ;
and in order to it, I took feveral glafs chy-
mical retorts, b a p ( Fig. 9. ) and put the
boughs of feveral forts of trees, as they
were growing with their leaves on, into
the retorts, flopping up the mouth p of the
retorts with bladder. By this means I got
feveral ounces of the perfpiring matter of
Vines, Fig-trees, Apple-trees, Cherry-trees,
Apricot and Peach-trees ; Rue, Horfe-radilh,
Rheubarb, Parfnip, and Cabbage leaves:
the liquor of all of them was very clear,
nor could I difcover any different tafte in
the feveral liquors: But if the retort ftand
expofed to the hot fun, the liquor will
tafte of the clodded leaves. Its fpecifick
gravity was nearly the fame with that of

E common

jo Vegetable Staticks.

common water; nor did I find many air-
bubbles in it, when placed in the exhaufted
receiver, which I expected to have found ;
but when referved in open viols, it ftinks
fooner than common water; an argument
that it is not pure water ; but has fome he-
terogeneous mixtures with it.

I put alfo a large Sun-flower full-blown,
and as it was growing, into the head of a
glafs-flill, and put its roftrum into a bottle,
by which means there diftilled a good quan-
tity of liquor into the bottle. It will be
very eafy in the fame manner to colled: the
perfpirations of fweet-fcented Flowers, tho*
the liquor will not long retain its grateful
odor, but ftink in few days.

Experiment XVIII.

In order to find out what ftores of moi-
flure nature had provided in the earth,
(againft the dry fummer feafon) that might
anfwer this great expence of it, which is fo
neceffary for the produ&ion and fupport of
vegetables 3

July$ 1. *724- l dug up a cubick foot
earth, in an alley which was very little
trampled on; it weighed (after deducing
the weight of the containing veffel ) 104

pounds

3*lA

/>. 5<?

J.C.

Vegetable Statich. 5 1

pounds 4 ounces + f. A cubick foot of
water weighs nearly 62- pounds, which is
little more than half the fpecifick gravity
of earth. This was a dry feafon, with a
mixture of fome few fhowers, fo that the
grafs-plat adjoining was not burnt up.

At the fame time I dug up another cubick
foot of earth, from the bottom of the for-
mer; it weighed 106 pound 6 ounces -j- 4-.

I dug up alfo a third cubick foot of earth,
at the bottom of the two former ; it weighed
in pounds ~{~-j.

Thefe three feet depth were a good brick
earth, next to which was gravel, in which
at 2 feet depth, viz. 5 feet below the fur-
face of the earth, the fprings did then run.

When the firft cubick foot of earth was
fo dry and dufty, as to be unfit for vegeta-
tion, I weighed it, and found it had loft
6 pounds ~j- n ounces, or 184 cubick in-
ches of water, near -§• part of its bulk. '

Some days after, the fecond cubick foot
being drier than either the firft or third,
was decreafed in weight 10 pounds.

The third cubick foot, being very dry
and dufty, had loft 8 pounds 8 ounces, of
247 cubick inches, viz. \ part of its
bulk.

E 2 Now

54 Vegetable Staticks.

In a long dry fcafott, therefore, efpecially
within the Tropicks, we muft have recourfe
for fufficienc moifturc (to keep Plants and
Trees alive) to the moift ftrata of earth,
which lie next below that in which the
roots are. Now moift bodies always com-
municate of their moifturc to more dry
adjoining bodies; but this flow motion of
the afcent of moift u re is much accelerated
by the Sun's heat to confiderable depths in
the earth, as is probable from the following
20th Experiment.

Now 1 80 grains of Dew filling in one
night, on a circle of a foot diameter, =
113 fquare inches; thefe 180 grains being
equally fpread on this furface, its depth

will be 77 0 part of an inch =

r 113x254

I found the depth of Dew in a winter night
to be the -^ part of an inch ; ib that, if we
allow 159 nights for the extent of the fum-
tner's Dew, it will in that time arife to one
inch depth. And reckoning the remaining
206 nights for the extent of the winter's
Dew, it will produce 2.28 inches depth,
which makes the Dew of the whole year
amount to 3.28 inches depth.

And the quantity which evaporated in a
ftii ;•..;.. ;:ci's day frqm the fame furface, be-
ing

Vegetable Statkks. 5 5

ing 1 ounce + 282 grains, gives ■£$ part of
an inch depth for evaporation, which is
four times as much as fell at night.

I found, by the fame means, the evapo-
ration of a winter's day to be nearly the
fame as in a fummer's day 5 for the earth
being in winter more faturate with mos
fture, that excels of moifture anfwers to the
excefs of heat in fummer.

Nic. Cruquius, NQ 381 of the Philofo-
phical Tranfadtions, found that 28 inches
depth evaporated in a whole year from wa-
ter, /. e. ~z °f an inch each day, at a mean
rate ; but the earth in a fummer's day evapo-
rates -|~ of an inch ; fo the evaporation of
a furface of water, is to the evaporation of
a furface of earth in fummer, as Tj to 7V .

The quantity of Rain which falls in a
year is at a medium 22 inches: The quan-
tity of the earth's evaporation in a year is
at leaft 9.15 inches, fince that is the rate,
at which it evaporates in a fummer 's day :
From which 9.15 inches, are to be deduc-
ed 3.39 inches for circulating daily Dew;
there remain 5.76 inches, which 5.76 inches
dedudled from the quantity of Rain which
falls in a year, there remain at leaft 16.24

E 4 inches

5 6 Vegetable Staticls.

inches depth, to replenilh the earth with
moiilure ior vegetation, and to fupply the
Springs and Rivers.

In the cafe of the hop-ground, the eva-
poration from the hops may be confidered
only for three months atT£7 part of an inch
each day, which will be T9o of an inch ;
but before we allowed 5.76 inches vapour to
evaporate from the furface of the ground,
which added to T% inch, gives 6.66 inches
which is the utmoft that can be evaporated
from a furface of hop-ground in a year. So
that of 22 inches depth of rain, there re-
main 15.34 inches to fupply fprings; which
are more or lefs exhausted, according to
the drinefs or wetnefs of the year. Hence
we find that 22 inches depth of rain in a
year is fufficient for all the purpoles of na-
ture, in fuch flat countries as this about
tfeddington near Hampton-Court. But in
the hill countries, as in Lancafiirc, there
falls 42 inches depth of rain-water; from
which deducting 6.66 inches for evaporation,
there remains 35.34 inches depth of water
for the fprings ; befides great fupplies from
much more plemiful dews, than fall in plain
countries: Which vail ftores feem fo abun-
dantly fufficient to anfwer the great quantity

Vegetable Statuks. 57

of water, which is conveyed away, by fprings
and rivers, from thofe hills, that we need
not have recourfe, for fupplies, to the great
Abyfs, whofe furface, at high water, is fur-
mounted fome hundreds of feet by ordi-
nary hills, and fome thoufands of feet by
thofe vaft hills from whence the longeft
and greateft rivers take their rife. See vol. II.

A *S7-

Experiment XX.

I provided me fix Thermometers, whofe
items were of different lengths, viz. from
1 8 inches to 4 feet. I graduated them all by
one proportional fcale, beginning from the
freezing point ; which may well be fixed as
the utmofl boundary of vegetation on the fide
of cold, where the work of vegetation ceafes,
the watry vehicle beginning then to condenfe
and be fixed •, tho' many trees, and fome plants
as grafs, mofs, &c. do furvive it ; yet they
do not vegetate at that time.

The greateft degree of heat, which I at
firft marked on my Thermometers, was equal
to that of water, when heated to the great-
eft degree that I could bear my hand in it,
without ftirring it about. But finding by
experience, that plants can endure, with-
out

58 Vegetable Staticks.

out prejudice, a fomething greater heat
than this, I have pitched upon the heat in
which melted wax fwimming on hot water
firft begins to coagulate ; for fince a greater
heat than this will diflblve the wax, which
is a vegetable fubftance, this may therefore
well be fixed as the utmoft boundary of ve-
getation, on the warm fide ; beyond which
plants will rather fade than vegetate, fuch
degree of heat feparating and difperfing, in-
ftead of congregating and uniting the nu-
tritive particles.

This fpace I divided into 100 degrees
on all the Thermometers, beginning to num-
ber from the freezing point. Sixty-four of
thefe degrees are nearly equal to the heat of
the blood of animals -y which I found by
the rule given in the Philofophical Tranf-
a&ions, Vol. II. p. 1. of Mr. Mottes Abridg-
ment, which is fuppofed to be Sir Ifaac
Nrwtotii eftimate ; viz. by placing one of
the Thermometers in water heated to the
greateft degree that I could bear my hand
in it ftirring it about : And which I was
further affured of, by placing the ball of my
Thermometer in the flowing blood of an ex-
piring Ox. The heat of the blood to that
of boiling water is as 14.27 to 33.

. By

Vegetable Stattcks. 59

By placing the ball of one of thefe Ther-
mometers in my bofom, and under an arm-
fit, I found the external heat of the body
54 of thefe degrees. The heat of milk, as
it comes from the Cow, is equal to 55 de-
grees, which is nearly the fame with that
for hatching of eggs -, the heat of urine
58 degrees. The common temperate point
in thermometers is about 18 degrees.

The hotteft Sun-fhine in the year 1727
raifed the fpirit in the Thermometer expofed
to it, 88 degrees j a heat 24 degrees greater
than that of the blood of animals : And
tho' plants endure this, and a confiderably
greater heat within the Tropicks, for fome
hours each day, yet the then hanging of the
leaves of many of them fhews that they
could not long fubfift under it, were they
not frequently refreshed by the fucceeding
evening and night.

The common noon-tide heat in the Sun
in July is about 50 degrees : The heat of
the air in the {hade in July is at a medium
38 degrees. The May and June heat is from
17 to 30 degrees: the mod genial heat for
the generality of plants, in which they flou-
rish moft, and make the greatefl progrefs in
their growth. The autumnal and vernal

heat

60 Vegetable Staticks,

heat may be reckoned from 10 to 20 de-
grees : The winter heat from the freezing
point to 10 degrees.

The fcorching heat of a hot-bed of horfe-
dung, when too hot for plants, is equal to
85 degrees and more; and hereabout is pro-
bably the heat of blood in high fevers.

The due healthy heat of a hot-bed of
horfe-dung, in the fine mold, where the
roots of thriving Cucumber-plants were,
in Feb. was equal to 56 degrees, which is
nearly the bofom heat, and that for hatch-
ing of eggs. The heat of the air under the
glais-frame of this hot-bed was equal to
34 degrees; fo the roots had 26 degrees
more heat than the plants above ground.
The heat of the open air was then 17 de-
grees.

It is now grown a common and very rea-
fonable praclice, to regulate the heat of
ftoves and green-houfes, by means of Ther-
mometers hung up in them. And for
greater accuracy, many have the names of
fome of the principal exoticks written up-
on their Tiber mometers^ over-againft the fe-
veral degrees of hear, which are found by
experience to be propereft for them. And
I am informed that many of the moft cu-
rious

Vegetable Staticks. 6\

rious Gardeners about London have agreed
to make ufe of Thermometers of this fort ;
which are made by Mr. John Fowler in
Swithirfs- Alley, near the Royal-Exchange*
which have the names of the following
plants, oppofite to their refpeftive moft
kindly degrees of heat ; which in my Ther-
mometers anfwer nearly to the following de-
grees of heat above the freezing point, viz.
Melon-thiftle 31, Ananas 29, Piamento 26,
Euphorbium 24, Cereus 2J-, Aloe 19, In-
dian-fig i6~, Ficoides 14, Oranges 12^ Myr-
tles 9.

Mr. Boyle, by placing a Thermometer in
a cave, which was cut ftrait into the bot-
tom of a cliff, fronting the Sea, to the depth
of 130 feet, found the fpirit flood, both in
winter and fummer, at a fmall divifion above
temperate; the cave had 80 feet depth
of earth above it. Boyle's Works, Vol. III.
p. 54.

I marked my fix Thermometers numeri-
cally, 1, 2, 3, 4, 5, 6. The Thermometer
numb. 1, which was fhorteft, I placed with
a South afpedt, in the open air; the ball
of numb. 2, I fet two inches under ground ;
that of numb. 3, four inches under ground;
numb. 4, 8 inches; numb. 5,1 6 inches; and

numb,

6 i Vegetable Staticks.

numb. 6, 24 inches underground. And that
the heat of the earth, at thefe feveral depths,
may the more accurately be known, it is
proper to place near each Thermometer a
glafs-tube fealed at both ends, of the fame
length with the ftems of the feveral Ther-
mometers -, and with tinged fpirit of wine
in them, to the fame height, as in each
correfponding Thermometer ; the fcale of
degrees, of each Thermometer ■, being mark-
ed on a Aiding ruler, with an index at the
back of it, pointing to the correfponding
tube. When at any time an obfervation is
to be made, by moving the index, to point
to the top of that fpirit in the tube, an ac-
curate allowance is hereby made, for the
very different degrees of heat and cold, on
the ftems of the Thermometers, at all depths ;
by which means the fcale of degrees will
fhew truly the degrees of heat in the balls
of the Thermometers, and confequently, the
refpe&ive heats of the earth at the feveral
depths where they are placed. The ftems
of thefe Thermometers, which were above
ground, were fenced from weather and in-
juries by fquare wooden tubes \ the ground
they were placed in was a brick earth in
the middle of my garden.

Vegetable Staticks. 63

July 30. I began to keep a regifter of
their rife and fall. During the following
month of Augujl, I obferved that when
the fpirit in the thermometer, numb. 1,
( which was expofed in the Sun ) was about
noon rifen to 48 degrees, then the fecond
Thermometer was 45 degrees, the fifth 33,
and the fixth 3 1 5 the third and fourth at
intermediate degrees. The fifth and fixth
Thermo??ieter kept nearly the fame degree
of heat both night and day, till towards
the latter end of the month ; when, as the
days grew fhorter and cooler, and the nights
longer and cooler, they then fell to 25 and
27 degrees.

Now, fo con fider able a heat of the Sun,
at two feet depth, under the earth's furface,
muft needs have a ftrong influence in rail-
ing the moifture at that and greater depths ;
whereby a very great and continual wreak
muft always be afcending, during the warm
fummer feafon, by night as well as day; for
the heat at two feet depth is nearly the fame
night and day, the impulfe of the Sun-
beams giving the moifture of the earth a
brifk undulating motion, which watery par-
ticles, when feparated and rarefied by heat,
do afcend in the form of vapour : And the

vigour

^4 Vegetable Staticks.

vigour of warm and confined vapour (fuch
as is that which is i, 2, or 3 feet deep in
the earth) muft be very confiderable, fo as
to penetrate the roots with fome vigour;
as we may reafonably fuppofe, from the
vaft force of confined vapour in /Eolipiles,
in the digefter of bones, and the engine to
raife water by fire. See. Vol. II. p. 259.

If plants were not in this manner fup-
plied with moifture, it were impoflible for
them to fubfifl under the fcorching heats
within the Tropicks, where they have no
rain for many months together: For tho'
the dews are much greater there, than in
thefe more Northern climates ; yet doubtlefs,
where the heat io much exceeds ours, the
whole quantity evaporated in a day there,
does as far exceed the quantity that falls
by night in dew, as the quantity evaporat-
ed here in a fummer's day, is found to ex-
ceed the quantiry of dew which falls in the
night. But the dew, which fidls in a hot
fummer feafon, cannct poflibly be of any
benefit to the roots of trees; becaufe it is
remanded back from the earth by the fol-
lowing day's heat, before {o fmall a quantity
of moifture can have foaked to any con-
fiderable depth. The great benefit there-
fore

Vegetable Staticks. 6j

fore of dew, in hot weather, muft be, by
being plentifully imbibed into vegetables ;
thereby not only refrefhing them for the
prefent, but alfo furnifhing them with a
frefh fupply of moifture towards the great
expences of the fucceeding day.

'Tis therefore probable, that the roots of
trees and plants are thus, by means of the
Sun's warmth, conftantly irrigated with
frefh fupplies of moifture; which, by the
fame means, infinuates itfelf with fome
vigour into the roots. For, if the moifture
of the earth were not thus actuated, the roots
muft then receive all their nourifhment
merely by imbibing the next adjoining
moifture from the earth ; and confequently
the fhell of earth, next the furface of the
roots, would always be confiderably drier,
the nearer it is to the root; which I have
not obferved to be fo. And by Exper. 1 8,
and 19, the roots would be very hard put to
it to imbibe fufficient moifture in dry fum-
mer weather, if it were not thus conveyed
to them by the penetrating warmth of the
Sun : Whence by the fame genial heat, in
conjunction with the attraction of the ca-
pillary fap-vefTels, it is carried up thro* the
bodies and branches of vegetables; and
F thence

66 Vegetable Staticks.

thence pa (Ting into the leaves, it is there
moft vigoroufly acted upon, in thofe thin
plates, and put into an undulating motion,
by the Sun's warmth, whereby it is moft
plentifully thrown off, and perfpired thro'
their furface ; whence, as foon as it is dif-
intangled, it mounts with great rapidity in
the free air.

But when, towards the latter end of
Oflober, the vigour of the Sun's influence is
fo much abated, that the firft Thermometer
was fallen to 3 degrees above the freezing
point, the fecond to 10 degrees, the fifth
to 14 degrees, and the fixth Thermometer to
16 degrees j then the brisk undulations of
the moifture of the earth, and alfo of the
afcending fap, much abating, the leaves faded
and fell off.

The greateft degree of cold, in the fol-
lowing winter, was in the firft 12 days of
November ; during which time, the fpirit in
the firft Thermometer was fallen 4 degrees
below the freezing point, the deepeft Ther-
mometer 10 degrees, the ice on ponds was
an inch thick. The Sun's greateft warmth,
at the winter folftice, in a very ferene, calm,
frofty-day, was, againft a South afpedl of a
wall, 19 degrees and in a free open air, but

11 de-

Vegetable Staticks. 67

1 1 degrees above the freezing point. From
the 10th of January to the 29th of March
was a very dry feafon ; when the green
Wheat was generally the fineft that was
ever remembred. But from the 29th of
March J 72 5, to the 29th of September fol-
lowing, it rained more or lefs almoft every
day, except ten or twelve days about the
beginning of July, and that whole feafon
continued fo very cool, that the fpirit in
the firft Thermometer rofe but to 24 degrees >
except now and then in a fhort interval of
Sunfhine ; the fecond only to 20 degrees ;
the fifth and fixth to 24 and 23 degrees,
with very little variation: So that during
this whole fummer, thofe parts of roots which
were two feet under ground, had three or
four degrees more warmth than thofe which
were but two inches under ground : And at
a medium the general degree of heat thro*
this whole fummer, both above and under
ground, was not greater than the heat of
the middle of the preceding September.

The year 1725 having been, both in this
ifland, and in the neighbouring nations, moft
remarkably wet and cold; and the year
J723, in the other extreme, as remarkably
dry, as ha« ever been known ; it may not
Fa be

68 Vegetable Statich.

be improper here to give a fhort account of*

them, and the influence they had on their

productions.

Mr. Miller, in the account which he
took of the year 1723, obferved, " That the
<c winter was mild and dry, except that in
" February it rained almoft every day, which
" kept the fpring backward. March, April,
" May, June, to the middle of July, proved
" extremely dry, the wind North-eaft moft
" part of the time. The fruits were for-
<c ward, and pretty good ; but kitchen-ftuflf,
<c efpecially Beans and Peas, failed much.
<c The latter half of July the weather proved
" very wet, which caufed the fruits to
C£ grow fo faft, that many of them rotted
" on the trees; fo that the autumn fruits
" were not good. There were great plenty
cc of Melons, very large, but not well tailed.
" Great plenty of Apples -, many kinds of
" fruits bloffomed in Augujl, which pro-
<c duced many fmall Apples and Pears in
c< October, as alfo Strawberries and Rafp-
<c berries in great plenty. Wheat was good,
" little Barley, much of which was very un-
€C equally ripe, fome not at all, becaufe fown
<c late, and no timely rain to fetch it up.
£ There were innumerable Wafps -, how it

" fared

Vegetable Staticks. 69

" fared with the hops this dry year, is men-
'f tioned under Exper. 9.

" The following winter, 1724, proved
" very mild ; the fpring was forward in Ja-
" nuary, fo that the Snow-drops, Crocus's,
" Polyanthus's, Hepaticas, and Narcijfuss,
C{ were in flower. And it was remarkable,
cc that moft of the Colliflower-plants were
■•" deftroyed by the mildew, of which there
u was more, all this winter, than had been
" known in the memory of man. In Fe-
cc bruary we had cold fharp weather, which
" did fome damage to the early crops, and
" it continued variable till April, fo that
" much of the early Wall-fruit was cut off:
ct And again the 6th of May was a very
<c (harp froft, which much injured tender
c< plants and fruits. The fummer in general
fcC was moderately dry, the common fruits
cc proved pretty good, but late: Melons
c< and Cucumbers were good for little;
*' Kitchenrftuff was in great plenty in the
€c markets/'

In the very wet and cold year 1725, moft
things were a full month backwarder than
ufual. Not half the Wheat in by the 24th
of Augujl, in the Southern parts of England-.
very few Melons or Cucumbers, and thofe

F 3 no£

?o Vegetable Staticks.

not good. The tender Exoticks fared but ill;
fcarce any grapes, thofe fmall, and of very
unequal fizes, on the fame bunch, not ripe ;
Apples and Pears green and infipid ; no fruit
nor products of the ground good, but crude:
Pretty good plenty of Wheat, tho' coarfe,
and long ftraw ; Barley coarfe, but plenty
of it in the uplands. Beans and Peas mod
flourifhing and plentiful ; few Wafps or
other infects, except Flies on hops. Hops
were very bad thro' the whole kingdom. Mr.
Aujlin of Canterbury fent me the following
particular account, how it fared with them
there \ where they had more than at Farnham,
and moft other places, viz.

Cl At mid- April not half the fhoots ap-
<< peared above ground ; fo that the plant-
<c ers knew not how to pole them to the
" beft advantage. This defect of the flioot,
«c upon opening the hills, was found to be
" owing to the multitude and variety of
" vermin that lay preying upon the root;
<c the increafe of which was imputed to
<c the long and almoft uninterrupted feries
<c of dry weather, for three months pafl :
<c Towards the end of April, many of the
?c hop-vines were infefted with the Flies.
* About the 20th of May there was a

« very

Vegetable Statich. 71

u very unequal crop, fome Vines being
" run feven feet, others not above three or
" four feet -> fome juft tied to the poles, and
<c fome not vifible : And this difpropor-
li tionate inequality in their lize continued
" through the whole time of their growth.
u The Flies now appeared upon the leaves
(< of the forwarded Vines, but not in fuch
'* numbers here, as they did in moft other
'* places, About the middle of Juney the
u Flies increafed, yet not fo as to endanger
*c the crop 5 but in diftant plantations they
*c were exceedingly multiplied, fo as to
a fwarm towards the end of the month.
** June 27th fome fpecks of Fen appeared :
" From this day to the 9th of July, was
" very fine dry weather. At this time,
" when it was faid that the Hops in moft
u ocher parts of the kingdom looked black
" and fickly, and feemed pail: recovery, ours
*f held it out pretty well, in the opinion
IC of the moft skilful planters. The great
" leaves were indeed difcoloured, and a lit-
M tie withered, and the Fen was fomewhat
" increafed, From the 9th of July to the
cc 23d the Fen increafed a good deal, but
<c the Flies and Lice decreafed, it raining
M daily much : In a week more the Fen,
F 4 " which

71 Vegetable Staticks.

" which feemed to be almoft at a (land,
u was confiderably increafed, efpecially in
M thofe grounds where it firft appeared.
u About the middle of Augtijl, the Vines
<: had done growing, both in ftem and
" branch ; and the forwarded began to be
*' in Hop, the reft in Bloom : The Fen
" continued fpreading, where it was not
€t before perceived, and not only the leaves,
t% but many of die Burs alfo were tainted
cz with it. About the 20th of Aiigujl,
u fome of the Hops were infected with the
" Fen, and whole branches corrupted by it.
u Half the Plantations had hitherto pretty
" well efcaped, and from this time the Fen
" increafed but little: But feveral days vio-
<c lent wind and rain, in the following
cc week, fo difordered them, that many of
(i them began to dwindle, and at laft came
c: to nothing 5 and of thofe that then re.
11 mained in bloom, fome never turned to
11 Hops; and of the reft which did, many
" of them were fo fmall, that they very
iC little exceeded the bignefs of a good
lc thriving Bur. We did not begin to pick
" till the eighth of September, which was
" eighteen days later than we began the
'f year before. The crop was little above

" two

Vegetable Statich. 7$

« two hundred on an acre round, and not
" good." The beft Hops fold this year
at Way -Hill Fair for fixteen pounds the
hundred.

The almoft uninterrupted wetnefs and
coldnefs of the year 1725, very much af-
fe&ed the produce of the Vines the enfu-
ing year ; and we have fufficient proof from
the obfervations that the four or five laft
years afford us, that the moifture or drinefs
of the preceding year has a confiderable in-
fluence on the productions of the Vine the
following year. Thus in the year 1722,
there was a dry feafon, from the beginning
of Augujl thro' the following autumn and
winter, and the next fummer there was
good plenty of Grapes. The year 1723 was
a remarkably dry year, and in the following
year 1724, ihere was an unufual plenty of
Grapes. The year 1724 was moderately
dry, and the following fpring the Vines
produced a fufficient quantity of bunches;
but by reafon of the wetnefs and coldnefs
of the year T725, they proved abortive, and
produced hardly any Grapes. This very
wet year had an ill effect, not only upon its
own productions, but alfo on thofe of the
following year: For notwithftanding there

,was

74 Vegetable Staticks.

was a kindly fpring, and blooming feafon, in
the year 1726, yet there were few bunches
produced, except here and there in fome
very dry foils. This many Gardeners fore-
faw early, when, upon pruning of the Vines,
they obferved the bearing (hoots to be crude
and immature j which was the reafon why
they were not fruitful. The firft crop thus
failing in many places, the Vines produced
a fecond, which had not time to come to
maturity before the cold weather came on.

Mr. Miller fent me the following ac-r
count of the long and fevere winter in the
year 1728; and of the effedl it had on the
plants and trees in this and the neighbour-
ing countries, 'viz.

" The autumn began with cold North
H and Eaft winds, and early in November
" the nights were generally frofty ; tho' the
" froft did not enter the ground deeper than
" the fucceeding days thaw'd. But towards
" the end of November the winds blew ex-
" tremely cold from the North, which was
c< fucceeded by a great fnow, which fell in
M fuch quantities in one night, as to break
<c off large arms and tops of many ever-green
" trees, on which it lodged.

« After

Vegetable Stathks. 75

*c After the fnow was down, it began to
<c freeze again, the wind continuing to
« blow from the North ; the days were
" dark and cloudy for fome time, bucaf-
" terwards it cleared up, and the Sun ap*
cc peared almoft every day, which melted
■" the fnow where expofed to it, whereby
P the froft penetrated the deeper into the
ic ground. It was pbfervable, that during
" thefe clear days, a great mift or vapour
" appeared in the evenings, floating near
" the furface of the ground, till the cold
P* of the night came on, when it was fud-
" denly condenfed and difappeared ; the
P nights now began to be extreme fharp.
<c The fpirit in the Thermometer was 18 de-
" grees below the freezing point, (as mark-
" ed upon Mr. Fowler's Thermometers) and
*c it was at this time that vaft quantities of
" Lauriiftimis'sy Phyllyreas, Alaternuss^ Rofe-
" wary, and other tender plants began to
P fufferj efpecially fuch as were trimm'd
" up to naked items, or had been clipp'd
" late in the fummer. At this time alfo
P there were great numbers of trees diC-
" barked, fome of which were of a confi-
M derable bulk ; particularly two Weft-India
U Plane Trees^ in the Phyfick Garden at

P Chelfea,

7 6 Vegetable Statich.

<< Chelfea, which are near forty feet high.
<c and a fathom in circumference, were dif-
" barked almoft from the bottom to the
" top, on the weft fide of the trees. And
" in a nurfery belonging to Mr. Francis
il Hurji, great numbers of large Pear-trees
<c were all of them disbarked on the Weft or
« South-Weft fides of 'em. And in feveral
« other places I obferved the like accident,
" and foun^ it was conftantly on the fame
M fide of the trees.

<( About the middle of December the
" froft abated of its intenfenefs, and feemed
<< to be at a Hand, till the 23d of the month,
«c when the wind blew extreme fharp and
«' cold from the Eaft, and the froft continued
" very hard to the 28th day, at which time
lt it began to abate again, and feemed to be
H going off, the wind changing to rhe Scuih ;
" but it did not continue long id this point,
" before it changed to the Eaft again, and
" the froft returned, tho' not fo violent as
<•' before.

iC Thus the weather continued for the
cc moft part frofty, till me middle of March,
" with a fevy intervals of mild weather,
li which brought forward fome of the early
u flowers i but the cold returning, foon de-

a ftroyed

Vegetable Staticks* 77

ct ftroyed them ; io that thofe plants which
" ufually flower in January and February,
ci did not this year appear till the latter end
" of March) or the beginning of April \ as
" the Crocus's, Hepaticas6 Perfian Iris's,
" Black Hellebores, Polyanthus's, Mezereons,
u and many others.

u The Colliflower - plants which were
ct planted out during the intervals between
" the froft, were moft of them deftroyed,
" or fo much pinched, as to lofe the great-
" eft part of their leaves 5 whereas thofe
" which had been planted out in Ottober
cc efcaped very well. The early Beans and
" Peas were moft of them deftroyed ; and
" great quantities of timber and fruit-trees,
" which had been lately removed, were quite
" killed.

" The lofs was very great in moft cu-
" rious collections of plants ; there being
" a great deftru&ion made of many trees,
" fhrubs, and plants, which had endured
" the open air many years, wichout being
" the leaft hurt by cold; as the Granadilla
" or Paffion-flowe?\ Arbutus or Straw-
l£ berry Tree, Cork Tree, with moft of the
<c Aromatick Plants, as Rofemary, Laven-
€i ' der, Stcechas, Sage, Maftick, Mar urn,

" and

7% Vegetable Staticks.

H and many others, which were deftroyed
u to the ground, and were by many people
" pulled up and thrown away ; but in warm
'■• dry foils, where they were fuffered to re-
<c main undifturbed, many of them broke
u out from the root again, tho' it was very
u late in the fummer before they fhewed any
cc figns of recovery.

u The plants in the confervatories fuffered
<c very much by being fo long (hut up clofe ;
e< for the days being for the moft part cloudy,
*c and the wind blowing very ftiarp, the
<c windows of the green-houfes could not be
<c with fafety opened, which occafioned a
<c noxious damp in the houfes, whereby the
c£ plants became fickly, languifhed and de-
€< cayed foon after.

" Nor was the froft more fevere with us
" than in other parts of Europe, but on
" the contrary in comparifon favourable -,
l< for in the Southern parts of France the
<£ Olives, Myrtles , Ci/luss, and other trees
" and fhrubs, which grow there almoft
c< fpontaneoufly, were deftroyed ; and in the
<c Northern parts of France, as about Paris,
" &c. the buds of many kinds of fruit-trees
u were deftroyed, although clofed, fo that
c< many of them never opened, but decayed

" and

Vegetable Statuks. 79

*< and perifhed; and the Fig-trees which
" were expofed to the open air, were alfo
ic deftroyed.

" In Holland the Pines, Firs, and other
" hardy refinous trees, were moft of them
cl killed, altho' many of them are natives
<c of the Alps, and other mountainous cold
" countries ; but this I apprehend to be ow-
" ing to the lownefs of their fituation and
" foil, whereby their roots eafily ran down
" into the water, which is more injurious to
11 thefe trees than froft.

<c But it was obferved, that the trees and
" fhrubs which are natives of Virginia and
a Carolina, efcaped well in Holland-, when
" almoft all thofe which were b/ought from
" Italy, Spain, or the South parts of France,
<c were intirely deftroyed. Which will greatly
<c inhance the value of the former trees, ef-
" pecially fuch of them as are either proper
" for ufe or beauty.

" In Germany the winter was fo fevere as
* to deftroy almoft all their plants and flowers,
<c which were not either removed into the
" green - houfes, or protedled by coverings
u from the froft, as I was informed by letters
u from thence.

« And

8o Vegetable Statich.

" And in Scotland the froft and fnow did
" great damage, fome of the particulars of
€i which I fhall tranfcribe from a letter,
<l which I received from a gentleman living
" near Edinburgh who is a curious ob-
u ferver.

" About the 20th of November, he fay9,
cc they had much fnow, which lay ten days,
<c and then went off very pleafantly without
" rain 5 and from that time till the middle
" of December, we had very good winter
ct weather, when a great fnow fell, which
" was attended with a ftorm from the North-
<c eaft -, which fnow lay very thick upon the
" ground till the 12th day of January, du-
" ring which time there was a very intenfe
" froft: After which the cold abated, and
cc the fnow went off gradually •, and about
" the end of January, I obferved in my
cc green- houfe the flowers and young fhoots
" of the Orange and other exotick trees did
" begin to appear, and all of them began to
" prepare for vegetation. In the open ground
" we had Spring Cyclamens, Primrofes, Win-
" ter Aconites, Snowdrops, Hellebores, Poly-
" anthuss, Glajlenbury Thorn, Winter Hya-
c cinths, and Mezereons in flowv \

But

Vegetable Staticks. 81

u But before I proceed to give a farther
cc account of the weather, I fhail offer you
<c my thoughts upon the reafon of this ve-
cc gecation fo early, whilft the cold was fo
" intenfe with you. Firft, it is to be obferved,
" that our ftorms of fnow at that feafon
" came on before the froft had entered the
" ground; fo that the fnow kept the ground
" warm and fecure from the froft, which
" only crufted the top of the fnow : Du-
" ring this feafon the wind blew from the
(c Eafr, which coming off the fea, (from
<c which we are but eight miles diftant) was
<c not attended with fo much cold as if it
" had blown over the land, which was
cc covered with fnow, where there is no
cc fea for two hundred miles. Till the fifth
li of February we enjoyed this weather \ at
<c which time we had a violent fnow with
<c a ftorm from the South-w7eft, and the
<c froft having entered the ground before it
" fell, checked our early flowers from ap-
" pearing : During this fnow, which con-
" tinued moft part of February, we had a
" great deal of fun-mine, which contributed
■ very much to our early crops of Cu-
" cumbers and Melons ; but during the nights
" it froze very hard, which deftroyed great
G " numbers

8 1 Vegetable Statieks.

" numbers of plants that were not fhel-
" tered.

" Every thing was now at a ftand ; the
iC Apricot and Peac h bloflbms continued tur-
" gid; but not being opened, they fuffered
" very little; the Laurujlinuss fuffered
u extremely by this laft fevere feafon, efpe-
" cially where the (how had been melted from
cl their roots.

" This fnow went off with a violent

<c South-well wind, which was very bleak

<£ and cold ; and where the fun had no ac-

" cefs, the fnow lay till the 12th of Marchy

" at which time we had for fix days very

M mild weather, which occafioned our put-

if ting abroad our Carnatiojis, thereby we

* loft moft of them. The wind continued

" cold, varying from the South-weft to the

c< North-weft, and fometimes North-eaft>

" and upon the 23d day it was very cold,

« the wind at North-weft and by North;

" in the evening the fun was clouded, and

<•' the wind abated, the Mercurv in the Ba-

¥ rometer fell at night; at two o' clock the

<f next morning a violent hurricane at

" North-eaft brought a fnow in many

" places, 6, 10, and 12 feet deep, with a

" moft piercing cold; the fnow continued

•' to

Vegetable Staticks. 83

«« to fall till ten o' clock in the morning,
" when the wind chopped about to the
u North-weft with incredible fiercenefs,
« and extreme cold. Now it was that in-
" numerable fheep and other cattle were
<c loft in the mountains of fnow; and many
cc poor people going that morning to
<c look after their cattle, the remembrance
" of which is terrible, were equally fuf-
" ferers with them, being buried in the
cc fnow.

" The Apricots and Peaches v/hich were
<c now in bloffom upon warm walls, were
u all deftroyed, and not only the bloflbms,
" but the trees alfo, their bark burfting
»■ off."

I have often obferved from thefe Ther-
mometers, when that kind of hovering lam-
bent fog arifes, ( either mornings or even-
ings) which frequently betokens fair wea-
ther, that the air which in the preceding
day was much warmer, has upon the ab-
fence of the fun become many degrees
cooler than the furface of the earth ; which
being near 1500 times denfer than the air,
cannot be fo foon affected with the alter-
nates of hot and cold ; whence 'tis pro-
bable, that thole vapours which are raifed

G 2 by

84 Vegetable Staticks.

by the warmth of the earth, are by the
cooler air foon condenfed into a vifible
form. And I have obferved the fame dif-
ference between the coolnefs of the air, and
the warmth of water in a pond, by putting
my Thermometer, which hung all night in'
the open air in fummer time, into the water,
juft before the rifing of the fun, when the
like wreak or fog was rifing on the furface of
the water.

CHAP. II.

Experiment ls> whereby to find out the force
with which trees imbibe moijlure.

HAving in the firft chapter fecn many
proofs of the great quantities of li-
quor imbibed and perfpired by vegetables,
I propofe in this, to inquire with what force
they do imbibe moifture.

Tho' vegetables (which are inanimate)
have not an engine, which, by its alternate
dilatations and contractions, does in animals
forcibly drive the blood through the arte-
ries and veins; yet has nature wonderfully

contrived

Vegetable Staticks. 85

contrived other means, moft powerfully to
raife and keep in motion the fap, as will in
fome meafure appear by the experiments in
this and the following chapter.

I (hall begin with an experiment upon roots,
which nature has providently taken care to
cover with a very fine thick ftrainer ; that
nothing (hall be admitted into them, but what
can readily be carried off by perfpiration, vege-
tables having no other provifion for difcharg-
ing their recrement.

Experiment XXI.

Auguft 13. in the very dry year 1723,
I dug down 2 + ~ feet deep to the root
of a thriving baking Pear-tree, and laid
bare a root ~ inch diameter n (Fig. 10.) I
cut off the end of the root at i3 and put
the remaining ftump i n into the glafs tube
dr, which was 1 inch diameter, and 8 inches
long, cementing it faft at r; the lower part
of the tube d z was 1 8 inches long, and \
inch diameter in bore.

Then I turned the lower end of the tube

z uppermoft, and filled it full of water, and

then immediately immerfedthe fmall end z

into the ciftern of mercury x ; taking away

G 3 my

86 Vegetable Staticks.

my finger, which flopped up the end of the
tube z.

The root imbibed the water with fo much
vigour, that in 6 minutes time the mercury
was railed up the tube d z as high as zy viz.
8 inches.

The next morning at 8 o' clock, the mer-
cury was fallen to 2 inches height, and z
inches of the end of the root i were yet im-
meried in water. As the root imbibed the
water, innumerable air-bubbles hTued out at
/, which occupied the upper part of the tube
at r3 as the water left it.

Experiment XXII.

The eleventh experiment mews, with what
great force branches imbibe water, where a
branch with leaves imbibed much more than
a column of 7 feet height of water could in
the fame time drive through 13 inches length
of the biggeft part of its item. And in the
following experiments wc fhali find a farther
proof of their ftrpng imbibing power.

MiiX 25, I cut off a branch of a young
thriving yi/^/t'-Zra? b, (Fig. 11.) about 3 feet
long, with lateral branches ; the diameter of
ti.e tranfverfe cut /, where it was cut off,

was

Vegetable Staticks. 87

was \ of an inch : The great end of this branch
I put into the cylindrical glafs e r, which
was an inch diameter within, and eight inches
long.

I then cemented faft the joint r, firfl fold-
ing a ftrap of fheeps-skin round the Hem, fo
as to make it fit well to the tube at r ; then
I cemented faft the joint with a mixture of
Bees-wax and Turpentine melted together in
fuch a proportion, as to make a very ftiff
clammy pafte when cold, and over the cement
I folded feveral times wet bladders, binding
it firm with packthread.

At the lower end of the large tube e was
cemented, on a lefier tube z e, {■ inch dia-
meter in bore, and 1 8 inches long : The fub-
ftance of this tube ought to be full f of an
inch thick, elfe it will too eafily break in
making this experiment

Thefe two tubes were cemented together
at ey firft with common hard brick-duft ce-
ment to keep the tubes firm to each other ;
but this hard cement would, both by being
long moift, and by the different dilatations
and contractions of the glafs and cement,
feparate from the glafs in hot weather, fo
as to let in air ; to prevent which incon-
venience, I further fecured the joint with

G 4 the

8 8 Vegetable Statkks.

the cement of Bees-wax and Turpentine,
binding a wet bladder over all. If the hard
cement be made of powder'd chalk inftead
of brick-duft, it is more binding, and is not
fo apt to be loofened by water.

When the branch was thus fixed, I turned
it downwards, and the glafs tube upwards,
and then filled both tubes full of water ;
upon which I immediately applied the end
of my finger to clofe up the end of the
fmall tube, and immerfed it as faftaslcould
into the glafs ciflern x, which was full of
mercury and water.

When the branch was now uppermoft,
and placed as in this figure, then the lower
end of the branch was immerfed 6 inches in
water, viz. from r to i.

Which water was imbibed by the branch,
at its tranfverfe cut /; and as the water af-
cended up the fap-veffels of the branch, fo
the mercury afcended up the tube e z from
the cittern x ; fo as in half an hour's time
the mercury was rifen 5 inches and | high
up to z.

And this height of the mercury did in
feme meafure ihew the force with which the
fa p was imbibed, tho' not near the whole
force; for while the water was imbibing,

(he

Vegetable Staticks. 89

the tranfverfe cut of the branch was covered
with innumerable little hemifpheres of air,
and many air-bubbles iffued out of the fap-
veffels, which air did in part fill the tube e r,
as the water was drawn out of it 5 fo that
the height of the mercury could only be
proportionable to the excefs of the quantity
of water drawn off, above the quantity of
air which iffued out of the wood.

And if the quantity of air, which iffued
from the wood into the tube, had been equal
to the quantity of water imbibed, then the
mercury would not rife at all •> becaufe there
would be no room for it in the tube.

But if 9 parts in 1 2 of the water be im-
bibed by the branch, and in the mean time
but three fuch parts of air iffueinto the tube,
then the mercury muft needs rife near 6
inches, and fo proportionably in different
cafes.

I obferved in this, and moft of the follow-
ing experiments of this fort, that the mer-
cury rofe higheft, when the fun was very
clear and warm; and towards evening it
would fubfide 3 or 4 inches, and rife again
the next day as it grew warm, but feldom
to the fame height it did at firft. For I have
always found the fap-veffels grow every day,

after

90 Vegetable Staticks.

after cutting, lefs pervious, not only for water,
but alio for the fap of the vine, which never
paries to and fro fo freely thro' the tranfverfe
cut, after it has been cut 3 or 4 days, as at
firft ; probably, becaufe the cut capillary
veffels are fhrunk, the veficles alfo, and in-
terfaces between them, being faturate and
dilated with extravafated fap, much more
than they are in a natural ftate.

If I cut an inch or two off the lower
part of the ftem, which has been much fa-
turated by Handing in water, then the branch
will imbibe water again afrefh ; tho' not alto-
gether fo freely, as when the branch was firft
cut off the tree.

I repeated the fame experiment as this
2 2d, upon a great variety of branches of
feveral fizes and of different kinds of trees,
fome of the principal of which are as fol-
low, viz.

Experiment XXIII.

July 6th and 8th, I repeated the fame
experiment with feveral green fhoots of the
Viney of this year's growth, each of them
full two yards long.

The mercury rofe much more leifurely in
thefe experiments, than with the Apple-tree

branch -,

Vegetable Statkks. 91

branch ; the more the fun was upon it, the
fafter and higher the mercury rofe, but the
Vine-branches could not draw it above 4
inches the firft day, and 2 inches the third
day.

And as the fun fet, the mercury fometimes
fubfided wholly, and would rife again the
next day, as the fun came on the Vine-
branch.

And I obfei'ved, that where fome of thefe
Vine-branches were fix'd on the North-fide
of the large trunk of a Pear-tree, the mer-
cury then rofe mod in the evening about 6 o*
clock, as the fun came on the Vine-branch.

Experiment XXIV.

