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SPcoi-\, roLLFCTIONS

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14-55
This book must not be
taken from the Library
building.

JUN 7 '966

Barrs Buffvn,

Buffon's Natural History.

CONTAINING

A THEORY OF THE EARTH,

A GENERAL

HISTORY OF MAK

OF THE BRUTE CREATION, AND OF
VEGETABLES, MINERALS,

FROM THE FRENCH.
WITH NOTES BY THE TRANSLATOR.

IN TEN VOLUMES.

VOL. X.

PRINTED FOR THE PROPRIETOR,

A>iD SOLD BY II. D. SYMONDS, PATERNOSTER-ROW.

1807.

T. Gillet, Printer, Crovrn-CoUTt, Fleet-Street.

=?a

CONTENTS.

OF

THE TENTH VOLUxMJE,

Pa^ie

D

Of the Degeneration of Animals - |

Nature and Properties of Miucrals,
Vegetables, &c.
X^ighty Heat, and Fire - - 27

Of Air, Water y and Jgarth - - 75
Experiments on the Progress of Heat in

Mineral Substances - - - 1C9
A Table of the Relations of different Mine-

ral Substances - - - 1S5

Observations on the Nature of Platina 15(i
Experiments on Light, and on the
Heat it can produce.
Invention of Mirrors to burn at great dis-
tances - - - - 193
Observations and Experiments on Trees

and other Vegetables - - 245

On the Temperature of the Planets - 279

General Views of Nature.
First View - - - S25

Second View - - - 343

^^'

s.

BUFFON'S
NATURAL HISTORY.

OF THE DEGENERATION OF ANIMALS.

npHE deer-kind whose horns arc a sort Of
wood, and of a solid texture, although ru-
minating, and internally formed like those
whose horns arc hollow and porous, seem to
form a separate family, in which the elk is the
trunk, and therein-deer, stag, axis, fallow-deer,
and roe-buck, are the lesser and collateral
branches ; for there are only six species of ani-
mals whose heads are armed with branched
horns that fall off and are renewed every j'ear.
Independently of this generic character, they
resemble each other still more in formation and
natural habitude ; we should, therefore, sooner
expect mules from thestagor fallow-deer, join-
ed with the rein-deer or the axis, than from a
union of the stag with the cow

Wc mio]jtbe still belter authorised to resrard
all the different kinds of sheep and goats as
composing but one- family, since ihey produce
VOL. X. B together

2 BUFFON S

together mules, "wliich imracdiatelj, and iil
the first generation, ascend to the species of
sheep. We might even add to tli is numerous
family of sheep and goats those of the gazelles
and bubalus, which are not less in number.
The mufion, the wild goat, the chamois, the
antelope, the bubalus, the condoraa, &c. seem
to be the principal trunks of this genus, which
contains more than thirty different species, and
the others are only accessary branches which
have retained the principal characters of the
stocks from which they issued ; but which, at
the same time, have prodigiously varied by
the influence of the climate, the difference of
the food, and by the state of slavery to which
man has reduced most animals.

The dog, the wolf, the fox, the jackal, and
Iheisatis, form another genus, the different spe-
cies of which resemble each other so strongly,
especially in their internal conformation, and
in the organs of generation, that it isdiflicult
to conceive why they do not intermix. From
the experiments which I made to form a union
of the dog with the wolf and fox, the repug-
nance to copulate seemed to proceed from the
wolf and fox rather than from the dog, that is,
from the wild animal and not from the tame ;
for those bitches which I put to the trial would
readily have permitted the >volfand fox, where-
as

NATURAL HISTOHY. 3

as the females of the two latter would never
suffer the approaches of the dog. The domes-
tic state seems to render animals less faithful to
their species : It gives tliem also a greater de-
gree of heat and fecundity, for the bitcli gener-
ally produces twice a year, while the females
of the wolf and fox litter only once ; and it
is to be presumed, that those dogs which have
been left in desert countries, and which have
so greatly multiplied in the island of JaanFer-
nandes, and in the mountains of St. Domingo,
&:c. produce only once a year, like the wolfand
ihe fox. This circumstance, if it were proved
to be the fact, would fully establish the unit^'
of genus in these three animals, which resem/-
ble each other in conformation so strongly as
to oblige us to attribute their repugnance to
some external circumstances.