Auguft 9, at 10 ante Merid. (very hot
funftiine) I fixed in the fame manner as Ex.
22. a Non-pareil branch, which had 20 Apples
on it ; it was 2 feet high, with lateral branches,
its tranfverfe cut £ inch diameter : It imme-
diately began to raife the mercury moft vigo-
roufly, fo as in 7 minutes it was got up to
z 12 inches high.

Mercury being 13 | times fpecifically
heavier than water, it may eafily be eftima-
ted to what height the feveral branches in

thefe

$> i Vegetable Staticks.

thefe experiments would raife water; for
if any branch can raife mercury 12 inches,
it will raife water 13 feet 8 inches: A fur-
ther allowance being alfo made for the per-
pendicular height of the water in the tubes,
between r and z the top of the column of
mercury ; for that column of water is lifted
np by the mercury, be it more or lefs.

At the fame time, I tried a Golden Re-
nate branch 6 feet long ; the mercury rofe
but 4 inches, it rifing higher or lower in
branches nearly of the fame fize and of the
fame kind of tree, according as the air iffued
thro' the ftem, more or lefs freely. In the
preceding experiment on the Nonpareil branch,
I had fucked a little with my mouth at the
fmall end of the tube, to ge£ fome air-bub-
bles out of it, before I immerfed it in the
mercury $ (but thefe air-bubbles are beft got
out by a fmall wire run to and fro in the
tube) and this faction made air-bubbles arife
out of the tranfverfe cut of the branch : but
tho* the quantity of thofe air-bubbles thus
fucked out, was but fmall ; yet in this and
many other "experiments, I found, that after
fuch faction, the water was imbibed by the
branch much more greedily, and in much
greater quantity, than the bulk of the air was,

which

Vegetable Stathks, <?j

which was fucked our. Probably therefore,
thefe air-bubbles, when in the fap-veffels, do
flop the free afcent of the water, as is the cafe
of little portions of air got between the water
in capillary glafs tubes.

When the mercury is raifed to its great-
eft height, by precedent fudtion with the
mouth, (which height it reaches fometimes
in 7 minutes, fometimes in half an hour or
an hour) then from that time it begins to
fall, and continues fo to do, till it is fallen
5 or 6 inches, the height the branch would
have drawn it to, without fucking with the
mouth.

But when, in a very warm day, the mer-
cury is drawn up 5 or 6 inches, (without
precedent fudtion with the mouth) then it
will ufually hold up to that height for feve-
ral hours, viz. during the vigorous warmth
of the fun; becaufe the fun is all that time
ftrongly exhaling moifture from the branch
thro1 the leaves -y on which account it muft
therefore imbibe water the more greedily,
as is evident by many experiments in the firft
chapter.

When a branch is fixed to a glafs tube
fet in mercury, and the mercury fubfides at
night, it will not rife the next morning,

(as

9 4 J' e get able Staticks.

(as the warmth of the fun increafes upon it)
unlefs you fill the tube fir ft full of water:
For if half or I of the large tube cr be full
of air, that air will be rarefied by the fun ;
which rarefaction will deprefs the water in
the tube, and confequently the mercury can-
not rife.

But where little water is imbibed the firft
day, (as in the cafe of the green fhoots of the
Vine, Exper. XXIII.) then the mercury will
rife the fecond and third day, as the warmth
of the fun comes on, without refilling the
little water that was imbibed.

Exper iment XXV.

In order to make the like experiment on
larger branches, (when I expected the mer-
cury would have rifen much higher than in
fmall ones) I caufed glafilrs to be blown
of the fh ape of this here defcribed (Fig. 12.)
of feveral dimenfions at r, from two to
five inches diameter, with a proportionably
large cavity c; the ftem z as near i_ inch
diameter as could be, the length of the ftem
16 inches.

I cemented one of thefe glafs veffels to
a large fmooth barked thriving branch of an

Apple-

9 6 Vegetable Statkks.

the glafs tube z r, to the remaining branch
i r> and then filling the tube with water, fet
its lower end in the mercury x -y fo that now
the branch was placed with its top i down-
wards in the water, in the Aqueomercurial

gage.

It imbibed the water with fuch ftrength, as
to raife the mercury with an almoft equable
progreffion 1 1 + 4 inches by 3 o' clock (the
fun mining then very warm) 3 at which time
the water in the tube r i being all imbibed,
fo that the end i of the branch was out of the
water, then the air-bubbles paffing more freely
down to /, and no water being imbibed, the
mercury fubfided 2 or 3 inches in an hour.

At a quarter pad 4 o' clock, I refilled the
gage with water ; upon which the mercury
rofe afrefh from the ciftern, viz. 6 inches
the firft ^ of an hour, and in an hour more
the mercury reached the fame height as be-
fore, viz. 1 1 + \ inches. And in an hour
and \ more, it rofe -J. inch more than at firft ;
but in half an hour after this it began gently
to fubfide; viz. becaufe the fun declining
and fetting, the perfpiration of the leaves
decreafed, and confequently the imbibing of
the water at i abated, for the end i was then
an inch in water,

July

Vegetable Staticks. 97

July 3 lft, it raining all this day, the mer-
cury rofe but 3 inches, which height it
flood at all the next night. Aitguft ift, fair
fun-mine ; this day the mercury rofe to 8 in-
ches : This mews again the influence of the
fun, in raifing the mercury.

This Experiment proves that branches will
ftrongly imbibe from the fmall end immer-
fed in water to the great end; as well as
from the great end immerfed in water to
the fmall end; and of this we mall have
further proof in the fourth chapter.

Experiment XXVII.

In order to try whether branches would
imbibe with the like force with the bark
off, I took two branches, which I call M
and N\ I fixed M in the fame manner as
the branch in the foregoing Experiment,
with its top downwards, but firft I took off
all the bark from i to r. Then fix'dl in the /

fame manner the branch N> but with its
great end downwards, having alfo taken off
all the bark from / to r- both the branches
drew the mercury up to z, 8 inches; fo
they imbibed with equal ftrength at either
end, and that without bark.

H Expe-

Vegetable Statichi 99

tube : And if thefe wounds (thro* which the
air always iflued plentifully) were well co-
vered with fheeps gut, bound over with
packthread, it would in a good meafure
prevent the inconvenience : But I always
found that my experiments of this kind
fucceeded beft, when that part of the branch
which was to enter the tube r i9 was clear
of all knots or wounds j for when there
were no knots, the liquor paiTed moil free-
ly, and lefs air iffued out.

The fame day I fixed in the fame man-
ner a gage to an Apricot-tree ; it raifed the
mercury three inches; and tho' all the water
was foon imbibed, yet the mercury role
every day an inch, for many days, and fub-
fided at night j fo that the branch muft
daily imbibe thus much air, and remit it at
night.

Experiment XXX.

We have a further proof of the influence
of the leaves in raifing the fap in this fol-
lowing Experiment.

Auguft 6th, I cut off a large Ruffet
Pippin a, (Fig. 15.) with a ftalk 1 ~f \ inch
long, and 12 adjoining leaves g growing to
it.

H 2 I ce-

ioo Vegetable Staticks.

I cemented the flalk faft into the upper
end of the tube d, which tube was 6 inches
long, and \ inch diameter -y as the ftalk im-
bibed the water, it raifed the mercury to z>
four inches high.

I fixed another Apple of the fame fizeand
tree in the fame manner, but firft pulled
off the leaves ; it raifed the mercury but I
Inch. I fixed in the fame manner a like
bearing twig with 12 leaves on it. but no
apple; it raifed the mercury 3 inches.

I then took a like bearing twig, without
either leaves or apple; it raifed the mercury

I inch

o a twig with an apple and leaves raif-
ed the mercury 4 inches, one with leaves
only 3 inches, one with an apple without
leaves 1 inch.

A Quince which had two leaves, juft at
the twig's infertion into it, raifed the mer-
cury 2 + \ inches, and held it up a confi-
derable time.

A fprig of Mint fix'd in the fame manner,
raifed the mercury 3 -j- \ inch, equal to 4
feet 5 inches height of water.

Expe-

Vegetable Staticks. 101

Experiment XXXI.

I tried alfo the imbibing force of a great
variety of trees, by fixing Aqueo-mercuriai
gages to branches of them cut off, as in Ex-
periment 22.

The Pear, Quince, Cherry, Walnut, Peach,
Apricot, Plum, Black-thorn, White-thorn,
Goofeberry, Water-elder, Sycamore, raifed
the mercury from 6 to 3 inches high : Thofe
which imbibed water moft freely, in the Ex-
periments of the firft chapter, raifed the
mercury higheft in thefe Experiments, ex-
cept the Horfe-Chefnut, which, though it
imbibed water moft freely, yet raifed the
mercury but one inch, becaufe the air paf-
fed very fait through its fap-veffels into the

gage.

The following raifed the mercury but 1
or 2 inches, viz. the Elm, Oak, Horfe-
Chefnut, Filberd, Fig, Mulberry, Willow,
Sallow, Ofier, Am, Lynden, Currans.

The Ever-greens, and following trees and
plants, did not raife it at all ; the Laurel,
Rofemary, Lauruftinus, Phyllyrea, Fuz, Rue,
Berberry, Jeffamine, Cucumber-branch, Pum-
kin, Jerufalem Artichoke.

H 3 Expe-

102 Vegetable Staticks.

EXPERIMEN T XXXII.

We have a further proof of the great
force with which vegetables imbibe moi-
fture, in the following Experiment, viz. I
filled near full with Peas and Water, the
iron Pot ( Fig. 37.) and laid on the Peas a
leaden cover, between which and the fides
of the Pot, there was room for the air which
came from the Peas to pafs freely. I then
laid 184 pounds weight on them, which (as
the Peas dilated by imbibing the water)
they lifted up. The dilatation of the Peas
is always equal to the quantity of Water
they imbibe : For if a few Peas be put in-
to a VeiTel, and that Veffel be filled full of
water, tho' the Peas dilate to near double
their natural fize, yet the water will not
flow over the veiTel, or at moll very incon-
fiderably, on account of the expanfion of
little air-bubbles, which are hTuing from the
Peas.

Being defiious to try whether they would
raife a much greater weight, by means of a
lever with weights at the end of it, I com-
preffed feveral frefh parcels of Peas in the
fame Pot, with a force equal to 1600, 800,
and 400 pounds> in which Experiments, tho'

the

Vegetable Statich. i o ;

the Peas dilated, yet they did not raife the
lever, becaufe what they increafed in bulk
was, by the great incumbent weight, prefled
into the interfaces of the Peas, which they
adequately filled up, being thereby formed
into pretty regular Dodecahedrons.

We fee in this Experiment the vaft force
with which fwelling Peas expand ; and 'tis
doubtlefs a confiderable part of the fame
force which is exerted, not only in pufhing
the Plume upwards into the air, but alfo in
enabling the firft (hooting radicle of the Pea,
and all its fubfequent tender Fibres, to pene-
trate and moot into the earth.

Experiment XXXIII.

We fee, in the Experiments of this chap-
ter, many inftances of the great efficacy of
attraction; that univerfal principle which
is fo operative in all the very different
works of nature; and is moft eminently fo
in vegetables, all whofe minuteft parts are
curioufly ranged in fuch order, as is bcfl
adapted, by their united force, to attract pro-
per nourishment.

And we mall find in the following Ex-
periment, that the diflevered particles of
vegetables, and of other bodies, have a

H 4 ftrong

1 04 Vegetable Staticks.

flrong attractive power when they lie con-
fjfed.

That the panicles of wood are fpecifical-
ly heavier than water, ( and can therefore
flrongly attract it ) is evident, becaufe feveral
forts of wood fink immediately; others
(even cork) when their fnterftfceS are well
foaked, and filled with water: As Dr. Def-
aguliers informed me, he found a cork
which had been fealed up in a tube with
water for 4 years, to be then fpecifically
heavier than water; others (as the Peruvian
Bark) fink when very finely pulverized, be-
caufe all their cavities which made them
ivvim, are thereby deltroyed.

In order to try the imbibing power of
common wood allies, I filled a elafs tube
c r i> 3 feet long, and | of an inch diameter,
(Fig. 16.) with well dried and fiftcd wood
aihc?, prefiing them clofe with a rammer; I
tied a piece of linen over the end of the
tube at /, to keep the allies from falling out ;
I then cemented the tube c h(l at r to the
Aqueo-mercurial gage r z ; and when I had
filled the £a<:e full of water, I immerfed it
iti the ciftern of mercury x ; the 1 to the
upper end of the tube c7 ac oa I fcrewed on
the mercurial gzge a t.

The

Vegetable Stattcks. 105

The afhes, as they imbibed the water, drew
the mercury up 3 or 4 inches in a few hours
towards z -, but the three following days it
role but 1 inch, •£• inch, and •£, and fo lefs
«nd lefs, fo that in 5 or 6 days it ceafed
rifing : The higheft it rofe was 7 inches,
which was equal to raifing water 8 feet
high.

This had very little effect on the mer-
cury in the gage a b, unlefs it were, that it
would rife a little, viz. an inch or little
more in the gage at a, as it were by the fuc-
tion of the afhes, to fupply fome of the air-
bubbles which are drawn out at i.

But when I feparated the tube c 0 from
the gage r z, and fet the end i in water,
then the moifture (being not reftrained as
before) rofe fafter.and higher in the afhes
c 0, and deprefled the mercury at a, fo as
to be 3 inches lower than in the leg by by
driving the air upwards, which was inter-
mixed with the afhes.

I filled another tube 8 feet long, and ~
inch diameter, with red lead 5 and affixed it
in the place, of c 0 10 the gages a b, r z,
The mercury rofe gradually 8 inches to z.

In both thefe Experiments, the end i was
covered with innumerable air-bubbles, many

1 06 Vegetable Staticks.

of which continually patted off, and were
fucceeded by others, as at the tranfverfe ctm
in the Experiments of this chapter. And as
there, fo in thefe, the quantity of air-bub-
bles decreafed every day, fo as at laft to have*
very few : The part i immerfed in the wa-
ter, being become fo fatarate therewith, as
to leave no room for air to pafs.

After 20 days I picked the minium' out
of the tube, and found the water had rifen
3 feet 7 inches, and would no doubt have
rifen higher, if it had not been clogged
by the mercury in the gage z. For which
reafon the moifture rofe but 20 inches in
the afhes, where it would otherwife have
rifen 30 or 40 inches.

And as Sir Ifaac Newton (in his Op-
tkks, query 31.) obferves, lt The water rifes
" up to this height, by the aftion only of
" thofe particles of the afhes which are up-
" on the furface of the elevated water ; the
" particles which are within the water, at-
" tradting or repelling it as much down-
,f wards as upwards ; and therefore the ac-
" tidn of the particles is very flrong : But
" the particles of the allies being not fo"
" denfe and clofe together as thofe of glafs,
H their adion is not fo flrong as that of

!c glafs*

Vegetable Statkks. 107

4< glafs, which keeps quick-filver fufpended
" to the height of 60 or 70 inches, and
cc therefore ads with a force, which would
" keep water fufpended to the height of
" above 60 feet.

" By the fame principle, a fponge fucks
<c in water; and the glands in the bodies of
" animals, according to their feveral natures
te and difpoiitions, fuck in various juices
" from the blood."

And by the fame principle it is, that we
fee, in the preceding Experiments, plants im-
bibe moifture fo vigoroufly up their fine ca-
pillary veflets; which moifture, as it is car*
ried off in perfpiration, ( by the action of
warmth) thereby gives the fap-veflels liber-
ty to be almoft continually attracting of
frefli fupplies ; which they could not do, if
they were full faturate with moifture : For
without perfpiration the fap muft neceflarily
ftagnate, notwithstanding the fap-veffels are
fo curioufly adapted by their exceeding fine-
nefs, to raife the fap to great heights, in a
reciprocal proportion to their very minute
diameters.

C H A 1\

io8 Vegetable Statich.

CHAP. IIL

Experiments, jhewing the force of the jap
in the Vine in the bleeding feafon.

HAVING in the firft chapter (hewn
many inflances of the great quanti-
ties imbibed and perfpired by trees, and in
the fecond chapter feen the force with
which they do imbibe moiflure -y I propofe
next to give an account of thofe Experi-
ments, which will prove with what great
force the fap of the Vine is pufhed forth, in
the bleeding feafon.

Experiment XXXIV.

March 30th at 3 p. m. I cut off a Vine
on a weflern afpe<ft, within feven inches of
the ground ; the remaining flump c (Fig. 17.)
had no lateral branches : It was 4 or 5 years
old, and -| inch diameter. I fix'd to the top
of the flump, by means of the brafs collar
hy the glafs tube b f\ feven feet long, and
-J inch diameter ; I fecured the joint b with
fliff cement made of melted Bees- wax and
Turpentine, and bound it fafl over with fe-
veral folds of wet bladder and packthread :

I then

Vegetable Staticks. lop

I then fcrewed a fecond tube/g to the firft,
and then a third g ay to 25 feet height.

The ftem not bleeding into the tube, I
filled the tube two feet high with water;
the water was imbibed by the ftem within
3 inches of the bottom, by 8 o' clock thac
evening. In the night it rained a fmall
Ihower. The next morning at 6 and ~, the
water was rifen three inches above what it
was fallen to laft night at eight o' clock.
The thermometer which hung in my porch
was 1 1 degrees above the freezing point.
March 3 1 from 6 and \ a, m. to id p. m.
the fap rofe 8 -j- \ inches. April ift, at 6
a. m. T'hermofneter 3 degrees above the
freezing point, and a white hoar froft, the
fap rofe from ten o' clock laft night 3 + \
inches more ; and fo continued riling daily
till it was above 21 feet high, and would
very probably have rifen higher, if the joint
b had not feveral times leaked: After flop-
ping of which it would rife fometimes at
the rate of an inch in 3 minutes, fo as to
rife 10 feet or more in a day. In the chief
bleeding feafon it would continue rifing
night and day ; but much more in the day
than night, and moft of all in the greateft
heat of the day ; and what little finking it

had

1 1 o Vegetable Staticks.

had of 2 or 3 inches was always after fun-
fet; which I fufpecl was principally occa-
fioned by the fhrinking and contraction of
the cement at b, as it grew cool.

When the fori fhined hot upon the Vine,
there was always a continued feries of air-
bubbles, conftantly afcending from the ftem
thro' the fap in the tube, in fo great plenty
as to make a large froth on the top of the
fap, which mews the great quantity of air
which is drawn in thro" the roots and ftem.

From this Experiment we find a confide-
rable energy in the root to pufh up fap in
the bleeding feafon.

This put me upon trying, whether I
could find any proof of fuch an energy,
when the bleeding feafon was over. In or-
der to which,

Experiment XXXV.

July 4th, at noon, I cut off within 3 in-
ches of the ground, another Vine on a
fouth afpecl, and fixed to it a tube 7 feet
high, as in the foregoing Experiment: I
filled the tube with water, which was im-
bibed by the root the firft day, at the rate
of a foot in an hour, but the next day much
more (lowly ; yet it was continually finking,

Vegetable St Micks. i 1 1

fe that at noon day I could not fee it fo
much as ftationary.

Yet by Experiment the 3d, on the Vine
in the garden pot, it is plain, that a very
confiderable quantity of fap was daily pref-
fing thro' this ftem, to fupply the perfpira-
tion of the leaves, before I cut the Vine off.
And if this great quantity were carried up by
pulfion or trufion, it muft needs have rifen
out of the ftem into the tube.

Now, fince this flow of fap ceafesat once,
as foon as the Vine was cut off the ftem,
the principal caufe of its rife muft at the
fame time be taken away, viz. the great
perfpiration of the leaves.

For tho' it is plain by many Experiments,
that the fap enters the fap-veflels of plants
with much vigour, and is probably carried
up to great heights in thofe veflels, by the
vigorous undulations of the fun's warmth,
which may reciprocally caufe vibrations in
the veficles and fap-veflels, and thereby make
them dilate and contract a little ; yet it feems
as plain, (from many Experiments, as parti-
cularly Exper. 13, 14, 15, and Exper. 43.
where, tho' we are allured that a great quan-
tity of water pafled by the notch cut 2 or 3
feet above the end of the ftem 5 yet was the

notch

! 1 1 Vegetable Statkks.

notch very dry, becaufe the attraction of the
perfpiring leaves was much greater than the
force of trufion from the column of water:
From thefe Experiments, I fay, it feems
evident) that the capillary fap-vefiels, out of
the bleeding feafon, have little power to pro-
trude fap in any plenty beyond their ori-
fices ; but as any fap is evaporated off, they
can by their ftrong attraction ( affifted by
the genial warmth of the fun) fupply the
great quantities of fap drawn off by perfpi-
ration.

Experiment XXXVI.

April 6th, at 9. a. m. rain the evening be-
fore, I cut off a Vine on a Southern afpecl,
at a, (Fig. 18.) two feet nine inches from
the ground ; the remaining ftem a b had
no lateral branches ; it was \ inch diameter ;
I fixed on it the mercurial gage ay. At 1 1
a. m. the mercury was rifen to z, 15 inches
higher than the leg xy being pufhed down
at x, by the force of the fap which came
out of the ftem at a.

At /[.p.m. it was funk an inch in the leg zy.

April 7th at 8 a. ;;;. rifen very little, a
fog : at 1 1 a. 777 . 'tis 17 inches high, and the
fog gone.

April

Vegetable Statich. 1 1 j

April ioth, at 7 a. #;. mercury 18 inches
high; I then added more mercury, fo as to
make the furface z 23 inches higher than x;
the fip retreated very little into the ftem,
upon this additional weight, which fhews
with what an abfolute force it advances: at
noon it was funk one inch.

April 1 ith, at 7 a. m. 24 -p | inches high,
fun-mine: at 7 p. m> 18 inches high.

April 14th, at 7 a. m. 20+1 inches high,
at 9 a.m. 22 ~f"a> fine warm fun-mine ; here
we fee that the warm morning fun gives a
frefti vigour to the fap. At 1 1 a. m. the fame
day i6~-f-~, the great perfpiration of the Hem
makes it fink.

April 1 6th at 6 a. m. 19 -j- 4 rain. At 4
p. m. 13 inches. The fap (in the foregoing
experiment, numb. 34.) rifen this day fince
noon 2 inches, while this funk by the perfpi-
ration of the ftem ; which there was little
room for, in the very fhort ftem of the other.
April 17th, at 1 1 a. m. 24 + \ incrl high,
rain and warm; at yp. m. 29 + ~, finewarm
rainy weather, which made the fap rife all
day, there being little perfpiration by reafon
of the rain.

April 1 8th, at 7 a. m. 32 -J- \ inches high,
and would have rifen higher, if there had

I been

1 1 4. Vegetable Staticks.

been more mercury in the gage; it being all
forced into the leg y z. From this time to
May 5th, the force gradually decreafed.

The greateft height of the mercury being
32 -f- i inches; the force of the fap was
then equal to 36 feet 5 + -j inches height
of water.

Here the force of the riling fap in the
morning is plainly owing to the energy of
the root and ftem. In another like mercurial
gage, (fixed near the bottom of a Vine, which
run 20 feet high) the mercury was raifed by
the force of the fap 38 inches equal to 43
feet -f- 3 inches + ~ height of water.

Which force is near five times greater than
the force of the blood in the great crural ar-
tery of a Horfe ; fevtn times greater than
the force of the blood in the like artery of
a Dog; and eight times greater than the
blood's force in the fame artery of a fallow
Doe: Which different forces I found by
tying thofe feveral animals down alive upon
their backs ; and then laying open the great
left crural artery, where it firft enters the
thigh, I fixed to it (by means of two brafs
pipes, which run one into the other) a glafs
tube of above ten feet long, and i- of an
inch diameter in bore: In which tube the

blood

Vegetable StaUcks. 1 i 5

blood of one Horfe rofe eight feet three
inches, and the blood of another Horfe eight
feet nine inches. The blood of a little
Dog fix feet and half high : In a large
Spaniel feven feet high. The blood of
the fallow Doe mounted five feet feven
inches.

Experiment XXXVII.

April 4th, I fixed three mercurial gages,
(Fig. 19.) A, B, C, to a Vine, on a South-
eaft afpecl, which was 50 feet long, from
the root to the end ru. The top of the wall
was 1 1 -jf | feet high ; from i to k, 8 feet 5
from k to e, 6 feet + i. ; from e to A, 1 foot
10 inches ; from e to 0, 7 feet ; from 0 to B,
5 + 4 feet; from 0 to C, 22 feet 9 inches;
from 0 to u, 32 feet 9 inches.

The branches to which A and C were fixed,
were thriving moots two years old, but the
branch 0 B was much older.

When I firft fixed them, the mercury was
pufhed by the force of the fap, in- all the gages
down the legs 4, 5, 13, fo as to rife nine
inches higher in the other legs.

The next morning at 7 a. m. the mercury
in A was pufhed 14 -f- \ inches high, in B
12 -f-i, in Cj3 -p-i.

I 2 The

i ! 6 Vegetable Statich.

The grcateft height to which they puttied
the fap feverally, was ^2 1 inches, £26 inches,
C 26 inches.

The mercury conftantly fubfided by the
retreat of the fap about 9 or 10 in the morn-
ing, when the fun grew hot; but in a very
moift foggy morning the fap was later before
it retreated, viz. till noon, or fome time after
the fog was gone.

About 4 or 5 o' clock in the afternoon,
when the fun went off the Vine, the fap be-
gan to pufli afrefh into the gages, fo as to
make the mercury rife in the open legs ; but
it always rofe faftefl from fun-rife till 9 or
10 in the morning.

The fap in Z? (the oldefl flem) play'd the
mod freely to and fro, and was therefore
fooneft affected with the changes from hot to
cool , or from wet to dry, and vice verfd.

And April 10, toward the end of the
bleeding feafon, B began firft to fuck up the
mercury from 6 to 5, fo as to be 4 inches
higher in that leg than the other. But
April 24, after a night's rain, B puihed the
mercury 4 inches up the other leg; A did not
begin to fuck till April 29, viz. 9 days after
B > C did not begin to fuck till May 3, viz.
13 days after B> and 4 days after A\ May 5,

Vegetable Statich. 1 1 7

at 7 a. ?n. A pufhed 1 inch, Ci+Ij but to-
wards noon they all three fucked.

I have frequently obferved the fame dif-
ference in other Vines, where the like gages
have been fixed at the fame time, to old and
young branches of the fame Vine, viz, the
oldefl began firft to fuck.

In this experiment we fee the great force
of the fap, at 44 feet 3 inches diftance from
the root, equal to the force of a column of
water 30 feet 11 inches ~j~l high.

From this experiment we fee too, that
this force is nor from the root only, but
muft alfo proceed from fome power in the
ftem and branches : For the branch B was
much fooner influenced by changes from
warm to cool, or dry to wer, and vice verfa%
than the other two branches A or C -, and
B was in an imbibing flare, 9 days before
Ay which was all that time in a ftate of
pufhingfap; and C pufhed 13 days after B
had ceafed pufhing, and was in an imbibing
ftate.

Which imbibing ftate Vines and Applet
trees continue in, all the fummer, in every
branch, as I have found by fixing the like,
gages to the, m in July.

I 3 Expe-

1 1 8 Vegetable Staticls.

Experiment XXXVIII.

March io, at the beginning of the bleed-
ing feafon, (which is many days fooner or
later, according to the coldnefs or warmth,
inoifture or drinefs of the feafon) I then cut
off a branch of a vine bfcg at b, (Fig. 20.)
which was 3 or 4 years old, and cemented
faft on it a brafs-collar, with a fcrew in it;
to that I fcrewed another brafs collar, which
was cemented faft to the glafs tube zy 7 feet
long and - inch diam. (which I find to
be the propereft diam.) to that I fcrewed
ethers, to 38 feet height. Thefe tubes were
fattened and fecured in long wcoden tubes,
3 inches fquare, one fide of which was a
door opening upon hinges ; the ufe of thofe
wooden tubes was to preferve the glafs tubes
from being broke by the freezing of the fap
in them in the night. But when the danger
of hard frofts was pretty well over, as at the
beginning of April, then I ufually nVd the
glaffes without the wooden tubes, fattening
them to fcaffold poles, or two long ironfpikes
drove into the wall.

Before I proceed to give an account of
the rife and fall of the fap in the tubes, I

will

Vegetable Staticks. i 1 9

will firft defcribe the manner of cementing
on the brafs collar b, to the ftem of the
Vine, in which I have been often difappointed,
and have met with difficulties ; it mud there-
fore be done with great care.

Where I defign to cut the ftem, I firft
pick off all the rough ftringy bark carefully
with my nails to avoid making any wound
thro' the green inner bark 5 then I cut ojk^
the branch at /, (Fig. 21.) and immediately
draw over the ftem a piece of dried fheeps-
gut, which I tie faft, as near the end of the
ftem as I can, fo that no fap can get by it,
the fap being confined in the gut if: Then
I wipe the ftem at i very dry with a warm
cloth, and tie round the ftem a ftiff paper
funnel x i> binding it faft at x to the ftem ,
and pinning clofe the folds of the paper from
x to i : Then I Aide the brafs collar r ever
the gut, and immediately pour into the pa-
per funnel melted chalk cement, and then
fet the brafs collar into it ; which collar is
warmed, and dipped before in the cement,
that it may the better now adhere : When
the cement is cold, I pull away the gut, and
fcrew on the glafs tubes.

Buc finding fome inconvenience in this

hot cement, (becaufe its heat kills the fap-

I 4 vefTels

\ 20 Vegetable Staticks.

vefTels near the bark, as is evident by their
being difcoloured) I have fince made ufe of
the cold cement of Bees-wax and Turpentine,
binding it faft over with wet bladder and pack-
thread, as in Exper. 34.

Inftead of brafs-collars, which fcrewed
into each other, I often (efpecially with the
Syphons in Exper. 36, and 37.) made life
^f two brafs collars, which were turned a
little tapering, fo that one entered and exactly
fitted the other.

This joining of the two collars was ef-
fectually fecured from leaking, by firft
anointing them with a foft cement ; and
they were fecured from being disjoined, by
the force of the afcending fap, by twilling
packthread round the protuberant knobs on
the fides of the collars. When I would
feparate the collars, I found it neceflary
(except in hot fun-fliine) to melt the foft
cement by applying hot irons on the out-
fide of the collars.

It is needful to made all the cemented
joints from the fun with loofe folds of pa-
per, elfe its heat will often melt them, and
fo dilate the cement, as to make it be drove
forcibly up the tube., which defeats the ex-
periment

The

Vegetable Staticks. ! 1 1

The Vines to which the tubes in this ex-
periment were fixed, were 20 feet high from
the roots to their top; and the glafs tubes
fixed at feveral heights b from the ground,
from 6 to 2 feet.

The fap would rife in the tube the firft
day, according to the different vigour of the
bleeding ftate of the Vine, either 1, 2, 5,
12, 15, or 25 feet; but when ic had got
to its greateft height for that day, if it was
in the morning, it would conftantly begin
to fubfide towards noon.

If the weather was very cool about the
middle of the day, it would fubfide only
from 11 or 12 to 2 in the afternoon; but
if it were very hot weather, the fap would
begin to fubfide at 9 or 10 oV clock, and
continue fubfiding till 4, 5, or 6 in the even-
ing, and from that time it would continue
ftationary for an hour or two ; after which
it would begin to rife a little, but not
much in the night, nor till after the fun
was up in the morning, at which time ic
rofe fafteft.

The frefher the cut of the Vine was, and
the warmer the weather, the more the fap
would rife, and fubfide in a day, us 4 or 6
feet.

But

121 Vegetable Statich.

But if it were 5 or 6 days fince the Vine
was cut, it would rife or fubfide but little ;
the fap-vefTels at the tranfverfe cue being
faturate and contracted.

But if I cut off a joint or two off the
Hem, and new fixed the tube, the fap would
then rife and fubfide vigoroufly.

Moifture and warmth made the fap mod
vigorous.

If the beginning or middle of the bleed-
ing feafon, being very kindly, had made the
motion of the fap vigorous, that vigour would
immediately be greatly abated by coldeafterly
winds.

If in the morning, while the fap is in a
rifmg ftate, there was a cold wind with a
mixture of fun-fhine and cloud ; when the
fun was clouded, the fap would immediately
viiibly fubfide, at the rate of an inch in a
minute for feveral inches, if the fun con-
tinued fo long clouded: But as foon as the
fun-beams broke out again, the fap would
immediately return to its then rifing ftate,
juft as any liquor in a thermometer rifes and
falls with the alternacies of heat and cold 5
whence 'tis probable, that the plentiful rife
of the fap in the Vine in the bleeding feafon,
is effected in the fame manner,

When

Vegetable Statkks. 123

When three tubes were fixed at the fame
time to Vines on an eaftern, a fouthern, and
a weftern afpedt, round my porch, the fap
would begin to rife in the morning firft in
the eaftern tube, next in the fouthern, and
laft in the weftern tube : And towards noon it
would accordingly begin to fubfide, firft in
the eaftern tube, next in the fouthern, and
laft in the weftern tube.

Where two branches arofc from the
fame old weftern trunk, 15 inches from
the ground; and one of thefe branches
was fpread on a fouthern, and the other
on a weftern afpedt ; and glafs tubes were
at the fame time fixed to each of them 5
the fap would in the morning, as the fun
came on, rife firft in the fouthern, then in
the weftern tube; and would begin to fub-
fide, firft in the fouthern, then in the weftern
tube.

Rain and warmth, after cold and dry,
wrou!d make the fap rife all the next day,
without fubfiding, tho' ic would rife then
flowed about noon; becaufe in this cafe
the quantity imbibed by the root, and
raifed from it, exceeded the quantity per-
fpired.

The

H4 Vegetable Statich.

The fap begins to rife fooner in the morn-
ing in cool weather, than after hot days;
the reafon of which may be, becaufe in
hot weather much being evaporated, it is not
fo foon fupplied by the roots as in cool wea-
ther, when lefs is evaporated.

In a prime bleeding feafon I fix'd a tube
25 feet long to a thriving branch two years
old, and two feet from the ground, where
it was cut off; the fap flowed fo briskly,
as in two hours to flow over the top of the
tube, which was feven feet above the top of
the Vine ; and doubtlefs would have rifen
higher, if I had been prepared to lengthen
the tube.

When at the diftance of four or five days,
tubes were affixed to two different branches,
which came from the fame ftem, the fap
would rife higheft in that which was laft
fixed; yet if in the fixing the fecond tube
there was much fap loft, the fap would fub-
fide in the firft tube; but they would not
afterwards have their fap in equilibrio; i. e.
the furface of the fap in each was at very
unequal heights ; the reafon of which is, be-
caufe of the difficulty with which the fap
paffes thro* the almoft faturate and contracled
capillaries of the firfl-cut ftem,

Vegetable Stattch. i x 5

In very hot weather many air-bubbles would
rife, fo as to make a froth an inch deep, oil
the top of the fap in the tube.

I fix'd a fmall air-pump to the top of a long
tube, which had 12 feet height of fap in it 5
when I pumped, great plenty of bubbles arofe*
tho* the fap did not rife, but fall a little, after
I had done pumping.

In Experiment 34. (where a tube was
fixed to a very {hort ftump of a Vine, with-
out any lateral branches) we find the fap
rofe all day, and fafteft of all in the greateft
heat of the day : But by many obfervations
under the 37th and this 38th Experiments,
we find the fap in the tubes conftantly fub-
fided as the warmth came on towards the
middle of the day, and fafteft in the greateft
heat of the day. Whence .we may reafon-
ably conclude, (confidering the great perfpi-
rations of trees, fhewn in the firft chapter)
that the fall of the fap in thefe fap-gages,
in the middle of the day, efpecially in the
warmer days, is owing to the then greater
perfpiration of the branches, which perfpi-
ration decreafes, as the heat decreafes towards
evening, and probably wholly ceafes when
the dews fall.

But

\l6 Vegetable Staticks.

But when towards the latter end of Jlprtl
the fpring advances, and many young fhoots
are come forth, and the furface of the Vine
is greatly increafed and inlarged by the ex-
panfion of feveral leaves, whereby the per-
fpiration is much increafed, and the fap more
plentifully exhaufted, it then ceafes to flow
in a vifible manner, till the return of the
following fpring. *

And as in the Vine, To is the cafe the
fame in all the bleeding trees, which ceafe
bleeding as foon as the young leaves begin
to expand enough to perfpire plentifully, and
to draw off the redundant fap. Thus the
bark of Oaks, and many other trees, mod:
eafily feparates, while it is lubricated with
plenty of fap : But as foon as the leaves
expand fufficiently to perfpire off plenty of
fap, the bark will then no longer run, (as
they term it) but adheres rnoft firmly to
the wood.

Experiment XXXIX.

Jn order to try if I could perceive the flem
of the Vine dilate and contract with heat or
cold, wet or dry, a bleeding or not bleeding
feaibn, fome time in February y I hVd to the

ftem

Vegetable Statich. 117

ftem of a Vine an inftrument in fuch a man-
ner, that if the ftem had dilated or contracted
but the one hundredth part of an inch, it
would have made the end of the inftrument
(which was a piece of ftrong brafs-wire, 18
inches long) rife or fall very fenfibly about
one tenth of an inch ; but I could not per-
ceive the inftrument to move, either by heat
or cold, a bleeding or not bleeding feafon.
Yet whenever it rained, the ftem dilated fo as
to raife the end of the inftrument or lever
-^ of an inch; and when the ftem was dry,
it fubfided as much.

This Experiment fhews, that the fap (even
in the bleeding feafon) is confined in its proper
veflels, and that it does not confufedly per-
vade every interftice of the ftem, as the rain
does, which entering at the peripiring pores*
foaks into the interftices, and tfeereby dilates
the ftem.

CHAP.

iiB Vegetable Stattch.
CHAP. IV.

Experiments, Jhcwing the ready lateral mo-
tion oj the fapy and confequently- the late-
ral communication of the fap-vejjels. The
free fajjage of it fro?n the f mall branches
towards the ft em y as well as from the ft em
to the branches. With an account of fome
Experiments, relating to the circulation or
non-circulation of the jap.

Experiment XL.

IN order to find whether there was any
lateral communication of the fap and fap-
veiTels, as there is of the blood in animals,
by means of the ramifications, and lateral
communications of their vefTels ;

Augufl 15th, I took a young Oak-branch
Y inches diameter, at its tranfverfe cut, fix
feet high, and full of leaves. Seven inches
from the bottom, I cut a large gap to the
pith, an inch long, and of an equal depth
the whole length ; and four inches above
that, on the oppofite fide, I cut fuch ano-
ther gaps I let the great end of the ftem
in water : It imbibed and perfpired in two
nights and two days thirteen ounces, while

another
j

Vegetable Statkks. 129

another like Oak-branch, fomewhat bigger
than this, but with no notch cat in its ftem,
imbibed 25 ounces of water.

At the fame time I tried the like experi-
ment with a Duke-cherry-branch 5 it imbibed
and penpired 23 ounces in 9 hours the fxrft
day, and the next day 15 ounces.

At the fame time I took another Duke-
cherry '-branch, and cut 4 fuch fquare gaps
to the pith, 4 inches above each other; the
i& North, 2d Eajl, 3d South, /phWeft: It
had a long (lender ftem, 4 feet length, with-
out any branches, only at the very top ; yet
it imbibed in 7 hours day 9 ounces, and in
two days and two nights 24 ounces.

We fee in thefe experiments a moil free
lateral comuunication of the fap and fap-vef-
fels, thefe great quantities of liquor having
paffed laterally by the gaps ; for by Experiment
13, 14, 15, (on cylinders of wood) little
evaporated at the gaps.

And in order to try whether it would not
be the fame in branches as they grew on trees,
I cut 2 fuch oppofite gaps in a 'Duke-cherry-
branch, 3 inches diftant from each other: The
leaves of this branch continued green, within
8 or 1 o days, as long as the leaves on the other
branches of the fame tree.

K The

i}o Vegetable Staticks.

The fame day, viz* Aug. 15th, I cut two
fuch oppofite gaps four inches diftant, in an
horizontal young thriving Oak-branch -, it was
one inch diameter, eighteen days after many
of the leaves begun to turn yellow, which
none of the leaves of other boughs did
then.

The fame day I cut off the bark for one
inch length, quite round a like branch of the
fame Oak; eighteen days after the leaves
were as green as any on the fame tree ; but
the leaves fell off this and the foregoing branch
early in the winter ; yet continued on all the
reft of the boughs of the tree (except the top
ones) all the winter.

The fame day I cut four fuch gaps, two
inches wide, and nine inches diftant from
each other, in the upright arm of a Golden-
renate - tree -> the diameter of the branch
was 2 -f-i inch, the gaps faced the four
cardinal points of the compafs; the apples
and leaves on this branch flourifhed as
well as thofe on other branches of the fame
tree.

Here again we fee the very free lateral
paffage of the fap, where the direft paflage
is feveral times intercepted. See Vol II. p.

262.

Expe-

Vegetable Staticks. 1 3 1

Experiment XLI.

Aug. 13th, at noon I took a large branch
of an Apple-tree, (Fig. 22.) and cemented
up the tranfverfe cut, at the great end x9 and
tied a wet bladder over it : I then cut off the
main top branch at b ; where it was -| inch
diameter, and fet it thus inverted into the
bottle of water b.

In three days and two nights it imbibed
and perfpired four pounds two ounces ~j- -
of water, and the leaves continued green ; the
leaves of a bough cut off the fame tree at
the fame time with this, and not fet in
water, had been withered forty hours be-
fore. This, as well as the great quantities
imbibed and perfpired, mews, that the wa-
ter was drawn from b moft freely to e, fy
g, b, and from thence down their refpeclive
branches, and fo perfpired off by the leaves.

This experiment may ferve to explain
the reafon, why the branch b, (Fig. 23.)
which grows out of the root c xy thrives
very well, notwithftanding the root c x is
here fuppofed to be cut off at cy and to,
be out of the ground : For by many expe-
riments in the firft and fecond chapters, it
K 2 is

ip Vegetable Statkks.

is evident, that the branch b attradts fap
at x with great force: And by this pre-
fent experiment, 'tis as evident, that fap
will be drawn as freely downwards from
the tree to x, as from c to x, in cafe the
end c of the root were in the ground ;
whence 'tis no wonder, that the branch b
thrives well, tho' there be no circulation of
the fap.

This Experiment 41, and Experiment 26,
do alfo fhew the reafon why, where three
trees ( Fig. 24. ) are inarched, and thereby
incorporated at x and z, the middle tree
will then grow, tho' it be cut off from its
roots, or the root be dug out of the ground,
and fufpended in the air; viz. becaufe the
middle tree b attracts nourifliment ftrongly
at x and z, from the adjoining trees a cy
in the fame manner as we fee the inverted
boughs imbibed water in thefe Exper. 26,
and 41.

And from the fame reafon it is that
Elders, Sallows, Willows, Briars, Vines,
and mod Shrubs, will grow in an inverted
ftate, wTidi their tops downwards in the
earth.

Exp e-

Vegetable Staticks. 133

Experiment XLII.

July 27th, I repeated Monfieur Peraulfs
Experiment ; viz. I took Duke-cherry, Ap-
ple and Curran- boughs, with two branches
each, one of which a c (Fig. 25.) I immer-
fed in the large veilel of water e dy the
other branch hanging in the open air: I
hung on a rail, at the fame time, other
branches of the fame forts, which were then
cut off. After three days, thofe on the rails
were very much withered and dead, but the
branches b were very green ; in eight days
the branch b of the Duke-cherry was much
withered : but the Curram and Apple-branch
b did not fade till the eleventh day: Whence
'tis plain, by the quantities that muftbeper-
fpired in eleven days, to keep the leaves b
green fo long, and by the wafte of the water
out of the veffel, that thefe boughs b muft
have drawn much water from and through
the other boughs and leaves c, which were
immerfed in the veffel of water.

I repeated the like experiment on the
branches of Vines and Apple-trees, by run-
ning their boughs, as they grew, into large
glafs chymical retorts full of water3 where
K 3 the

1 54 Vegetable Staticks.
the leaves continued green for feveral
weeks, and imbibed confiderable quantities
of water.

This mews how very probable it is, that
rain and dew is imbibed by vegetables, efpe-
cially in dry feafons.

Which is further confirmed by experi-
ments lately made on new -planted trees;
where, by frequently warning the bodies of
the moft unpromifing, they have out-ftrip-
ped the other trees of the fame plantation.
And Mr. Miller advifes, « Now and then
" in an evening to water the head, and with
€C a brufh to wafh and fupple the bark all
" round the trunk, which (fays he) I have
ci often found very ferviceable."

Experiment XLIII.

Aiiguji 20th, at i p. ?n. I took an Apple-
branch b, (Fig. 26. ) nine feet long, 1 -j^
I inch diameter, with proportional lateral
branches ; I cemented it faft to the tube ay
by means of the leaden fyphon /: But firft
I cut away the bark, and laft year's ringlet of
wood, for three inches length to r. I then
filled the rube with water, which was twelve
feet long, and \ inch diameter, having firft

cut

PL -12

p- 13 +

S.G.

Vegetable Statich. i 5 5

cut a gap at y through the bark, and laft year's
wood, twelve inches from the lower end of
the ftem : the water was very freely imbibed,
viz. at the rate of three -j- \ inches in a
minute. In half an hour's time I could
plainly perceive the lower part of the gap y
to be moifter than before ; when at the fame
time the upper part of the wound looked
white and dry.

Now in this cafe the water muft necef-
farily afcend from the tube, thro' the inner-
most wood, becaufe the laft year's wood
was cut away, for 3 inches length, all round
the ftem ; and confequently, if the fap in
its natural courfe defcended by the laft
year's ringlet of wood, and between that and
the bark, (as many have thought) the water
fhould have defcended by the laft year's
wood, or the bark, and fo have firft moiftened
the upper part of the gap y -, but on the con-
trary, the lower part was moiftened, and not
the upper part.

I repeated this experiment with a large
Duke- cherry -branchy but could not perceive
more moifture at the upper than the lower
part of the gap -y which ought to have been,
if the fap defcends by the laft year's wood,
or the bark.

K 4 It

\]6 Vegetable Staticks.

It was the fame in a Quince- branch as the
Duke- cherry.

N. B. When I cut a notch in either of
thefe branches, 3 feet above r, at qy I could
neither fee nor feel any moifture, notwith-
flanding there was at the fame time a great
quantity of water paffing by ; for the branch
imbibed at the rate of 4^ 3, or 2 inches per
minute, of a column of water which was
half inch diameter.

The reafon of which drinefs of the notch
q is evident from Experiment 11, viz. be-
caufe the upper part of the branch above
the notch imbibed and perfpired three or four
times more water, than a column of kvtn
feet height of water in the tube could im-
pel from the bottom of the ftem to q, which
was three feet length of ftem ; and confe-
quently, the notch muft neceflarily be dry,
notwithftanding lb large a ftream of water
was pafling by j viz. becaufe the branch and
ftem above the notch was in a ftrongly im-
bibing ftate, in order to fupply the great per-
foration of the leaves.

ExpEr

Vegetable Staticks. \ 3 7

Experiment XLIV.

Augufl 9th, at 10 a. m. I fix'd in the fame
manner (as in the foregoing experiment) a
Duke-cherry-branch five feet high, and one
inch diameter, but did not cut away any of
the bark or wood at the great end ; I filled the
tube with water, and then cut a flice off the
bark an inch long, 3 inches above the great
end ; it bled at the lower part mod freely,
while the upper part continued dry.

The fame day I tried the fame experi-
ment on an Apple- branch, and it had the fame
efFecl.

From thefe experiments 'tis probable, that
the fap afcends between the bark and wood,
as well as by other parts.

And fince by other experiments it is
found that the greateft part of the fap is
raifed by the warmth of the fun on the
leaves, which feem to be made broad and
thin for that purpofe ; for the fame reafon,
it's moft probable, it fhould rife alfo in thofe
parts which are moft expofed to the fun, as
the bark is.

And when we confider, that the fajp-vcf-
fels are fo very fine as to reduce the fap almoft

138 Vegetable Staticks.

to a vapour, before it can enter them, the

fun's warmth on the bark fhould moft eafily

difpofe fuch rarefied fap to afcend, inftead of

defcending.

Experiment XLV.

July 27th, I took feveral branches of Cur-
ram, Vines, Cherry, Apple, Pear and Plum-
tree^ and fet the great ends of each in veffels
of water x (Fig. 31.) 5 but firft took the bark
for an inch off one of the branches, as at z,
to try whether the leaves above z at b would
continue green longer than the leaves of any
of the other branches a, c, d-, but I could
find no difference, the leaves withering all at
the fame time : Now, if the return of the fap
was flopped at z, then it would be expected,
that the leaves at b fhould continue green lon-
ger than thofe on the other branches; which
did not happen, neither was there any moi-
fture at z.

Experiment XL VI.

In Aitgujl, I cut off the bark for an inch
round, of a young thriving Oak -branch,
on the North -weft fide of the tree. The

leaves

Vegetable Staticks. 1 3 9

leaves of this and another branch, which
had the bark cut at the fame time, fell early,
viz. about the latter end of OBobery when the
leaves of all the other branches of the fame
tree, except thofe at the very top of the tree,
continued on all the winter,

This is a further proof, that lefs fap goes
to branches which have the bark cut off, than
to others.

The 19th of April following, the buds of
this branch were 5 or 7 days forwarder than
thofe of other branches of the fame tree ;
the reafon of which may probably be, be-
caufe lefs frefli crude fap coming to this
branch than the others, and the perfpira-
tions in all branches being, cceteris paribus,
nearly equal, the lefler quantity of fap in
this branch muft fooner be infpiffated into
a glutinous fubftance, fit for new produc-
tions, than the fap of other branches, that
abounded with a greater plenty of frefh
thin fap.

The fame is the reafon why Apples,
Pears, and many other fruits, which have
fome of their great fap-veffels eaten afun-
der by infects bred in them, are ripe many
days before the reft of the fruit on the
fame trees y as alfo that fruit which is ga-
thered

140 Vegetable Staticks.
thered fome time before it is ripe, will ri-
pen fooner than if it had hung on the tree,
tho* it will not be fo good ; becaufe in thefe
cafes the worm- eaten fruit is deprived of part
of its nourishment, and the green-gathered
fruit of all.

And for the fame reafon fome fruits are
fooner ripe towards the tops of the trees,
tlian the other fruit on the fame tree; viz.
not only becaufc they are more expofed to
the fun ; but alfo, becaufe being at a greater
diftance from the root, they have fomewhat
lefs nourishment.

And this is, doubtlefs, one reafon why
plants and fruits are forwarder in dry, fandy,
or gravelly foils, than in moifter foils; viz.
not only, becaufe thofe foils are warmer,
on account of their drinefs; but alfo, be-
caufe lefs plenty of moifture is conveyed up
the plants; which plenty of moifture, tho'
it promotes their growth, yet retards their
coming to maturity. And for the fame rea-
fon, the uncovering the roots of trees for
fome time, will make the fruit be confiderably
the forwarder.

And on the other hand, where trees abound
with too great a plenty of frefh-drawn fap,
as is the cafe cf trees whofe roots are planted

too

Vegetable Staticks. 141

too deep in cold moift earth, as alfo of too
luxuriant Peach and other wall trees; or,
which comes almoft to the fame, where
the fap cannot be perfpired off in a due pro-
portion; as in orchards, where trees ftand too
near each other, fo as to hinder perfpiration,
whereby the fap is kept in too thin and crude
a ftate ; in all thefe cafes little or no fruit is
produced.

Hence alfo, in moderately dry fummers,
cateris paribus, there is ufually greateft plenty
of fruit; becaufe the fap in the bearing
twigs and buds is more digefted, and brought
to a better confidence, for {hooting out
with vigour and firmnefs, than it is in
cool moift fummers : And this obfervation
has been verified in the years 1723, 1724,
and 1725. See an account of them under
it, Exper. 20.

But to return to the fubjedl of the mo-
tion of the fap: When the fap has firftpaffed
thro' that thick and fine ftrainer, the bark
of the root, we then find it in greateft quan-
tities, in the moft lax part, between the bark
and wood, and that the fame thro* the whole
tree. And if in the early fpring, the Oak
and feveral other trees were to be examined
near the top and bottom, when the fap firft

begins

141 Vegetable Staticks.

begins to move, (o as to make the bark
eafily run, or peel off, I believe it would be
found, that the lower bark is firft moiftened ;
whereas the bark of the top branches ought
firft to be moiftened, if the fap defcends by
the bark : As to the Vine, I am pretry well
affured that the lower bark is firft moiftened.
See Vol II. p. 264.

We fee in many of the foregoing expe-
riments, what quantities of rnoifture trees
do daily imbibe and perfpire : Now the ce-
lerity of the fap muft be very great, if that
quantity of rnoifture muft, moft of it, afcend
to the top of the tree, then defcend, and
afcend again, before it is carried oft by per-
fpiration.

The defect of a circulation in vegetables
feems in fome meafure to be iupplied by
the much greater quantity of liquor, which
the vegetable takes in, than the animal,
whereby its motion is accelerated; for by
Experiment 1. we find the fun-flower, bulk
for bulk, imbibes and perfpires feventeen
times more frefh liquor than a man, every
24 hours.

Befides, nature's great aim in vegetables
being only that the vegetable life be carried
on attd maintained, there was no occafion

Vegetable Stathks. 145

to give its fap the rapid motion which was
necefTary for the blood of animals.

In animals, it is the heart which fets the
blood in motion, and makes it continually
circulate ; but in vegetables we can difco-
ver no other caufe of the fap's motion, but
the ftrong attraction of the capillary fap-
veflels, affifted by the brisk undulations and
vibrations, caufed by the fun's warmth,
whereby the fap is carried up to the top of
the talleft trees, and is there perfpired oft
thro' the leaves : But when the furface of
the tree is greatly diminished by the lofs of
its leaves, then alfo the perfpiration and
motion of the fap is proportionably dimi-
nifhed, as is plain from many of the fore-
going experiments : So that the afcending
velocity of the fap is principally accelerated
by the plentiful perfpiration of the leaves,
thereby making room for the fine capillary
veffels to exert their vaftly attracting power,
which perfpiration is effected by the brisk
rarefying vibrations of warmth : A power
that does not feem to be any ways well
adapted to make the fap defcend from
the tops of vegetables by different veflels
to the root.

144 Vegetable Stathh.

If the fap circulated, it muft needs have
been feen defcending from the upper part
of large games cut in branches fet in wa-
ter, and with columns of water prefling on
their bottoms in long glafs tubes, in Ex-
periment 43, and 44. In both which
cafes, it is certain that great quantities of
water paffed thro' the ftem, fo that it muft
needs have been feen defcending, if the return
of the fap downwards were by trufion or pul-
fion, whereby the blood in animals is re-
turned thro* the veins to the heart: And
that pulfion, if there were any, muft necef-
farily be exerted with prodigious force, to
be able to drive the fap thro* the finer capil-
laries. So that, if there be a return of rhe
fap downwards, it muft be by attraction,
and that a very powerful one, as we may
fee by many of thefe experiments, and par-
ticularly by Experiment 11. But it is hard
to conceive, what and where that power is,
which can be equivalent to that provifion
nature has made for the afcent of the fap
in confequence of the great perfpiration of
the leaves.

The inftances of the JefTamine tree, and
of the Paflion tree, have been looked upon
as ftrong proofs of the circulation of the

ftp.

Vegetable Stathks. 145

lap, becaufe their branches, which were far
below the inoculated Bud, were gilded:
But we have many vifible proofs in the Vine,
and other bleeding trees, of the Tap's recede-
ing back, and pufhing forwards alternately,
at different times of the day and night.
And there is great reafon to think, that the
fap of all other trees has fuch an alternate^
receding and progreffive motion, occafioned
by the alternacies of day and night, warm
and cool, moift and dry.

For the fap in all vegetables does proba^
bly recede in fome meafure from the tops
of branches, as the fun leaves them ; be-
caufe its rarefying power then ceafing, the
greatly rarefied fap, and air mixt with it,
will condenfe, and take up lefs room than
they did, and the dew and rain will then
be ftrongly imbibed by the leaves, as is pro-
bable from Exper. 42. and feveral others;
whereby the body and branches of the ve-
getable which have been much exhaufted by
the great evaporation of the day, may at
night imbibe fap and dew from the leaves;
for by feveral Experiments in the firft chap-
ter, plants were found to increafe consider-
ably in weight, in dewy and moift nights.
And by other experiments on the Vine in

L the

\<\6 Vegetable Staticks.

the third chapter, ic was found, that the
trunk and branches of Vines were always
in an imbibing ftate, caufed by the great
perfpirarion of the leaves, except in the
bleeding feafon ; but when at night that
perfpiring power ceaies, then the contrary
imbibing power will prevail, and draw the
fap and dew from the leaves, as well as
moifture from the roots.

And we have a farther proof of this in
Experiment 12, where, by fixing mercurial
gages to the ftems of feveral trees, which
do not bleed, it is found that they are al-
ways in a ftrongly imbibing ftate, by draw-
ing up the mercury feveral inches: whence
it is eafy to conceive, how fome of the
particles of the gilded Bud, in the inocu-
lated JefTamine, may be abforbed by it,
and thereby communicate their gilding
Miafma to the fap of other branches; efpe-
cially when fome months after the inocu-
lation, the ftock of the inoculated JefTa-
mine is cut off a little above the Bud;
whereby the ftock, which was the counter-
acting part to the ftem, being taken away,
the ftem attracts more vigoroufly from the
Bud.

Another

Vegetable Statich. 147

Another argument for the circulation of
the fap, is that fome forts of graffs will
infect and canker the flocks they are grafted
on : But by Exper. 12, and 37, where mer-
curial gages were fixed to frefh cut flems of
trees, it is evident that thofe flems were
in a flrongly imbibing flate ; and confe-
quently the cankered flocks might very like-
ly draw fap from the graft, as well as the
graff alternately from the flock; jufl in the
fame manner as jeaves and branches do
from each other, in the viciffitudes of day
and night. And this imbibing power of
the flock is fo great, where only fome of
the branches of a tree are grafted, that the
remaining branches of the flock will, by
their ftrong attraction, flarve thofe graffs;
for which reafon it is ufual to cut off the
greatefl part of the branches of the flock,
leaving only a few fmall ones to draw up
the fap. See. Vol. II, ^.265,

The inflance of the Ilex grafted upon the
Englijh Oak, feems to afford a very confi-
derable argument againfl a circulation. For,
if there were a free uniform circulation of
the fap thro' the Oak and Ilex, why fhould
the leaves of the Oak fall in winter, and not
thofe of the Ilex ?

L 2 Another

148 Vegetable Stattch.

Another argument againft an uniform cir-
culation of the fap in trees, as in animals,
may be drawn from Exper. $j. where ic
was found by the three mercurial gages
fix'd to the fame Vine, rhat while fome of
its branches changed their flate of protrude-
ing fap into a ftate of imbibing, others con-
tinued protruding fap, one nine, and the
other thirteen days longer.

In the fecond Vol. of Mr. Lowthorp's
Abridgment of the Philof. T^ranfaB, p. 708.
is recited an Experiment of Mr. Brother-
tons -, viz. A young Hazel n (Fig. 27.) was
cut into the body at x z with a deep gam ;
the parts of the body below at z> and
above at x> were cleft upwards and down-
wards, and the fplinters x z by wedges were
kept off from touching each other, or the
reft of the body. The following year, the
upper fplinter x was grown very much, but
the lower fplinter x did not grow 3 but the
reft of the body grew, as if there had been
no gafh made: I have not yet fucceeded in
making this Experiment, the wind having
broken at x z all the trees I prepared for
it : But if there was a Bud at x which (hot
out leaves, and none at z, then, by Experi-
ment 41, 'tis plain that thofe leaves might

draw

Vegetable Staticks. 149

draw muchnourifhment thro'/ x, and there-
by make it grow -> and I believe, if, vice
verfa, there were a leaf-bearing Bud at z>
and none at x, that then the fpl inter z
would grow more than x.

The reafon of my conjecture I ground
upon this Experiment, viz. I chofe two
thriving moots of a dwarf Pear-tree, 1 1 a ay
Fig. 28, 29. At three quarters of an inch
diftance I took half an inch breadth of bark
off each of them, in feveral places, viz,
2,4, 6, 8, and at 10, 12, 14. Every one of
the remaining ringlets of bark had a leaf-
bearing bud, which produced leaves the
following fummer, except the ringlet 13,
which had no fuch Bud. The ringlet 9
and 11 of a a grew and fwelled at their
bottoms till Augujl, but the ringlet 13 did
not increafe at all, and in Auguft the whole
moot a a withered and died ; but the (hoot
/ / lives and thrives well, each of its ringlets
fwelling much at the bottom: Whch fwel-
lings at their bottoms muft be attributed
to fome other caufe than the floppage of
the fap in its return downwards, becaufe in
the (hoot //, its return downwards is in-
tercepted three feveral times by cutting
away the bark at 2, 4, 6. The larger and
L 3 mors

1 5 o Vegetable Statich.

more thriving the leaf-bearing Bud was, and
the more leaves it had on ir, fo much the
more did the adjoining bark fwell at the
bottom.

Fig. 30. reprefents the profile of one of
the divifions in Fig. 28. fplit in halves; in
which may be feen the manner of the
growth of the lafl; year's ringlet of wood
mooting a little upwards at x x -, and moot-
ing downwards and fwelling much more at
z z 5 where we may obferve, that what is
fhot end-ways is plainly parted from the
wood of the preceding year, by the narrow
interflices x r, z r\ whence it mould feem,
that the growth of the yearly new ringlets
of wood confiits in the mooting of their
fibres lengthways under the bark.

That the fap does not defcend between
the bark and the wood, as the favourers
of a circulation fuppofe, feems evident from
hence, viz. that if the bark be taken off
for three or four inches breadth quite round,
the bleeding of the tree above that bared
place will much abate, which ought to have
the contrary effect, by intercepting the courfe
of the refluent fap, if the fap defcended by
the bark.

But

Vegetable St Micks. 1 5 i

Eut the reafon of the abatement of the
bleeding in this cafe may well be account-
ed for, from the man if eft proof we have
in thefe Experiments, that the fap is ftrong-
]y attracted upwards by the vigorous ope-
ration of the perfpiring leaves, and attract-
ing Capillaries : But when the bark is cut
off for fome breadth below the bleeding
place, then the fap which is between the
bark and the wood below that disbarked
place, is deprived of the ftrong attracting
power of the leaves, &c. and confequently
the bleeding wound cannot be fupplied fo
fad with fap, as it was before the bark was
taken off.

Hence alfo we have a hint for a probable
conjecture, why in the alternately disbarked
flicks, 1 1 a a, Fig. 2829. the bark fwelled
more at the upper part of the disbarked
places than at the lower; viz, became thofe
lower parts were thereby deprived of the
plenty of nourifhment which was brought
to the upper parts of thofe disbarked places
by the ftrong attraction of the leaves on the
Buds 7, Gfc. of which we have a further
confirmation in the ringlet of bark, N°. i?a
Fig. 29. which ringlet did not fwell or grow
$t either end? being not only deprived of

L 4 the

i J* Vegetable Statich.

the attraction of the fuperior leaves, by the
bark placed N°. 12. but alfo without any
leaf-bud of its own, whole branching fap-
veffels, being like thofe of other leaf-buds
rooted downwards in the wood, might
thence draw fap, for the nourifnment of it-
felf and the adjoining bark, N°. 13. But
had thefe rooting fap veffels run upwards,
inftead of downwards, 'tis probable, that in
that cafe the upper part of each ringlet of
bark, and not the lower, would have fwel-
led, by having nourifhment thereby brought
to it from the inmoft wood.

We may hence alfo fee the reafon why,
when a tree is unfruitful, it is brought to
bear fruit, by the taking ringlets of bark off
from its branches; viz. becaufe thereby a
lefs quantity of fap arifing, it is better di-
gefted and prepared for the nourifhment of
the fruit; which from the greater quantity
of oil, that is ufually found in the feeds,
and their containing veffels, than in other
parts of plants, (hews that more fulphur and
air is requifite for their production, than
there is for the production of wood and
leaves.

But the rnoft confideratle cbjedicn
againft this progreffive motion of the fap,

without

PC &

[J- 1JQ

tflL.ZZ. \

xmu

s.c.

Vegetable Staticks. 15$

without a circulation, arifes from hence,
viz. that it is too precipitate a courfe, for
a due digeftion of the fap, in order to nu-
trition : Whereas in animals nature has pro-
vided, that many parts of the blood mall
run a long courfe, before they are either
applied to nutrition, or difcharged from the
animal.

But when we confider, that the great
work of nutrition, in vegitables as well as
animals, ( I mean, after the nutriment is got
into the veins and arteries of animals) is
chiefly carried on in the fine capillary vef-
fels, where nature felects and combines, as
ihall beft fuit her different purpofes, the fe-
veral mutually attracting nutritious particles,
which were hitherto kept disjoined by the
motion of their fluid vehicle; we fhall find
that nature has made an abundant provifion for
this work in the ftrudture of vegetables ; all
whofecompofition is made up of nothing elfe
but innumerable fine capillary veffels, and glan-
dulous portions or veficles. See Vol. W.p. 265.

Upon the whole, I think we have, from
thefe experiments and cbfervations, fuffici-
ent ground to believe, that there is no cir-
culation of the fap in vegetables; notwith-
standing many ingenious perfons have been

induced

f54 Vegetable Staticks.

induced to think there was, from leveral
curious obfervations and experiments, which
evidently prove, that the fap does in fome
meafure recede from the top towards the
lower parts of plants, whence they were
with good probability of reafon induced to
think that the fap circulated.

The likelieft method effectually and con-
vincingly to determine this difficulty, whe-
ther the fap circulates or not, would be by
ocular infpe&ion, if that could be attained :
And I fee no reafon we have to defpair of
it, fince by the great quantities imbibed and
perfpired, we have good ground to think,
that the progreffive motion of the fap is
confiderable in the largeft fap-veffels of the
tranfparent ftems of leaves: And if our eyes,
affifted with microfcopes, could come at this
defirable fight, I make no doubt but that
we fhould fee the fap which was progreffive
in the heat of day, would on the com-
ing on of the cool evening, and the falling
dew, be retrograde in the fame veffels.

CHAP,

Vegetable Staticks. 155

CHAP. V.

Experiments, whereby to prove, that a con-
siderable quantity of air is i?jfpired by
Plants.

IT is well known that air is a fine ela-
ftick fluid, with particles of very diffe-
rent natures floating in it, whereby it is ad-
mirably fitted by the great Author of na-
ture, to be the breath of life of vegeta-
bles, as well as of animals, without which
they can no more live nor thrive, than ani-
mals can.

In the Experiments on Vines, Chap. III.
we faw the very great quantity of air which
was continually afcending from the Vines,
thro' the fa p in the tubes; which manifestly
fhews what plenty of it is taken in by vege-
tables, and is perfpired off* with the fap thro*
the leaves.

Experiment XL VII.

Sept. 9th, at 9 a. m. I cemented an Apple-
branch b (Fig. 11.) to the glafs tube r i e z:
I put no water in the tube, but fet the end
of it in the ciftern of water x. Three

hours

156 Vegetable Statich.

hours after, I found the water fucked up in
the tube many inches to z; which fhews,
that a confiderable quantity of air was im-
bibed by the branch, out of the tube r i e z :
and in like manner did the Apricot-branch
(Exper. 29.) daily imbibe air.

Experiment XLVIII.

I took a cylinder of Birch with the bark
on, 16 inches long and -| diameter, and ce-
mented it fail at z (Fig. 32.) to the hole
in the top of the air-pump receiver p py
fetting the lower end of it in the ciftern of
water x ; the upper end of it at n was well
clofed up with melted cement.

1 then drew the air out of the receiver,
upon which innumerable air-bubbles iffued
continually out of the ftick into the wa-
ter x. I kept the receiver exhaufted all that
day, and the following night, and till the
next day at noon, the air all the while if-
fuing into the water *: I continued it thus
long in this ftate, that I might be well af-
fured, that the air muft pafs in through the
bark, to fupply that great and long flux of
air at x. I then cemented up five old eyes
in the ftick, between z and n> where little

(hoots had formerly been^ but were now

perifhed \

Vegetable Stattcks. 157

perifhed 5 yet the air flill continued to flow
freely at x.

It was obfervable in this, and many of
the Experiments on flicks of other trees,
that the air which could enter only thro'
the bark between z and ?t, did not iffue in-
to the water, at the bottom of the flick,
only at or near the bark, but thro' the
whole and inmofl fubflance of the wood ;
and that chiefly, as I guefs, by the largenefs
of the bafes of the hemifpheres of air thro*
the largefl veflels of the wood ; which ob-
fervation corroborates Dr. Grew's and Mal-
fight % opinion, that they are air-vefTels.

I then cemented upon the receiver the
cylindrical glafs y yy and filled it full of wa-
ter, fo as to fland an inch above the top n
of the flick.

The air flill continued to flow at xy but
in an hours time it very much abated, and
in two hours ceafed quite ; there being
now no pafTage for frefh air to enter, and
fupply what was drawn out of the flick.

I then with a glafs crane drew off the
water out of the cylinder^ y\ yet the air
did not iflue thro* the wood at x.

I therefore took the receiver with the
ftick in it, and held it near the fire, till the

bark

1 5 8 Vegetable Statuks.

bark was well dried ; after which I fet it
upon the air-pump, and exhaufled the air;
upon which the air iflued as freely at xy as
it did before the bark had been wetted, and
continued fo to do, tho* I kept the receiver
exhausted for many hours.

I fixed in the fame manner as the pre-
ceding Birch-flick, three joints of a Vine-
branch, which was two years old, the up-
permofl knot r being within the receiver;
when I pumped 5 the air pafled moft freely
into the water x x.

I cemented fafl the upper end of the flick n%
and then pumped 3 the air flill iflued out at*,
tho' I pumped very long ; but there did not
now pafs the twentieth part of the air which
pafled when the end n was not cemented.

I then inverted the flick, placing n fix
inches deep in the water, and covered all the
bark from the furface of the water to z
the top of the receiver with cement; then
pumping the air which entered at the top
of the flick, pafled thro' the immerfed pare
of the bark: When I ceafed pumping for
fome time, and the air had ceafed ifluing
out; upon my repeating the pumping it
would again iflue out.

I found
I

Vegetable Statich. 159

I found the fame event in Birch and Mul-
berry flicks, in both which it iffued moft plen-
tifully at old eyes, as if they were the chief
breathing places for trees.

And Dr. Grew obferves, that " the pores
<c are fo very large in the trunks of fome
" plants, as in the better fort of thick walk-
u ing canes, that they are vifible to a good
" eye, without a glafs 5 but with a glafs the
" cane feems as if it were fluck top-full of
" holes, with great pins, being fo large as
" very well to refemble the pores of the
cc skin, in the end of the fingers, and ball
" of the hand.

" In the leaves of Pine they are likewife,
<c thro' a glafs, a very elegant fhew, (landing
" all moft exactly in rank and file, through
<c the length of the leaves." Grew's Anatomy
of Plants^ p. 127.

Whence it is very probable, that the air
freely enters plants, not only with the prin-
cipal fund of nourishment by the roots, but
alfo through the furface of their trunks and
leaves, efpecially at night, when they are
changed from a perfpiring to a flrongly im-
bibing flate.

I fix'd in the fame manner to the top of
the air-pump receiver, but without the cy-
lindrical

\6o Vegetable Statich.
lindrical glafs y y, the young {hoots of the
Vine, Apple-tree, and Honeyfuckle, both
erefted and inverted ; but found little or no
air came either from branches or leaves,
except what air lay in the furrows, and the
innumerable little pores of the leaves, which
are plainly vifible with the microfcope. I
tried alfo the fingle leaf of a Vine, both by
immerfing the leaf in the water x, and let-
ting the ftalk ftand out of the receiver, as
alfo by placing the leaf out of the receiver,
and the ftalk in the glafs of water x-> but
little or no air came either way.

I obferve in all thefe Experiments, that
the air enters very flowly at the back of
young (hoots and branches, but much more
freely thro' old bark: And in different kinds
of trees it has very different degrees of more
or lefs free entrance.

I repeated the fame Experiment upon fe-
veral roots of trees : The air patted moft
freely from n to x ; and when the glafs- vef-
felyy was full of water, and there was no
water in x, the water paffed at the rate of
3 ounces in 5 minutes; when the upper
end n was cemented up, and no water in yy>
fome air, tho' not in great plenty, would
enftr the bark at zf, and pafs thro* the wa-
ter at x. And

I PL -14-

Vegetable Stathks. \6t

And that there is fome air both in an
elaftick and unelaftick ftate, mix'd with the
earth, (which may well enter the roots with
the nourifhment) I found by putting into
the inverted glafs z z a a full of water
(Fig. 35.) fome earth dug up in an alley in
the garden, which, after it had flood foaking
for feveral days, yielded a little elaftick air,
tho' the earth was not half diflblved. And
in Experiment 68. we find that a cubick
inch of earth yielded 43 cubickinches of air
by diftillation, a good part of which was
roufed by the action of the fire from a fixed
to an elaftick ftate.

I fixed alfo in the fame manner young
tender fibrous roots, with the fmall end up-
wards at », and the vcffel y y full of water j
then upon pumping large drops of water fol-
lowed each other faft, and fell into theciftern
x, which had no water in it, See Vol II,

A 267.

M C H A p.

1 6 i jinaJyfts of the Air.
CHAP. VI.

A Specimen of an attempt to analyfe the Air
by a great variety of chymio-flatical Ex-
periments, which Jhew in hew great a
proportion Air is wrought into the com-
poftion of animal, vegetable, and mineral
Subflances, and withal how readily it re-
fumes its former elajlick fate, when in the
difjblution of thofe Subfances it is dif engaged
from them,

HAving in the preceding chapter pro-
duced many Experiments, to prove
that the Air is freely infpired by vegetables,
not only at their roots, but alfo thro' feveral
parts of their trunks and branches, which
Air was moft vifibly fcen afcending in great
plenty thro' the fap of the Vine, in tubes
which were affixed to them in the bleeding
feafon ; this put me upon making a more
particular inquiry into the nature of a fluid,
which is fo abfolutely neceffary for the fup-
port of the life and growth of Animals and
Vegetables.

The excellent Mr. Boyle made many Ex-
periments on the Air, and among other dif-

coveries,

Analyfis of the Air. 1 6 $

coveries, found that a good quantity of Air
was producible from Vegetables, by putting
Grapes, Plums, Goofeberries, Cherries, Peas,
and feveral other forts of fruits and grains
into exhaufted and unexhaufled recei\%s,
where they continued for feveral days emit-
ting great quantities of Air.

Being defirous to make fome further re-
fearches into this matter, and to find what
proportion of this Air I could obtain cut
of the different fubftances in which it was
lodged and incorporated, I made the fol-
lowing chymio-ftatical Experiments : For,
as whatever advance has here been made in
the knowledge of the nature of Vegetables,
has been owing to flatical Experiments, fo,
fince nature, in all her operations, acts con-
formably to thofe mechanick laws, which
were eftablifhed at her firft inflitution -? it
is therefore reafonable to conclude, that the
likeliefh way to inquire, by chymical ope-
rations, into the nature of a fluid, too fine
to be the object of our fight, mud be by
finding out fome means to eftimate what
influence the ufual methods of analyfing
the animal, vegetable, and mineral king-
doms, has on that fubtle fluid $ and this I
effected by affixing to retorts and boltheads
M 2 hydro-

1 64 Analyfis of the Ah.

hydroftatical gages, in the following man-
ner, viz.

In order to make an eftimate of the quan-
tity of x^ir which arofe from any body by
diftillation or fufion, I firft put the matter
which I intended to diftil into the fmall
retort r (Fig. 33.) ; and then at a cemented
faft to it the glafs veffel a by which was very
capacious at £, with a hole in the bottom.
I bound bladder over the cement which was
made of tobacco-pipe clay and bean flour,
well mixed with fome hair, tying over all
four fmall flicks, which ferved as fplinters
to ftrengthen the joint ; fometimes, inftead
of the glafs veflel a b, I made ufe of a large
bokhead, which had a round hole cut, with
a red hot iron ring at the bottom of it;
through which hole was put one leg of an
inverted fyphon, which reached up as far as
z. Matters being thus prepared, holding
the retort uppermoft, I immerfed the bolt-
head into a large veflel of water, to a the
top of the bolthead ; as the water rufhed in
at the bottom of the bolthead, the Air was
driven out through the fyphon: When the
bolthead was full of water to z, then I clofed
the outw7ard orifice of the fyphon with the
end of my finger, and at the fame time drew

the

Analyfis of the Air. 1 6 j

the other leg of it out of the bolthead ; by
which means the water continued up to zy
and could not fubfide. Then I placed under
the bolthead, while it was in the water, the
veffel xx ; which done, I lifted the veffel x xy
with the bolthead in it, out of the water,
and tied a waxed thread at z to mark the
height of the water : And then approached
the retort gradually to the fire, taking care
to fcreen the whole bolthead from the heat
of the fire.

The defcent of the water in the bolthead
{hewed the fums of the expanfion of the
Air in the retort, and of the matter which
was diftilling : The expanfion of the Air
alone, when the lower part of the retort was
beginning to be red hot, was, at a medium,
nearly equal to the capacity of the retorts, fo
that it then took up a double fpace ; and in
a white and almoft melting heat, the Air took
up a triple fpace, or fomething more : for
which reafon the leaft retorts are beft for
thefe Experiments. The expanfion of the
diftilling bodies was fometimes very little,
and fometime many times greater than that
of the Air in the retort, according to their
different natures.

M ? When

1 66 Jnalyjis of the Air.

When the matter was fufficiently diflilled,
the retort, &c. was gradually removed from
the fire j and when cool enough, was carried
into another room, where there was no fire.
When all was throughly cold, either the
following day, or fometimes three or four
days afier, I marked the furface of the water
v, where it then flood j if the furface of the
water was below z, then the empty fpace
between y and z (hewed how much Air was
generated, or raifed from a fix'd to an ela-
ftick ftate, by the aftion of the fire in diftil-
lation : But if v, the furface of the water,
was above z, the fpace between z and r,
which was filled with water, fhewed the
quantity of Air which had been abforbed in
the operation, i. e. was changed from a re-
pelling elaflick to a fix'd ftate, by the flrong
attraction of other particles, which I there-
fore call abforbing.

When I would meafure the quantity of
this new generated air, I feparated the bolt-
head from the retort ; and putting a cork
into the fmall end of the bolthead, I inverted
it, and poured in water to z. Then from
another vefTel ( in which I had a known
quantity of water by weight) I poured iri
water to *j fo the quantity of water which

Analyfis of the Ah. \ 67

was wanting, upon weighing this veffel again,
was equal to the bulk of the new generated
Air. I chofe to meafure the quantities of Air,
and the matter from whence it arofe, by
one common meafure of cubick inches,
eftimated from the fpecifick gravities of the
feveral fubftances, that thereby the propor-
tion of one to the other might the more
readily be feen.

I made ufe of the following means to
-meafure the great quantities of Air, which
were either raifed and generated, or ab-
forbed by the fermentation arifing from the
mixture of variety of folid and fluid fub-
ftances, whereby I could eafily eftimate the
furprizing effeds of fermentation on the
Air; viz.

I put into the bolthead b (Fig. 34.) the
ingredients, and then run the long neck of
the bolthead into the deep cylindrical glafs
ay, and inclined the inverted glafs ay, and
bolthead, almoft horizontally in a large vef-
felj of water, that the water might run into
the glafs a y\ when it was almoft up to a
the top of the bolthead, I then immerfed
the bottom of the bolthead, and lower part
y of the cylindrical glafs under water, rait-
ing at the fame time the end a uppermoft.

M 4 Then,

1 68 Analyfis of the Ah.

Then, before I took them out of the water,
I fet the bolthead and lower part of the cylin-
drical glafs a y into the earthen veffel x x,
full of water ; and having lifted all out of
the great veffel of water, I marked the fur-
face z of the water in the glafs ay.

If the ingredients in the bolthead, upon
fermenting, generated Air, then the water
would fall from z toy, and the empty fpace
z y was equal to the bulk of the quantity
of Air generated : But if the ingredients,
upon fermentation, did abforb or fix the
2c~tive particles of Air, then the furface of
the v/ater would afcend from z to n9 and
the fpace z ;/, which was filled with water,
was equal to the bulk of Air, which was
abforbed by the ingredients, ox by the fume
arifing from them : When the quantities of
Air, either generated or abforbed, were very
great, then I made ufe of large chymical re-
ceivers inflead of the glafs a y: But if thefe
quantities were very fmall, then, inftead of
the bolthead, and deep cylindrical glafs a y\
I made ufe of a fmall cylindrical glafs, or
a common beer glafs inverted, and placed
under it a phial or jelly-giafs, taking care that
the water did not come at the ingredients
in them., which was eafily prevented by

drawing

VLi5

j6~S>,

S.C.fcuipS,

Jnalyfis of the Air. \ 6 9

drawing the water up under the inverted
glafs to what height I pleafed by means of
a fyphon : I meafured the bulk of the fpaces
z y or z ny by pouring in a known quan-
tity of water, as in the foregoing Experi-
ment, and making an ' allowance for the
bulk of the neck of the bohhead within
the fpace z y.

When I would take an eftimate of the
quantity of Air abforbed and fixed, or ge-
nerated by a burning candle, burning brim-
ftone or nitre, or by the breath of a living
animal, &c. I firfl placed a high fland, or
pedeftal in the veflel full of water x x
(Fig. 3 5.) -, which pedeftal reached a little
higher than z z. On this pedeftal I placed
the candle, or living animal, and then
whelmed over it the large inverted glafs
z z a a, which was fufpended by a cord,
fo as to have its mouth r r three or four
inches under water ; then with a fyphon I
fucked the Air out of the glafs veflel, till the
water rofe to z fe. But when any noxious
thing, as burning brimftone, aquafortis, or
the like, were placed under the glafs ; then
by affixing to the fyphon the nofe of a large
pair of bellows, whofe wide fucking orifice
was clofed up, as the bellows were inlarged,

liic V

1 7 o Analyjis of the Air.

they drew the Air briskly out of the glafs
z z a a thro* the fyphon ; the other leg of
which fyphon I immediately drew from under
the glafs veflel, marking the height of the
water z z.

When the materials on the pedeftal ge-
nerated Air, then the water would fubfide
from zz to a a, which fpace z z a a was
equal to the quantity of Air generated : But
when the materials deflroyed any part of the
Air's elafticity, then the water would rife
from a a (the height that I in that cafe at
firft fucked it to) to z z, and the fpace aazz
was equal to the quantity of air, whofe elafti-
city was deflroyed.

Ifomeiimes fired the materials on the pe-
deftal by means of a burning glafs, viz. fuch
as phofphorus and brown paper dipped in
water, ftrongly impregnated with nitre, and
then dried.

Sometimes I lighted the candle, or large
matches of brimftone, before I whelmed the
glafs zz a a over them -, in which cafe I
inftantiy drew up the water to a a, which
by the expanfion of the heated Air would
at firft fubfide a little, but then immediately
turned to a rifing ftate; notwithftanding the
flame continued to heat and rarefy the Air

for

Analyjis of the Air. \ y \

for two or three minutes : As foon as the flame
was out, I marked the height of the water
z z-, after which the water would for twenty
or thirty hours continue rifing a great deal
above z z.

Sometimes, when I would pour violently
fermenting liquors, as aquafortis, &t\ on any
materials, I fufpendedthe aquafortis in a phial
at the top of the glafs velTel z z a a3 in fuch
manner, that by means of a firing, which
came down into the veffel x x, I could by
inverting the phial pour the aquafortis on
the materials, which were in a veiTel on the
pedeflal.

I fhall now proceed to give an account of
the^event of a great many Experiments, which
I made by means of thefe inftruments, which
I have here at firft defcribed, to avoid the fre-
quent repetition of a defcription of 'em.

It is confonant to the right method of phi-
lofophifing, firft, to analyfe the fubjecl:,
whofe nature and properties we intend to
make any refearches into, by a regular and
numerous feries of Experiments : And then,
by laying the event of thofe Experiments be-
fore us in one view, thereby to fee what
jight their united and concurring evidence

will

1 7 1 jinalyjis of the Air.

will give us. How rational this method is,

the fequel of thefe Experiments will (hew.

The illuftrious Sir Ifaac Newton (query
31ft of his Opticks) obferves, That " true
«c permanent Air arifcs by fermentation or
«c heat, from thofe bodies which the chy-
<c mifts call fixed, whofe particles adhere by
" a ftrong attraction, and are not therefore
" feparated and rarefied without fermenta-
" tion ; thofe particles receding from one
" another with the greater! repulfive force,
" and being molt difficultly brought toge-
" ther, which upon contact: were moil
u ftrongly united." And, query 30. "Denfe
cc bodies by fermentation rarefy into feveral
" forts of Air ; and this Air by fermen-
<c tation, and fometimes without it, re-
<c turns into denfe bodies." Of the truth of
which we have evident proof from many of
the following Experiments, viz.

That I might be well affured that no part
of the new Air which was produced in di-
ftillation of bodies, arofe either from the
greatly heated Air in the retorts, or from
the fubftance of the heated retorts, I firft
gave a red hot heat both to an empty glafs
retort, and alfo to an iron retort made of a
musket barrel ; when all v/as cold, I found

the

Analyfis of the Air. \ 7 }

the Air took up no more room than before it
was heated : whence I was allured, that no
Air arofe, either from the fubftance of the re-
torts, or from the heated air.

As to animal fubjlancesy a very confiderable
quantity of permanent Air was produced by
diftillation, not only from the blood and fat,
but alfo from the moft folid parts of animals.

Experiment XLIX.

A cubick inch of Hogs blood> diftilled to
dry fcoria, produced 33 cubick inches of Air,
which Air did not arife till the white fumes
arofe ; which was plain to be fctn by the
great defcent of the water at that time, in the
receiver az y (Fig. 33.)

Experiment L.

Lefs than a cubick inch of Tallow, being all
diftilled over into the receiver a z y, (Fig. 33.)
produced 18 cubick inches of Air.

Experiment LI.

241 Grains, or half a cubick inch of the
lip of zjalhw Deers horn, being diftilled in

the

t 7 4 Analyjis of the Ah.

the iron retort, made of a musket barrel,
which was heated at a fmith's forge, pro-
duced 117 cubick inches, that is, 234 times
its bulk of Air, which did not begin to rife
till the white fumes arofe; but then rufhed
forth in great abundance, and in good plenty,
alio with the fetid oil which came laft. The
remaining calx was two thirds black, the reft
afli-coloured; it weighed 128 grains, fo it
was not half wafted, whence there muft re-
main much fulphur in it ; the weight of water
to Air being nearly as 885 to one, as Mr.
Hawksbee found it, by an accurate Experi-
ment. A cubick inch of Air will weigh -| of
a grain, whence the weight of air in the horn
was 33 grains, that is, near \ part of the
whole horn.

We may obfcrve in this, as alfo in the pre-
ceding Experiment, and many of the follow-
ing ones, that the particles of new Air were
detached from the blood and horn, at the
fame time with the white fumes, which con-
ftitute the volatile fait: But this volatile fait,
which mounts with great adtivity in the Air,
is fo far from generating true elaftick Air, that
on the contrary it abforbs it, as I found by the
following Experiment.

Expe-

Analyfis of the AW. 1 7 5

Experiment LII.

A dram of volatile fait offal armoniack
foon diftilled over with a gentle heat 5 but
tho' the expanfion in the receiver was double
that of heated Air alone, yet no Air was ge-
nerated, but two and an half cubick inches
were abforbed.

Experiment LIII.

r Half a cubick inch of Oyfter-Jbell, or 266
grains, diftilled in the iron retort, generated
162 cubick inches, or 46 grains, which is a
little more than £ part of the weight of
the (hell.

Exp er 1 men t LIV.

Two grains of Phofphorus eafily melted
at fome diftance from the fire, flamed and
filled the retort with white fumes \ it ab-
forbed three cubick inches of Air. A like
quantity of Phofphorus^ fired in a large re-
ceiver, (Fig. 35.) expanded into a fpace equal
to fixty cubick inches, and abforbed 28 cu-
bick inches of Air: When three grains of
Phofphorus were weighed, foon after it was
burnt, it had loft half a grain of its weight;
but when two grains of Phofphorus were

weighed,

1 7 6 Analyjls of the Air.

weighed, fome hours after it was burnt, hav-
ing run more per deliquhim by abforbing the
moifture of the Air, it had increafed a grain
in weight.

Experiment LV.

As to vegetable fubftances, from half a
cubick inch, or 135 grains of heart of Oaki
frefh cut from the growing tree, were gene-
rated 108 cubick inches of Air, u e. a quan->
tity equal to 2 16 times the bulk of the piece
of Oak-, its weight was above thirty grains,
-J. part of the weight of 135 grains of Oak.
I took a like quantity of thin fhavings from
the fame piece of Oak, and dried them gently
at fome diftance from a fire for twenty-four
hours, in which time 44 grains weight of
moifture had evaporated ; which being de-
ducted from the 135 grains, there remain 91
grains for the folid part of the Oak : Then
the 30 grains of Air will be -| of the weight
of the folid part of the Oak.

Eleven days after this Air was made, I put a
live Sparrow into it, which died inftantly*

Experiment LVI.

From 388 grains weight of Indian Wheat \

which grew in my garden, but was not

come
1

Analyjis of the Air. 17 7

come to full maturity, were generated 270
cubick inches of air, the weight of which
air was 77 grains, viz. \ of che weight
of the Wheat.

Experiment LVII.

From a cubick inch, or 318 grains of
Peas, were generated 396 cubick inches of
air, or 113 grains, i. e. fomething more
than ■ of the weight of the Peas.

Nine days after this air was made, I
lifted the inverted mouth of the receiver
which contained it, out of the water, amd
put a lighted candle under it, upon which
it inftantly flafhed: Then I immediately im-
merfed the mouth of the receiver in the wa-
ter, to extinguilh the flame: This I repeated
8 or 10 times, and it as often flafhed, after
which it ceafed, all the fulphureous fpirrt be-
ing burnt. It was the fame with air of di-
ftilled Oyfter-fhell and Amber, and with new
diftilled air of Peas and Bees-wax. I found
it the fame alfo with another like quantity
of air of Peas; notwithstanding I wafhed
that air no lefs than eleven times, by pour-
ing it fo often under water, upwards, out
of the containing vefleL into another in-
verted receiver full of water,

N ExpE-

1 7 8 Ana l)fis of the Ah.

Experiment L VIII.

There were raifed from an ounce, or 437
grains of Mujlard-jeed, 270 cubick inches
of air, or yy grains; which is fomething
more than £ part of the ounce weight.
There was doubtlefs much more air in the
feed , but it rofe in an unelaftick ftate, be-
ing not difentangled from the Oil, which
was in fuch plenty within the gun-barrel,
that when I heated the whole barrel red hot,
in order to burn it our, it flamed vigoroufly
out at the mouth of the barrel. Oil alfo
adhered to the infide of the barrel, in the
diftillation of many of the other animal,
vegetable, and mineral fubftances ; fo that
the elaftick air which I meafured in the re-
ceiver, was not all the air contained in the
feveral diftill'd fubftances; fome remaining
in the Oil, for there is unelaftick air in Oil,
part being alfo reforbed by the fulphureous
fumes in the receiver.

Experiment LIX.

From half a cubick inch of Amber, or
135 grains, were raifed 135 cubick inches
of air, or 38 grains, viz. j\j Part °f *ts
weight. E x p e-

Analyfls of the Air. 179

Experiment LX.

From 142 grains of fay 'Tobacco were raifed
153 cubick inches of air, which is little
lefs than | of the whole weight of the To-
bacco ; yet it was not all burnt, part being
out of the reach of the fire*

Experiment LXI.

Camphire is a moft volatile fulphureous
fubftance fublimed from the Rofin of a tree
in the Eajl-Indies. A dram of it melted
into a clear liquor, at fome diflance from
the fire, and fublimed in the form of white
cryftals, a little above the liquor, it made
a very fmall expanfion, and neither gene-
rated nor abforbed air. The fame Mr. Boyle
found, when he burnt it in vacuo, Vol II.
p. 605.

Experiment LXIL

From about a cubick inch of chymical
Oil of Anifeed, I obtained 22 cubick inches
of air 5 and from a like quantity of Oil of
Olives, 88 cubick inches of air. Finding
that the Oil of Anifeed came plentifully
over into the receiver, in the diftillation of
N 2 the

1 8o Atialyjis of the Air.

the Oil of Olives, I raifed the neck of the
retort a foot higher ; by which means the
Oil could not fo eafily afcend, but fell back
again into the hottefl part of the retort;
whereby, as well as on account of the lefs
volatile nature of this Oil, more air was
feparated j yet in this cafe good flore of Oil
came over into the receiver ; in which
there was doubtlefs plenty of unelaftick
air : Whence, by comparing this with Ex-
periment 58, we fee that air is in greater
plenty feparated from the Oil, when in the
Muftard- feed, than it is from exprefTed or
chymical Oil.

Experiment LXIII.

From a cubick inch, or 359 grains of Ha-
?ieyy mixed with calx of bones, there arofe
144 cubick inches of air, or 41 grains, viz.
a little more than -£ part of the weight of
the whole.

Experiment LXIV.

From a cubick inch of yellow Bees-wax,
or 243 grains, there arofe 54 cubick inches
of air, or 15 grains -, the ^ part of the
whole.

Expe-

Analyjis of the Ait. 1 8 1

Experiment LXV.

From 373 grains, or a cubick inch of,
the, coarfeft Sugar, which is the effential
fait of the fugar-cane, there arofe 126 cu-
bick inches of air, equal to 36 grains, a lit-
tle more than 7V part of the whole.

Experiment LX VI.

I found very little air in 54 cubick inches
of Brandy, but in a like quantity of Well-
water I found one cubick inch. And it
was the fame in a little quantity of Brijlol
hot well water, and of Holt water. In
Piermont water there is near twice as much
air, as in Rain or common water, which air
contributes to the brisknefs of that and
many other mineral waters. I found thefe
feveral quantities of air, in thefe waters,
by inverting the nofes of bottles full of
thefe feveral liquors, into fmall glafs cif-
terns full of the fame liquor; and then
fetting them all together in a boiler, where
having an equal heat, the air was thereby
feparated, and afcended to the upper parts
of the bottles. See Vol. II. p. 269, 272.

N 3 Expe-

1 8 z Analyfis of the Air.

Experiment LXVJI.

By the fame means alfo, I found plenty
of air might be obtained from minerah.
Half a cubick inch, or 158 grains of New-
caflle coal, yielded in diftillation 180 cu-
bick inches of air, which arofe very fad
from the coal, efpecially when the yel-
lowifh fumes afcended. The weight of this
air is 5 1 grains, wThich is nearly ■§■ of the
weight of tne coals.

Experiment LXVIII.

A cubick inch of freih dug untried Earth
off the common, being well burnt in diftil-
lation, produced 43 cubick inches of air.
From Chalk alfo I obtained air in the fame
manner,

Experiment LXIX.

From a quarter of a cubick inch of An-
timo?iyy I obtained 28 times its bulk of air.
It was diftilled in a glafs retort, becaufe it
will demetalize iron.

Experiment LXX.

I proc red a hard, dark, grey Pyrites, a
vitriolick miner aljubjlance, which was found

7 feet

Analyjis of the Air. 1 8 j

7 feet under ground, in digging for fprings
on Walton-Heathy for the fervice of the
Right Honourable the Earl of Lincoln, at
his beautiful Seat at Oatlands in Surrey. This
mineral abounds not only with fulphur,
which has been dra^vn from it in good plen-
ty, but alfo with faline particles, which
fnoot vifibly on its furface. A cubick inch
of this mineral yielded in distillation 83
cubick inches of air.

Experiment LXXI.
Half a cubick inch of well decrepitated
Sea-falty mix'd with double its quantity of
calx of bones, generated 32 times its bulk
of air: It had fo great a heat given it, that
all being diftilled over, the remaining fco-
ria did not run per deliquium. I cleared
the gun-barrel of thefe and the like (bo-
na, by laying the end of the retort on an
anvil, and ftriking long on the outfide with
a hammer.

Experiment LXXII.

From 211 grains, or half a cubick inch
of Nitre, mixed with calx of bones, there
arofe 90 cubick inches of air, /. e. a quanti-
ty equal to 180 times its bulk ; fo the weight

N 4. of

1 84 Anatyfes of the Aw.

of air in any quantity of nitre is about \
part. Vitriol diftilled in the fame manner
yields air too.

Experiment LXXIII.

From a cubick inch, or 443 grains of
Kenijh 'Tartar, there arofe very fall 504 cu-
bick inches of air ; fo the weight of the air
in this Tartar was 144 grains, ;. e. \ part of
the weight of the whole: The remaining
fcoria, which was very little, run per deli-
quium, an argument that there remained
fome Sal Tartar % and confequently more air.
For,

Experiment LXXIV.

Half a cubick inch, or 304 grains of Sal
Tartar, made with nitre and tartar, and
mixed with a double quantity of calx of
bones, yielded in diftillation 112 cubick
inches of air; that is, 224 times its bulk
of air; which 112 cubick inches weighing
32 grains, is nearly ■§ part of the weight of
the Sal Tartar. There is a more intenfe de-
gree of heat required to raife the air from
Sal Tartar than from nitre.

Hence we fee, that the proportion of
air in equal bulks of Sal Tartar and nitre is

Analyjls of the Air, 185

as 224 to 180. But weight for weight, nitre
contains a little more air in it, than this Sal
Tartar made with nitre. But Sal Tartar
made without nitre, has probably a little
more air in it than this had, becaufe it is
found to make a greater explofion in the
Pulvis Fulminans, than the nitrated Sal
Tartar. But fuppofing, as is found by this
Experiment, that Sal Tartar, according to
its fpecifick gravity, contains j part more
in it than nitre ; yet this excefs of air is not
fufficient to account for the vaftly greater
explofion of Sal Tartar than of nitre ; which
feems principally to arife from the more
fix'd nature of Sal Tartar $ which therefore
requires a more intenfe degree of fire, to
feparate the air from the ftrongly adhering
particles, than is found requifite to raife the
air from nitre. Whence the air of Sal Tar-
tar muft neceffarily thereby acquire a greater
elaftick force, and make a more violent ex-
plofion, than that of nitre. And from the
fame reafon it is, that Aurum Fulmiiiam
gives a louder explofion than Pulvis Ful-
minant. The fcoria of this operation did
not run per deliquium, a proof that all the
Sal Tartar was diftilled over. See Vol. II.
p. 282.

From

i86 Analjfis oj the Air.

From the little quantity of air which is
obtained by the diftillation of that very fixe
body fea-falt, in Experiment 71. in compa-
rifon of what arifes from nitre and Sal Tar-
tary we fee the reafon why it will not go
off with an explofive force, likethofe when
fired. And at the fame time we may hence
obferve, that the air included in nitre and
Sal Tartar, bears a confiderable part in their
cxplofion. For fea-falt contains an acid
fpirit as well as nitre; anvd yet that without
a greater proportion of air does not qualify
it for explofion, thro* mixed like nitre in the
compofition of gun-powder, with fulphur
and charcoal.

Mr. Boyle found, that Aqua-fortis,}pouxzA

on a ftrong folution of fait of tartar, did not
fhoot into fair cryflals of falt-petre, till it
had been long expofed to the open air ;
whence he fufpected, that the air contribu-
ted to that artificial production of falt-petre.
And fays, " Whatever the air hath to do in
" this Experiment, we have known fuch
<c changes made in fome faline concretes>
<c chiefly by the help of the open air, a
(i very few would be apt to imagine." Vol.
I. p. 302. and Vol III. p. 80. And Chy-
rnifts obferve, that when the elTential falts

'of

Jnalyjis of the Air. 1 87

of vegetables are fet to cryftallize, it is
needful to take off the skin or Pellicle,
which covers the liquor, before the falts
will (hoot well.

We fee from the great quantity of air,
which is found in falts, of what ufe it is
in their cryflallization and formation; and
particularly, how neceflary it is in making
falt-petre from the mixture of fait of tartar,
and fpirit of nitre. For fince, by Experiment
72 and 73, a great deal of air flies away, in
the making of Sal Tartar, either from nitre
and tartar, or from tartar alone ; it muft
needs be neceflary, in order to the forming
of nitre from the mixture of Sal Tartar and
fpirit of nitre, that more air fhould be in-
corporated with it, than it contained either
in the Sal Tartar or fpirit of nitre.

Experiment LXXV.

Near half acubickinch of compound Aqua-
fortis, which bubbled, and made a con-
siderable expanfion in diftillation, was foon
diftilled off: as it cooled, the expanfion
abated very fa ft, and a little air was abforb-
ed. Whence it is evident, that the air ge-
nerated by the diftillation of nitre, did not
arife from the volatile fpirituous particles.

Hence

1 88 Analyfis of the Air.

Hence alfo it is probable, that there is
fome air in acid fpirirs, which is reforbed
and fixed by them in diftillation. And this
is furth crconfirmed from the many air-
bubbles which arife from Aqua-regiay in
the folution of gold ; for fince gold lofes
nothing of its weight in being diflblved, the
air cannot arife from the metalline part of
the gold, but muft either arife from the
Aqua-regia, or from latent air in the pores
of the gold.

Experiment LXXVJ.

A cubick inch of common Brimflone ex-
panded very little in diftrllation in a glafs
retort; notwitbftanding it had a great heat
given it, and was all diftilled over into the
receiver without flaming. It abforbed fome
air ; but flaming brimflone, by Experiment
103, abforbs much air.

A good part of the air thus raifed from
feveral bodies by the force of fire, was apt
gradually to loofe its elaflicity, in ftanding
feveral days -, the reafon of which was, ( as
will appear more fully hereafter) that the
acid fulphureous fumes railed with that air,
did rel'orb and fix the elaftick particles.

Expe-

Analyjis of the Air. 189

Experiment LXX VII.

To prevent which, I make ufe of the fol-
lowing method of diftillation, which is
much more commodious than with Glafs
Retorts, whofe juncture at a (Fig. 33.) it is
not eafy to fecure. Having firft put the
matter to be diftilled into the iron retort
r r (Fig. 38.) which was made of a musket
barrel, I then fixed a leaden fyphon to the
nofe of the retort 5 and having immerfed
the fyphon in the veffel of water x x, I
placed over the open end of the fyphon the
inverted chymical receiver a iy which was
full of water ; fo that, as the air which was
raifed in diftillation, paffed thro* the water
up to the top of the receiver a b, a good
part of the acid fpirit and fulphureous fumes
were by this means intercepted and retain-
ed in the water ; the confequence of which
Was, that the new generated air continued
in a more permanently elaftic'k ftate, very
little of it lofmg its elasticity, viz. not
above a 15th or 18th part, and that chiefly
the firft 24 hours ; after which the remain-
der continued in a conftantly elaftick ftate ,
excepting the airs of tartar and calcullus hu-
ymnus, which in 16 or 8 days loft conftantly

above

ipo Analyjis of the Air.

above one third of their elaflicity 5 aftef
which the remainder was permanently ela-
ftical. In which flate it has continued,
without any fenfible alteration, for thefe
fix years, that I have kept fome of the
air of calculus humanus by me.

That the great quantities of air, which are
thus obtained from thefe feveral fubflances
by diftillation, are true air, and not a mere
flatulent vapour, I was afTured by the fol-
lowing Trials; viz. I filled a large receiver,
which contained 540 cubick inches, with air
of tartar; and when it was cool, Ifufpended
the receiver on the end of a balance while its
mouth was inverted in water. Then, upon
lifting the mouth of the receiver out of water,
I immediately covered it by tying a piece of
bladder over it. When I had found the ex-
ad: weight, I blew out all the air of tartar
with a pair of bellows which had a long ad-
ditional nofe that reached to the bottom of
the receiver. And then tying the bladder
on, I weighed it again, but could find no
difference in the fpecifick gravity of the two
airs -, and it was the fame with an air of
tartar, which was 10 days old.

As to the other property of the air, elafli-
city, I found it exa&ly the fame in the air

Analyjis of the Jir. '191.

of tartar, which was 15 days old, and com-
mon air, by filling two equal tubes with
thefe different airs, the tubes were 10 inches
long, and fealed at one end ; I placed them
at the fame time in a cylindrical glafs con-
denfing receiver, where I compreffed them
with two additional atmofpheres, taking
care to fecure myfelf from danger in cafe
the glafs fliould burft, by placing it in a
deep wooden vcffel 5 the water rofe to equal
heights in both tubes. This receiver was
gently annealed, and thereby toughened, by
being boiled in Urine, where it lay till all
was cold.

I put alfo into the fame tubes fome new-
made air of tartar, both the tubes Handing
in cifterns of water; the air of one of thefe
tubes I compreffed in the condenfing en-
gine for fome days, to try whether in that,
compreffed ftate, more of the air's elafticity
would be deftroyed by the abforbing vapours,
than io an uncompreffed ftate; but I did
not perceive any fenfible difference.

Lemery\ in his courfe of chymiftry, p, 592.
obtained, in the diftillation of 48 ounces of
Tartar, 4 ounces of phlegm, 8 of fpirits,
3 of oil, and 32 of fcoria, L e. two thirds
of the whole; fo one ounce was loft in the
operation, In

lyi Analyjis of the Air.

In my diftillation of 443 grains of Tar-
tar m Exper. 73. there remained but 42
grains of fcoria, which is little more than
7V of the Tartar; and in this remainder,
there was, by Exper. 74. air; for there was
Sal Tartar , it running per deliquiujn.

Whence, by comparing Lemery's and my
diftillation together, we fhall find, that there
remained in this 32 ounces of fcoria, and
in the ounce that was loft, ( which was
doubtlefs moft of it air) fubftance enouah to
account for the great quantity of air, which
in Exper. 73. was raifed from Tartar; efpe-
cially, if we take into the account the pro-
portion of air, which was contained in the
oil, which was T^ part of the whole Tar-
tar, for there is much air in oH.

The bodies which I diftilled in this man-
ner, ( Fig. 38.) were Horn, Calculus lnimamisy
Oyfter-fhcll, Oak, Muftard-feed, Indian-
wheat, Peas, Tobacco, oil of Anifeed, oil
of Olives, Honey, Wax, Sugar, Amber, Coal,
Earth, Walton Mineral, Sea-falt, Salt-petre,
Tartar, Sal Tartar, Lead, Minium. The
greateft part of the air obtained from all
which bodies was very permanent, except
what the air of Tartar and calculus humanus
loft in ftanding feveral days. Particularly that

from

Analyjis of the Air. 193

from nitre loft little of its elafticity, where-
as moft of the air obtained from nitre, in
diftilling with the receiver (Fig. 33.) was
reforbed in a few days, as was alfo the air
which was generated from detonized nitre
in Experiment 102. Hence alfo we fee the
reafon why 19 parts in 20, of the air which
was generated by the firing of Gunpowder*
was in 18 days reforbed by the fulphureous
fumes of the Gunpowder -, as Mr. Hawksbee
obferved, in his phyfico-mechanical Experi-
ments, page 83.

In the diftillation of Horn, it was obferv-
able, that when towards the end of the ope-
ration the thick fetid oil arofe, it formed
very large bubbles, with tough unctuous
skins, which continued in that flate forne
time; and when they broke, there arofe
t)ut of them volumes of fmoak, as out of
•a chimney, and it was the fame in the di-
stillation of Muftard-feed.

An Account of some Experiments made

on Stones taken ou t of human
Urine, and Gall-bladders.

Aving procured, by the favour of Mr.
Ranby, Surgeon to His Majejtfs

O Roupjcti,

1 94 Analyfis of the Air.
Houjho/d, fome calculi humanly I made the
following Experiments with them, which I
fhall here infer t, viz.

I diftilled a calculus in the iron retort
(Fig. 38.) ; it weighed 230 grains, it was
fomeihing lefs in bulk than | of a cubick
inch : There arofe from it very briskly, in
diftillation, 516 cubick inches of elaftick air,
that is, a bulk equal to 645 times the bulk
of the ftone -, fo that above half the ftone
was raifed by the adtion of the fire into ela-
ftick air > which is a much greater propor-
tion of air than I have ever obtained by
fire from any other fubftances, whether ani-
mal, vegetable or mineral. The remaining
calx weighed 49 grains, that is, ^-^ part
of the calculus ; which is nearly the fame
proportion of calx, that the worthy Dr. Slave
found remaining, after the diftilling and cal-
cining two ounces of calculus \ " one ounce
u and three drams of which (he fays) eva-
porated in the open fire, (a material cir-
cumftance, which the chymifts rarely in-
quire after) of which we have no account."
Philof. Tra?7faB. Lowthorp's Abridgment, Vol.
III. p. 179. The greateft part of which was,
we fee by the prefent Experiment, raifed into

permanently elaftick air.

€<

Analyfis of the Ah. \ 9 5

By comparing this diftillation of the cal-
culus with that of Renijh Tartar \ in Expe-
riment 73, we fee that they both afford more
air in diftillation, than any other fubftances :
And it is remarkable, that a greater propor-
tion of this new raifed air from thefe two
fubftances, is reforbed, and lofes its elafti-
city, in ftanding a few days, than that of any
other bodies; which are ftrong fymptoms
that the calculus is a true animal Tartar*
And as there was very confiderably lefs oil,
in the diftillation of Renijh Tartar, than
there was in the diftillation of the feeds and
folid parts of vegetables ; fo I found that
this calculus contained much lefs oil than
the blood or folid parts of animals.

I diftilled in the fame manner as the above-
mentioned calculus, fome ftones taken out
of a human gall bladder j they weighed fifty-
two grains, fo their bulk was equal to .i part
of a cubick inch, as I found by taking their
fpecifick gravity. There were 108 cubick
inches of elaftick air raifed from them in
diftillation, a quantity equal to 648 times
their bulk; much the fame quantity that
was raifed from the calculus, About i. part
of this elaftick air was in four days reduced
into a fix'd ftate, There arofe much morq

O 2 oi

i p 6 Analyfis of the An.

oil in the diftillation of thefe Scones, than
from the calculus, part of which oil did
arife from the gall, which adhered to and
was dried on the furfaces of the ftones.;
which oil formed large bubbles, like thofe
which arofe in the diftillation of Deers-
horn, p. 193.

A fmall ftone of the gall bladder, which
was as big as a Pea, was diffolved in a Li-
xivium of Sal Tartar in feven days, which
Lixivium will alfo diffolve Tartar-, yet it
will not diffolve the calculus, which is more
firmly , united in its parts.

A quantity of calculus equal to one half
of what was diftilled, viz. 115 grains, did,
when a cubick inch of fpiric of nitre was
poured on it, diffolve in 2 or 3 hours, with
a large froth, and generated 48 cubick inches
of air, none of which loft its elafticity, tho'
it flood many days in the glafs veffel. (Fig.
34.). And a like quantity of Tartar being
mixed with fpirit of nitre, was in the fame
time diffolved ; but no elaftick air was gene-
rated, notwithftanding Tartar abounds fo
much with air.

Small pieces of Tartar and Calculus were
in 12 or 14 days both diffolved by oil of
Vitriol y the like pieces of Tartar and Cal-
culus

Analyfis of the An. \ <)j

cuius were diffolved in a few hours by oil of
Vitriol, into which there was gradually poured
near an equal quantity of fpirit of Harts-
horn, made with Lime, which caufed a cons-
iderable ebullition and heat.

Tho' the remaining calx of the diftillation
of Tartar, in Experiment 73. run per deli-
quiu?n, and had therefore Sal Tartar in it >
and tho* the calx of the diftilled Calculus did
not run per deliquium, and had confequently
no Sal Tartar in it ; yet it cannot thence
be inferred, that the Calculus is not a tar-
tarine fubftance : Becaufe by Experiment 74.
it is evident, that Sal Tartar itfelf, when
mixed wTith an animal calx, diftils all over,
fo that the calx will not afterwards run per
deliquium.

By the great fimilitude there is therefore
in fo many refpe&s between thefe two fub-
ftances, we may well look upon the Calculus,
and the Stone in the Gall Bladder, as true
animal Tartars ; and doubtlefs Gouty concre-
tions are the fame.

From the great quantities of Air that are
found in thefe Tartars, we fee that unela-
flick Air particles, which by their ftrongly
attracting property are fo inftrumental in form-
ing the nutritive matter of Animals and Ve-
O 3 getables,

i p 8 Analyfis of the Air.

getables, are by the fame attractive power apt
fometimes to form anomalous concretions,
as the Stone, &c. in Animals, efpccially in
thofe places where any animal fluids are in
a ftagnant ftate, as in the Urine and Gail-
Bladders 'y they ftrongly adhere alfo to the
fides of Urinals, ©V. The like tartarine con-
cretions are alfo frequently formed in fome
fruits, particularly in Pears ; but they do then
efpecially coalefce in greateft plenty, when
the vegetable juices are in a ftagnant ftate, as
in wine veffels, &c.

This great quantity of ftrongly attra&ing,
unelaftick Air particles, which we find in the
calculus, {hould rather encourage than dif-
courage us, in fearching after fome proper
diffolvent of the Stone in the Bladder, which,
upon the Analyfis of ir, is found to be well
ftored with adtive principles, fuch as are the
principal agents in fermentation. For Mr.
Boyle found therein a good quantity of vola-
tile fait, with fome oil ; and we fee by the
prefent Experiment, that there is ftore of
unelaftick Air particles in it. The difficulty
feems chiefly to lie, in the over-proportion
of thefe laft-mentioned particles, which are
firmly united together by fulphur and fait;

the

Anal)Jis of the Ah. 1 9 9

the proportion of caput moriuum, or earth,
bekig very fmall. Vide Vol. II. p. 189.

Experiment LXXVIII.

One eighth of a cubick inch of Mercury
made a very infenfible expanfion in diftilla-
tion, notwithftanding the iron retort had an
almoft melting heat given it at a fmith's forge,
fo that it made an ebullition, which could be
heard at fome diftance, and withal fhook the
retort and receiver. There was no Air gene-
rated, nor was there any expanfion of Air in
the following Exper. viz.

Experiment LXXIX.

I put into the fame retort half a cubick
Inch of Mercury, affixing to the retort a very
capacious receiver, which had no hole in the
bottom. The wide mouth of the receiver
was adapted to the fmall neck of the retort
(which was made of a mufket barrel) by means
of two large pieces of cork,which entered and
filled the mouth of the receiver, they having
holes bored in them of a fit fize for the neck
of the retort; and the jundlure was farther
fecured, by a dry fupple bladder tied over it •
O 4 for

2 oo Analyfn of the Air.

for I purpofely avoided making ufe of any
moift lute, and took care to wipe the infide
of the receiver very dry with a warm cloth.

The Mercury made a great ebullition, and
came fomc of it over into the receiver, as foon
as the retort had a red heat given it, which
was increafed to a white and almoft melting
hear, in which ftate it continued for half an
hour. During which time, I frequently co-
hobated fome part of the Mercury which
condenfed, and was lodged on an horizontal
level, about the middle of the neck of the
reron : And which, upon raifing the receiver,
flowed down into the bottom of the retort, and
there made a frefh ebullition \ which had
ceafed, when all the Mercury was diflilled
from the bottom of the retort. When all
was cool, I found about two drams of Mercury
in the retort, and loft in the whole forty-three
grains, but there was not the leaft moiflure in
the receiver-.

Whence it is to be fufpected that Mr. Boyle
and others were deceived by fome unheeded
circumftance, when they thought they ob-
tained a water from Mercury in the diflilla-
tion of it 5 which he fays he did once, but
could not make the like Experiment after-
wards fucceed. Boyle, Vol. III. p. 416.

I re

Jnalyfis of the Air. i o i

I remember that about twenty years fince, I
was concerned with feveral others in making
this Experiment at the Elaboratory in Trinity
College Cambridge ; when imagining there
would be a very great expanfion, we luted a
German earthen retort to three or four large
Alodals, and a capacious receiver; as Mr.
WUfon did in his courfe of chymiftry. Four
pounds of Mercury were poured by little and
little into the red hot retort, thro' a tobacco-
pipe purpofely affixed to it. The event was,
that we fpund fome fpoons full of water with
the Mercury in the Alodals, which I then fuf-
pedted to arife from the moifture of the earthen
retort and lute, and am now confirmed in
that fufpicion. It rained inceflantly all the
day, when I made this prefent Experiment 5
fo that, when water is obtained in the diflil-
lation of Mercury^ it cannot be owing to a
moifler temperature of the Air.

The Effecls of Fermentation on the Air.
See Vol. II. page 295.

HAving from the foregoing Experiments
feen very evident proof of the produc-
tion of confiderable quantities of true elaflick
Air, from liquors and folid bodies, by means

202 Analyjis of the Air.

of fire ; we fliall find in the following Expc-r
riments many inftances of the production,
and alfo of the fixing or abforbing of great
quantities of Air, by the fermentation arifing
from the mixture of variety of folids and fluids:
Which method of producing and of abforbing,
and fixing the elaftick particles of Air by fer-
mentation, feems to be more according to
nature's ufual way of proceeding, than the
other of fire.

Experiment LXXX.

I put into the bolthcad b (Fig. 34.) fixteen
cubick inches of Sheep's blood, with a little
water to make it ferment the better. I found
by the defcent of the water from z to y, that
in eighteen days fourteen cubick inches of Air
were generated.

Experiment LXXXL

Volatile Salt of Sal Ammoniac > placed in aa
open glafs ciftern, under the inverted glafs
z z a a, (Fig. 35.) neither generated nor ab-
forbed Air. Neither did feveral other vola-
tile liquors, as fpirits of Harts-horn, fpirits of
Wine, nor compound Aquafortis, generate

anv

Analyjls of the AW. 105

any Air. But Sal Ammoniac, Sal -Tartar,
and fpirits of Wine mixed together, generated
twenty-fix cubick inches of Air, two of which
were in four days reforbed, and after that ge-
nerated again.

Experiment LXXXII.

Haifa cubick inch of Sal Ammoniac, and
double that quantity of Oil oi Vitriol, gene-
rated the firft day 5 or 6 cubick inches: But
the following days it abforbed 15 cubick inches,
and continued many days in that ftate.

Equal quantities of fpirit of Turpentine,
and Oil of Vitriol, had near the fame effedt,
except that it was fooner in an abforbing ftate
than the other.

Mr. Geoffroy fhews, that the mixture of
any vitriolic fairs, with inflammable fubftan-
ces, will yield common Brimftone; and by
the different compolitions he has made of
fulphur, and particularly from Oil of Vitriol,
and Oil of Turpentine, and by the Analyfis
thereof, when thus prepared, he difcovered
it to be nothing but vitriolic fait, united with
the combuftibie fubftance. French Memoirs,
Anno 1704. p. 381. or Boyle's Works, Vol
III. p. 273. Notes.

Expe-

204 Analyfis of the Air.

Experiment LXXXIII.

In February I poured on fix cubick inches
of powdered Oyfter-Jloell, an equal quantity of
common white-wine Vinegar. In five or fix
minutes it generated feventeen cubick inches
of Air, and in fome hours twelve cubick inches
more ; in all twenty-nine inches. In nine
days it had llowly reforbed 2 1 cubick inches
of Air. The ninth day I poured warm water
into the veflel x x> (Fig. 34.) and the follow-
ing day, when all was cool, I found (hat it
had reforbed the remaining eight cubick inches.
Hence we fee, that warmth will fometimes
promote a reforbing as well as a generating
ftate, viz. by raifing the reforbing fumes, as
will appear more hereafter.

Half a cubick inch of Oyfter-Jhell, and a
cubick inch of 0/7 of Vitriol, generated thirty-
two cubick inches of Air.

Oyjlerfoell, and two cubick inches of four
Rennet, of a Calf's ftomach, generated in
four days, eleven cubick inches, But Oyjier-
JJpell with fome of the liquor of a Calf's fto-
mach, which had fed much upon Hay, did
not generate air. It. was the fame vrithOv/ler -
Jhell and Ox-gall, Urine and Spittle.

Half

Analyfis of the Air. 205
Half a cubick inch oWyJler-fielUn&Sevil
Orange juice generated the firft day thirteen
cubick inches of Air, and the following days
it reforbed that, and three or four more cu-
bick inches of Air, and would fometimes
generate again. It was the fame with Limon
juice.

x Oyjlerfiell and Milk generated a little Air :
But Limon juice and M/7/£did at the fame time
abforb a little Air ; as did alfo Calves Rennet
and Vinegar ; fome of the fame Rennet alone
generated a little Air, and reforbed it again the
following day. It had the fame eftedt when
mixed with crums of bread.

Experiment LXXXIV.

A cubick inch of Limonjuice, and near an
equal quantity of fpirifs of Harts-horn, perfe,
i. e. not made with Lime, did in four hours
abforb three or four cubick inches of Air j
and the following day it remitted or generated
two cubick inches of Air: The third day;
turning from very warm to cold, it again re-
forbed that Air, and continued in an abforb-
ing flate for a day or two.

That there is great plenty of Air incorpo-
rated into the fubftanceof Vegetable's, which

io6 Analyjis of the Air.

by the a&ion of fermentation is rouzed into
an elaftick ftate, is evident by thefe following
Experiments, viz.

Experiment LXXXV.

March the fecond I poured into the bolt-
head b (Fig. 34.) forty-two cubitk inches of
Ale from the tun, which had been there fet
to ferment thirty-four hours before: From
that time to the ninth of "June it generated 63 9
cubick inches of Air, with a very unequal
progreffion, more or lefs as the weather was
warm, cool, or cold j and fometimes, upon a
change from warm to cool, it reforbed Air,
in all thirty-two cubick inches^

Experiment LXXXVI.

March the fecond, twrelve cubick inches of
Malaga Raifins, with eighteen cubick inches
of water, generated by the 1 6th of April 411
cubick indies of Air ; and then in two or three
cold days it reforbed thirty-five cubick inches.
From the 2 ift of April to the 16th of May it
generated 78 cubick inches; after which to
the 9th of June it continued in a reforbing
ftate, fo as to reforb 13 cubick inches -, there

were

Analyjis of the Air. 1 07

were at this feafon many hot days, with much
thunder and lightning, which deftroys the Airs
elafticity; fo there were generated in all 489
cubick inches, of which 48 were reforbed.
The liquor was at laft very vapid.

From the great quantity of Air generated
from Apples, in the following Experiment, 'tis
probable, that much more Air would have
rifen from the laxer texture of ripe undried
Grapes, than did from thefe Raifins.

We fee from thefe Experiments on Raifins
and Ale, that in warm weather Wine and Ale
do not turn vapid by imbibing Air, but by fer-
menting and generating too much, whereby
they are deprived of their enlivening principle,
the Air; for which reafon thefe liquors are
beft preferved in cool cellars, whereby this
a&ive invigorating principle is kept within due
bounds, which when they exceed, Wines are
upon the fret and in danger of being fpoiled.

Experiment LXXXVII.

Twenty-fix cubick inches of Apples being
mzftied Augujl 10, they did in thirteen days
generate 968 cubick inches of Air, a quantity
equal to 48 times their bulk ; after which they
did in three or four days reforb a quantity equal

t o 8 Analyfts of the Air.

to their bulk, notwithftanding it was very
hot weather ; after which they were ftatio-
nary, neither reforbing nor generating Air in
many days.

A very coarfe Brown-fugar, with an equal
quantity of water, generated nine times its
bulk of Air; Rice-four fix times its bulk;
Scurvy-grafs leaves generated and abforbed
Air; Peas, Wheat and Barley did in Fer-
mentation alfo generate great quantities of
Air.

That this Air, which arifes in fuch great
quantities from fermenting and dhTolving
vegetables, is true permanent Air, is certain,
by its continuing in the fame expanded elaftick
ftate for many weeks and months; which ex-
panding watry vapours will not do, but foon
condenfe when cool. And that this new gene-
rated Air is elaftical, is plain, not only by its
dilating and contracting with heat and cold,
as common Air does, but alfo by its being
compreffible, in proportion to the incumbent
weight, as appears by the two following Ex-
periments, which fhew what the great force
of thefe aerial particles is, at the inftant they
cfcape from the fermenting vegetables.

E X P E-

Analyjis of the Air. 209

Experiment LXXXVIII.

I filled the ftrong Hungary-water Bottle I? c
(Fig, 3 6.) near half full of Peas, and then full
of water, pouring in, firft, half an inch depth
of Mercury ; then I fcrewed at b into the
bottle the long {lender tube a z, which reached
down to the bottom of the bottle ; the water
was in two or three days all imbibed by the
Peas, and they thereby much dilated ; the
Mercury was alfo forced up the flender glafs
tube near eighty inches high ; in which ftate
the new generated air in the bottle was com-
prefled with a force equal to more than two
atmofpheres and an half $ if the bottle and
tube were fvvung to and fro, the Mercury
would make long vibrations in the tube be-
tween z and 6S which proves the great elafti-
city of the compreffed air in the bottle.

Exp eriment LXXXIX.

I found the like elaftick force by the fol-
lowing Experiment, viz. I provided a ftrong
iron pota&cd, (Fig. 37.) which was two and
3. inches diameter within fide, and five inches
deep. I poured into it half an inch depth of

P Mercury j

2 1 o Jnaly/is of the Ait.
Mercury; then I put a little coloured honey
at x, into the bottom of the glafs-tube z xy
which was fealed at the top. I fet this tube
in the iron cylinder n n, to fave it from break-
ing by the fwelling of the Peas. The pot
being filled with Peas and water, I put a lea-
thern collar between the mouth and lid of the
pot, which were both ground even, and then
preffed the lid hard down in a Cyder-prefs:
The third day I opened the pot, and found
all the water imbibed by the Peas; the Honey
was forced up the glafs-tube by the Mercury
to zy (for fo far the glafs was dawbed) by
which means I found the preflure had been
equal to two atmofpheres and ' y and the dia-
meter of the pot being two -{- -| inches, its
area was fix fquare inches, whence the dilate-
ing iorce of the air againft the- lid of the pot
was equal to 200 pounds.

And that the expanfive force of new gene-
rated air is vaftly fuperior to the power with
which it acted on the Mercury in thefe two
Experiments, is plain from the force with
which fermenting Muft will burfl the ftrongefl
veffels ; and from the vaft explofive force with
which the air generated from nitre in the
firing of gun-powder, will burlt afunder the

ftrongeft

Analyfis of the Air. 1 1 1

ftrongeft bombs or cannon, and whirl fortifi-
cations in the air.

This fort of mercurial gage, made ufe of
in Experiment #9, with fome un&uous mat-
ter, as Treacle, or the like tinged liquor,
on the Mercury in the tube, to note how
high it rifes there, might probably be of fer-
vice, in finding out unfathomable depths of
the fea, viz. by fixing this fea-gage to fome
buoyant body, which (hould be funk by a
weight fix'd to it, which weight might by
an eafy contrivance be detached from the
buoyant body, as foon as it touched the bot-
tom of the fea ; fo that the buoyant body
and gage would immediately afcend to the
furface of the water. The buoyant body ought
to be pretty large, and much lighter than the
water, that by its greater eminence above the
water it might the better be feen ; for 'tis
probable that from great depths it may rife
at a confiderable diftance from the {hip, tho*
in a calm.

For greater accuracy it will be needful,
firft, to try this fea-gage, at feveral different
depths, down to the greateft depth that a
line will reach, thereby to difcover, whe-
ther or how much the fpring of the air is
difturbed or condenfed, not only by the great
P 2 preflure

2 1 1 Analyfts of the Jir.

preflure of the incumbent water, but alfo by
its coldnefs at great depths; and in what pro-
portion, at different known depths, and in
different lengths of time, that an allowance
may accordingly be made for it at unfatho-
mable depths. See Vol. II. p. 332.

This gage will alfo readily ihew the de-
grees of compreffion in the condenfing en-
gine.

But to return to the fubjedt of the two laft
Experiments, which prove the elafticity of
this new generated air; which elafticity is
fuppofed to confift in the adtive aerial par-
ticles, repelling each other with a force,
which is reciprocally proportional to their
diftances: That illuftrious Philofopher, Sir
Ifaac Newton, in accounting how air and
vapour is produced, Opticks g*uer. 31. fays,
" The particles, when they are fhaken off
" from bodies by heat or fermentation, fo
" foon as they are beyond the reach of the
l< attraction of the body receding from it,
" as alfo from one another, with great ftrength
" and keeping at a diftance, fo as ibmetimes
<l to take up above a million of times more
" fpace than they did before in the form of
" a denfe body ; which vaft contraction and
<c expanfion feems unintelligible, by feign-

* ing

AnaJyJts of the Air. 1 1 3

Ci ing the particles of air to be fpringy and
M ramous, or rolled up like hoop?, or by any
<c other means than by a repulfive power."
The truth of which is further confirmed by
thefe Experiments, which mew the great
quantity of air emitted from fermenting bo-
dies ; which not only proves the great force
with which the parts of thofe bodies muft
be diftended ; but (hews alfo how very much
the particles of air muft be coiled up in that
ftate, if they are, as has been fuppofed, fpringy
and ramous.

To inftance in the cafe of the pounded
Apples, which generated above 48 times
their bulk of air ; this air, when in the
Apples, mud be compreffed into lefs than
a forty-eighth part of the fpace it takes up
when freed from them, and it will confe-
quently be forty-eight times more denfe \
and fince the force of compreffed air is pro-
portional to its denfity, that force which
compreffes and confines this air in the Ap-
ples, mud be equal to the weight of forty-
eight of our atmofpheres, when the Mer-
cury in the Barometer ftands at fair, that is,
30 inches high,

P 3 Now

1 1 4 Analyjis of the Air.

Now a cubick ineh of Mercury weighing
3580 grains, thirty cubick inches (which is
equal to the weight of our atmofphere on
an area of a cubick inch) will weigh fifteen
pounds, five ounces, 215 grains; and forty-
eight of them will weigh above 836 pounds;
which is therefore equal to the force with
which an inch fquare of the furface of the
Apple would comprefs the air, fuppofing
there were no other fubflance but air in the
Apple: And if we take the furface of an
Apple at fixteen fquare inches, then the
whole force with which that furface would
comprefs the included air, would be 13383
pounds. And fince action and reaction
are equal, this would be the force, with
which the air in ttif Apple would endea-
vour to expand itfelf, if it were there in
an elaflick and flrongly compreiTed ftate :
But fo great an expanfive force in an Apple
would certainly rend the fubflance of it with
a ftrong explofion, efpecially when that force
was increafed by the vigorous influence of
the Sun's warmth.

We mav make a like eflimate alfo, from
the great quantities of air which arofe either
by fermentation, or the force of fire from
feveral other bodies. Thus in Exp. 55. there

arofe

Anal)Jis of the Air. 1 1 J

arofe from a piece of heart of Oak> 216
times its bulk of air. Now 216 cubick
inches of air, compreffed into the fpace of
one cubick inch, would, if it continued there
in an elaftick ftate, prefs againft one fide of
the cubick inch with an expanfive force equal
to 3393 pounds weight, fuppofing there were
no other fubflance but air contained in its
and it would prefs againft the fix fides of
the cube, with a force equal to 20350
pounds, a force fufHcient to rend the Oak
with a vaft explofion: It is very reafonable
therefore to conclude, that mod of thefe
now adtive particles of the new generated
air, were in a fixed ftate in the Apple and
Oak before they were roufed, and put into
an adlive repelling ftate, by fermentation and
fire.

The weight of a cubick inch of Apple
being 191 grains, the weight of a cubick
inch of air f of a grain, forty-eight times
that weight of air is nearly equal to the four-
teenth part of the weight of the Apple.

And if to the air thus generated from a
vefiel cf any vegetable liquor by fermenta-
tion, we add the air that might afterwards
be obtained from it by heat or diftillation j
and to that alfo the vaft quantity of air which

P4 by

2 1 6 dnalyfis of the Jir.

by Experiment 73 is found to be contained
in its Tartar, which adheres to the fides of
the veflel ; it would by this means be found
that air makes a very confiderable part of
the fubftance of Vegetables, as well as of
Animals.

But though from what has been faid, it
is reafonable to think, that many of thefe
panicles of air were in a fixed ftate, ftrongly
adhering to, and wrought into the fubftance
of Apples ; yet on the other hand it is rnoft
evident from Exper. 34. and 38, where in-
numerable bubbles of air inceffantly arofe
through the fap of Vines, that there is a con~
fiderable quantity of air in Vegetables, upon
the wing, and in a very a&fve ftate, efpeci-
ally in warm weather, which inlarges the
fphere of their adivity.

7*he Eff'eEls of the Fermentation of mineral
Subjlancis on the Air,

I Have above fhewn that Air may be pro-
duced from mineral Subftances, by the
adtion of fire in diftillation. And we have,
in the following Experiments, many inftances
of the great plenty of air, which is generated
by fome fermenting mixtures, abrorbed by

others.,

JnaJyfis of the Ah\ 2 1 7

others, and by others alternately generated
and abforbed.

Experiment XC.

I poured upon a middle-fized Gold Ring,
beat into a thin plate, two cubick inches of
Aqua Regia ; the Gold was all diffolved the
next day, when I found four cubick inches
of air generated ; for air-bubbles were conti-
nually arifing during the folution : But fince
Gold lofes nothing of its weight in being thus
diffolved, the four cubick inches of air, which
weighed more than a grain, muft arife either
out of the pores of the Gold, or from the
Aqua Regia ; which makes it probable, that
there are air particles in acid fpirits ; for by
Experiment feventy - five, they abforb air ;
which air parjicles regained their elafticity,
when the acid fpirits which adhered to them
were more ftrongly attracted by the Gold,
than by the air particles.

Experiment XCI.

A quarter pf a cubick inch of Antimony,
and two cubick inches of Aqua Regia, gene-
rated thirty-eight cubick inches of air, the

firft

1 1 & Analyfa of the Air.

firft three or four hours, and then abforbed.
fourteen cubicle inches in an hour or two.
It is very obfervable, that air was generated
while the ferment was fmall, on the firft mix-
ing of the ingredients : But when the ferment
was greatly increafed, fo that the fumes rofe
very vifibly, then there was a change made
from a generating to an abforbing ftate; that
is, there was more aL abforbed than gene-
rated.

That I might find whether the air was ab-
forbed by the fumes only of the Aqua Regia,
or by the acid fulphureous vapours, which
afcended from the Antimony, I put a like
quantity of Aqua Regia into a bolthead b>
(Fig. 34.) and heated it, by pouring a large
quantity of hot water into the ciftcrn x xy
which flood in a larger veffel, that retained
the hot water about it, but no air was ab-
forbed 5 for when all was cold, the water
ftoad at the point zy where I firft placed it :
And I found it the fame, when, inftead of
Aqua Regia, I put only fpirit of Nitre into
the bolthead b-y yet in the diftillation of com-
pound Aqua-fortis, Exper. 75. a little was ab-
forbed. Hence therefore it is probable, that
the greareft part, if not all the air, was ab-
forbed by the fumes which arofe from the
Antimony, E x-

Analyfis of the Air. 1 1 9

Experiment XCII.
Some time in February, the weather very
cold, I poured upon a quarter of a cubick
inch of powdered Antimony, a cubick inch
of compound or double Aqua-fortis, in the
bolthead b (Fig. 34.) : in the firft 20 hours
it generated about 8 cubick inches of air ;
after that, the weather being fomewhat
warmer, it fermented fafter, fo as in two or
three hours to generate 82 cubick inches of
air more ; but the following night being very
cold, little was generated : So the next morn-
ing I poured hot water into the veffel x xt
which renewed the ferment, fo that it gene-
rated 4 cubick inches more, in all 130 cubick
inches, a quantity equal to 520 times the
bulk of the Antimony.

The fermented mais looked like Brim-
ftone, and when heated over the fire, there
fublimed into the neck of the boithead a red
fulphur, and below it a yellow; which ful-
p.hur, as Mr. Boyle obfecves, Vol. IIL ^.272.
cannot be obtained by the, bare action of fire,
without being firft well digefted ia oil o£
Vitriol, or fpirit of Nirre. And by com-
paring the quantity of aix obtained by fermen-
tation in this Experiment, with the quantity

obtained

120 Analyfis of the Air.

obtained by the force of fire in Exper. 69.
we find that five times more air was generated
by fermentation than by fire, which fhews
fermentation to be a more fubtle diffolvent
than fire ; yet in fome cafes there is more air
generated by fire than by fermentation.

Half a cubick inch of oil of Antimonw
with an equal quantity of compound Aqua-
fortis, generated 36 cubick inches ofelaftick
air, which was all reforbed the following
day.

Expert me nt XCIII.

Some time in February, a quarter of a
cubick inch of filings of Iron, and a cubick
inch of compound Aqua-fortis, without any
water, did, in four days, abforb 27 cubick
inches of air. It having ceafed to abforb, I
poured hot water into the veffel * x, to try if
I could renew the ferment. The effect of
this was, that it generated three or four cu-
bick inches of air, which continued in that
ftate for fome days, and was then again re-
forbed.

1 repeated the fame Experiment in warm
weather in April, when it more briskly ab-
foiDed 12 cubick inches in an hour.

Ex-

Jnalyfis of the Air. 1 1 1

Experiment XCIV.

March 12th, - of a cubick inch of filings
of Iron, with a cubick inch of compound
Aqua-forth, and an equal quantity of water,
for the firft half hour abforbed five or fix
cubick inches of air; but in an hour more
it had emitted that quantity of air; and in
two hours more it again reforbed what had
been juft befQre emitted. The day following
it continued abforbing, in all 12 cubick in-
ches: And then remained ftationary for j£
or 20 hours. The third day it had again re-
mitted or generated three or four cubick
inches of air, and thence continued ftationary
for five or fix days.

It is remarkable, that the fame mixtures
fhould change from generating to abforbing,
and from abforbing to generating flates ; fome-
times with, and fometimes without any fen-
fible alteration of the temperature of the air.
See Vol. II. p. 237, 293.

A like quantity of filings of Iron, and oil
of Vitriol, made no fenfible ferment, and
generated a very little air; but upon pouring
in an equal quantity of water, it generated
in 21 days 43 cubick inches of air; and in 3
or 4 days more it reforbed 3 cubick inches of

air;

ill Aiialyfn of the Ah.

air ; when the weather turned warmer, it was
generated again* which was again reforbed
when it grew cool.

One fourth of a cubick inch of filings of
Iron, and a cubick inch of oil of Vitriol, with
three times its quantity of water, generated
1 08 cubick inches of ain

Filings of Iron, with fpirit of Nitre, either
with an equal quantity of 'Water, or without
water, abfojbed air, but moft without water.

One fourth of a cubick inch of filings of
Iron, and a cubick inch of Limon- juice, ab-
forbed two cubick inches of air.

Experiment XCV.

Half a cubick inch otfpirits of Harts-
horn, with filings of Iron, abforbed 1 -j- i.
cubick inches of air, with filings of Copper,
double that quantity of air, and made a very
deep blue tin&ure, which it retained long,
when expofed to the open air. It was the
fame with Jpirit of Sal Armoniac, and filings
of Copper.

A quarter of a cubick inch of filings of
Iron, with a cubick inch of powdered Brim-
flone, made into a parte with a little water,
abforbed 19 cubick inches of air in two days.

N.B.

Analyfis of the Air. 1 1 $

N B. I poured hot water into the ciftern xx,
(Fig. 34.) to promote the ferment.

A like quantity of filings of Iron, and pow-
dered Newcajlle Coal, did in three or four
days generate feven cubicle inches of air. I
could not perceive any fenfible warmth in
this mixture, as was in the mixture of Iron
and Brimjione.

Powdered Brimfione and Newcafile Coal
neither generated nor abforbed.

Filings of Iron and Water abforbed three
or four cubick inches of air ; but they do not
abforb fo much, whenimmerfed deep in wa-
ter ; what they abforb isufualjy the firft three
or four days.

Filings of Iron, and the above-mentioned
Walton Pyrites, in Exper. 70. abforbed in
four days a quantity of air nearly equal to
double their bulk.

Copper Oar, and compound Aqua-fortis,
neither generated nor abforbed air; but, mixed
with water, it abforbed air.

A quarter of a cubick inch of Tin, and
double that quantity of compound Aqua-fort is y^

t generated two cubick inches of air ; part of
the Tin was diffolved into a very white fub-
ftance.

Expe-

z 2 4 Analyjis of the Air.

Experiment XCVI.

April 1 6th, a cubick inch of the afore-
mentioned Walton Pyrites powder'd, with a
cubick inch of compound Aqua-fortis, expanded
with great violence, heat and fume into a fpace
equal to 200 cubick inches, and in a little time
it condenfed into its former fpace, and then
abforbed 85 cubick inches of air.

But the like quantity of the fame Mineral,
with equal quantities of compound Aqua-fort is
and Water, fermented more violently, and ge-
nerated above 80 cubick inches of air.

I repeated thefe Experiments feveral times,
both with and without water, and found con-
ftantly the fame effect. Yet Oil of Vitriol
and Water, with fome of the fame Mineral,
abforbed air. It was very warm, but did not
make a great ebullition.

But this Walton Mineral, with equal quan-
tities of fpirit of nitre and water, generated
air, which air would abforb frefh admitted
air. See Vol II. p. 283, 292.

Experiment XCVII.

I chofe two equal-fized boltheads, and
put into each of them a cubick inch of

powdered
s

Analyjis of the Air. 225

powdered Walton Pyrites, with only a cu-
bicle inch of compound Aqua-fortis into one,
and a cubick inch of Water and compound
Aqua-fortis into the other : Upon weighing
all the ingredients and veflels exadtly, both
before and after the fermentation, I found
the bolthead with compound Aqua-fortis alone
had loft in fumes 1 dram 5 grains : But the
other bolthead with Water and compound
Aqua-fortis, which fumed much more, had
loft 7 drams, 1 fcruple, 7 grains, which is
fix times as much as the other loft.

Experiment XCVIIL
A cubick inch of Newcajlle Coal pow-
dered, and an equal quantity of compound
Aquafortis poured on it, did in three days
abforb 18 cubick inches of air; and in 3
days more it remitted and generated 12 cu-
bick inches of air; and on pouring warm
Water into the veffel x x, (Fig. 34.) it re-
mitted all that had been abforbed.

Equal quantities of Brim/lone and com-
pound Aqua-fortis neither generated nor ab-
forbed any air, notwithstanding hot Water
was poured into the veffel x x.

A cubick inch of finely powdered Flinty
and an equal quantity of compound Aqua-

Q_ fortis,

ix6 Analyfis of the Atr.

fortis, abforbed in 5 or 6 days 12 cubick
inches of air.

Equal quantities of powdered Brijlol
Diamond, and compound Aqua-fortis, and
Water , abfored 16 times their bulk of air.

The like quantities without Water ab-
forbed more flowly 7 times their bulk of
air.

Powder'd Briftol Marble (viz. the fhell
in which thofe Diamonds lay) covered pretty
deep with Water, neither generated nor
abforbed air ; and it is well known that
Brijlol Water does not fparkle like fome
other Mineral Waters,

Experiment XCIX.

When the Aqua Regia was poured on Oleum
Tartari per deliquium, much air was gene-
rated, and that probably chiefly from the
Oleum Tartaric for by Exper. 74. Sal Tar-
tar has plenty of air in it.

It was the lame when the oil of Vitriol
Wiis poured on &ieum 'Tartaric and Oleum
Tartar! dropped on boiling Tartar generated
much 2ir.

When equal quantities of Water and oil*
fcf Vitriol were poiwed on fea fait, it ab-
forbed 15 cubick inches of air; but when

Analyfts of the Air. 227

in the like mixture the quantity of Water
was double to that of the oil of Vitriol,
then but half fo much air was abforbed.

Experiment C.

I will next mew, what effedt feveral Al-
kaline Mineral bodies had on the air in fer-
menting mixtures.

A folid cubick inch of unpowdered Chalky
with an equal quantity of oil of Vitriol^ fer-
mented much at firft, and in fome degree
for 3 days 5 they generated 31 cubick inches
of air. The Chalk was only a little diflblved
on its furface.

One hundred and forty-fix grains, or near
one third of a cubick inch of Chalky being
let fall on two cubick inches of fpirit of
fait, 8 1 cubick inches of air were generated,
of which 36 cubes were reforbed in 9 days.

Yet Lime made of the fame Chalk abforb-
ed much air, when oil of Vitriol was poured
on it; and the ferment was fo violent, that
it breaking the glafs vefTels, I was obliged to
put the ingredients in an Iron veiTel.

Two cubick inches of frefh Lime, and
four of common white wine Vinegar abforb-
ed in 15 days 22 cubick inches of air.

Q_2 The

2 1 8 Analyfii of the Ait.

The like quantity of frefh Lime and
Water abforbed in 3 days 10 cubick inches
of air.

Two cubick inches of Lime, and an equal
quantity of Sal Ammoniac ', abforbed 115 cu-
bick inches: Tlie fumes of this mixture are
therefore doubtlefs very fuffocating.

A quart of unflacked Lime, left for 44
days, to flacken gradually by it-felf, without
any mixture, abforbed no air.

March 3d, a cubick inch of powdered
Belemnitis, taken from a Chalk pit, and an
equal quantity of oil of Vitriol, generated
in five minutes 35 cubick inches of air.
March 5th, it had generated 70 more.
March 6th, it being a hard froft, it reforb-
ed 12 cubick inches ; fo it generated in all
105 inches, and reforbed 12.

Powdered Belemnitis and Limon juice ge-
nerated plenty of air too; as did alfo the
Star-jlone, Laps Judaicus, and Selenitis
with oil of Vitriol.

Eyperiment CI.

Gravel, that is well burnt, Wood-ajhes,
decrepitated Salt, and Colcothar of Vitriol,
placed feverally under the inverted glafs
zzaa, (Fig. 35.) increased in weight by

im-

Jnalyfis of the Air. 229

imbibing the floating moifture of the air:
But they abforbed no elaftick air. It was
the fame with the remaining lixivious Salt
of a diftillation of Nitre.

But 4 or 5 cubick inches of powdered
frefh Cinder of Newca/l/e Coal did in feven
days abforb 5 cubick inches of elaftick air.
And 13 cubick inches of air were in 5 days
abforbed by Puhis Urem, a powder which
immediately kindles into a live Cole, up-
on being expofed to the open air.

Experiment CII.

What effect burning and flaming bodies,
and the refpiration of Animals, have on the
air, we fliall fee in the following Experi-
ments ; viz.

I fix'd upon the pedeftal under the in-
verted glafs z z a a, (Fig. 35.) a piece of
Brown Paper, which had been dipped in a
fclution of Nitre, and then well dried; I
fet fire to the Paper by means of a burn-
ing-glafs: The Nitre detonized, and burnt
briskly for ibme time, till the glafs z z a a
was very full of thick fumes, which extin-
guifhed it. The expanfion caufed by the
burning Nitre, was equal to more than two
quarts: When all was coo!, there were near

Q 3 80 cu-

2 3 o AnaJyfts of the AW.

80 cubick inches of new generated air, which
arofe from a fmall quantity of detonized
Nitre ; but the elaflicity of this new air dai-
ly decreafed, in the fame manner as Mr.
Hawksbee obferved the air of fired Gun-
powder to do, Phyfico-mechanical Exper.
p. 83. fo that he found 19 of 20 parts occu-
pied by this air to be deferted in 18 days,
and its fpace filled by the afcending water;
at which flation it relied, continuing there
for 8 days without alteration : And in like
manner, I found that a confiderable part of
the air which was produced by fire in the
diftillation of feveral fubftances, did gra-
dually lofe its elaflicity in a few days after
the diftillation was over ; but it was not fo
when I diftilled air thro* water, as in Expe-
riment 77. (Fig. 38. )

Experiment CHI.

I placed on the fame pedeftal large Matches
made of linen rags dipped in melted Brim-
ftone: The capacity of the veflel, (Fig. 35.)
above z z the furface of the water, was
equal to 2024 cubick inches. The quantity
pf air which was abforbed by the burning
Match, was 198 cubick inches, equal to -$
part of the whole air in the vefle!.

I made

Analyfis of the Air. 2 5 1

I made the fame Experiment in a leffer
veffel z z a a, (Fig. 35.) which contained
but 594 cubick inches of air, in which 150
cubick inches were abforbed; /. e. full $
part of the whole air in the receiver: So
that tho' more air is abforbed by burning
Matches in large veffels, where they burn
longeft, than in fmall ones, yet more air,
in proportion to the bulk of the veffel, is
abforbed in fmall than in large veffels : If a
frefh Match were lighted and put into this
infected air, tho' it would not burn i part
of the time that the former Match burnt
in frefh untainted air, yet it would abforb
near as much air in that fhort time ; and it
was the fame with Candles.

Experiment CIV.

Equal quantities of ^filings of Iron and
Brim/lone, when let fall on a hot Iron on
the pedeftal under the inverted glafs zz a ay
(Fig. 35.) did in burning abforb much aif ;
and it was the fame with Antimony and
Brimjione : Whence 'tis probable, that Vul-
cano's, whofe fewel confifts chiefly of Brim-
jione, mix'd with feveral mineral and me-
talline fubftances, do not generate, but ra-
ther abforb air.

CL4 We

2 3 l Analyjis of the Ah.

We find in the foregoing Experiment 102
on Nitre, that a great part of the new ge-
nerated air is in a few days reforbed, or
loies its elafticity: But the air which is ab-
forbed by burning Brimjiofte, or the flame
of a Candle, does not recover its elafticity
again, at leaft, not while confined in my
glafles.

Experiment CV.
I made feveral attempts to try whether
air full of the fumes of burning Brim/lone
was as compreffible as common frefh air,
by compreffing at the fame time tubes full
of each of thefe airs in the condenfing en-
gine y and I found that clear air is very lit-
tle more compreffible than air with fumes
of Brimjione in it : But I could not come to
an exa£t certainty in the matter, becaufe the
fumes were at the fame time deftroying the
elafticity of the air. I took care to make
the air in both tubes cf the fame tempera-
ture, by firft immerfing them in cold water,
before I compreffed them. See appendix
Vol II. p. 319, 320.

Experiment C VI.
I let a lighted tallow Candle, which was
about -/-- of an inch diameter, under the in-
verted

Analysis of the* Air. 1 3 5
verted receiver zzaa, (Fig. 35. ) and with
a fyphon I immediately drew the water up
to z z : Then drawing out the fyphon, the
water would defcend for a quarter of a mi-
nute, and after that afcend, notwithftand-
ing the Candle continued burning, and heat-
ing the air for near 3 minutes. It was ob-
fervable in this Experiment, that the fur-
face of the water z z did not afcend with
an equal progreffi.on, but would be fome-
times ftationary ; and it would fometimes
move with a flow, and fometimes with an
accelerated motion; but the denfer the fumer,
the fafter it afcended. As foon as the Can-
dle was out, 1 marked the height of the
water above z z, which difference was
equal to the quantity of air, whofe elafti-
city was deftroyed by the burning Candle.
As the air cooled and condenfed in the re-
ceiver, the water would continue riling
above the mark, not only till all was cool,
but for 20 or 30 hours after that, which
height it kept, tho' it flood many days;
which fhews that the air did not recover the
elafticity which it had loft.

The event was the fame, when for great-
er accuracy I repeated this Experiment by
lighting the Candle after it was placed un-
der

234 Analyfis of the Ah.

der the receiver, by means of a burning-glais,
which fet fire to a fmall piece of brown pa-
per fixed to the wick of a Candle, which
paper had been firft dipped in a ftrong folu-
tion of Nitre in Water; and when well
dried, part of it was dipped in melted Brim-
fione ; it will alfo light the Candle without
being dipped in Brim/lone. Dr. Mayow,
found the bulk of the air lefTened by -fa part,
but does not mention the fize of the glafs
vefTel under which he put the lighted Can-
dle, ^De Sp. Nitro aereo^ p. 101. The capa-
city of the vefTel above z z, in which the
Candle burnt in my Experiment, was equal
to 2024 cubick inches; and the elafticity of
the ~\ part of this air was deftroyed.

The Candle cannot be lighted again in
this infected air by a burning-glafs: But if
I firft lighted it, and then put it into the
fame infe&ed air, tho' it was extinguished
in - part of the time, that it would burn in
the fame vefTel, full of frefh air; yet it
would deftroy the elafticity of near as much
air in that fhort time, as it did in five times
that fpace of time in frefh air; this I re-
peated feveral times, and found the fame
event : Hence a grofs air, which is loaded
wivh vapours, is more apt in equal times to

lofe

Analyfis of the AW. 235

lofe its elafticity in greater quantities, than
a clear air.

I obferve that where the vefTels are equal,
and the fize of the Candles unequal, the
elafticity of more air will be deftroyed by
the large than by the fmall Candle : and where
Candles are equal, there moft air in propor-
tion to the bulk of the veffel will be ab-
forbed in the fmalleft veffel : tho' with
equal Candles there is always moft elaftick:
air deftroyed in the largeft veffa], where the
Candle burns longeft.

I found alfo in fermenting liquors, that,
Ceteris paribus, more air was either gene-
rated or abforbed in large, than in fmajl
veffels, by generating or abforbing mixtures.
As in the mixture of Aqua Regia and Antl*
mony in Experiment 91. by inlarging thea
bulk of the air in the veffel, a greater quan-
tity of air was abforbed. Thus alfo filings
of Iron and Brimjtone, which in a more capa-
cious veffel abforbed 19 cubick inches of
air, abforbed very little, when the bulk of
air, above the ingredients, was but 3 or 4
cubick inches: For I have often obferved,
that when any quantity of air is faturated
with abforbing vapours to a certain degree,
then no more elaftick air is abforbed: Not-

withftanding;

1^6 Analyjis of the Aif.

withftanding the fame quantity of abforbing
fubftances would, in a larger quantity of air,
have abforhed much more air; and this is
the reafon why I was never able to deflroy
the whole elafticity of any ineiudcd bulk of
air, whether it was (common air, or new
generated air.

Experiment CVII.

May 1 8. which was a very hot day, I
repeated Dr. Mayow's Experiment, to find
how much air is abforbed by the breath of
Animals inclofed in glaffes, which he found
with a moufe to be T'T part of the whole
air in the glafs vefTel, JDe Sp. Nitro aereo,
p. 104.

I placed on the pedeftal, under the invert-
ed glafs zz a a, (Fig. 35. ) a full-grown
Rat. At firft the water fubfided a little,
which was occalioned by the rarefa&ion of
the air, caufed by the heat of the animal's
body. But after a few minutes the water be-
gan to rife, and continued riling as long
as the Rat lived, which was about 14 hours.
The bulk of the air in which the Rat
lived fo many hours, was 2024 cubick inches;
the quantity of elaftick air which was ab-
forbed, was 73 cubick inches, above yf part

Analyfn of the Air. 237

of the whole, nearly what was abforbed
by a Candle in the fame veffel, in Experi-
ment 106.

I placed at the fame time, in the fame

manner, another almoft half-grown Rat
under a veffel, whofe capacity above the
furface of the water z z> (Fig. 35.) was bus
594 cubick inches, in which it lived 10
hours ; the quantity of elaftick air which
was abforbed, was equal to 45 cubick
inches, viz. ri Part °f tne wn°le air, which
the Rat breathed in : A Cat of three months
old lived an hour in the fame receiver,
and abforbed 16 cubick inches of air,
viz. -3% part of the whole j an allowance
being made in this eftimate for the bulk of
the Cat's body. A Candle in the fame veffel
continued burning but one minute, and ab-
forbed 54 cubick inches, TV part of the
whole air.

And as in the cafe of burning Brim/lone
and Candles, more air was found to be ab-
forbed in large veffels than in fmall ones ;
and vice verfa, more air, in proportion to the
capacity of the veffel, was abforbed in fmall
than in large veffels, fo the fame holds true
here too in the cafe of animals.

Expe-

138 Analyfis of the Mr.

Experiment CVIII.

The following Experiment will (hew,
that the elaflicity of the air is greatly de-
ftroyed by the refpiration of human Lungs -3
viz.

I made a bladder very fupple by wetting
of it, and then cut off fo much of the neck
as would make a hole wide enough for the
biggeft end of the largeft foffet to enter, to
which the bladder was bound faft. The
bladder and foffet contained 74 cubicle
inches. Having blown up the bladder, I
put the fmall end of the foffet into my
mouth ; and at the fame time pinched my
noftrils clofe, that no air might pafs that
way, fo that I could only breath to and fro
the air contained in the bladder. In lefs
than half a minute I found a confiderable
difficulty in breathing, and was forced after
that to fetch my breath very faft; and at
the end of the minute, the fuffocating un-
eafinefs was fo great, that I was forced to
take away the bladder from my mouth.
Towards the end of the minute the blad-
der was become fo flaccid, that I could not
blow it above half full with the greateft
expiration that I could make : And at the

fame

Analyjis of the Ait . ity

fame time I could plainly perceive, that my
lungs were much fallen, juft in the fame
manner as when we breath out of them
all the air we can at once. Whence it is
plain that a confiderable quantity of the
elafticicy of the air contained in my lungs,
and in the bladder, was deftroyed; which
fuppofing it to be 20 cubick inches, it will
be T' part of the whole air, which I breath-
ed to and fro; for the bladder contained
74 cubick inches, and the lungs, by the
following Experiment, about 166 cubick
inches, in all 240.

Thefe effects of refpiration on the ela-

rfticity of the air put me upon making an
attempt to meafure the inward furface of
the lungs, which by a wonderful artifice
are admirably contrived by the divine Ar-
tificer, fo as to make their inward furface
to be commenfurate to an expanfe of air
many times greater than the animal's body;
as will appear from the following efiimate

viz.

Experiment CDC

I took the lungs of a Calf, and cut off
the heart and wind-pipe an inch above its
branching into the lungs j I got nearly the

fpecific^

140 Analyfis of the Air.
fpecifick gravity of the fubftance of the
lungs, (which is a continuation of the branch-
ii es of the wind-pipe, and blood- vefiels) by
finding the fpecifick gravity of the wind-
pipe, which I had cut off; it was to Well-
water as 1.05 to 1. And a cubick inch of
water weighing 254 grains; I thence found
by weighing the lungs the whole of their
folid fubftance to be equal to 37 +~ cubick
inches.

I then filled a large earthen veflel brim-
full of water, and put the lungs in, which
I blew up, keeping them under water with
a pewter plate. Then taking the lungs out,
and letting the plate drop to the bottom of
the water, I poured in a known quantity of
water, till the vefTel was brim-full again; that
water was 7 pounds 6 ounces and \y equal
to 204 cubick inches; from which deduct-
ing the fpace occupied [by the folid fubftance
of the lungs, viz. 37 +? cubick inches,
there remains 166 -j- 7 cubick inches for
the cavity of the lungs. But as the Pul-
monary Veins, Arteries and Lymphaticks,
will, when they are in a natural ftate, re-
plete with blood and lymph, occupy more
fpace than they do in their prefent empty
ftate; therefore fome allowance muft alfo

Analyjis of the Air. 241

be made out of the above taken cavity of
the lungs, for the bulk of thofe fluids ; for
which 25 + i. cubick inches feem to be a
fufficient proportion, out of the 166 + \ cu-
bick inches 5 fo there remain 141 cubick
inches for the cavity of the lungs.

I poured as much water into the BrGtichia
as they would take in, which was one pound
eight ounces, equal to 41 cubick inches;
this deducted from the above-found cavity
of the lungs, there remain 100 cubick
inches for the fum of the cavity of the
veficles.

Upon viewing fome of thefe veficles with
a microfcope, a middle-fized one feems to
be about -^- part of an inch diameter ; then
the fum of the furfaces in a cubick inch of
thefe fmall veficles (fuppofing them to be
fo many little cubes, for they are not fphe-
rical) will be 600 fquare inches -, for if the
number of the divifions of the fide of the
cubick inch be 100, there will be 100
planes, containing each one fquare inch, in
each dimenfion of the cube ; which having
three dimenfions, the fum of thofe planes
will be 300 fquare inches, and the fum of
the furfaces of each fide of thofe planes
will be 600 fquare inches ; which multiplied

R by

24 1 Anahfis of the Air.

by the fum of all the veficles in the lungs,
viz. ioo cubick inches, will produce 60000
fquare inches; one third of which muft be
dedu&ed, to make an allowance for the ab-
fence of two fides in each little veficular
cube, that there might be a free communi-
cation among them for the air to pais to
and fro ; fo there remain 40000 fquare
inches for the fum of the furface of all the
veficles.

And the Brofichice containing 41 cubick
inches, fuppofing them at a medium to be
cylinders of ~i6 of an inch diameter, their
furface will be 1635 fquare inches, which
added to the furface of the veficles, makes
the fum of the furface of the whole lungs
to be 41635 fquare inches, or 289 fquare
feet, which is equal to 19 times the furface
of a man's body, which at a medium is com-
puted to be equal to 15 fquare feet.

I have not had an opportunity to take in
the fame manner the capacity and dimen-
fions of human lungs; the bulk of which
Dr. James Keill, in his Tentamina Medico-
pbyfica, p. 80. found to be equal to 226 cu-
bick inches. Whence he eftimated the fum
of the furface of the veficles to be 21906
fquare inches. But the bulk of human

lungs

dnalyjis of the Air. 245

lungs is much mote capacious than 226 cu-
bick inches; for Tir.Jurin, by an accurate
Experiment, found that he breathed out, at
one large expiration, two hundred and twenty
cubick inches of air; and I found it nearly
the fame, when I repeated the like Experi-
ment in another manner: So that there mull
be a lar^e allowance made for the bulk of the
remaining air, which could not be expired
from the lungs; and alfo for the fubflance
of the lungs.

Suppofing then, that, according to T)r.Ju-
riris eftimate, (in Mott *s Abridgment of the
Philofophical TiranfaEl. Vol. I. p. 415.) we
draw in at each common infpiration forty
cubick inches of air, that will be 48000 cu-
bick inches in an hour, at the rate of twenty
infpirations in a minute. A confiderable part
of the elafiicity of which air is, we fee by
the foregoing Experiment, coriftantly de-
ftroyed, and that chiefly among the veficlesj
where it is charged with much vapour.

But it is not eafy to determine how much
is deftroyed. I attempted to find it out by
the following Experiment, which I fhall here
give an account of, tho' it did not fucceed
fo well as I could have wifhed, for want cf
much larger vefiels ; for if it was repeated

R 2 with

H4 Analyfis of the Air.

with more capacious veffels, it would deter-
mine the matter pretty accurately 5 becaufe
by this artifice frefli air is drawn into the
lungs at every infpiration, as well as in the
free open air.

Experiment CX.
I made ufe of the fyphon (Fig. 39.) take^
ing away the bladders, and diaphragms i i
n no: I fixed, by means of a bladder, one
end cf a ftiort leaden fyphon to the lateral
folTet i i : Then I fattened the large fyphon
in a veffel, and filled it with water, till it
rofe within two inches of a, and covered
the other open end of the fhort fyphon,
which was deprefTed for that purpofe. Over
this orifice I placed a large inverted chymi-
cal receiver full of water ; and over the other
leg 0 s of the great fyphon, I whelmed an-
other large empty receiver, whofe capacity
was equal to 1224. cubicle inches; the
mouth of the receiver being immerfed in
the water, and gradually let down lower
and lower by an afliftant, as the water
afcended in it. Then flopping my noftrils,
I drew in breath at a, thro' the fyphon from
the empty receiver : And when that breath
was expired, the valve b i flopping its return

down

Analyjis of the Jir. 245

down thro* the fyphon, it was forced thro*
the valve r, and thence through the fmall
leaden fyphon into the inverted receiver full
of water, which water defcended as the
breath afcended. In this manner I drew all
the air, except five or fix cubick inches, out
of the empty receiver at 0, the water at the
fame time afcending into it, and filling it ;
by which means all the air in the empty
receiver, as alfo all the air in the fyphon
0 s b was infpired into my lungs, and breathed
out through the valve r into the receiver,
which was at firft full of water. I marked
the boundary of air and water, and then
immerfed the whole receiver, which had
the breath in it, under water, and there gra-
dually poured the contained breath up into
the other full receiver, which flood inverted
over 0 S'y whereby I could readily find whe-
ther the air had loft any of its elafticity :
And for greater furety, I alfo meafured the
bulk of breath, by filling the receiver with a
known quantity of water up to the above-
mentioned mark; making alfo due allow-
ance for a bulk of air, equal to the capacity
of the large fyphon 0 s b} which was at laffc
fucked full of water.

* R 7 The

a 46 Jnalyjis of the Air.

The event was, that there were 18 cubick
inches of air wanting; but as thefe receivers
were much too fmall to make the Experi-
ment with accuracy ; that fome allowance
may be made for errors, I will fet the lofs
of elaftick air at nine cubick inches, which
is but TT6 Parc °f the whole air refpired,
which will amount to 353 cubick inches in
one hour, or 100 grains, at the rate of 84000
cubick inches infpired in an hour, or five
ounces 210 grains, in 24 hours.

By pouring the like quantity of air to and
fro under water, I found that little or none
of it was loft; fo it was not abforbed by the
water : To make this trial accurately, the
air muft be detained fome time under water,
to bring it firft to the fame temperature with
the water. Care alfo muft be taken in make-
}ng this Experiment, that the lungs be in the
fame degree of contraction at the laft breath-
ing, as at the firft ; elfe a confiderable error
may arife from thence.

But tho' this be not an exact eftimate, yet
it is evident from the foregoing Experiments
on refpiration, that fome of the elafticity of
the air which is infpired is deftroyed; and
that chiefly among the veficles, where it is
moil loaded with vapours ; whence probably

fome

Analyfis of the Air. 247

fome of it, together with the acid fpirits,
with which the air abounds, are conveyed
to the blood, which we fee is by an admi-
rable contrivance there fpread into a vafl
expanfe, commenfurate to a very large fur-
face of air, from which it is parted by very
thin partitions ; fo very thin, as thereby pro-
bably to admit the blood and air-particles
(which are there continually changing from
an elaftickto a ftrongly attracting ftate) with-
in the reach of each other's attraction, where-
by a continued fucceffion of frefh air may be
abforbed by the blood.

And in the Analyfis of the blood, either
by fire or fermentation in Exper. 49. and 80,
we find good plenty of particles ready to re-
fume the elaftick quality of air : But whe-
ther any of thefe air -particles enter the
blood by the lungs, is not eafy to deter-
mine ; becaufe there is certainly great ftore
of air in the food of animals, whether it be
vegetable or animal food. Yet, when we
confider how much air continually lofes its
elafticity in the lungs, which feem purpofely
framed into innumerable minute meanders,
that they may thereby the better feize and
bind that volatile Hermes : It makes it very
probable, that thofe particles which are now
R 4 changed

M 8 Analjfis of the Air.

changed from an elaftick, repulfive, to a
ftrongly attracting ftate, may eafily be at-
tracted thro1 the thin partition of the veficles,
by the fulphureous particles which abound in
the blood.

And nature feems to make ufe of the like
artifices in vegetables, where we find that
air is freely drawn in ; not only with the
principal fund of nourishment at the root,
but alfo thro* feveral parts of the body of
the vegetable above ground ; which air was
ktn to afcend in an elaftick ftate mod: freely
and vifibly through the larger trachece of the
Vine; and is thence doublefs carried with
the fap into minuter veflels, where being in-
timately united with the fulphureous, faline,
and other particles, it forms the nutritive
duftile matter, out of which all the parts of
vegetables do grow.

Experiment CXI.

It is plain from thefe effects of the fumes
of burning Brimfio?ie, lighted Candle, and
the breath of Animals, on the elafticity of
the air, that its elafticity in the veficles of
the lungs muft be continually decreafing, by
reafon of the vapours it is there loaded wTith ;
(6 that thole veficles would in a little time

fubfide

Jnalyfis of the Ak. 249

fubfide and fall flat, if they were not fre-
quently replenished with frefh elaftick air at
every infpiration, thro* which the inferior
heated vapour and air afcends, and leaves
room for the frefh air to defcend into the
veficles, where the heat of the lungs makes it
expand about £ part ; which degree of ex-
panfion of a temperate air, I found by in-
verting a fmall glafs bubble in water, a little
warmer than a thermometer is, by having its
ball held fome time in the mouth, which
may reafonably be taken for the degree of
warmth in the cavity of the lungs. When
the bubble was cool, the quantity of water
imbibed by it was equal to \ of the cavity of
the whole bubble.

But when, inftead of thefe frequent recruits
of frefh air, there is infpired an air, fur-
charged with acid fumes and vapours, which
not only by their acidity contract the exqui-
fitely fenfible veficles, but alfo by their grofT-
nefs much retard the free ingrefs of the air
into the veficles, many of which are exceed-
ing fmall, fo as not to be vifible without a
microfcope -y which fumes are alfo continu-
ally rebating the elafticity of that air; then
the air in the veficles will, by Exper. 107,
and 108, lofe its elafticity very faftj and

con-

2 jo Analyfn of the Air.
confequently the veficles will fall flat, not-
withftanding the endeavours of the extend-
ing Thorax to dilate them as ufual j whereby
the motion of the blood thro' the lungs being
flopped, inftant death enfues.

Which Hidden and fatal effect of thefe
noxious vapours, has hitherto been fuppofed
to be wholly owing to the lofs and wafte of
the vivifying fpirit of air ; but may not
unreafonably be alfo attributed to the lofs
of a considerable part of the air's elafticity,
and the groflhefs and denlity of the vapours,
which the air is charged with 5 for mutually
atta&ing particles, when floating in fo thin a
medium as the air, will readily coalefce into
grofler combinations : which effect of thefe
vapours having not been duly obferved be-
fore, it was concluded, that they did not
affect the air's elafticity ; and that confe-
quently the lungs muft needs be as much
dilated in infpiration by this, as by a clear
air.

But that the lungs will not rife and dilate
as ufual, when they draw in fuch noxious
air, which decreafes faff in its elafticity, I
was aflured by the Experiment I made on
myfelf, in Exper. 108. for when towards the
latter end of the minute, the fuffbeating qua-
lity

AnaJyJiS of the AW. 251

lity of the air in the bladder was greateft, it
was with much difficulty that I could dilate
my lungs a very little.

From this property in the vapours arife-
ing from animal bodies, to rebate and de-
ftroy part of the elafticity of the air, a pro-
bable account may be given of what be-
comes of a redundant quantity of air, which
may at any time have gotten into the cavity
of the Thorax, either by a wound, or by
fome defed: in the fubftance of the lungs,
or by very violent exercife. Which, if it
was to continue always in that expanded
ftate, would very much incommode refpi-
ration, by hindering the dilatation of the
lungs in infpiration. But if the vapours,
which do continually arife in the cavity of
the Thorax, deftroy fome part of the elafti-
city of the air, then there will be room for
the lungs to heave : And probably, it is in
the fame manner that the winds are reforb-
ed, which, in their elaftick ftate, fly from
one part of the body or limbs to another,
caufing by their diftention of the veflels much
pain.

Expe-

1 5 * jlnalyjis of the AW.

Experiment CXII.

I have by the following Experiment found,
that the air will pafs here and there thro* the
fubftance of the lungs, with a very fmall
force, 'viz.

I cut afunder the bodies of feveral young
and fmall animals juft below the Diaphragm,
and then taking care not to cut any veffel
belonging to the lungs, I laid the Thorax
open, by taking away the Diaphragm, and
fo much of the ribs, as was needful to ex-
pofe the lungs to full view, when blown up.
And having cut off the head, I fattened the
wind-pipe to a very fhort inverted leg of a
glafs fyphon; and then placed the inverted
lungs and fyphon in a large and deep glafs
veffel x full of water, (Fig. 32.) under the
air-pump receiver p p; and paffing the longer
leg of the fyphon through the top of the
receiver, where it was cemented faft at z, as
I drew the air out of the receiver, the lungs
dilated, having a free communication with
the outward air, by means of the glafs fy-
phon ; forne of which air would here and
there pafs in a few places thro* the fubftance
of the lungs, and rife in fmall ftreams thro'
the water, when the receiver was exhaufted

Analyfis of the Air. 1 5 5
no more than to make the Mercury in the
<*age fife lefs than two inches. When I ex-
haufted the receiver, fo as to raife the Mer-
cury feven or eight inches, though it made
the air rufh with much more violence thro*
thofe fmall apertures in the furface of the
lungs, yet I did not perceive that the num-
ber of thofe apertures was increafed, or at
leaft very little. An argument that tj^ofe
apertures were not forcibly made by exhauit-
ing the receiver lefs than two inches, but
were originally in the live animal. And
that the lungs of living animals are fome-
times raifed with the like force, efpecially in
violent exercife^ I found by the following
Experiment; viz*

Experiment CXIII.
I tied down a live Dog on his back, near
the edge of a table, and then made a fmall
hole through the intercoftal mufcles into his
Thorax, near the Diaphragm. I cemented
faft into this hole the incurvated end of a
glafs tube, whofe orifice was covered with a
litde cap full of holes, that the dilatation
of the lungs might not at once flop the ori-
fice of the tube. A fmall phial full of fpirit
of Wine was tied to the bottom of the per-
pendicular

254 Analyjis of the Air.

pendicular tube, by which means the tube
and vial could eafily yield to the motion of
the Dog's body, without danger of breaking
the tube, which was 36 inches long. The
event was, that in ordinary infpirations, the
fpirit rofe about fix inches in the tube; but
in great and laborious infpirations, it would
rife 24 and 30 inches, viz. when I flopped
the Dog's nofirils and mouth, fo that he
could not breathe : This Experiment fhews
the force with which the lungs are raifed
by the dilatation of the Thorax, either in
ordinary or extraordinary and laborious in-
fpirations. When I blew air with fome force
into the Thorax, the Dog was juft ready to
expire.

By means of another {hort tube, which
had a communication with that which was
fixed to the Thorax, near its infertion into
the Thorax, I could draw the air out of the
Thorax, the height of the Mercury, inftead
of fpirit in the tube, (hewing to what degree
the Thorax was exhaufled of air : The Mer-
cury was hereby raifed nine inches, which
would gradually fubfide as the air got into
the Thorax thro' the lungs.

I then laid bare the wind-pipe, and having
cut it off a little below the Larynx, I affixed

Analyjis of the Air. 255

to it a bladder full of air, and then conti-
nued fucking air out of the 'Thorax, with a
force fufficient to keep the lungs pretty much
dilated. As the Mercury fubfided in the
gage, I repeated the fudtion for a quarter of
an hour, till a good part of the air in the
bladder was either drawn thro* the fubftance
of the lungs into the Thorax, or had loft its
elafticity. When I prefTed the bladder, the
Mercury fubfided the fafter ; the Dog was all
the while alive, and would probably have
lived much longer, if the Experiment had
been continued 3 as is likely from the follow-
ing Experiment, viz.

Experiment CXIV.

I tied a middle-fized Dog down alive on
a table, and having laid bare his wind-pipe,
I cut it afunder juft below the Larynx, and
fixed faft to it the fmall end of a common
foffet ; the other end of the foffet had a large
bladder tied to it, which contained 162 cu-
bick inches ; and to the other end of the
bladder was tied the great end of another
foffet, whofe orifice was covered wich a valve,
which opened inward, fo as to admit any air
that was blown into the bladder, but none
could return that way ; yet for further fecu-

rity,

156 Analyjis of the Air.

rity, that paffage was alfo flopped with a

fpigot.

As foon as the firft foffet was tied faft to
the wind-pipe, the bladder was blown full of
air thro' the other foffet -, when the Dog had
breathed the air in the bladder to and fro
for a minute or two, he then breathed very
faft, and (hewed great uneafinefs, as being
almoft fuffocated.

Then with my hand I preffed the bladder
hard, fo as to drive the air into his lungs with
fome force -, and thereby make his Abdomen
rife by the preffure of the Diaphragm, as in
natural breathings : Then taking alternately
my hand off the bladder, the lungs with the
Abdomen fubfided ; I continued in this man-
ner to make the Dog breathe for an hour ;
during which time I was obliged to blow
f;efh air into the bladder every five minutes,
three parts in four of that air being either
abforbed by the vapours of the lungs, or
efcaping thro' the ligatures, upon my pref-
fing hard on the bladder.

During this hour, the Dog was frequently
near expiring, whenever I preffed the air
but weakly into his lungs 5 as I found by
his pulfe, which was very plain to be felt
in the great crural artery near the groin,

which
4

Analyfis of the Air. 257

which place an affiftant held his finger on
moft pare of the time; but the languid pulfe
was quickly accelerated, fo as to beat fart ;
foon after I dilated the lungs much, by pref-
ling hard upon the bladder, efpecially when
the motion of the lungs was promoted by
preffing alternately the Abdomen and the blad-
der, whereby both the contraction and dila-
tation of the lungs was increafed.

And I could by this means roufe the lan-
guid pulfe whenever I pleafed, not only at
the end of every five minutes, when more air
was blown into the bladder from a man's
lungs, but alfo towards the end of the five
minutes, when the air was fulleft of fumes.

At the end of the hour, I intended to try
whether I could by the fame means have kept
the Dog alive fome time longer, when the
bladder was filled with the fumes of burning
Brimftone : But being obliged to ceafe for a
little time from prefiing the air into his lungs,
while matters were preparing for this addi-
tional Experiment, in the mean time the Dog
died, which might otherwife have lived lon-
ger, if I had continued to force the air into
his lungs.

Now, though this Experiment was fo fre-
quently diflurbed, by being obliged to blow

S more

258 dnalyjis of the Air.

more air into the bladder twelve times da-
ring the hour; yet fince he was almoft fuf-
focated in lefs than two minutes, by breath-
ing of himfelf to and fro the firft air in the
bladder, he would, by Experiment 106. on
Candles, have died in lefs than two minutes,
when one fourth of the old air remained in
the bladder, immediately to taint the new
admitted air from a man's lungs -> to that his
continuing to live through the whole hour,
muft be owing to the forcible dilatation of
the lungs, by compre fling the bladder, and
not to the vivifying fpirit of air. For with-
out that forcible dilatation, he had, after the
firft five or ten minutes, been certainly dead
in lefs than a minute, when his pulfe was fo
very low and weak, which I did not find to be
revived barely by blowing three parts in four
of new air from the lungs of a man into the
bladder : But it was conftantly roufed and
quickned, whenever I increafed the dilata-
tions of the lung?, by comprefling the bladder
more vigoroufly ; and that whether it was at
the beginning or end of each five minutes,
yet it was more eafily quickned, when the
bladder was at any time newly filled, than
when it was near empty.

From

dnalyfis of the Air. 259

From thefe violent and fatal cffeds of very
noxious vapours on the refpiratibn and life
of animals, we may fee how the refpiration
is proportionately incommoded, when the air
is loaded with leiTer degrees of vapours, which
vapours do, in fome meafure, clog and lower
the air's elafticity $ which it befl regains by
having thefe vapours difpelled by the venti-
lating motion of the free open air* which
is rendered wholefome by the agitation of
winds : Thus, what we call a clofe warm
air, fuch as has been long confined in a room,
without having the vapours in it carried off
by communicating with the open air, is apt
to give us more or lefs uneafinefs, in pro-
portion to the quantity of vapours which
are floating in it. For which reafon the
German ftoves* which heat the air in a room
without a free admittance of fre(h air to
carry off* the vapours that are raifed, as alfo
the modern invention to convey heated air
into rooms through hot flues, feem not fo
well contrived, to favour a free refpiration,
as our common method of fires in open
chimneys, which fires are continually car-
rying a large ftream of heated air out of the
rooms up the chimney, which ftream muft
neceflarily be fupplied with equal quantities
S 2 of

i6o Analyfis of the Air.

of frefli air, through the doors and windows,

or the cranies of them.

And thus many of thofe who have weak
lungs, but can breathe well enough in the
frefh country air, are greatly incommoded
in their breathing, when they come into
large cities, where the air is full of fuligi-
nous vapours, ariiing from innumerable coal
fires, and flenches from filthy lay-ftalls and
fewers : And even the moft robuft and heal-
thy, in changing from a city to a country
air, find an exhilarating pleafure, arifing from
a more free and kindly infpiration, whereby
the lungs being lefs loaded with condenfing
air and vapours, and thereby the veficles
more dilated, with a clearer and more e|a-
ftick air, a freer courfe is thereby given to
the blood, and probably a purer air mixed
with it 5 and this is one reaibn why in the
country a ferene dry conftitution of the air
is more exhilarating than a moifl thick air.

And for the fame reafon, it is no wonder,
that peftijential and other noxious epidemi-
cal infections are conveyed by the breath to
the blood (when we confider what a great
quantity of the airy vehicle lofes its elafti-
city among the veficles, whereby the infe-
ctious Miafma is lodged in the lungs).

When

Jnalyjis of the Air. 2 6 1
When I reflect on the great quantities of
elaftick air, which are deftroyed by fulphu-
reous fumes ; it feems to me not improba-
ble, that when an animal is killed by light-
ning without any vifible wound, or imme-
diate ftroke, that it may be done by the air's
elafticity, being inftandy deftroyed by the
fulphureous lightning near the animal;
whereby the lungs will fall flat, and caufe
fudden death ; which is further confirmed
by the flatnefs of the lungs of animals thus
killed by lightning, their veficles being found
upon diflection to be fallen flat, and to have
no air in them : The burfting alio of glafs-
windows outwards, fecms to be from the
fame effect of lightning on the air's elafti-
city.

It is likewife by deftroying the air's elafti-
city in fermented liquors, that lightning ren-
ders them fiat and vapid: For fince fulphu-
reous fteams held near or under veflels will
check redundant fermentation, as well as the
putting of fulphureous mixtures into the li-
quor, it is plain, thofe fteams can eaiily pe-
netrate the wood of the containing vefTels.
No wonder then, that the more fubtile
lightnings fhould have the like effects. I
S 3 know

i6x JnaJyJis of the Air.

know not whether the common practice of
laying a bar of iron on a veffel, be a good
prefervative againft the ill effects of lightning
on liquors. I fhould think, that the cover-
ing a veffel with a large cloth dipped in a
ftrong brine, would be a better prefervative;
for falts are known to be ftrong attraclers of
fulphur.

The certain death which comes on the
explofion of Mines, feems to be effected in
the fame manner : For though at firft there
is a great expanfion of the air, which muff
dilate the lungs, yet that air is no fooner
filled with fuliginous vapours, but a good
deal of its elafticity is immediately deftroyed:
As in the cafe of burning Matches in Expe-
riment 103. the heat of the flame at firft
expanded the air ; but notwithstanding the
flame continued burning, it immediately con-
tracted, and loft much of its elafticity, as
foon as fome quantity of fulphureous fleams
afcended in it.

Which fteams have doubtlefs the fame
effect on the air, in the lungs of animals held
over them, as in the Grotto di caniy or when
a clofe room is filled with them, where they

certainly fuffocate.

Analjjts of the Air. 265

It is found by Experiments 103, 106, and
107, that an air greatly charged with vapours
lofes much of its elafticity, which is the rea-
fon why fubterraneous damps fuffocate ani-
mals, and extinguish the flame of candles-
And by Experiment 106, we fee that the
fooner a Candle goes out, the fafter the air
lofes its elafticity.

Experiment CXV.

This put me upon attempting to find fome
means to qualify and rebate the deadly noxi-
ous quality of thefe vapours : And in order
to it, I put thro' the hole, in the top of the
air-pump receiver, (Fig. 32.) which contained
two quarts, one leg of an iron fyphon made
of a gun-barrel, which reached near to the
bottom of the receiver : It was cemented fail
at z. I tied three folds of woollen cloth over
the orifice of the fyphon, which was in the
receiver. The candle went out in lefs than
two minutes, tho* I continued pumping all
the while, and the air pafled fo freely thro'
the folds of cloth into the receiver, that the
Mercury in the gage did not rife above an
inch.

When I put the other end of the fyphon
into a hot iron pot, with burning Brimjione

S 4 in

1 6 f Analyfis of the Ah.

in it ; upon pumping, the candle went out
in 15 feconds of a minute; but when I took
away the three folds of cloth, and drew the
fulphureous fleams thro' the open fyphon,
the light of the candle was inftantly extin-
guifhed ; whence we fee the 3 folds of cloth
preferved the candle alight 15". And where
the deadly quality of vapours in mines is not
fo ftrong as thefe fulphureous ones were, the
drawing the breath through many folds of
woollen cloth may be a means to prefervelife
a little longer, in proportion to the more or
lefs noxious quality of the damps.

When, infteadof the three folds of cloth, I
immerfed the end of the fyphon three inches
deep in water in the veffel xy (Fig. 32.) tho'
upon pumping the fulphureous fumes did
afcend vifibly through the water, yet the
candle continued burning half a minute, i. e.
double the time that it did when fumes pafTed
thro' folds of woollen cloth.

Experiment CX VI.

I bored a hole in the fide of a large wooden
foflet ab, (Fig. 30.) and glewed into it the
great end of another fofiet i /, covering the
1 Gee with a bladder valve r: Then I fit-
ted a valve b i7 to the orifice of the iron

fyphon

Analyjis of the Air. 165

fyphon S Sy fixing the end of the fyphon faft
at b into the foflet a b : Then by means of
narrow hoops I placed four Diaphragms of
flannel at half an inch diftance from each
other, into the broad rim of a fieve, which
was about feven inches diameter. The fieve
was fixed to, and had a free communication
with, both orifices of the fyphon, by means
of two large bladders i i n ?i 0.

Linen would probably be more proper to
make thefe Diaphragms of than flannel, be-
caufe oil or greafe is ufed in the making of
flannel : And as I have heard, it is whitened
by the fumes of burning Brimjlone; which I
was not aware of, when I made uie of flannel
in thefe Experiments.

The inftrument being thus prepared,
pinching my noftrils clofe, when I drew in
breath with my mouth at a, the valve i b
being thereby lifted up, the air paflfed freely
through the fyphon from the bladders,
which then fubfided, and fhrunk confider-
ably: But when I breathed air out of my
lungs, then the valve i b clofing the orifice
of the fyphon, the air pafied thro' the valve
r into the bladders, and thereby ^- dilated
them •> by which artifice the air which I ex-
pired muft necefiarily pafs thro' all the Dia-

phragms,

266 Analyfis of the Air.

pbragms, before it could be infpired into my
lungs again. The whole capacity of the
bladders and fyphon was 4 or 5 quarts.

Common fea-falt, and Sal Tartar, being
ftrong imbibers of fulphureous fteams, 1 dip-
ped the four Diaphragms in ftrong folutions
of thofe falts, as alfo in white- wine vinegar,
which is looked upon as a good anti-pefti-
lential : Taking care after each of thefe Ex-
periments to cleanfe the fyphon and bladder
well from the foul air, by filling them with
water.

I could breathe to and fro the air inclofed
in this inftrument for a minute and half,
when there were no Diaphragms in it ; when
the four Diaphragms were dipped in vinegar,
three minutes ; when dipped in a ftrong folu-
tion of fea-falt, three minutes and an half.
In a Lixivium of Sal Tartar, three minutes;
when the Diaphragms were dipped in the
like Lixivium, and then well dried, five mi-
nutes ; and once 8 -j- \ minutes, with very
highly calcined Sal Tartar -, but whether
this was owing to the Tartar s being greatly
calcined, whereby it might more ftrongly
attradl fulphureous grofs vapours, or whe-
ther it was owing to the bladder and fyphon's
being intirely dry, or whether it was occa-

fioned

Analyjis of the Air. 2^7

iioned by fome unheeded paiTage for the air
thro' the ligatures, I am uncertain ; neither
did I care to afcertam the matter by repeated
Experiments, fearing I might thereby fome
way injure my lungs, by frequently breathing
in fuch grofs vapours.

Hence Sal Tartar fhould be the bell: pre-
fervative againft noxious vapours, as being a
very ftrong imbiber of fulphureous, acid and
watry vapours, as is fea-falt alfo : For having
carefully weighed the four Diaphragms be-
fore I fixed them in the inftrument, I found
that they had increafed in weight 30 grains
in five minutes 5 and it was the fame in two
different trials; fo they increafed in weight
at the rate of 1 9 ounces in 24 hours. From
which deducting £ part of the quantity of
moifture, which I found thofe Diaphragms
attracted in 5 minutes in the open air ; there
remain 15 -J- -| ounces, for the weight of
the moifture from the breath in 24 hours :
But this is probably too great an allowance,
confidering that the Diaphragms might at-
tract more than £ part from the moifture of
the bladders and of the fyphon. See Exper. 6.
Vol. II. Appen. p. 323.

I have found, that when the Diaphragms
had fome fmall degree of dampnefs, they

increafed

268 Analyfis of the Air.

increafed in weight fix grains in three minutes -,
but they made no increafe in weight in the
fame time, when in the open air : which fix
grains in three minutes is at the rate of about
6 + |ounces in 24 hours 3 and this is nearly
the fame proportion of moifture that I ob-
tained by breathing into a large receiver full
of fpunges. But the fix grains imbibed by
the four Diaphragms in three minutes, was
not near all the vapours which were in that
bulk of inclofed air ; for at the end of the
three minutes, the often refpired air was fo
loaded with vapours, which in that floating
ftate were eafily, by their mutual attraction,
formed into combinations of particles, too
grofs to enter the minute veficles of the
lungs, and was therefore unfit for refpira-
tion ; fo that it is not eafy to determine what
proportion is carried off by refpiration, efpe-
cially confidering that fome of the infpired
air, which has loft its elafticity in the lungs,
is mingled with it. But fuppofing 6 + x
ounces to be the quantity of moifture car-
ried off by refpiration in twenty-four hours,
then the furface of the lungs being found,
as above, 41635 fquare inches, only y^T Part
of an inch depth will be evaporated off
their inward furface in that time, which

AnaJyJis of the Air. 269

is but JL part of the depth of what is per-
fpired off the furface of a man's body in that
time.

If then life can by this means be fupported
for five minutes with four Diaphragms and
a gallon of air, then doubtlefs, with double
that quantity of air and eight Diaphragms,
we might well expect to live at leaft ten mi-
nutes. It was a confiderable difadvantage,
that I was obliged to make ufe of bladders,
which had been often wetted and dried, fo
that the unfavoury fumes from them muft
needs have contributed much to the unfitting
the included air for refpiration : Yet there
is a neceffity for making ufe of either blad-
der or leather in thefe cafes ; for we cannot
breathe to and fro the air of a veffel, whofe
fides will not dilate and contract in confor-
mity with the expirations and infpirations,
unlefs the veffel be very large, and too big
to be conveniently portable.

Having flopped up the wide fucking ori-
fice of a large pair of kitchen bellows, they
being firfl dilated, I could breathe to and fro
at their nofe, the air contained in them for
more than three minutes, without much in-
convenience, they heaving and falling very
eafily by the action of refpiration. Some

fuch-

17 o Analyjis of the Air.

fuch-like inftrument might be of ufe in any
cafe, where a room was filled with fuffbca-
ting vapours, where it might be neceffary to
enter for a few minutes, in order to remove
the caufe of them, or to fetch any perfon or
thing out; as in the cafe when houfes are
firft beginning to fire, in the Chymifts ela-
boratories ; and in many other cafes, where
places were filled with noxious deadly va-
pours, as in the cafe of ftink-pots thrown
into (hips, in mines, &c. And might it not
alfo be ferviceable to Divers ?

But in every apparatus of this kind great
care muft always be taken, that the infpira-
tion be as free as poffible, by making large
paffages and valves to play moll: eafily. For
tho' a man by a peculiar action of his mouth
and tongue may fuck Mercury 22 inches,
and fome men 27 or 28 high ; yet I have
found by experience, that by the bare infpi-
ring aftion of the Diaphragm, and dilating
Thorax y I could fcarcely raife the Mercury
two inches. At which time the Diaphragm
muft a£t with a force equal to the weight of
a Cylinder of Mercury, whofe bafe is com-
menfurate to the area of the Diaphragm, and
its height two inches, whereby the Dia-
phragm muft at that time fuftain a weight

equal

AnaJyJis of the Air. 271

equal to many pounds. Neither are its
counter-aCting mufcles, thofe of the Abdomen*
able to exert a greater force.

For notyvithftanding a man, by ftrongly
compreffing a quantity of air included in his
mouth, may raife a column of Mercury in
an inverted fyphon, to five or feven inches
height, yet he cannot, with his utmoft {train-
ings, raife it above two inches, by the con-
tracting force of the mufcles of the Abdomen;
whence we fee that our loudeft vociferations
are made with a force of air no greater than
this. So that any fmall impediment in breathe-
ing will haften the fuffocation, which con-
fifts chiefly in the falling flat of the lungs,
occafioned by the groflhefs of the particles
of a thick noxious air, they being in that
floating ftate mod eafily att rafted by each
other : As we find in the foregoing Experi-
ments that fulphur and the elaftick repelling
particles of air do : And confequently unela-
ftick, fulphureous, faline, and other floating
particles will moft eafily coalefce ; whereby
they are rendered too grofs to enter the mi-
nute veficles; which are alfo much con-
tracted, as well by the lofs of the elafticity
of the contained air, as by the contraction
Occafioned by the ftimulating, acid, fulphu-
reous

27 * Analyfis of the Air.

reous vapours. And it is not improbable,
that one great defign of nature, in the ftru-
cture of this important and wonderful vifcus,
was to frame its veficles fo very minute,
thereby effectually to hinder the ingrefs of
grofs feculent particles, which might be inju-
rious to the animal oeconomy.

This quality offalts ftrongly to attract ful-
phurecus, acid, and other noxious particles,
might make them very beneficial to man-
kind in many other refpects. Thus in feve-
ral unwholefome trades, as the fmelters of
metals, the cerufs-makers, the plumbers, GV.
it might not unlikely be of good fervice to
them, in preferving them, in fome meafure
at leaft, from the noxious fumes of the ma-
terials they deal in, which by many of the
foregoing Experiments we are allured mufl
needs coalefce with the elaftick air in the
lungs, and be lodged there ; to prevent which
inconvenience the workmen might, while
they are at work, make ufe of pretty broad
mufflers, filled with two, four, or more
Diaphragms of flannel or cloth dipped in a
folution of Sal Tartar or Pot-aft, or Sea-Salt,
and then dried.

The like mufflers might alfo be of fervice
in many cafes where perfons may have urgent

occafion

Analyjis of the Ak. 275

occafion to go for a fhort time into an in-
fectious air : Which mufflers might, by an
eafy contrivance, be fo made as to draw in
breath thro' the Diaphragms, and to breache
it out by another vent.

In thefe and the like cafes this kind of
mufflers may be very ferviceable 5 but in the
cafe of the damps of mines they are by no
means to be depended on, becaufe they are
not a fufficient fcreen from fo very noxious
vapours.

Experiment CXVII.

We have from the following Experiment
a good hint, to make thefe Salts of fervice to
us in fome other refpedls, GV.

I fet a lighted Candle under a large receiver
(Fig. 35) which contained about four gal-
lons 5 it continued burning for 3 + i. mi-
nutes, in which time it had abforbed about
a quart of air. I then filled the receiver with
frefh air, by pouring it full of water, and
then emptying of it , when having wiped it
dry, I lined all the infide with a piece of
flannel dipped in a Lixivium of Sal clartary
and then dried ; the flannel was extended
with little hoops made of pliant twigs. The
Qandle continued burning under the receiver

T thus

274 Analyfis of the Air.

thus prepared 3 + \ minutes ; yet it abforbed
but two thirds of the quantity of air which
it abforbed when there was no flannel in the
receiver.

The reafon of which difference in the
quantities of elaftick air abforbed, appears
from Experiment 106, where leaft air was
always abforbed in leaft receivers, which was
the prefent cafe: For the flannel lining, be-
iides the fpace it took up, could not be fo
clofely adapted, but that there was left a full
third of the capacity of the receiver, between
the lining and the receiver : So that the Candle
burnt in a bulk of air lefs by one third than
the whole capacity of the receiver > for which
reafon lefs air alfo was abforbed.

And we may further obferve, that fince the
Candle continued burning as long in a quan-
tity of air, equal but to two thirds of the re-
ceiver, as in the whole air of the receiver j
this muft be owing to the Sal "Tartar in the
flannel lining, which muft needs have abforbed
one third of the fuliginous vapours, which
arofe from the burning candle. Hence we may
not unreafonably conclude, that the pernicious
quality of noxious vapours in the air might,
in many cafes, be much rebated and qualified
fey the ftrcngly abforbing power of Salts.

Whe-

Analyfis of the Air. 275

Whether Salts will have a good effect in
all, or any of thefe cafes, experience will
beft inform us. There is certainly fufficient
ground, from many of the foregoing Expe-
riments, to encourage us to make the trial,
and they may at leaft be hints for further im-
provements.

We fee that Candles and burning Brim-
fione do in a much greater degree deftroy
the elafticity of the air, than the breath of
Animals ; becaufe their vapours are more
plentiful, and abound more with acid ful-
phureous particles, and are alfo lefs diluted
with watry vapours, than the breath of Ani^
mals is: In which alfo there are fulphureous
particles, tho' in leffer degrees; for the ani-
ma-1 fluids, as well as folids, are ftored with
them: And therefore the Candle and Matches
ceafing to burn, foon after they are confined
in a fmall quantity of air, feems not to be
owing to their having rendred that air effete,
by having confumed its vivify i?ig fpirit ; but
mould rather be owing to the great quantity
of acid fuliginous vapours, with which that
air is charged, which deftroy a good deal of
its elafticity, and very much clog and retard
the elaftick motion of the remainder.

T 2 And

27 6 Anatyfis of the Air.

And the effedt the half exhaufting of a
receiver has upon the elafticrty of the remain-
ing half of the air, feems to be the reafon
why the flame of a Candle does not con-
tinue burning, till it has filled the receiver
it ftands in with fumes ; but goes out the
quicker, the fooner the air is drawn out to
that degree ; which feems therefore to be
owing to this, that an air rarefied to double
its fpace, will not expand fo briskly with the
warmth of flame, as a more condenfed air
will do r And confequently action and re-
action being reciprocal, will not give fo brisk
a motion to the flame, which fubfifts by a
conftant fucceffion of frefli air, to fupply the
place of the either abforbed, or much dilated
air, which is continually flying off. And the
quicker the fucceflion of this frefli air is, by
blowing, the more vigoroufly does a fire
burn.

If the continuance of the burning of the
Candle be wholly owing to the vivifying
Jpirit, then fuppofing in the cafe of a re-
ceiver, capacious enough for a Candle to burn
a minute in it, that half the vivifying fpirit
be drawn out with half the air, in ten fecond3
of time ; then the Candle fhould not go out
at the end of thole ten feconds> but burn

twenty

Analyjis of the An. 17 7

twenty feconds more, which it does not ;
therefore the burning of the candle is not
wholly owing to the vivifying fpirit, but to
certain degrees of the air's elafticity. When
a wholly exhaufted receiver was by means of
a burning-glafs firft filled with the fumes of
brown paper with Nitre, and then filled
with frefh air, the nitrous paper, upon ap-
plying the burning-glafs, did freely detonize;
and a Candle put into a like air, burnt for 2 8" 5
which in a frefh air, in the fame receiver?
burnt but 43" ; but when the fame receiver,
with air in it, was filled full of fumes of
detonized Nitre, and a Candle placed in that
thick vapour, it went out inflantly ; for a
Candle will not burn, nor the Nitre deto-
nize in a very rare, nor a very thick air ;
whence the reafon why the Nitre detonized,
and the Candle burnt, when placed in the
receiver, after frefh air was let in upon
the fumes which were made in vacuo, was,
that thofe fumes were much difperfed and
condenfed on the fides of the glafs, upon
the rufhing in of the frefh air; for the fumes
were then much more rare and tranfparent,
than before the air was let in.

That a Fire which is fupplied with a hot
air will not burn fo briskly as a Fire which

T 3 is

2/8 Jnalyfis of the Air.

is fed by a cool air, is evident from hence ;
that when the Sun fhines on a Fire, and
thereby too much rarefies the ambient air,
that Fire will not burn well ; nor will a
final 1 Fire burn fo well near a large one, as
at fome diftance from it. And e centra, it
is a common obfervation, that in very cold
frofty weather, Fires burn moft briskly ; the
reafon of which feems to be this, that the
elaftick expanfion of the cold condenfed air
to a rarefied Hate, when it enters the Fire, is
much brisker than that of an air already
rarefied in a good meafure by heat, before it
enters the Fire; and confequently a conti-
nued fucceffion of cold air muft give a brisker
motion to the Fire, than the like fucceflion
of hot air: And fuch colder and more con-
denfed air will alfo (as Sir Ifaac Newton ob-
ferves qu. 11) by its greater wreight check
the afcent of the vapours and exhalations of
the Fire, more than a warmer lighter air.
So that between the action and re-action of
the air and fulphur of the fuel, and of the
colder and denfer circumambient air, which
rarefies much upon entring the Fire, the heat
of the Fire is greatly increafed. See Vol. II.

/•329-

This

Jnalyfis of the Air. 179

This continual fupply of frefh air to the
fuel, feems hence alfo very neceffary for keep-
ing a Fire alive ; becaufe it is found, that a
Brimfione Match will not take fire in a va-
cuum, but only boil and fmoke ; nor will
Nitre incorporated into Brown Paper then
detonize, except here and there a fingle grain,
that part only of the Paper turning black, on
which the focus of the burning-glafs falls ;
nor would they burn when a half-exhaufted
receiver with fumes in it was filled with frefli
air added to thofe fumes : In which cafe it
is plain, that a good quantity of the fup-
pofed vivifying fpirii of air muft enter
the receiver with the frefli air, and confe-
quently thofe fubftances fhould take fire, and
bum for a fhort time at leaft, which yet they
did not.

And that the air's elafticity conduces much
to the intenfe burning of Fires, feems evident
from hence ; that Spirit of Nitre (which, by
Experiment 75, has but little elaflick air in
it) when poured upon live Coals, extinguishes
inftead of invigorating them : But Spirit of
Nitre, when by being mixt with Sar Tartar
it is reduced to Nitre, will then flame, when
thrown into the Fire, viz. becaufe Sal Tartar
abounds with elaflick aereal particles, as ap-

T 4 pears

2 8 o Analyjis of the Ah.

pears by Experiment 74, where 224 times
its bulk of air arofe from a quantity of Sal
Tartar. And for the fame reafon it is that
common Nitre, when thrown into the Fire,
flames, tho' its Spirit will not, viz. becaufe
there is much elaftick air in it, as appears
from Experiment 72, as well as from the
great quantity of it, generated in the firing
of Gun-powder.

The reafon why Sal Tartar ', when thrown
on live Coals, does not detonize and flame
like Nitre, (notwithftanding, by Experiment
74, plenty of elaftick particles did arife from
it) is this, viz. becaufe by the fame Experi-
ment, compared with Experiment 72, it is
found, that a much more intenfe degree of
heat was required to extricate the elaftick air
from Sal Tartar, the more fix'd body, than
from Nitre -, the great degree of Fire with
which Sal Tartar is made, rendering the
cohefion of its parts more firm : For it is
well known that Fire, inftead of difuniting,
does in many cafes infeparably unite the parts
of bodies: And hence it is that Pidvis Ful-
mi'rians, which is a mixture of Sal Tartar,
Nitre and fulphur, gives a greater explofion
than Gun-powder : Becaufe the particles of
the Sal Tartar cohering more firmly in a

fix'd

Analyfis of the Air. 8 1 \

fix'd ftate than thofe of 'Nitre, they are there-
fore thrown off with a greater repulfive force,
by the united action and re-action of all thofe
ingredients armed each with its acid Spirit.

Experiment CXVIII.

Which acid Spirits, confifting of a volatile
acid Salt diluted in phlegm, do contribute
much to the force of explofion; for when
heated to a certain degree, they make a great
explofion, like water heated to the fame de-
gree, as I found by dropping a few drops of
Spirit of Nitre, oil of Vitriol, water, and
fpittle, on an Anvil; and then holding over
thofe drops a piece of Iron, which had a
white heat given it ; upon flriking down the
hot Iron with a large Hammer, there was a
very great explofion made by each of thofe
liquors: But frothy fpittle, which had air in
it, made a louder explofion than water; which
fhews that the van: explofion of the Nitre and
Sal Tartar, which are compofed of elaftick
air-particles, included in an acid Spirit, is
owing to their united force.

We may therefore, from what has been
faid, with good reafon conclude, that Fire is
^hiefly invigorated by the action and re-aftion.

2 8 1 Analyfis of the Air.

of the acid fulphureous particles of the fuel,
and the elaftick ones, which arife and enter
the Fire, either from the fuel in which they
abound, or from the circumambient air : For
by Experiment 103, and many others, acid
fulphureous particles act vigoroufly on air ;
and fince action and re-action are reciprocal,
fo muft air on fulphur ; and there is, we fee,
plenty of both, as well in mineral as vege-
table fuel, as alfo in animal fubftances, for
which reafon they will burn.

But when the acid fulphur, which we fee
acts vigoroufly on air, is taken out of any
fuel, the remaining Salt, water and earth, are
not inflammable, but on the contrary, quench
and retard fire; and as air cannot* produce
fire without fulphur, fo neither can fulphur
burn without air : Thus Charcoal heated to
an intenfe degree for many hours in a clofe
veflel, will not burn as in the open air; it
will only be red-hot all the time, like a mafs
of Gold, without wafting : But no fooner is
it expofed to the free air, but the fulphur,
by the violent action and re-action between
that and the elaftick air, is foon feparated and
carried off from the Salt and Earth, which
are thereby reduced from a folid and hard, to
a foft impalpable Calx.

And

Analyfis of the Air. 285

And when a Brimjlone Match, which was
placed in an exhaufted receiver, was heated
by the focus of a burning-glafs fo as to melt
the Brimjlone, yet it did not kindle into fire,
nor confume, notwithstanding the ftrength
and vigour of the adtion and re-adtion that is
obferved between light and fulphureous bo-
dies. Which is affigned by the illuftrious Sir
Ifaac Newton, as " one reafon why fulphu-
" reous bodies take fire more readily, and
" burn more vehemently than other bodies
u do, Qu. 7." What his notion of fire and
flame is, he gives us in Qu. 9. and 10. Qu^c?.
" Is not Fire a body heated fo hot as to emit
" light copioufly ? For what elfe is a red-hot
" Iron than Fire ? And what elfe is a burn-
<c ing Coal, than red-hot Wood?" Qu. 10.
<c Is not Flame a vapour, fume or exhalation,
" heated red-hot, that is, fo hot as to flame?
<c For bodies do not flame without emitting
" a copious ftfme, and this fufne burns in

<c the flame. Some bodies heated bv

motion or fermentation, if the heat grow
intenfe, fume copioufly ; and if the heat be
great enough, the fumes will fhine, and
ic become flame : Metals in fufion do not
" flame for want of a copious fume, except
" fpelter, which fumes copioufly, and there-

" by

284 Analyfis of the Air.

" by flames: All flaming bodies, as Oil,
Tallow, Wax, Wood, foffil Coals, Pitch,
Sulphur, by flaming wafte and vanifh into
burning fmoak ; which fmoak, if the flame
<c be put out, is very thick and vifible, and
lc fometimes fmells ftrongly, but in flame
u lofes its fmell by burning ; and according
<c to the nature of the fmoak the flame is
u of feveral colours, as that of fulphur, blue ;
€C that of copper opened with fublimate,
<c green; that of tallow, yellow; that of
" camphire, white ; fmoak pafling through
cc flame cannot but grow red-hot ; and red-
cc hot fmoak can have no other appearance
cc than that of flame."

But Mr. Lemery the younger fays, " That
" the matter of light produces fulphur, be-
cc ing mixt with compofitions of fait, earth,
" and water, and that all inflammable mat-
t€ ters are fuch only in virtue of the parti-
<{ cles of fire which they contain. For in
" the Analyfis, fuch inflammable bodies pro-
" duce fait, earth, water, and a certain fubtle
" matter, which pafles through the clofeft
" veflels ; fo that what pains foever the artift
<c ufes, not to lofe any thing, he ftill finds a
u confiderable diminution of weight.

!.'

Now

Analyfts of the Ait. 285

" Now thefe principles of fait, earth and
" water, are inactive bodies, and of no ufe,
u in the compofition of inflammable bodies,
" but to detain and arreft the particles of fire,
" which are the real and only matter of
u flame.

" It appears therefore to be the matter of
<c flame that the artift lofes in decompound-
<c ing inflammable bodies, Mem. de I'Acad.
cc anno 1713."

But by many of the preceding Experiments
it is evident, that the matter loft in the Ana-
lyfis of thefe bodies was elaftick air, a very
adtive principle in fire, but not an elemental
fire, as he fuppofes.

" Mr. Geoffrey compounded fulphur of
" acid Salt, Bitumen, a little Earth, and Oil
" of Tartar." Mem.de V Acad, anno 1703.
In which Oil of Tartar there is much air by
Experiment 74, which air was doubtlefs by
its elafticity very inftrumental in the inflam-
mability of this artificial fulphur.

If Fire was a particular diftinft kind of
body inherent in fulphur, as Mr. Homberg>
Mr. Lemery, and fome others imagine, then
fuch fulphureous bodies, when ignited, (hould
rarefy and dilate all the circumambient air j
whereas it is found by many of the precede-

ing

28 6 Analyfis of the Ah.

ing Experiments, that acid fulphureous fuel
conftantly attradts and condenfes a conlider-
able part of the circumambient elaftick air ;
An argument, that there is no fire endued
with peculiar properties inherent in fulphur ;
and alfo, that the heat of fire confifts princi-
pally in the brisk vibrating aftion and re-
action, between the elaftick repelling air, and
the ftrongly attracting acid fulphur, which
fulphur in its Analyfis is found to contain an
inflammable oil, and acid fait, a very fix'd
earth, and a little metal.

Now fulphur and air are fuppofed to be
afted by that ethereal medium, 'c by which
" ( the great Sir Ifaac Newton fuppofes )
<c light is refradted and reflected, and by
" whofe vibrations light communicates heat
" to bodies, and is put into fits of eafy re-
C£ fledtion, and eafy tranfmiffion : And do
<c not the vibrations of this medium in hot
<£ bodies contribute to the intenfenefs and
<c duration of their heat? And do not hot
<c bodies communicate their heat to conti-
<c guous cold ones, by the vibrations of this
<c medium, propagated from them into cold
" ones ? And is not this medium exceed-
" ingly more rare and fubtle than the air,
" and exceedingly more elaftick and adive ?

« And

Analyjis of the Air. 287
" And does it not readily pervade all bodies,
<c Optic, qu. 18. The elaftick force of this
" medium, in proportion to its denfity, muft
u be above 490,000,000,000 times greater
« than the elaftick force of the air is, in pro-
u portion to its denfity, ibid.qu. 21." A force
fufficient to give an intenfe degree of heat,
efpecially when its elafticity is much increafed
by the brisk aCtion and re-adlion of particles
of the fuel and ambient air.

From this manifeft attraction, aCtion and
re-a&ion, that there is between the acid^ ful-
phureous and elaftick aereal particles, we
may not unreafonably conclude, that what
we call the fire-particles in Lime5 and feve-
ral other bodies, which have undergone the
fire, are the fulphureous and elaftick parti-
cles of the fire fix'd in the Lime j which par-
ticles, while the Lime was hot, were in a
very a&ive, attracting and repelling ftatej
and being, as the Lime cooled, detaiped in
the folid body of the Lime, at the feveral at-
tracting and repelling diftances they then hap-
pended to be at, they muft neceffarily con-
tinue in that fix'd ftate, notwithstanding the
ethereal medium, which is fuppofed freely
to pervade all bodies, be continually follicit-
ing them to aCtion : But when the folid fub-

ftance
3

-i 8 8 lUnalyfts of the Air.
fiance of the Lime is difTolved, by the affu-
fion of fome liquid, being thereby emanci-
pated, they are again at liberty to be influ-
enced and agitated by each others attraction
and repulfion ; upon which a violent ebul-
lition enfues, from the action and re-action
of thefe particles; which ebullition ceafes
not, till one part of the elaftick particles are
fubdued and fix'd by the ftrong attraction
of the fulphur, and the other part is got
beyond the fphere of its attraction, and
thereby thrown off into true permanent air:
And that this is a probable folution of the
matter, there is good reafon to conclude,
from the frequent inftances we have in many
of the foregoing Experiments, that plenty
of elaftick air is at the fame time both gene-
rated and abforbed by the lame fermenting
mixture ; fome of which were obferved
to generate more air than they abforbed,
and others, e contra, abforbed more than
they generated, which was the cafe of
Lime.

Experiment CXIX.

And that the fulphureous and aereal par-
ticles of the fire are lodged in many of thofe

bodies

Analyfis of the Am 2 8 9 '

bodies which it ads upon, and thereby con-
siderably augments their weight, is very evi-
dent in Minium or Red Lead, which is ob-
ferved to increafe in weight about JL part in
undergoing the adion of the fire; the ac-
quired rednefs of the Minium, indicating the
addition of plenty of fulphur in the opera-
tion : For fulphur, as it is found to ad: moil:
vigouroufly on light, fo it is apt to refled
the ftrongeft, viz. the red rays. And that
there is good ftore of air added to the Mi-
nium, I found by diftilling firft 1922 grains
of Lead, from whence I obtained only feven
cubick inches of air ; but from 1922 grains*
which was a cubick inch of Red Lead,
there arofe in the like fpace of time thirty-
four cubick inches of air ; a great part of
which air was doubtlefs abforbed by the
fulphureous particles of the fuel, in the
•reverberatory furnace, in » which the Mi-
nium was made; for by Experiment 106.
the more the fumes of a fire are confined,
the greater quantity of elaftick air they ab-
forb.

It was therefore doubtlefs this quantity
of air in the Minium, which bur ft the her-
metically fealed glaffes of the excellent Mr.
Boyle, when he heated the Minium contain'd

U in

290 Analyjis of the Air.

in them by a burning-glafs ; but the pious
and learned Dr. Nieuwentyt attributes this
effect wholly to the expanfion of the fire-
particles lodged in the Minium, " he fup-
" poling fire to be a particular fluid mat-
" ter, which maintains its own effence and
" figure, remaining always fire, though not
cc always burning. Religious Philofopher, p.
« 310."

To the fame caufe alfo, exclufive of the
air, he attributes the vaft expanfion of a
mixture of compound Aqua-fortis and Oil of
Carraways, whereas by Experiment 62. there
is a great quantity of air in all Oils. And by
pouring fome compound Aqua-fortis on Oil
of Cloves, the mixture expanded into a fpace
equal to 720 times the bulk of the oily that
part of the expanfion, which was owing to
the watry part of the oil and fpirit, was foon
contracted ; whereas the other part of the
expanfion, which was owing to the elaftick
air of the oil, wras not all contracted till the
next day, by which time the fulphureous
fumes had reforbed it.

It has been the opinion of fome, that pu-
trefaction is the effect of inherent fire : that
Vegetables alone are the fubject of Fermen-
tation, but both Vegetables and Animals of

putre-

Analyjis of the Air. 191

putrefaction ; which operations they attri-
bute to very different caufes. The immediate
caufe of fermentation is (they fay) the mo-
tion of the air intercepted between the fluid
and vifcous parts of the fermenting liquors
but the caufe of putrefaction they would
have to be, fire itfelf, collected or included
within the putrefying fubject. But I do not
fee why thefe may not reafonably enough
be looked upon as the effects of different
degrees of fermentation ; nutrition being the
genuine effect of that degree of it, in which
the fum of the attracting action of the par-
ticles is much fuperior to the fum of their
repulfive power : But when their repelling
force far exceeds their attractive, then the
component parts of Vegetables are diflblved.
Which diflblving fubflances, when they are
diluted with much liquor, do not acquire a
great heat in the diffblution, the brisknefs of
the inteftine motion being checked by the
liquor : But when they are only moift, like
green and damp Hay, in a large heap, then
they acquire a violent heat fo as to fcorch,
burn and flame 5 whereby the union of their
conftituent parts being more throughly dif-
folved, they will neither produce a vinous,
nor an acid fpirit : Which great degree of
U 2 folution

2 9 1 Analyfis of the Air.

folution may well be effected by this means,
without the a&ion of a fire, fuppofed to be
included within the putrefying fubjedt. Where-
fore, according to the old Axiom, Entia ?ion
funt temere neque ahfque necejjitate multipli-
canda.

If the notion of fermentation be reftrained
to the greater repelling degrees of fermen-
tation, in which fenfe it has commonly been
underflood; then it is as certain, that the
juices of Vegetables and Animals do not fer-
ment in a healthy ftate, as it is, that they do
not at the fame time coalefce and difunue :
But if fermentation be taken in a larger {Qn(ey
for any the fmalleft to the greatest degree
of intefiine motion of the particles of a fluid,
then all vegetable and animal fluids are in a
natural (late, in fome degree of ferment; for
they abound both with elaftick and fulphu-
reous particles : And it may with as much
reafon be argued, that there is no degree
of warmth in Animals and Vegetables, be-
caufe a great degree of heat will caufe a
folution of continuity, as to fay, there is no
decree of ferment in the fluids of thofe bo-
dies, becaufe a great repelling degree of fer-
ment will moil; certainly diffolve them.

That

Analyjis of the An. 293

That illuflrious Philofopher, Sir Tfaac New-
ton, in his thoughts about the nature of acids,
gives this rational account of the nature of

fermentation. " The particles of acids

" are endued with a great attractive force,

" in which force their acYivitv confifts ■

" By this attractive force they get about the
" particles of bodies, whether they be of a
<c metallick or ftony nature, end adhere to
" them moft clofely on all fides, fo that they
cc can fcarce be feparated from them by diftil-
u lation or fublimation 5 when they are at-
cc traded and gathered together about the
" particles of bodies, they raife, disjoin, and
" make them one from another, that is, they
" diffolve thofe bodies.

" By their attractive force alio, by which
" they rum towards the particles of bodies,
" they move the fluid, and excite heat, and
<c they make afunder fome particles, fo much
<c as to turn them into air, and generate bub-
" bles : And this is the reafon of diflblution,
" and all violent fermentation. Harris's
u Lexicon Tech. Vol. II. Introduction."

Thus we have from thefe Experiments
many manifefl proofs of confiderable quan-
tities of true permanent air, which are by
means of fire and fermentation raifed from,
U 3 and

294 dnalyjis of the Air.
and abforbed by animal, vegetable and mine-
ral fubftances.

That this air confifts of particles which are
in a very adtive ftate, repelling each other
with force, and thereby conflituting the (lime
kind of elaftick fluid with common air, is
plain from its raifing the Mercury in Expe-
riment 88 and 89, and from its continuing
in that elaftick ftate for many months and
years, tho' cool'd by fevere frofts j whereas
watry vapours, tho* they expand much with
heat, yet are found immediately to condenfe
into their firft dimenfions when cold.

The air generated by fire was not, in many
inftances, feparated without great violence
from the fix'd bodies, in which it was incor-
porated ; as in the cafe of Nitre, Tartar, Sal
Tartar and Copperas \ whence it ftiould feem,
that the air generated from thefe Salts, may
probably be very inftrumental in the union
of Salts, as well as that central, denfer, and
compacter particle of earth, which Sir Ifaac
Newton obferves, does by its attraction make
the watry acid flow round it, for compoling
the particles of Salt, §w. 3 1. For fince, upon
thediflblution of the conftituent parts of Salt
by fire, it is found, that upon feparating and
volatilizing the acid ipirit, the air-particles do

Analyfis of the Ah. 295

in great abundance rufh forth from a fixt to
a repelling elaftick ftate ; it muft needs be,
that thefe particles did, in their fixt ftate,
ftrongly attradt the acid fpirits, as well as the
fulphureous earthy parts of the Salt; for the
moft ftrongly repelling and elaftick particles
are obferv'd, in a fixt ftate, to be the moft
ftrongly attracting.

But the watry acid, which, when fepa-
rated from Salt by the adtion of fire, makes
a very corrofive fuming fpirit, will not make
elaftick air, though its parts were put into a
brisk motion by fire in Experiment 75. And
the event was the fame with feveral other
volatile fubftances, as volatile Salt of Sal
Ammoniac, Camphire and Brandy; which,
though diftilled over with a confiderable hear,
yet generated no elaftick air, in Experiment
52, 61, 66. Whence it is plain, the acid
vapours in the air only float in it like the
watry vapours ; and when ftrongly attra-
cted by the elaftick particles of the air,
they firmly adhere to them, and make
Salts.

Thus in Experiment 73. we fee, by the

vaft quantity of air there is found in Tartar,

that tho' it contains the other principles of

vegetables, yet air, with fome volatile Salt,

U 4 feems

*96 Analyfn of the Ah.

feems to make up a confiderable part of its
compofition ; which air, when by the action
of fire it is more firmly united with the earth,
and acid fulphureous particles, requires a more
intenfe degree of heat, to extricate it from
thofe adhering fubftances, as we find in the
diftillation of Sal Tartar, Exper. 74. which
Air and volatile Salt are moft readily fepa-
rated by fermentation.

And by Experiment 72. plenty of air arifes
alfo from Nitre, at the fame time that the
acid fpirit is feparated from it by the action
of fire.

We find alfo by Experiment 71. that fome
air is by the fame means obtained from com-
mon Sea-fair, tho' not in fo great plenty, nor
fo eafily, as from Tartar and Nitre, it being
a more fixt body, by reafon of the fulphur
which abounds in it; neither is it io eafily
changed in animal bodies, as other Sales are;
yet, fince it fertilizes ground, it muft needs be
changed by vegetables.

There is good reafon alfo to fufpedt, that
thefe acid fpirits are not wholly free from
air-particles, notwithstanding there were no
elaftick ones produced, when they were put
into a brick motion, by the action of fire in
Experiment 75. which might be cccaficned

Analyfis of the Air. 297

by the great quantity of acid fpirit, in which
they were involved. For we fee in Experi-
ment 90. that when the acid fpirit of Aqua
Regia was more ftrongly attracted by the
diflblving gold, than by the air- particles,
then plenty of air-particles, which were thus
freed from the acid fpirit, did continually
arife from the Aqua Regia, and not from the
gold, at leaf! not from the metallick particles
of the gold, for that lofes nothing of its
weight in the folution ; fo that if any does
arife from the gold, it muft be what may
be latent in the pores of the gold. Whence
it is probable, that the air which is obtained
by the fermenting mixture of acid and alka-
line fubftances, may not arife wholly from
the diflblved alkaline body, but in part alfo
from the acid. Thus the great quantity of
elaflick air, which in Experiment 83. is gene-
rated from the mixture of Vinegar and Oyfler-
(hell, may as well arife in part from the Tar-
tar, to which Vinegar owes its acidity, as
from the diflblved Oyfterfhell. And what
makes it further probable is, that the Vine-
gar lofes its acidity in the ferment, that is,
its Tartar: for diflblving menftruums are
generally obferved to be changed in fermen-
tation, as well as the diflblved body.

Have

ip8 Analyjls of the Air.

Have we not reafon alfo hence to conclude,
that the energy of acid fpirits may, in fome
meafure, be owing to the ftrongly attracting
air-particles in them; which adtive princi-
ples may give an impetus to the acid Jpiculte,
as well as the earthy oily matter, which is
found in thefe acid fpirits?

There are, we fee, alfo great ftore of air-
particles found in the Analyfis of the blood,
which arifes doubtlefs as well from the ferum
as from the craffamentum^ for all the animal
fluids and folids have air and fulphur in them :
Which ftrongly attracting principles feem
to be more intimately united together in the
more perfect and elaborate part of it, its red
glpbules; fo that we may not unreafonably
conclude, that air is a band of union here as
well as in Salts : And accordingly we find the
greateft plenty of air in the mod folid parts
of the body, where the cohefion of the parts
is the ftrongeft -, for by comparing Experi-
ment 49. and 51. we fee that much more air
was found in the diftillation of horn, than of
blood. And the cohefion of animal fubftances
was nor, as we find by the fame Experiment,
diflblved even in the blood, without confi-
derable violence of fire ; tho' it is fometimes
done to a fatal degree in our blood, by that

AnaJyJis of the Air. 299

more fubtile diffolvent fermentation: But we
may obferve, that violent Salts, Spirits, and
fulphureous Oil, which are at the fame time
feparated from thefe fubftances, will not make
elaftick air.

Experiment CXX.

As elaftick air is thus generated by the force
of fire from thefe and many other fubftances,
fo is the elafticity of the air greatly deftroyed
by fulphureous bodies. Sir Ifaac Newton
obferves, <c That as light acts upon fulphur,
<c fo, fince all action is mutual, fulphurs ought
" to acl: moil upon light." And the fame
may be obferved of air and fulphur ; for by
Experiment 103. it is found that burning
fulphur, which is a very ftrongly attrad:ing
fubftance, powerfully attracts and fixes the
elaftick particles of air; fo that there muft
needs be a good quantity of unelaftick air-
particles in oil and flour of fulphur : The
firft of which is made by burning fulphur
under a bell, the other by fublimation : In
further confirmation of this it is obferved,
that Oleum Sulphuris per Campanam is with
more difficulty made in a dry than a moift
air ; and I have found by Experiment pur-

pofely

500 Analyjis of the Air.

pofely made, that a Candle, which burnt 70 "
in a very dry receiver, burnt but 64" in the
fame receiver, when filled with the fumes of
hot water ; and yet abforbed one-fifth part
more air, than when it burnt longer in the
dry air.

Sulphur not only abforbs the air when
burning in a homogeneal mafs, but alfo in
many fermenting mixtures ; and as Sir Ifaac
Newton obferved the attractive and refractive
power of bodies to be greater or lefs, as they
partook more or lefs of fulphureous oily par-
ticles -, fo there is good reafon from thefe Ex-
periments to attribute the fixing of the ela-
ftick particles of the air to the ftrong attra-
ction of the fulphureous particles, with which
he fays it is probable that all bodies abound
more or lefs. Electrical bodies are alfo ob-
ferved to attract more ftrongly, in proportion
to the greater quantity of fulphur which they
contain.

That great plenty of air is united with
fulphur in the oil of vegetables, is evident,
from the quantity of air that arofe from the
diftillation of oils of Annifeeds and Olives, in
Exper. 62. When by fermentation the con-
ftituent parts of a Vegetable are feparated,
part of the air flies off in fermentation into

Analyfis of the Air. 301
&n elaftick ftate; part unites with the eflen-
tial Salt, Water, Oil and Earth, which con-
ftitute the Tartar which adheres to the fides
of the veffel ; the remainder, which continues
in the fermented liquor, is there, fome of it
in a fix'd, and fome in an elaftick ftate, which
gives brisknefs to the liquor \ their expanding
bubbles rifing of a very vifible fize, when the
weight of the incumbent air is taken off the
liquor in a vacuum.

And as there was found a greater quantity
of air in the deer's horn than in blood, we
may alfo obferve it to be in a much greater
proportion in the more folid parts of Vege-
tables, than in their fluid : For we find in
Experiment 55. $j. and 60. that near one-
third part of the fubftance of the Peafe, heart
of Oak, and Tobacco, were, by the adlion of
fire, changed from an unelaftick ftate to an
elaftick air : And fince a much greater pro-
portion of air is found in the folid than the
fluid parts of bodies, may we not with good
reafon conclude, that it is very inftrumental,
as a band of union in thofe bodies ? " Thofe
" particles (as Sir Ifaac Newton obferves)
ic receding from one another with the great-
" eft repulfive force, and being moft diffi-
*j cultly brought together, which upon con-

" tadt

3d AnaJyJis of the Air.
" tacft cohere mod flrongly. <2>u. 3 1." And
if the attraction of cohefion of an unelaftick
air-particle be proportionable to its repulfive
force in an elaftick ftate; then, fince its ela-
ftick force is found to be fo vaftly great, fo
mull that of its cohefion be alfo. Sir Ifaac
Newton calculates from the inflexion of the
rays of light, that the attracting force of par-
ticles, near the point of contadt, is 10000,
0000, 0000, 0000 greater than the force of
gravity.

Sulphur in a quiefcent fix'd ftate in a large
body, does not abforb the elaftick air ; for a
hard roll of Brimftone does not abforb air :
But when fome of that Brimftone, by being
powdered and mix'd with filings of Iron, is
fet a fermenting, and thereby reduced into
very minute particles, whofe attraction in-
creafes as their fize decreafes ; then it abforbs
elaftick air vigoroufly: As may be feen in
many inftances under Experiment 95. The
Walton Mineral, in which there is a good
quantity of fulphur, did, when compound
Aqua-fortis was poured on it, in Experiment
96. make a confiderable fermentation, and
abforb a great quantity of elaftick air : But
when the ferment was much increafed, by
adding an equal quantity of water to the like

mix-

Analyjis of the Air. 305

mixture, then inftead of abforbing 85 cubicle
inches, as before, it generated 80 cubick
inches of air : So that fermenting mixtures,
which have fulphur in them, do not always
abforb, but fometimes ^generate air: The
reafon of which in the Experiment now under
confideration feems to be this, viz. in the firft
cafe a good quantity of elaftick air was gene-
rated by the inteftine motion of the ferment-
ing ingredients \ but there ariling thence a
thick, acid, fulphureous fume, this fume ab-
forbed a greater quantity of elaftick air than
was before generated : And we find by Expe-
riment 103, that the fulphureous particles
which fly off in the air, do by their attra&ion
deftroy its elafticity ; for in that Experiment
burning Brimftone greatly deftroyed the air's
elafticity -> which muft be done by the flame,
and afcending fumes ; becaufe in the burning
of any quantity of Brimftone the whole mafs
is in a manner wafted, there remaining only a
very little dry earth : And therefore the ab-
forbed air cannot remain there, but muft be
abforbed by the afcending fumes, which then
attrafl: moft ftrongly, when reduced ad mi-
nima : And it is well known, that a Candle in
burning flies all off into flame and vapour, fo
that what air it abforbs, muft be by thofe fumes.

E XPE-

304 Analyjis of the Ah*

Experiment CXXI.

And further, I have found that thefe fumes
deftroy the air's elafticity for many hours afcer
the Brimftone Match, which made them,
was taken out of the veflel z z a a: (Fig. 35.)
Thofe fumes being firft cooled by immerfing
that veflel and its ciftern x xy (or an inverted
wine flask, full of the fumes) under cold wa-
ter for fome time; then marking the furface
of the water z z, I immerfed the veflels in
warm water: And when all was cold again
the following day, I found a good quantity
of the air's elafticity was deftroy ed by the
water's afcending above z z. And the event
was the fame upon frequent repetitions of the
fame Experiment.

But if, inftead of the fumes of burning
Brimftone, I filled a flask full of fumes from
the fmoak of wood, after it had done flame-
ing, then there was but half as much air
abforbed by thofe fumes, as there was by
the fumes of Brimftone ; viz. becaufe the
fmoak of wood was much diluted with the
watry vapour which attended with it out
of the wood. And this is doublefs the rea~
fon why the fmoak of wood, though it in-
commodes

Analyjis of the Air. 305

commodes the lungs, yet it will not fuffocate
like that of Charcoal, which is withal more
fulphureous, without any mixture of watry
vapours.

And that new generated elaftick air is re-
forbed by thefe fumes, I found by attempting
to fire a Match of Brimftone with a burning-
glafs, by means of a pretty large piece of
Brown Paper, which had been dipped in a
ftrong folution of Nitre, and then dried ;
which Nitre indetonizing generated near twro
quarts of air; which quantity of air, and a
great deal more, was abforbed, when the
Brimftone took fire, and flamed vigoroufly.

So that the 85 cubick inches of air, Exper.
96. which I found upon meafuring, was ab-
forbed by the Walton Mineral and compound
Aqua-fortiS) was the excefs of what was ab-
forbed by thofe fumes above what was gene-
rated by the fermenting mixture.

And the reafon is the fame in Filings of
Iron, and Spirit of Nitre, Exper. 94. which
alfo abforbed more than they generated, whe-
ther with or without water.

Hence alfo we fee the reafon why Filings
of Iron and compound Aqua-fortis> in the
fame 94th Experiment, abforbed air $ and why,
when mix'd with an equal quantity of water,

X it

]o6 Analyjis of the Air.

it moftly abforbed, but did fometimes gene-
rate, and then abforb again : And it was the
fame with oil of Vitriol, filings of Iron and
Water, and N ewe aft I e Coal, and compound
Aqua-fortis, and others : viz. At firft, when
the ferment was brisk, the abforbing fumes
rofe fafteft, whereby more air was abforbed
than generated ; but as the ferment abated, to
fiich a degree as to be able ftill to generate
elaftick air, but not to fend forth a propor-
tionable quantity of fumes, in that cafe more
air would be generated than abforbed.

And in Experiment 95. there are feveral
inftances of the air's being in like manner ab-
forbed in lefler degrees, by other fermenting
mixtures : As in the mixture of fpirit of Harts-
horn with filings of Iron, and with filings of
Copper : And fpirit of Sal Ammoniac with
filings of Copper ; and alfo filings of Iron
and Water $ powdered Flint, and compound
Aqua-fvrth \ powdered Brijlol Diamond with
the fame liquor.

It is probable from Experiment 103 and
106. where it was found that the thicker
the fuliginous vapours were, the fafter they
abforbed the air, that if the above-mentioned
fermenting mixtures had not been confined
in clofe velTels, but in the open air, where

the

Analyfis of the Ah. 307

the vapours would have been lefs denfe, that
in that cafe much lefs air would have been
abforbed, perhaps a great deal lefs than wa9
generated.

In the fecond cafe of the Walton Mineral,
Experiment 96. when inftead of abforbing,
it generated air, the parts of the compound
Aqua-fortis were then more at liberty to ad:
by being diluted with an equal quantity of
water 5 whereby the ferment being more
violent, the particles which conftituted the
new elaftick air were thereby thrown off in
greater plenty, and perhaps with a greater
degree of elafticity, which might carry them
beyond the fphere of attraction of the ful-
phureous particles.

This is further illuftrated by Experiment
94. where filings of Iron and oil of Vitriol
alone generated very little, but the like quan-
tities of filings of Iron, with an equal quan-
tity of water, generated 43 cubick inches of
air; and the like ingredients, with three times
that quantity cf water, generated 108 cubick
inches.

And though the quantity of the afcending
fumes (which was in this cafe of the Walton
Mineral very great) mull needs in their afcent
abforb a good deal of elaftick air, (for they

X 2 will

3 o 8 Analyfis of the Air.

will abforb air) yet if, where the ferment was
(o much greater, more elaftick air was gene-
rated by the fermenting mixture, than was
abforbed by the afcending fumes, then the
quantity of new generated air, which I found
between zz and aa^ (Fig. 35.) when I mea-
fured it, was equal to the excefs of what was
generated above what was abforbed.

And probably in this cafe the air was not
abforbed fo much in proportion to the den-
fity of the fumes, as in the firft cafe ; becaufe
here the fulphureous fumes were much
blended with wratry vapours : for we find in
Experiment 97. that fix times more was
wafted in fumes in this cafe, than in the
other ; and therefore probably a good part
of the cubick inch of water afcended with
the vapour, and might thereby weaken its
abforbing power : For watry vapours do not
abforb elaftick air as the fulphureous ones do ;
tho' by Experiment 12,0. a Candle abforbed
more in a damp than in a dry air.

And it is from thefe diluting watry vapours,
that filings of Iron, with fpirit of Nitre and
Water, abforbed lefs than with fpirit of Nitre
alone -, for in both cafes it abforbs more than
it generates.

Thus

Analyjis of the Air. 3 09

Thus alfo oil of Vitriol and Chalk gene-
rate air, their fume being fmall, and that
much diluted with the watry vapours in the
Chalk.

But Lime, with oil of Vitriol, or White-
Wine Vinegar or Water, make a confiderable
fume, and abforb good quantities of air :
Lime alone left to flaken gradually, as it
makes no fume, fo it abforbs no air.

We fee in Experiment 92. where the fer-
ment was not very fudden nor violent, nor
the quantity of abforbing fumes large, that
the Antimony and Aqua-fort is generated a
quantity of air equal to 520 times the bulk
of the Antimony. Thus alfo in the mixture of
Aqua Regia and Antimony, in Experiment
91. while at firft the ferment was fmall, then
air was generated ; but when with the in-
creafing ferment plenty of fumes arofe, then
there was a change from a generating to an
abforbing ftate. , See Vol. II. ^.292.

Since we find fuch great quantities of ela-
ftick air generated in the folution of animal
and vegetable fubftances, it muft needs be,
that a good deal does conftantly arife from
the diflblving of thefe aliments in the flomach
and bowels, which diffolution it greatly pro-
motes : Some of which may very probably
X 3 be

3 i o dnalyfis of the Ah.
be reforbed again, by the fumes which arife
with them; for we fee in Experiment 83.
that Oyfter-fhell and Vinegar, Oyfter-fhell
and Rennet, Oyfter-fhell and Orange-juice,
Rennet alone, Rennet and Bread, firft gene-
rated, and then abforbed air ; but Oyfter-fhell
withfome of the liquor of a Calf's ftomach,
which had fed much upon Hay, did not gene-
rate air; and it was the fame with Oyfter-fhell
and Ox-gall, and Spittle and Urine ; Oyfter-
fhell and Milk generated a little air, but Li-
rncn-juice and Milk did at the fame time ab-
forb a little : Thus we fee, that the variety of '
mixtures in the ftomach appear fometimesto
generate, and fometimes to abforb air ; that
is, there is fometimes more generated than
abforbed, and fometimes an equal quantity,
and fometimes lefs, according to the propor-
tion the generating power of the diflblving
aliments bears to the abforbing power of the
fumes which arife from them. In a true
kindly digeftion, the generating power exceeds
the abforbing power but a little : But when-
ever the digeftion deviates in fome degree
from this natural ftate, to generate a greater
proportion of elaftick air, then are we trou-
bled more cr lefs with diftending Flatus's. I
had intended to make thefe, and many more,

Expe-

dnalyfis of the Air. 311

Experiments, relating to the nature of dige-
stion, in a warmth equal to that of the fto-
mach ; but have been hitherto prevented by
purfuing other Experiments.

Thus we fee that all thefe mixtures do in
fermentation generate elaftick air; but thofe
which emit thick fumes, charg'd with ful-
phur, reforb more than was generated, in pro-
portion to the fulphureoufnefs and thicknefs
of thofe fumes.

I have alfo fhewn in many of the forego-
ing Experiments, that plenty of true perma-
nent elaftick air is generated from the fer-
menting mixtures of acid and alkaline fub-
ftances, and efpccially from the fermentation
and difTolution of animal and vegetable bo-
dies, into whofe fubftances we fee it is in a
great proportion intimately and firmly incor-
porated; and confequcntly great quantities of
elaftick air muft be continually expended in
their production; part of which does, we fee,
refume its elaftick quality, when briskly
thrown off from thofe bodies by fermentation
in the difTolution of their texture. But part
may probably never regain its elafticity, or at
leaft not in many centuries, that efpecially
which is incorporated into the more durable
parts of Animals and Vegetables. However,

X 4 we

3 i 1 dnaljfis of the AiY.

we may with pleafure fee what immenfe trea-
fures of this noble and important element,
endued with a moft active principle, the all-
wife Providence of the great Author of na-
ture has provided, the conftant wafle of it
being abundantly fupplied by heat and fer-
mentation from innumerable denfe bodies ;
and that probably from many of thofe bodies,
which, when they had their afcending fumes
confined in my glafTes, abforbed more air
than they generated ; but would, in a more
free, open fpace, generate more than they ab-
forbed.

I made fome attempts both by fire, and
alio by fermenting and abforbing mixtures,
to try if I could deprive all the panicles of
any quantity of elaftick air of their elaflicity •
but I could not effect it : There is therefore
no direct proof from any of thefe Experi-
ments, that all the elaftick air may be ab-
forbed, tho' 'tis very probable it may, fince
we find it is in fuch great plenty generated
and abforbed \ it may well therefore be all
abforbed and changed from an elaftick to a
fixe ftate : For, as Sir Is a a c Newto n
obferves of light, " That nothing more is re-
•* quifite for producing all the variety of co~
•' lour:, and degrees of refrangibiliiy, than

" that

Analyfis of the Air. 3 1 3

« that the rays of light be bodies of different
" fizes, the lead of which may make the
" weakeft and darkeft of the colours, and be
" more eafily diverted, by refracting furfaces
<f from the right courfej and the reft, as
cr they are bigger and bigger, may make the

<c ftronger and more lucid colours and be

" more and more difficultly diverted, ^ut 29."
So %u. 30. he obferves of air, " That denfe
f< bodies, by fermentation, rarefy into feveral
" forts of air, and th:s air, by fermentation,
" and fometimes without, returns into denfe
u bodies.0 And fince we find in fadl from
thefe Experiments, that air arifes from a
great variety of denfe bodies, both by fire
and fermentation, it is probable that they
may have very different degrees of elafticity,
in proportion to the different fize and denfity
of i:s particles, and the different force with
vyhich they were thrown off into an elaftick
date. " Thofe particles (as Sir Isaac New-
<c ton obferves) receding from one another,
" with the greateft repulfive force, and being
M moft difficultly brought together, which
" upon contad: cohere mod ftrongly. "
Whence thofe of the weakeft elafticity will
be leaft able to refill a counter-ailing power,
and will therefore be fooneft changed from

3 1 4 Analyjis of the Air.

an elaftick to a fixt flate. And 'tis confonant
to reafon to think, that the air may confift
of infinite degrees of thefe, from the moft
elaftick and repelling, till we come to the
more fluggifh, watry, and other particles,
which float in the air; yet the repelling force
of the leaft elaftick particle, near the furface
of the earth, while it continues in that ela-
ftick ftate, muft be fuperior to the incumbent
preflure of a column of air, whofe height is
equal to that of the atmofphere, and its bafe
to the furface of the fphere of its elaftick
activity.

Thus, upon the whole, we fee that air
abounds in animal, vegetable, and mineral
fubftances -, in all which it bears a consider-
able part : if all the parts of matter were
only endued with a ftrongly attra&ing power,
whole nature would then immediately be-
come one unadtive cohering lump $ where-
fore it was abfolutely neceflary, in order to
the actuating and enlivening this vaft mafs of
attracting matter, that there fhould be every
where intermix'd with it a due proportion
of ftrongly repelling elaftick particles, which
might enliven the whole mafs, by the incef-
fant aftion between them and the attracting
particles : And fince thefe elaftick particles

are

Analyjis of the Air. 315

are continually in great abundance reduced
by the power of the ftrong attradters, from an
elaftick to a fixt ftate ; it was therefore ne-
ceflary, that thefe particles fhould be endued
with a property of refuming their elaftick
ftate, whenever they were difengaged from
that mafs in which they were fixt, that thereby
this beautiful frame of things might be main-
tained in a continual round of the produ-
ction and difiblution of animal and vegetable
bodies.

The air is very inftrumental in the pro-
duction and growth of animals and vegeta-
bles, both by invigorating their feveral juices
while in an elaftick acftive ftate, and alfo by
greatly contributing in a fix'd ftate to the
union and firm connection of the feveral con-
ftiment parts of thofe bodies, viz. their wa-
ter, fait, fulphur, and earth. This band of
union, in conjunction with the external air,
is alfo a very powerful agent in the diffolu-
tion and corruption of the fame bodies; for
it makes one in every fermenting mixture ;
the action and re-a&ion of the aereal and ful-
phureous particles is, in many fermenting
mixtures, fo great, as to excite a burning
heat, and in others a fudden flame : And it
is, we fee, by the like a&ion and re-aCtion

3 1 6 • Jnalyjis of the AW.

of the fame principles, in fuel and the am-
bient air, that common culinary fires are pro-
duced and maintained.

Tho' the force of its elafticity is fo great
as to be able to bear a prodigious preflure>
without lofing that elafticity, yet we have,
from the foregoing Experiments, evident
proof, that its elafticity is eafily, and in great
abundance deftroyed ; and is thereby reduced
to a fixt ftate, by the ftrong attraction of the
acid fulphureous particles, which arife either
from fire or from fermentation : And there-
fore elaflicity is not an ejfential immutable
property of air-particles ; but they are, we fee,
eafily changed from an elaftick to a fixt ftate,
by the ftrong attraction of the acid, fulphu-
reous, and faline particles, which abound in
the air. Whence it is reafonable to conclude,
that our atmofphere is a Chaos, confifting
not only of elaftick, but alfo of unelaftick
air-particles, which in great plenty float in it,
as well as the fulphureous, faline, watry and
earthy particles, which are no ways capable
of being thrown off into a permanently ela-
ftick ftate, like thofe particles which confti-
ftute true permanent air.

Since then air is found fo manifeftly to
abound in almoft all natural bodies ; fince we

find

Analyfis of the Air. 3 17
find it fo operative and aftive a * principle in
every chymical operation ; fince its constituent
parts are of fo durable a nature, that the
moft violent aftion of fire or fermentation
cannot induce fuch an alteration of its texture,
as thereby to difqualify it from refuming,
either by the means of fire, or fermentation,
its former elaftick ftate > unlefs in the cafe of
vitrification, when, with the vegetable Salt
and Nitre, in which it is incorporated, it
may perhaps fome of it, with other chymical
principles, be immutably fixt: Since then
this is the cafe, may we not with good reafon
adopt this now fixt, now volatile Proteus,
among the chymical principles, and that a
very aftive one, as well as acid fulphur 5 not-
withstanding it has hitherto been overlooked
and rejedted by Chymifls, as no way intitled
to that denomination ?

If thofe who unhappily fpent their time
and fubftance in fearch after an imaginary
production, that was to reduce all things to
gold, had, inftead of that fruitlefs purfuit, be-
llowed their labour in fearching after this
much negle&ed volatile Hermes, who has fo
often efcaped thro' their burft receivers, in

* Jonjls omnia plena, Virgil,

the

3 1 8 Of Vegetation.

the difguife of a fubtile fpirit, a mere flatu-
lent explofive matter; they would then, in-
ftead of reaping vanity, have found their
refearches rewarded with very confiderable
and ufeful difcoveries.

CHAP. VII.

Of Vegetation.

WE are but too fenfible, that our rea-
fonings about the wonderful and in-
tricate operations of nature are fo full of un-
certainty, that, as the Wife- man truly ob-
ferves, hardly do me guefs aright at the things
that are upon earth, and with labour do we
find the things that are before us. Wifdom,
Chap. ix. ver. 16. And this obfervation we
find fufhciently verified in vegetable nature,
whofe abundant productions, tho' they are
moft vifible and obvious to us, yet are we
much in the dark about the nature of them;
becaufe the texture of the veffels of plants is
fo intricate and fine, that we can trace but
few of them, though affifted with the beft
microfcopes. We have however good reafon

Of Vegetation. 3 19

to be diligent in making farther and farther
refearches -, for tho' we can never hope to
come to the bottom and firft principles of
things, yet in fo inexhauftible a fubjed:, where
every the fmalleft part of this wonderful fa-
brick is wrought in the moft curious and
beautiful manner, we need not doubt of have-
ing our inquiries rewarded, with fome fur-
ther pleafing difcovery ; but if this fhould
not be the reward of our diligence, we are
however fure of entertaining our minds after
the moft agreeable manner, by feeing in every
thing, with furprizing delight, fuch plain
fignatures of the wonderful hand of the Di-
vine Architect, as muft neceffarily difpofe and
carry our thoughts to an adt of adoration, the
beft and nobleft employment and entertain-
ment of the mind.

What I (hall here fay, will be chiefly found-
ed on the following Experiments; and on
feveral of the preceding ones, without repeat-
ing what has already been occafionally ob»
ferved on the fubjed: of Vegetation.

We find by the chymical Analyfis of Vege-
tables, that their fubftance is compofed of
fulphur, volatile fait, water and earth ; which
principles are all endued with mutually at-
tracting powers, and alfo of a large portion

320 Of Vegetation.

of air, which has a wonderful property of
ftrongly attracting in a fixt ftate, or of re-
pelling in an elaftick ftate, with a power
which is fuperior to vaft compreffing forces 3
and it is by the infinite combinations, action
and re-action of thefe principles, that all the
operations in animal and vegetable bodies are
effected.

Thefe active aereal particles are very fer-
viceable in carrying on the work of Vege-
tation to its perfection and maturity ; not
only in helping by their elafticity to diftend
each ductile part, but alfo by enlivening and
invigorating their fap, where, mixing with
the other mutually attracting principles, they
are by gentle heat and motion fet at liberty
to affimilate into the nourifhment of the re-
fpective parts : " The foft and moift nourifh-
11 ment eafily changing its texture by gentle
<c heat and motion, which congregates homo-
cc geneal bodies, and feparates heterogeneal
<c ones." Ncwtoris Opticksy qu. 31. The
fum of the attracting power of thefe mutu-
ally acting and re-acting principles being,
while in this nutritive ftate, fuperior to the
fum of their repelling power 5 whereby the
work of nutrition is gradually advanced
by the nearer and nearer union of thefe

prin-

Of Vegetation. 3 1 1

principles, from a leffer to a greater degree
of confiftency, till they are advanced to that
vifcid ductile ftate, whence the feveral parts
of Vegetables are formed -, and are at length
firmly compared into hard fubftances, by
the flying off of the watry diluting vehicle,
fooner or later, according to the different de-
grees of cohefion of thefe thus compacted
principles.

But when the watry particles do again foak
into and difunite them, and their repelling
power is thereby become fuperior to their
attracting power 5 then is the union of the
parts of Vegetables thereby fo thoroughly dif-
folved, that this ftate of putrefaction doesi
by a wife order of Providence, fit them to re-
fufcitate again in new vegetable productions,
whereby the nutritive fund of nature can ne-
ver be exhaufted ; which being the fame both
in Animals and Vegetables, it is thereby ad-
mirably fitted, by a little alteration of its tex-
ture, to nourifh either.

Now, tho' all the principles of Vegetables
are, in their due proportion, neceflary to the
production and perfection of them ; yet we
generally find greater proportions of oil in
the more elaborate and exalted parts of Vege-
tables : And thus feeds are found to abound

Y with

311 Of Vegetation.

with oil, and confequently with fulphur and
air, as we fee by Experiment 56. $j. 58.
Which feeds containing the rudiments of
future Vegetables, it was neceflary that they
fhould be well ftored with principles that
would both preferve the feed from putre-
faction, and alfo be very active in promoting
Germination and Vegetation. Thus alfo by
the grateful odours of flowers we are allured,
that they are ftored with a very fubtile, highly
fublimed oil, which perfumes the ambient
air ; and the fame may be obferv'd from the
high taftes of fruits.

And as Oil is an excellent prefervative
againft the injuries of cold, fo it is found
to abound in the fap of the more northern
trees; and it is this which in Ever-greens
keeps their leaves from falling.

But plants of a lefs durable texture, as
they abound with a greater proportion of
fait and water, which is not fo ftrongly at-
tracting as fulphur and air, fo are they lefs
able to endure the cold; and as plants are
obferved to have a greater proportion of fak
and water in them in the fpring, than in
the autumn, fo are they more eafily injured
by cold in the fpring, than in a more ad-
vanced

Of Vegetation. 323

vanced age, when their quantity of oil is in-
creafed wich their greater maturity.

Whence we find that Nature's chief bufi-
iiefs in bringing the parts of a Vegetable, efpe-
cially its fruit and feed, to maturity, is to com-
bine together in a due proportion, the more
active and noble principles of fulphur and air,
that chiefly conftitute oil, which in its moft
refined ftate is never found without fome de-
gree of earth and fait in it.

And the more perfect this maturity is, the
more firmly are thefe noble principles united.
Thus Rhenifh Wines, which grow in a more
northern climate, are found to yield their
Tartar, u e. by Exper.73. their incorporated
air and fulphur, in greater plenty* than the
ftronger Wines of hotter countries, in which
thefe generous principles are more firmly
united : And particularly in Madeira Wine,
they are fixt to fuch a degree, that that Wine
requires a confiderable degree of warmth,
fuch as would deftroy the more delicate tex-
ture of many other Wines, to keep it in order,
and give it a generous tafte 5 and 'tis from
the fame reafon, that fmall French Wines are
found to yield more fpirit in diftillation, than
ftrong Spanijh Wines,

Y 2 But

324 Of Vegetation.

But when, on the other hand, the crude
watry part of the nutriment bears too great a
proportion to the more noble principles either
in a too luxuriant ftate of a plant, or when
its roots are planted too deep, or it ftands in
too fhady a pofition, or in a very cold and wet
fummer; then it is found, that either no
fruit is produced, or if there be any, yet it
continues in a crude watry flate 3 and never
comes to that degree < f maturity, which a
due proportion of the more noble principles
would bring it to.

Thus we find in this and every other part
of this beautiful fcene of things, wThen we
attentively eoniider them, that the great Au-
thor of nature has admirably tempered the
conftituent principles of natural bodies, in
fuch due proportions as might befl fit them
for the flate and purpoles they were intended
for.

It is very plain from many of the foregoing
Experiments and Obfervations, that the leaves
are very ferviceable in this work of Vegeta-
tion, by being inflrumental in bringing nou-
rishment from the lower parts, within the
reach of the attraction of the growing fruit;
which, like young animals, is furnifhed with
proper inftruments to fuck it thence, But

the

Of Vegetation. 325

the leaves feem alfo defigned for many other
noble and important fcrvices ; for Nature
admirably adapts her iuflruments fo as to
be at the fame time ferviceabie to many
good purpoies. Thus the leaves, in which
are the main excretory ducts in Vegetables,
feparate and carry off the redundant watry
fluid, which by being long detained, would
turn rancid and prejudicious to the plant,
leaving the more nutritive parts to coalefce ;
part of which nourifhmenr, we have good
reafon to think, is conveyed into Vegetables
through the leaves, which do plentifully im-
bibe the dew and rain, which contain fait,
fulphur, &c. For the air is full of acid
and fulphureous particle?, which when they
abound much, do, by the action and re-action
between them and the elaiiick air, cauie that
fultry heat, which ufually ends in lightning
and thunder : And thefe new combinations
of air, fulphur, and acid fpirit, which are
constantly forming in the air, are doubtlefs
very ferviceabie in promoting the work of
Vegetation ; when being imbibed by the
leave?, they may not improbably be the
materials out of which the more fubtile and
refined principles of Vegetables are formed :
For fo fine a fluid as the air ieems to be a

Y 3 more

^i6 Of Vegetation.

more proper medium, wherein to prepare
and combine the more exalted principles of
Vegetables, than the groffer watry fluid of
the fap; and for the fame reafon, 'tis likely,
that the moft refined and adlive principles
of Animals are alfo prepared in the air, and
thence conveyed through the lungs into the
blood ; and that there is plenty of thele
fulphureo-aereal particles in the leaves, is
evident from the fulphureous exudations,
which are found at the edges of leaves,
which Bees are obierved to make their waxen
cells of, as well as of the duft of flowers:
And that wax abounds with fulphur i$ plain,
from its burning freely, &c.

We may therefore reafonably conclude,
that one great ufe of leaves is what has been
long fufpe&ed by many, viz. to perform in
fome meafure the fame office for the fup-
port of the vegetable life, that the lungs of
Animals do, for the fupport of the animal
life 5 Plants very probably drawing through
their leaves fome part of their nourifhment
from the air.

But as plants have not a dilating and con-
tracing 'Thorax, their infpirations and expi-
rations will no: be fo frequent as thofe of
^nirnals, but depend wholly on the alter-
nate

Of Vegetation. 327

nate changes from hot to cold for inspira-
tion, and vice verfa for expiration ; and 'tis
not improbable, that plants of more rich and
racy juices may imbibe and affimilate more
of this aereal food into their conftitutions,
than others, which have more watry vapid
juices. We may look upon the Vine as a
good inftance of this, which in Experiment
3. perfpired lefs than the Apple-tree. For
as it delights not in drawing much watry
nourishment from the earth by its roots, fo
it mud therefore neceffarily be brought to a
more ftrongly imbibing ftate at night, than
other trees, which abound more with watry
nourifhment ; and it will therefore confe-
quently imbibe more from the air. And
likely this may be the reafon, why plants in
hot countries abound more with fine aro-
matick principles, than the more northern
plants; for they do undoubtedly imbibe more
dew.

And if this conjecture be right, then it
gives us a farther reafon, why trees which
abound with moifture, either from too
(haded a pofition, or a too luxurious flare,
are unfruitful, viz. becaufe, being in theie
cafes more replete with moifture, they can-
not imbibe fo ftrongly from tht air, as

Y 4 Others

3 1 8 Of Vegetation.

others do, that? great bleffing, the dew oi
Heaven.

And as the moft racy generous taftes of
fruits, and the grateful odours of flowers,
do not improbably arife from thefe refined
aereal principles, fo may the beautiful colours
of flowers be owing, in a good meafure, to
the lame original ; for it is a known obfer-
vation, that a dry foil contributes much more
to their vaiiegation, than a ftrong moift one
does.

And may not Light alfo, by freely entring
the expanded furfaces of leaves and flowers,
contribute much to the ennobling the prin-
ciples of Vegetables ? For Sir Ifaac Newton
puts it as a very probable query, c: Are not
cc grofs bodies and Light convertible into
" one another ? And may not bodies receive
c< much of their activity from the particles
cc of Light, which enter their competition ?
" The change of bodies into light, and of
" light into bodies, is very conformable to
u the courfe of nature, which feems delighted
c' with tranfmutations, Opt. %u. 30."

Expe-

Of Vegetation. 319

Experiment CXXII.

That the Leaves and Stems of Plants do
imbibe elaftick air, there is fome reafon to
fufpedt, from the following Experiment,
which, in the firft Edition of this Book, I
mentioned as not made with accuracy enough;
but I have iince repeated it with greater ac-
curacy, viz, June 29. I fet a well-rooted
plant of Pepper-mint in a glafs-ciftern full of
earth, and then poured in as much water as
it would contain ; over this glafs-ciftern I
placed an inverted glafs z zy a ay as in Fig.
35. the water being drawn up by means of
a fyphon to a a. At the fame time alfo I
placed in the fame manner another inverted
glafs z z, a a, of equal fize with the former,
but without any plant under it: the capacity
of thefe veiTels above the water a a was equal
to 49 cubick inches. In a month's time the
Mint had made feveral weak flender fhoots,
and many fmall hairy roots fliot out at the
joints that were above water, occaiioned pro-
bably by the great moifture of the air, in
which the plant flood ; half the leaves of the
old item were now dead ; but the leaves and
|lem of the young (hoots continued green

mod:

3 3 o Of Vegetation.

mod part of the following winter: The wa-
ter in the two inverted 'glaffes rofe and fell,
as ic was either affefted by the different
weight of the Atmofphere, or by the dila-
tation and contraction of the air above a a.
But the wrater in the veffel in which the
Pepper-mint flood, rofe fo much above a a,
and above the furface of the water in the
other veffel, that one-feventh part of that
air mud have been reduced to a fixe ftate,
either by being imbibed into the fubftance
of the plant, or by the vapours which arofe
from the plant. This was chiefly done in
the two or three fummer months; for after
that no more air was abforbed. The begin-
ning of April in the following fpring, I took
out the old mint, and put a frefli plant in
its place, to try if ic would abiorb any
more of the air, but it faded in four or five
days. Yet a frefli plant put into the other
glafs, wrhofe air had been confined for nine
months, lived near a month, almoft as long
as another plant did in frefli confined air;
for I have found that a tender plant confined
in this manner in April, would not live fo
long as a ftronger grown plant, put in in
June,

The

Of Vegetation. 331

The like plants placed in the fame man-
ner feparately, in the diftilled airs of Tartar
and Newcajlle Coaly foon faded ; yet a like
plant confined in three pints of air, a quart
of which was diftilled from an Ox's tooth,
grew about two inches in height, and had
fome green leaves on it, after fix or feven
weeks confinement.

Finding that a frefh plant could not live
in the air, which had been for feveral months
infected by the mint which was placed in it
the 19th oijune ; inftead of a plant, I placed
in that air a mixture of powdered Brimftone
and filings of Iron moiftened with water ; this
mixture abforbed four cubick inches of this
air.

Experiment CXXIII.

In order to find out the manner of the
growth of young fhoots, I firft prepared the
following inftrument ; viz. I took a fmall
flicks, (Fig. 40.) and at a quarter of an inch
diftance from each other, I run the points of
five pins, 1, 2, 3, 4, 5, thro' the flick, fo far
as to ftand-J of an inch from the flick; then
bending down the great ends of the pins, I
bound them all faft with waxed thread ; I
provided alio fome red-lead mixed with oil.

3 5 x Of Vegetation.

In the fpring, when the Vines had made
fhort fhoots, I dipped the points of the pins
in the paint, and then pricked the young
fhoot of a Vine (Fig. 41.) with the five
points at once, from t to p : I then took
off the marking inftrumenr, and placing the
low.-ft point of it in the hole p, the upper-
mod mark, I again pricked frefli holes from
p to /, and then marked the two other points
i h \ thus the whole (hoot was marked every
JL inch, the red paint making every point
remain vifible.

(Fig. 42.) {hews the true proportion of
the fame {hoot, when it was full grown;
the September following ; where every cor-
refponding point is noted with the fame
letter.

The diftance from / to j was not en-
larged above 3— part of an inch ; from s to q,
the -£ of an inch ; from q to p, | ; from p
to 0, j ; from 0 to tf, tf; from n to my if;
from m to /, 1 *\- T£ of an inch ; from / to /,
1 + to inch nearly j and from i to l\ three
inches.

In this Experiment we fee, that the firft
joint to r extended very little, it being al-
nioft hardened, and come near to its full
growth, when I marked it: The next joint,

from

Of Vegetation. 333

from r to ;/, being younger, extended fome-
thin<* more ; and the third joinr, from n to k,
extended from | of an inch, to 3 + i inches ;
but from k to h> the very tender joint, which
was but \ inch long, when I marked it, was,
when full grown, three inches long.

We may obferve, that Nature, in order
to fupply thefe young growing {hoots with
plenty of ductile matter, is very careful to
furnifh, at fmall diftances, the young /hoots of
all forts of trees with many leaves throughout
their whole length, which ferve as fo many
jointly acting pov/ers placed at different fta-
tions, thereby to draw with more eafe plenty
of fap to the extending {hoot.

The like provilion has Nature made in
the Corn, Grafs, Cane, and Reed-kind ; the
leafy fpires, which draw the nourishment to
each joint, being provided long before the
ftem (hoots ; which {lender ftem, in its ten-
der ductile ftate, would moft eafily break,
and dry up too foon, fo as to prevent its due
growth, had not Nature, to prevent both
thefe inconveniencies, provided ftrong Thecas
or Scabbards, which both fupport and keep
long, in a fupple ductile ftate, the tender
extending ftem.

354 Of Vegetation.

I marked in the fame manner as the Vine^
at the proper feafons, young HoneyfuckU
fhoots, young Afparagus, and young Sun-
flowers ; and I found in them all a gradual
icale of unequal extenfions, thofe parts ex-
tending moll which were tendereft. The
white part of the Afparagus, which was
under-ground, extended very little in length,
and accordingly wc find the fibres of the
white part very tough and ftringy : But the
greateft extenfion of the tender green part,
which was about four inches above the
ground when I marked it, feparated the marks
from a quarter of an inch to twelve inches
diftance ; the greateft diftention of the Sun-
flower was from ± inch to four inches di-
flance.

From thefe Experiments it is evident, that
the growth of a young bud to a (hoot con-
fifts in the gradual dilatation and extenfion
of every part, the knots of a (hoot being
very near each other in the bud, as may
plainly and diftinctly be feen in the flit bud
of the Vine and Fig-tree -, but by this gra-
dual diftenfion of every part, they are ex-
tended to their full length. And we may
eafily conceive how the longitudinal capil-
lary tubes ftill retain their hollownefs, not-

with-

Of. Vegetation. 33^

withftanding their being diftended, from the
like effedt in melted glafs-tubes, which retain
a hollownefs; tho' drawn out to the fineft
thread.

The whole progrefs of the firft joint r is
very (hort in comparifon of the other joints,
becaufe at firft fetting out its leaves being
very fmall, and the feafon yet cooler than
afterwards, 'tis probable that but little fap
is conveyed to it ; and therefore it extending
but flowly, its fibres are in the mean time
grown tough and hard, before it can arrive
to any confiderable length. But as the feafon
advances, and the leaves inlarge, greater
plenty of nourifhment being thereby con-
veyed, the fecond joint grows longer than the
firft, and the third and fourth ftill on gra-
dually longer than the preceding; thefe do
therefore, in equal times, make greater ad-
vances than the former.

The wetter the feafon, the longer and
larger {hoots do Vegetables ufually make ;
becaufe their foft ductile parts do then con-
tinue longer in a moift, tender ftate : but in
a dry feafon the fibres fooner harden, and
flop the further growth of the (hoot -, and
this may probably be one reafon why the
two or three laft joints of every fhoot arc

ufually

3 ? 6 9/" Vegetation.

ufually fhorter than the middle joints, vivk
bccaufe they (hooting out in the more ad-
vanced hot dry fummer ffcafon, their fibres
are foon hardened and dried, and are withal
checked in their growth by the cool autum-
nal nights : I had a Vine-moot of one year's
growth, which was 14 feet long, and had 39
joints, all pretty nearly of an equal length,
except fome of the firft and laft.

And for the fame reafon, Beans and many
other plants, which ftand where they are
much fhaded, being thereby kept continually
moid, do grow to unufual heights, and are
drawn up, as they call it, by the over-fhadow-
ing trees, their parts being kept long, foft
and dudtile: fBut this very moid: fhaded ftate
is ufually attended with flerility; very long
joints of Vines are alfo obferved to be un-
fruitful.

This Experiment, which {hews the man-
ner of the growth of moots, confirms Borel/i's
opinion, who, in his Book De motu Ani-
malium, Part fecond, Chap. 13. fuppcfes
the tender growing moot to be diftended,
like fofc wax, by the expaniion of the moi-
fture in the fpongy pith ; which dilating
moifturc, he with good reafon concludes,
is hindered from returning back, (while it

expands)

Of Vegetation. 337

expands) by the fponginefs of the pith, with-
out the help of valves. For 'tis very pro-
bable, that the particles of water, which im-
mediately adhere to, and are ftrongly im-
bibed into, and attracted by every fibre of
the fpongy pith, will fufFer fome degree of
expanfion, before they can be detach'd by the
fun's warmth from each attracting fibre ; and
confequently the mafs of fpongy fibres, of
which the pith confifts, muft thereby be
extended.

And that the pith may be the more fer-
viceable for this purpofe, Nature has pro-
vided, in moft (hoots, a ftrong partition at
every knot ; which partitions ferve not only
as plinths or abutments for the dilating pith
to exert its force on, but alfo to prevent the
rarefied fap's too free retreat from the pith,
as well as for the (hooting forth of branches^
leaves and fruit.

But a dilating fpongy fubftance, by equally
expanding itfelf every way, would not pro-
duce an oblong fhoot, but rather a globofe
one, like an Apples to prevent which incon-
venience we may obferve, that Nature has
provided feveral Diaphragms, befides thofe
at each knot, which are placed at fmall di-
ftances acrofs the pith, thereby preventing

Z its

3 } 8 Of Vegetation.

its too great lateral dilatation. Thefe are very
plain to be feen in Walnut-tree fhoots : And
the fame we may obferve in the pith of the
branches of the Sun-flower, and of feveral
other plants ; where, tho' thefe Diaphragms
are not to be diftinguifhed, while the pith is
full and replete with moifture, yet when it
dries up, they are often plain to be feen : and
it is further obferved, that where the pith
confifts of diftinct veficles, the fibres of thofe
veficles are often found to run horizontally,
whereby they can the better refift the too
great lateral dilatation of the fhoot.

We may obferve, that Nature makes ufe of
the fame artifice in the growth of the feathers
of Birds, which is very vifible in the great pi-
nion feathers of the wing, the fmaller and
upper part of which is extended by a fpongy
pith, but the lower and bigger quill-part by a
feries of large veficles, which, when replete
with dilating moifture, do extend the quill,
and keep it in a fupple ductile flate -y but when
the quill is full grown, thefe veficles are always
dry : in which ftate we may plainly obferve
every veficle to be contracted at each end by
a Diaphragm or Sphincter, whereby its too
great lateral dilatation is prevented, but not
its diftenfion lengthwife.

And

Of Vegetation. 3 3 9

And as this pith in the quill grows dry and
ufelefs after the quill is full-grown, v/e may
obferve the Fame in the pith of trees, which
is always fucculent, and full of moifture, while
the fhoot is growing, by the expanfion of
which the tender ductile fhoot is diftended in
every part, its fibres being at the fame time
kepi fupple by this moifture ; but when each
year's moot is full grown, then the pith gra-
dually dries up, and continues for the future
dry and kecfey, its veficles being ever after
empty, Nature always carefully providing for
the fucceeding year's growth, by preferving
a tender ductile part in the bud replete with
fucculent pith.

And as in Vegetables, fo doub clefs in Ani-
mals, the tender ductile bones of young Ani-
mals are gradually increafed in every part,
that is not hardened and offiried $ but fince it
was inconfiflent with the motion of the joints
to have the ends of the bones foft and ductile,
as in Vegetables, therefore Nature makes a
wonderful provifion for this at the glutinous
ferrated joining of the heads to the flianks of
the bones ; which joining, while it continues
ductile, the Animal grows ; but when it offifie&v
then the Animal can no longer grow: As I
was affured by the following Experiment, viz*

Z 2, I

340 Of Vegetation.

I took a half-grown Chick, whole leg-bone
was then two inches long j and with a fharp-
pointediron, at half an inch diftance, I pierced
two fmall holes thro' the middle of the fcaly
covering of the leg and fhin-bone ; two months
after I killed the Chick, and upon laying the
bone bare, I found on it obfcure remains of
the two marks I had made at the fame diftance
of half an inch : So that that part of the bone
had not at all diftended lengthwife, fince the
time that I marked it} notwithstanding the
bone was in that time grown an inch more
in length, which growth was moftly at the
upper end of the bone, where a wonderful
provifion is made for its growth at the join-
ing of its head to the fhank, called by Anato-
mifts hymphyfis.

And as the bones grow in length and fize,
fo mud the membranous, the mufcular, the
nervous, the cartilaginous and vafcular fibres
of the animal body neceffarily extend and ex-
pand, from the duftile nutriment which Na-
ture furnifhes every part withal ; in which
refpe&s animal bodies do as truly vegetate as
do the growing Vegetables : Whence it mud
needs be of the greateft confequcnce, that the
growing Animal be fupplied with proper nou-
rishment for that purpofe, in order to form a

ftrong

Of Vegetation. 341

ftrong athletick conflitution ; for when grow-
ing Nature is deprived of proper materials for
this purpofe, then is me under a neceffity of
drawing out very {lender threads of life, as is
too often the cafe of young growing perfons3
who, by indulging in fpirituous liquors, or
other exceffes, do thereby greatly deprave the
nutritive duftile matter, whence all the dif-
tending fibres of the body are fupplied.

Since we are by thefe Experiments allured,
that the longitudinal fibres and fap-veffels of
wood in its firft year's growth, do thus diftend
in length by the extenfion of every part; and
fince Nature in limilar produftions makes ufe
of the fame, or nearly the fame methods, thefe
confiderations make it not unreafonable to
think, that the fecond and following years
additional ringlets of wood are not formed
by a merely horizontal dilatation of the vef-
fels; for it is not eafy to conceive, how lon-
gitudinal fibres and tubular fap-veffels fhould
thus be formed, but rather by the mooting
of the longitudinal tubes and fibres length-
ways from thofe of the laft year's wood,
whereby there is a free communication main-
tained between thefe and the fap-veffels of all
the preceding year's growth. The obferva-
tions on the manner of the growth of the
Z 3 ringlets

34* Of Vegetation.

ringlets of wood in Experiment 46. (Fig. 30.)

do further confirm this.

But whether it be bv an horizontal or Ion-
gitudinal (hooting, we may obferve that Na-
ture has taken great care to keep the parts
between the bark and wood always very fup-
ple with flimy moifture ; from which ductile
matter the woody fibres, veficles and buds are
formed.

Thus wc fee that Nature, in order to the
production and growth of all the parts of
Animals and Vegetables, prepares her du&ile
matter ; in doing of which (he felects and
combines particles of very different degrees
of mutual attraction, curioufly proportioning
the mixture according to the many different
purpofes (he defigns it for ; either for bony or
more lax fibres of very different degrees in
Animals, or whether it be for the forming
of woody or more foft fibres of various kinds
in Vegetables,

The great variety of which different fub-
ftances in the fame Vegetable prove, that
there are appropriated veffels for conveying
very different forts of nutriment. And in
many Vegetables fome of thofe appropriate
veffels are plainly to be ktn replete either
with milky, yellow, or red nutriment.

Dr.

Of Vegetation. 34$

Dr. KtilL in his account of animal fecre-
tion, page 49. obferves, that where Nature
intends to feparate a vifcid matter from the
blood, fhe contrives very much to retard its
motion^ whereby the inteftine motion pf the
blood being allayed, its particles can the bet-
ter coalefce, in order to form the vifcid fecre-
tion. And Dr. Grew, before him, obferved
an inftance of the fame contrivance in Vege-
tables, where a fecretion is intended, that is
to compofe a hard fubftance, viz. in the ker-
nel or feed of hard (tone fruits, which does
not immediately adhere to, and grow from
the upper part of the ftone, which would be
the {horteft and neareft way to convey nou-
rifhment to it ; but the fingle umbilical vef-
fel, by which the kernel is nourished, fetches
a compafs round the concave of the ftone,
and then enters the kernel near its cone; by
which artifice this veffel being much pro-
longed, the motion of the fap is thereby re-
tarded, and a vifcid nutriment conveyed to
the feed, which turns to hard fubftance.

The like artifice of Nature we may obferve
in the long capillary fibrous veflels, which lie
between the green hull and the hard fhell of
the Walnut, which are analogous to the
fibrous Mace of Nutmegs, the ends of whofe
Z 4 hairy

3 44 Of Vegetation.

hairy fibres are inferted into the angles of the
furrows in the Walnut-fhell : Their ufe is
therefore doubtlefs to carry in thofe long di-
ftincl veffels the very vifcous matter, which
turns, when dry, to a hard (hell \ whereas,
were the fhell immediately nourished from
the foft pulpous hull that furrounds it, it
would certainly be of the fame foft conftitu-
tion, the ufe of the hull being only to keep
the lhcl! in a foft ductile ftate, till the Nut has
done growing.

We may obferve the like effect of a flower
motion of the fap in Ever-greens, which per-
fpiring little, their fap moves much more
flowly than in more perfpiring trees, and is
therefore much more vifcid, whereby they
are better enabled to out-live the winter's
cold. It is obferved, that the fap of Ever-
greens in hot countries is not fo vifcous as the
fap of more northern Ever-greens, as the Fir,
&c. for the fap in hotter countries mud have
a brisker motion, by means of its greater per-
fpiration.

Experiment CXXIV.

In order to inquire into the manner of the
expanfion of leaves, I provided a little oaken
board or fpatula, a b c d> of this fhape and

fize

Of Vegetation. 34 j

fize (Fig. 43.) ; through the broad part, at a
quarter of an inch diftance from each other,
I run the points of 25 pins x x, which flood
\ inch thro', and divided a fquare inch into
16 equal parts.

With this inftrument in the proper feafon,
when leaves were very young, I pricked feve-
ral of them thro' at once with the points of
all thefe pins, dipping them firft in the redT
lead, which made lafting marks.

(Fig. 44.) reprefents the fhape and fize of
a young Fig-leaf, when firft marked with red
points, i. inch diftance from each other.

(Fig. 45.) reprefents the fame full-grown
leaf, and the numbers anfwer to the corre-
fponding numbers in the young leaf; whereby
may be feen how the feveral points of the
growing leaf were feparated from each other,
and in what proportion, viz. from a quarter
of an inch to about three quarters of an inch
diftance.

In this Experiment we may obferve, that
the growth and expanfion of the leaves is
owing to the dilatation of the veficles in every
part, as the growth of a young fhoot was
fhewn to be owing to the fame caufe in the
foregoing Experiment, and doubtlefs the cafe
is the fame in all fruits.

34*> Of Vegetation.

If thefe Experiments on leaves were further
purfued, there might probably be many curi-
ous obfervations made in relation to the fhape
of leaves, by obferving the difference of the
progreflive and lateral motions of thefe points
in different leaves, that were of very different
lengths in proportion to their breadths.

That the force of dilating fap and air, in-
cluded in the innumerable little veficles of
young tender fhoots and leaves, is abundantly
iufficient for the excending of fhoots, and ex-
panding of leaves; we have evident proof
from the great force we find in the fap of the
Vine, chap. 3. and from the vaft force with
which infinuating moifture expanded the
Peas. Experiment 3 2. we fee the great power
of expanding water, when heated in the
engine to raife water by fire j and water with
air and other active particles in capillary tubes,
and innumerable fmall veficles, do doubtlefs
act with a great force, tho' expanded with
no more heat than what the fun's warmth
gives them.

And thus we fee that Nature exerts a con-
fiderable, tho' fecret and filenc power, in car-
rying on all her productions; which demon-
strates the wifdom of the Author of nature,
in giving fuch due proportion and direction

PL- 13

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34^ 0/ Vegetation.

a very confiderable influence in expanding
the fap in all its parts. The warmth was
much greater on the body above-ground, than
on the roots which were two feet deep ; thofe
roots, and parts of roots, which are deeped,
as they feel much lefs of the fun's warmth,
fo are they not fo foon, n j; fo much affected
by the alternacies of day and night, warm
and cold : but that part of Vegetables which
is above-ground, mull have its fap consider-
ably rarefied, when the heat increafed from
morning to two o'clock afternoon, fo much
as to raife the fpirit in the ift Thermometer
from 21 to 48 degrees above the freezing
point.

When in the coldeft days of the winter
1724, the froft was fo intenfc as to freeze the
furface of ftagnant water near an inch thick,
then the fpirit in the Thermometer y which was
expofed to the open air, was fallen four de-
grees below the freezing point; the fpirit of
that whofe ball was two inches under-ground,
was four degrees above the freezing point;
the 3d, 4th and 5th Thermometers were pro-
porlionably fallen lefs and lefs, as they were
deeper, to the 6th Thermometer ; which being
two feet under-ground, the fpirit was ten
degrees above the freezing point. In this

ftate

Of Vegetation. 349

ftate of things the work of Vegetation feemed
to be wholly at a (land, at lead within the
reach of the froft.

But when the cold was fo far relaxed, as
to have the fpirit in the firft Thermometer
but five degrees above the freezing point, the
fecond 8 degrees, and the fixth 13 degrees,
tho' it was flill very cold, yet this being fome
advance from freezing towards warm, and
there being confequently fome expanfion of
the fap, feveral of the hardy Vegetables grew,
viz. fome Ever-greens, Snow-drops, Crocus's,
&c. which forward hardy plants do proba-
bly partake much of the nature of Ever-
greens in perfpiring little ; and the motion
of their fap being confequently very flow, it
will become more vifcous, as in Ever-greens,
and thereby the better able to refift the win-
ter's cold ; and the fmall expanfive force
which this fap acquires in the winter, is
moftly exerted in extending the plant, little
of it being wafted in proportion to the fum-
mer's perfpiration.

Supported by the evidence of many of the
foregoing Experiments, I will now trace the
Vegetation of a Tree from its firft feminal
plant in the Seed to its full maturity and pro-
duction of other Seeds, without cntring into

a par-

l$o Of Vegetation.

a particular defcripiion of the ftrudlure of the
parts of Vegetables, which has already been
accurately done by Dr. Grew and Malpighi.

We fee by Experiment 56. 57. 58. on di-
ftilled Wheat, Peas, and Muftard-feed, what
a wonderful provifion Nature has made, thac
the Seeds of Plants fhould be well ftored with
very active principles, which principles are
there compacted together by Him, who curi-
oufly adapts all things to the purpofes for
which they are intended, with fuch a juft
degree of cohefion, as retains them in that
ftate till the proper feafon of germination :
for if they were of a more lax conftitution,
they would too foon diffolve, like the other
tender annual parts of plants ; and if they
were more firmly connected, as in the heart
of Oak, they muft neceflarily have been many
years in germinating, though fuppled with
moifture and warmth.

When a Seed is fown in the ground, in
a few days it imbibes lb much moifture, as
to fwell with very great force ; as we fee in
the Experiment on Peas in an iron pot,
this forcible fwelling of the lobes of the
Seed a r, a r, (Fig. 46.) does probably pro-
trude moifture and nourifhment from the
capillary veffels r r, which are called the

Seed-

Of Vegetation. 3 5 1

Seed-roots, into the radicle c z d; which
radicle, when it has fhot fome length into
the ground, does then imbibe nourifhmcnt
from thence ; and after it has acquired fuf-
ficient ftrength, as this tender ductile root
is extending from z to c, it muft necefla-
rily carry the expanding Seed-lobes upwards,
at the fame time that the dilating from z to
d makes it fhoot downwards ; and when
the root is thus far grown, it fupplies the
Plume b with nourifhment, which thereby
fvvelling and extending, opens the lobes a rr
a r, which are at the fame time raifed
above ground with the Plume; where they,
by expanding and growing thinner, turn to
green leaves (except the Seeds of the Pulfe
kind); which leaves are of fuch importance
to the yet tender Plume, that it perifhes, or
will not thrive if they are pulled off; which
makes it probable, that they do the fame
office to the Plume, that the leaves adjoining
to Apples, Quinces, and other fruits, do to
them, viz, they draw fap within the reach
of their attraction; fee Exper. 8. and 30.
But when the Plume is fo far advanced in
growth, as to have branches and expanded
leaves to draw up nourifhment ; then thefe
fupplemental feminal leaves, a r, a r, being of

3 5 l Of Vegetation.

n^ farther ufe, do perifti; not only bccaufe
the now grown and more expanded leaves
of the young plant or tree do fo over-fhadow
the fupplemental leaves, that their former
more plentiful perfpiration is much abated,
and thereby alfo their power of attracting fap
fails ; but alfo, becaufe the fap is drawn from
them by the leaves, and they being thus de-
prived of nourifhment, do perifh.

As the tree advances in ftature, the firft,
fecond, third, and fourth order of lateral
branches (hoot out, each lower order being
longer than thofe immediately above them -,
not only on account of primogeniture, but
alfo, becaufe being inferted in larger parts of
the trunk, and nearer the root, they have the
advantage of being ferved with greater plenty
of fap, whence arifes the beautiful parabo-
lical figure of trees.

But when trees ftand thick together in
Woods or Groves, this their natural fhape is
altered, becaufe the lower lateral branches
faeing much fhaded, they can perfpire little ;
and therefore drawing little nourishment,
they perifh ; but the top branches being ex-
pofed to a free drying air, they perfpire plen-
tifully, and thereby drawing the fap to the
top, they advance much in height : But vice

versa,
5.

Of Vegetation. 353

versa, if, when fuch a Grove of tall trees is
cut down, there be left here and there a fingle
tree, that tree will then (hoot out lateral
branches $ the leaves of which branches now
perfpiring freely, will attradt plenty of fap,
on which account the top being deprived of
its nourifhment, it ufually dies.

And as trees in a Grove or Wood grow
only in length, becaufe all the nourifhment
is by the leaves drawn to the top, moft of
the fmall lateral (haded branches in the mean
time perifhing for want of perfpiration and
nutrition 5 fo the cafe is the very fame in the
branches of a tree, which ufually making an
angle of about 45 degrees with the ftem of
the tree, do thereby beautifully fill up, at equal
and proper diftances, the fpace between the
lower branches and the top of the tree, form-
ing thereby, as it were, a parabolical Grove or
Thicket, which (hading the arms, the fmall
lateral (hoots of thofe arms ufually perifti for
want of due perfpiration ; and therefore the
arms continue naked like the bodies of trees
in a grove, all the nourifhment being drawn
up to the tops of the feveral branches by the
leaves which are there expofed to the warm
fun} and free drying air, whereby the branches
of trees expand much.

A a And

3 54 Of Vegetation.

And where ihe lateral branches are very
vigorous, fo as to make ftrong (hoots, and
attract the nourimment plentifully, there the
tree ufually abates in its height : But where
the tree prevails in height, as in groves, there
commonly its lateral branches are (mailed.
So that we may look upon a tree as a com-
plicated Engine, which has as many different
powers as it has arms and branches, each
drawing from their common fountain of life
the root : and the whole of each yearly growth
of the tree will be proportionable to the fum
of their attracting powers, and the quantity
of nourifliment the root affords : But this at-
tracting power and nourishment will be more
or lefs, according to the different ages of the
tree, and the more or lefs kindly feafons of
the year.

And the proportional growth of their late-
ral and top branches, in relation to each other,
will much depend on the difference of their
feveral attracting powers. If the perforation
and attraction of the. lateral brances is little
or nothing, as in woods and groves, then the
top branches will mightily prevail -, but when
in a free open air the perfpiration and attra-
ction cf the lateral branches comes nearer to
an equality with that of the top, then are the

afpi-

Of Vegetation. * 355

aiplrings of the top branches greatly checked.
And the cafe is the fame in moft other Vege-
tables, which, when they ftand thick toge-
ther, grow much in length with very weak
lateral (hoots.

And as the leaves are thus ferviceable in
promoting the growth of a tree, we may ob-
ferve that Nature has placed the petals of the
lea ves-ftalks where moft nourimment is want-
ing, to produce leaves, {hoots and fruit ; and
fome fuch thin leafy expanfion is fo neceflary
for this purpofe, that Nature provides fmall
thin expanfions, which may be called pri-
mary leaves, that ferve to protect and draw
nourishment to the young (hoot and leaf-buds,
before the leaf itfelf is expanded.

And herein we fee the admirable contri-
vance of the Author of nature in adapting
her different ways of conveying nourishment
to the different circumftances of her produ-
ctions. For in this embryo ftate of the buds
a fuitable provifion is made to bring nourish-
ment to them in a quantity fufficient for their
then fmall demands : But when they are in
fome degree increafed and formed, a much
greater quantity of nourimment is neceflary,
in proportion to their greater increafe : Na-
ture, that fhe may then no longer fupply with
A a 2 a

35<* Of Vegetation.

a fcanty hand, immediately changes her me-
thod, in order to convey nourishment with
a more liberal hand to her productions;
which fupply daily increafes by the greater
expanfion of the leaves, and confequently the
more plentiful attra&ion and fupply of fap,
as the greater growth and demand for it in-
creafes.

We find a much more elaborate and beau-
tiful apparatus, for the like purpofe, in the
curious expanfions of blofToms and flowers,
which feem to be appointed by Nature not
only to protedl, but alfo to draw and convey
nourishment to the embryo fruit and feeds.
But as foon as the Calix is formed into a
fmall fruit, now impregnated with its minute
feminal tree, furnifhed with its Secondine,
Corion and Amnion, (which new-fet fruit
may, in that ftate, be looked upon as a com-
plete egg of the tree, containing its young
unhatched tree, yet in embryo) then the blof-
fom falls off, leaving this new-formed egg,
or firft-fet fruit, in this infant ftate, to im-
bibe nourifhment fufficient for itfelf, and the
Fcetus with which it is impregnated : Which
nourifhment is brought within the reach
and power of its futtion by the adjoining
leaves.

Of Vegetation. 357

If I may be allowed to indulge conjecture
in a cafe in which the mod diligent inquirers
are as yet, after all their laudable refearches,
advanced but little farther than mere con-
jecture, I would propofe it to their confidera-
tion, whether from the manifeft proof we
have that fulphur ftrongly attrafts air, a hint
may not be taken, to confider whether this
may not be the primary ufe of the Farina
fcecundans, to attradt and unite with itfelf
elaftick or other refined adtive particles. That
this Farina abounds with fulphur, and that
a very refined fort, is probable, from the
fubtle oil which Chymifts obtain from Saf-
fron. And if this be the ufe of it, was it
poflible that it could be more aptly placed
for the purpofe, than on very moveable apices
fix t on the flender points of the Stamina,
whereby it might eafily, with the lead breath
of wind, be difperfed in the air, thereby fur-
rqunding the plant, as it were, with an At-
mofphere of fublimed fulphureous pounce ?
(for many trees and plants abound with it)
which uniting with the air-particles, they,
or a very fublimed fpirit from them, may,
perhaps, be infpired or imbibed at feveral
parts of the plant, and efpecially at the Piftil-
lum7 and be thence conveyed to the Capjula
A a 3 femi~

358 Tlie Conclvjion.

feminalis, efpecially towards evening, and in
the night, when the beautiful Petala of the
flowers are clofed up, and they, with all the
other parts of the Vegetable, are in a ftrongly
imbibing flat-'. And if to thefe united ful-
phureous and aereal particles, we fuppofe
fome particles of light to be joined, (for Sir
Ijaac Ne<wton has found, that fulphur attracts
light ftrongly) then the refult of thefe three,
by far the moll: active principles in Nature,
will be a Punftum Saliens, to invigorate the
Jeminal plant : And thus we are at laft con-
ducted, by the regular Analyfis of vegetable
Nature, to the firft enlivening principle of
their minuteft Origin.

The Conchjion.

WE have, from the foregoing Experi-
ments, many proofs of the very great
and different quantities of moifture imbibed
and peripired by different kinds of Trees,
and alfo of the influence the feveral ftates of
the air, as to warm or cold, wet or dry, have
on that perfpiration. We fee alio what ftores
of moifture Nature has provided in the Earth
againft a dry feafon, to anfwer this great ex-
pence of it in the production and fupport of
Vegetables 3 hpw far the Dew can contribute

The Conchjkn. 359

to this fupply, and how inefficient its fmall
quantity is towards making good the great
demands of perfpiration : And that plants can
plentifully imbibe moifture thro' their Items
and leaves, as well as perfpire it.

We fee with what degrees of warmth the
Sun, that kindly natural genius of Vegetation,
ads on the feveral parts of Vegetables, from
their tops down to their roots two feet under
ground.

We have alfo many proofs of the great
force with which plants, and their feveral
branches and leaves, imbibe moifture up their
capillary fap-veffels : The great influence the
perfpiring leaves have in this work, and the
care Nature has taken to place them in fuch
order, and at fuch proper distances, as may
render them moft ferviceable to this purpofe,
efpecially in bringing plenty of nouridiment
to the young growing fhoots and fruit, whofe
item is ufually furrounded with them near
the fruit's infertion into the twig.

We fee here too, that the growth of fhoots,
leaves and fruit, confifts in the cxtenfion of
every part ; for the effecting of which, Nature
has provided innumerable little veiicles, which
being replete with dilating moifture, it does
thereby powerfully extend, and draw out every
dudile parr. A a 4 We

3^o The Conchfion.

We have here alfo many inftances of the
great force of the afcending fap in the Vine in
the bleeding feafon; as alfo of the fap's freely
either afcending or defcending, as it fhall hap-
pen to be drawn by the perfpiring leaves ; and
alfo of its ready lateral motion thro' the late-
rally communicating fap-veffels ; together
with many proofs of the great plenty of air
drawn in and mixt with the fap, and incor-
porated into the fubftance of Vegetables.

If therefore thefe Experiments and Obfer-
vations give us any farther infight into the
nature of plants, they will then doubtlefs be
of fome ufe in Agriculture and Gardening,
either by ferving to re&ify fome miftaken.
notions, or by helping farther to explain the
reafons of many kinds of culture, which long
repeated experience has found to be good, and
perhaps by leading us to make fome advances
therein : But as it requires a long feries and
great variety of frequently repeated Experi-
ments and Obfervations to make a very fmall
advance in the knowledge of the nature of
Vegetables, fo proportionably we are from
thence only to exped: fome gradual improve-
ments in the culture of them.

The fpecifick differences of Vegetables,
which are all fuftained and grow from the

fame

The Conclufion. $61

fame nourishment, is doubtlefs owing to the
very different formation of their minute vef-
fels, whereby an almoft infinite variety of
combinations of the common principles of
Vegetables is made $ whence fome abound
more with fome principles, and fome with
others. Hence fome are of a warmer and
more fulphureous, others of a more watry,
faline, and therefore colder nature; fome of a
more firm and lading, others of a more lax
and perifhable conftitution. Hence alfo it is
that fome plants flourish beft in one climate,
and others in another ; that much moifture is
kindly to fome, and hurtful to others; that
fome require a ftrong, rich, and others a poor,
fandy foil ; fome do beft in the {hade, and
others in the fun, &c. And could our eyes
attain to a fight of the admirable texture of
the parts on which the fpecifick differences in
plants depend, what an amazing and beautiful
fcene of inimitable embroidery fhould we be-
hold ? what a variety of mafterly ftrokes of
machinery ? what evident marks of confum-
mate wifdom fhould we be entertained with?

We may obferve, that the conftitution of
plants is curioufly adapted to the prefent ftate
of things, fo as to be moft flourifhing and
vigorous in a middle ftate of the air, viz.

when

3 6 2 The Conchjion.

when there is a due mixture and proportion
of warm and cold, wet and dry ; but when
thefeafons deviate far to any extreme of thefe,
then are they lefs or more injurious to the
feveral forts of Vegetables, according to the
very different degrees of hardinefs, or healthy
latitude they enjoy.

The different feafons in which plants thrive
beft, feem to depend, among other caufes, on
the very different quantities imbibed and per-
fpired by different kinds of plants. Thus
the Ever-greens perfpiring little, and having
thereby a thick, vifcid, oily fap, they can the
better endure the winter's cold, and fubfift
with little frefh nourishment : They feem
many of them to flourish moft in the tem-
perate feafons of the year, but not fo well in
the hotteft part of fummer, becaufe their per-
fpiration is then fomewhat too great, in pro-
portion to the flow afcent of the fap, which
makes fome of them at that feafon to abate of
their vigour : Thus fome plants, which grow
and thrive with the flow perfpiration of Ja-
nuary and February , perifh as the fpring ad-
vances, and the warmth and perfpiration is
too great for them. And thus Garden Peas
and Beans, which are fown in what is found
to be their proper feafon, viz. in November,

Janu-

The Conchjion. 363

January, or February, tho' they make but a
ilow progrefs in their growth upwards, du^
ring the cold feafon, yet their roots, as alfo
thofe of winter Corn, do in the mean time
fhoot well into the warmer earth, fo as to be
able to afford plenty of nourishment when
the feafon advances, and there is a greater
demand of it both for nutrition and perfpira-
tion. But when Peas are fown in June, in
order for a crop in September,- they rarely
thrive well, unlefs in a cool moift fummer,
by reafon of the too great perfpiration caufed
by the fummer's heat, which dries and har-
dens their fibres before they are full grown.

Tho* we have from thefe Experiments,
and from common obfervation, many proofs
of the great expanfive force, with which the
fibrous roots of plants moot, yet the lefs re-
finance thefe tender fhoots meet with, the
greater progrefs they will certainly make in
equal times : And therefore one confiderable
ufe of fallowing and trenching ground, and
of mixing therewith feveral forts of compoft,
as Chalk, Lime, Marie, Mould, &c. is not
only thereby to replenifh it with rich manure,
but alfo to loofen and mellow the foil, not
only that the air may the more eafily pene-
trate to the roots, but alfo that the roots may

the

364 7#£ Conch fion.

the more readily make vigorous flioots. And
the greater proportion the furface of the roots
bears to the furface of the plants above-
ground, fo much the greater quantity of
nourifhment they will afford; and confe-
quently the plants will be the more vigorous,
and better able to weather it out, againft
unkindly feafons, than thofe plants whofe
roots have made much (horter flioots. Herein
therefore confifts the great care and skill of
the Husbandman, to adapt his different forts
of Husbandry to the very different foils, feafons
and kinds of grain ; that the feveral forts of
earth, from the very ftiff and ftrong ground,
to the loofe light earths, may be wrought to
the beft temper they are capable of, for the
kindly fhooting and nourifliing of the roots.
And probably the Husbandman might get
many ufeful hints, to dired: him in adapt-
ing the feveral kinds of manure, and dif-
ferent forts and feafons of culture, to his
different foils and grains, if in the feveral
flages and growth of his Corn he would
not only make his obfervations on what
appears above-ground, but would alfo fre-
quently dig up, compare and examine the
roots of plants of each fort, efpecially cf
thofe which grew in different foils, and were

any

The Conclufion. 365

any how cultivated in a different manner from
each other; this would inform them alfo,
whether they fowed their Corn too thick or
too thin, by comparing the branchings and
extent of each root, with the fpace of ground
allotted it to grow in.

And fince we find fo great a quantity of
air infpired and mixt with the fap, and
wrought into the fubftance of Vegetables,
the advantage of ploughing and fallowing
ground feems to arife not only from the
killing the weeds, and making it more mel-
low, for the (hooting of the roots of Corn 3
but it is thereby alfo the better expofed to
have the fertilizing, fulphureous, aereal, and
acid particles of the air mixt with it, which
make land fruitful, as is evident from the
fertility which the fword or furface of land
acquires, by being long expofed to the air,
without any culture or manure whatever.

We have feen many proofs of the great
quantities of liquor imbibed and perfpired
by plants, and the very fenfible influence
which different ftates of the air had on their
more or lefs free perfpiration : A main in-
tention therefore to be attended to in the
culture of them, is to take due care, that
they be fown or planted in proper feafons

and

$66 The Conchjion.

and foils, fuch as will afford them their due
proportion of nourifhment ; which foils, as
they are exhaufted, muft, as 'tis well known,
from time to time, be replenifhed with frefh
compoft, fuch as is full of faline, fulphu-
reous and aereal particles, with which com-
mon dung, lime, afhes, fword, or burn-
bated turf abound ; as alfo fuch manures,
as have nitrous and other falts in them : for
tho' neither nitre nor common fait be found
in Vegetables, yet fince they are obfcrved to
promote fertility, it is reafonable to con-
clude, that their texture is greatly altered
in Vegetation, by having their acid volatile
falts feparated from the attracting central
air and earthy particles, and thereby make-
ing new combinations with the nutritive
juice ; and the probability of this is further
confirmed, from the great plenty of air and
volatile fait, which is found in another com-
bination of them, viz. in the Tartar of
fermenting liquors : For it is the opinion of
Chymifts, that there is but one volatile Salt
in nature, out of which all other kinds of
falts are formed by very different combina-
tions; all which nutritive principles do, by
various combinations of the cultivated earth,
compofe that nutritive dudtile matter, out

tfhe Conchjiori. ^67

of which the parts of Vegetables are formed,
and without which the watry vehicle alone
cannot render a barren foil fruitful.

Nor is this the only care : The thriving
and fertility of plants and trees depends
much upon the happy influence and con-
currence of a great variety of other cir-
cumftances. Thus many trees are unfruit-
ful by being planted too deep, whereby
their roots being in too moift a ftate, and
too far from the proper influence of the
Sun, whofe power greatly decreafes, the
deeper we go, as we fee in Experiment 20.
they imbibe too much crude moifture, which,
tho' productive of wood, is yet unkindly for
fruit.

Or if, when not planted too deep, they
are full of crude fap, either by being too
luxurious, or too much fhaded ; or are
planted in a moift, when they delighc in a
dry foil, then the fap is not fo fufficiently
digefted by the Sun's warmth, as to be in
that dudtile ftate, which is proper for the
producing of fruit.

And thus the Vine, which is known to
thrive w7ell in a dry, gravelly, rocky foil,
will not be fo fruitful in a moift, ftifF, clay
ground: And accordingly we -may obferve

3 68 The Conchjion.

in Experiment 3. that tho' the Vine imbibed
and perfpired more than the Ever-green, yet
it perfpired lefs than the Apple-tree, which
delights in, and bears beft in a ftrong brick-
earth clay ; for tho' the Vine bleeds moil
freely in its feafon, produces many long
fucculent fhoots, and bears great plenty of
a very juicy fruit, yet from that Experiment
it is plain, that it is not a great perfpirer,
and therefore thrives beft in a dry, rocky, or
gravelly foil.

The considerable quantity of moifture,
which by Experiment 16. is perfpired from
the branches of trees, during the cold winter
feafon, plainly (hews the reafon why, in a
long feries of cold North-eafterly winds, the
bloffoms, and tender young-fet fruit and
leaves, are in the early fpring fo frequently
blafted, viz. by having the moifture exhaled
fafter than it can be fupplied from the trees :
for doubtlefs that moifture rifes the flower
from the root, the colder the feafon is, tho' it
rifes in fome degree all the winter^ as is evi-
dent from the fame Experiment.

And from the fame caufe it is, that the
leafy fpires of Corn are, by thefe cold dry-
ing winds, often faded and turned yellow ;
which makes the Husbandman, on thefe oc-

cafions,

The Conclujion* ^6$

tafions, wifh for fnow ; which, tho* it be very
cold, yet it not only defends the root from
being frozen, but alfo fcreens the Corn from
thefe drying winds, and keeps it in a moid,
florid, fupple ftate.

It feems therefore to be a very reafonable
direction, which is given by fome of the
Authors, who write on Agriculture and Gar-
dening, viz% during thefe cold drying winds,
when little dew falls, to water the trees in
dry foils, in the blofibming feafon, and while
the young- fet fruit is tender; and provided
there is no immediate danger of a froft, or in
cafe of continued froft, to take care to cover
the trees well, and at the fame time to fprinkle
them with water, which is imitating Nature's
method of watering every part : But if the
fuccefs of this practice in cold weather may
be thought a little doubtful, yet the fprin-
kling the bodies and leaves of trees, in a very
hot and dry fummer feafon, feems mofl rea-
fonable 5 for by Exper. 42. they will imbibe
much moifture.

As to floping fhelters over Wall-trees, I
have often found, that when they are fo broad
as to prevent any rain or dew coming at the
trees, they do more harm than good, in thefe
long eafterly drying winds, becaufe they pre-
B b vent

370 The Conclufion.

vent the rain and dews falling on them, which
would not only refrefh and fupple them, but
alfo convey nourifhment to them : But in the
cafe of (harp frofts after fhowers of rain, thefe
fhelters, and other fences, mull needs be of
excellent ufe to prevent the almoft total de-
ftrudtion which is occafioned by the freezing
of the tender parts of Vegetables, when they
are full faturate with rain.

The full proof we have from thefe Expe-
riments, of the ferviceablenefs of the leaves in
drawing up the hip, and the care we fee Na-
ture takes in furnifhing the twigs with plenty
of them, principally near the fruit, may in-
ftrudt us on the one hand, not to be too lavifh
in pruning them off*, and to be ever mindful
to leave fome on the branch beyond the fruit}
and on the other hand, to be as careful to
cut oft all fuperflubus fhoots, which we are
allured to draw off in wafte great quantity of
nourifliment. And might it not be advife-
able, among many other ways which are
prefcribed, to try whether the too great luxu-
riancy of a tree or branch could not be much
checked by pulling off fome of its leaves ?
How many, Experience will beft teach us >
the pulling all off, will endanger the killing
the branch or tree.

There

The ConcJufion. 371

There is another very confiderable ufe of
the leaves, viz. to keep the growing fruit in
a fupple du&ile ftate, by defending it from
the fun and drying winds, which by tough-
ning and hardening its fibres fpoils its growth,
when too much expofed to them ; but when
full grown, or near it, a little more fun is
often very needful to ripen it. In hotter
climates fruits want more {hade than in this
country; and here too more fhade is needful
in a hot dry fummer, than in a wet cool one.

The confideration of the ftrong imbibing
power of the branches of trees, and the rea-
dinefs with which we fee the fap pafles to and
fro to follow the ftrongeft attraction, may per-
haps give forne ufeful hints to the Gardener,
in the pruning and fhaping of his trees, in
checking the too luxuriant, and helping and
encouraging the unthriving parts of trees.

It is a conftant rule among Gardeners,
founded on long experience, to /prune weak
trees early in the winter, becaufe they find
that late pruning checks them 5 and for the
fame reafbn to prune luxuriant trees late in
the fpring, in order to check their luxuriancy.
Now it is evident, that this check does not
proceed from any confiderable loft of fap at
lhe wounds of the pruned tree, (excepting

B b 2 che

%yi The Cbnchfion.

the cafe of a few bleeding trees when cut in
that feafon, but muft arife from fome other
caufe ; for by Experiment 12. and 37. where
mercurial gages were fixt to the ftems of frefh-
cut trees, thofe wounds were conftantly in a
ftrongly imbibing flate, except the Vine in
the bleeding feafon.

When a weak tree is pruned early in the
beginning of the winter, the orifices of the
fap-veffels are clofed up long before the fpring^
as is evident from many Experiments in the
1 ft, 2d, and 3d chapters : and confequently,
when in the fpring and fummer the warm
weather advances, the attracting force of the
perfpiring leaves is not then weakened by
many inlets from frefh wounds, but is wholly
exerted in drawing fap from the root. Whereas
on the other hand, when a luxuriant tree is
pruned late in the fpring, the force of its leaves
to attraft fap from the root will be much fpent
and loft at the feveral frefh-cut inlets.

Befides, the early pruned tree being eafed
of feveral of its twigs or branches, has thereby
the advantage of ftanding through the whole
winter, with a head better proportioned to its
weak root. And fince by Exper. 16. the fap
is found to afcend in the winter, lefs of that
Than cold crude iuice is drawn thro' the roors

and

77)e Conchjion. 373

and ftem, to fupply the perfpiration of the
remaining boughs, whereby the fap of the
tree is probably lefs depauperated than it
would have been, if all the boughs had re-
mained on. For thefe reafons early pruning
fhould, in the main, and excepting fome
cafes, be better than late.

And the reafonablenefs of this pfa&ice is
further confirmed by the experience of fome,
who have found, that by pruning Vines, and
pulling all the leaves off them in September^
as foon as the fruit was off, they have borne
greater plenty of Grapes than other Vines,
particularly in the year 1726. when, by reafon
of the extreme wetnefs and coldnefs of the
preceding fummer, the unripe {hoots produe'd
generally very little fruit. But early pruning
feems to be the more preferable, becaufe pull-
ing off the leaves may poffibly both wound
the adjoining bud, and injure it, by depriving
it of the nourifhment which the leaf would
have brought to it.

From many Experiments in the fecond
Chapter, the Gardener will fee with what
force his grafts imbibe fap from the ftock,
efpecially that dudlile nourifhment from be-
tween the bark and wood -, which correfpond-
ing parts he well knows, by conftant expe-

rience,

$74 %*be Conchjion.

rience, muft be carefully adapted to each
other in grafting, thofe grafts being always
beft, whofe buds are not far afunder, viz.
becaufe their expanding leaves can therefore
draw up fap the more vigoroufly.

The great quantities of moiflure, which
we find by Experiment 12. are imbibed at
wounds where branches are cut off, (hews
the reafonablenefs of the caution ufed by many
who are defirous to preferve their trees, viz.
either by plaiflering or covering with Sheet-
lead the very large wounds of trees, to defend
their trunks from being rotted by the foaking
in of rain.

And from the fame 12th Experiment a
hint may be taken to make fome attempts to
give an artificial tafte to fruits, by making
trees imbibe in the fame manner fome ftrongly
tinged or perfumed liquor, which is not fpi-
rituous : for that, we fee, will kill the tree. I
have made the ftem of a branch of a tree im-
bibe two quarts of water without killing it :
If any are defirous to make this Experiment,
they mould take care to cut the flump which
is to imbibe the liquor as long as they can,
that there may be the more room, from time
to time, to cut off an inch or two of the top,
when it is grown fo faturate with liquor, that
more will not pafs. Tho*

The Conchjion. 375

TW Ever-greens are found to imbibe and
perfpire much lefs than other trees, yet is the
quantity they perfpire fo confiderable, that it
has always been one of the greateft difficulties
in the ordering of a Green-houfe, to let in
frefh air enough without expofing the plants
to too much cold. For fince the perfpiration
of trees will not be free and kindly in a clofc
damp air, the fap will be apt to ftagnate,
which will make the plants grow mouldy,
or they will be fickly, by imbibing fuch damp
rancid vapours : For by Mr. Millers curious
obfervations on the perfpiration of the Plan-
tain tree of the JVejI-Indies, and of the Aloe
under Experiment 5. plants will often imbibe
moifture in the night, as well in Stoves as
common Green-houfe, without fire; it is cer-
tainly of as great importance to the life of
the plants to difcharge that infedted rancid
air, by the admittance of frefh, as it is to
defend them from the extreme cold of the
outward air, which will deftroy them, if let
in immediately upon them. It feems there-
fore to be a very reafonable method which
fome ufe, viz. to cover fome of the inlets of
their Green-houfes on all fides with canvas,
and in extreme cold weather with fhutters
made of reed or ftraw, thro* which the air can

only

376 The Conchjion.

only pafs in little ftreams: The like contri-
vance would probably alfo be of good fervice
to purify gradually the thick rancid fumes
which arife from the dung of hot beds, and
are often very defrru&ive of the tender plants:
This is to imitate Nature, which, while (he
provides for the defence of living creatures
againft: the cold, by a good covering of Hair,
Wool, or Feathers, at the fame time (he takes
care that the air may have admittance thro'
innumerable narrow meanders, in fuch quan-
tities, as may be fufficient to carry off the
perfpiring matter.

. I have here, and as occafion offered, under
feveral of thp foregoing Experiments, only
touch'd upon a few of the mod: obvious in-
ftances, wherein thefe kind of refearches may
poffibly be of fervice in giving us ufeful hints
in the culture of plants : Tho' I am very itn-
fible, that it is from long experience chiefly
that we are to expert the mod certain rules of
practice ; yet it is withal to be remembred, that
the likelieft method to enable us to make the
moft judicious obfervations, and to put us upon
ithe moll: probable means of improving any art,
is to get the bed infight we can into the nature
#nd properties of thofe things which we are
defirous to cultivate and improve.
FINIS.

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Full text of "Statical essays, containing vegetable staticks, or An account of some statical experiments on the sap in vegetables : being an essay towards a natural history of vegetation (3rd edition, with amendments)"

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