The dog seems to be (he intermediate spe-
cies between the fox and the wolf. The an-
cients have stated 5 that the dog, in some coun-
tries, and under particular circumstances, en-
genders with the wolfand fox. I was desir-
ous of verifying this assertion, and although I
did not succeed in the trials I made, yet we
must not conclude thai it is impossible^ for
ray experiments were with captive animals ;
and it is know n that in some species captivity
alone is sufficient to extingnish desire, and tp

give

buffon's

give tliem a repugnance to copulation, even
viith their own kind ; consequently thej would ^
still more refuse to unite with individuals of
another species: but I am persuaded, that
"when in a state of freedom, and deprived of
his own female, the dog would unite with the
■wolf and fox, particularly if he had become
■wild, lost his domestic cast, and approached
the manner andnaturalliabits of these animals.
The fox and wolf, however, never unite, though
they live in the same climate and country, but
support their species pure and unmixed ; we
must, therefore, suppose a more ancient de-
generation than history has recorded, if they
ever belonged to one species ; it was for
this reason I asserted that the dog was an
intermediate species between the fox and
wolf; and his species is also common, since
it can unite with both ; and if any thing
could shew that they all three originally
sprang from the same stock, it is this common
affinity between the dog, the fox, and the wolf,
and which seems to bring their species nearer
than all the conformities in their fisrures and
organization. To reduce the fox and wolf,
therefore, into one species, we must return to a
state of nature very ancient indeed; but in
their present condition, we must look upon

the

NATURAL HISTORY. 5

the wolf and fox as the chief trunks in the irc-
rtus of the five animals. The dog, the jackal,
and the isatis, are only lateral branches
placed betweeji the two first ; the jackal par-
ticipates of t!ie dog and wolf, and the isatis of
the jackal and fox. From a great number of
testimonies it appears that the jackal and the
dog engender easily together ; and it is ob-
servable, from the description and history of
the isatis, that it almost entirely resembles the
fox in iU form and temperament, that they
are equally found in cold countries, but that,
at the same time, it inclines to the jackal in its
dis])osition, continual barking, clamorous
voice, and the habit of always going in packs.
The shepherd's dog, which I have considered
as the original stock of every other dog, is, at
the same time, that which approaches nearest
in figure to the fox. lie is of the same size,
and, like the fox, he has erect ears, a pointed
muzzle, and a strait trailing tail. Re also ap-
proaches the fox in voice, sagacity, and in-
stinct. The dog, therefore, may orirrinally
Jiave been the issue of tlie fox, if not in a di-
rect, at least in a collateral line. The doir,
which Aristotle calls canis-lacomct/s, and
which he affirms to have proceeded from an
union of the fox and dog, might, possibly, be

the

BUFFON^S

the same as the shepherd's dog, or, at least, it
has more relation to him than to any other
dog. We miglit, therefore, be inclined to
imagine, tliat the epithet laconicus, left unin-
terpreted by Aristotle, was only given to thi&
dog because he was found in Laconia, a pro-
vince of Greece ; and of wliich Lacediemon
•was the capital ; but if we attentively consider
the origin of this laconic dog we shall perceive
that the breed was not confined to the country
of Laconia, alone but must have been found in
every country where there were foxes ; and this
induces me to presume, that the epithet laco^
nicus might possibly have been used by Aris-
totle in a moral sense, to express the brevity
and acutencss of his voice, because he did not
bark lilvc other dogs, but had a shorter and
shriller note, like that of the fox. Now our
shepherd's dog is that to which we can justly
apply this term of laconic^ for of all dogs his
voice is the sharpest and most rarely employed .
Bedsides, the characters which Aristotle gives to
his laconic dog agree with those of the shep-
herd's dog, and perfectly persuade me they are
the same.

The genus of cruel and rapacious animals is
one of the most numerous and most diversified ;
evils here, as in other cases, seem to be pro-

duccd

NATURAL histohy. 7^

duced under every shape, and to assume various
natures ; the lion and the tiger, being detached
species, rank in the first line ; all the others, as
tlie panther, the ounce, the leopard, the lynx,
the caracal, the jaguar, the cougar, the oce-
lot, the serval, the margai, and the cat, com-
pose only one cruel family, whose different
branches are more or less extended and diver-
sified according to the difference of climate.
All these animals resemble each other in natu-
ral dispositions, although they are very differ-
ent with respect to size and figure. They all
have sparkling eyes, short muzzles, and sharp,
crooked, and retractile claws. They are all
destructive, ferocious, and untameable. The
eat, which is the last and the least species, al-
though reduced to slavery, continues its fero-
city, and is no less perfidious. The wild cat
bas preserved the character of the family, and
is as cruel and mischievous as any of his lar-
gerkindred. They are allequally carnivorous,
and enemies to other animals. Man, with all
his art and power, has not been able to annihi-
late them : fire, steel, poison, pits, and every
method has been used against them without
attaining that point. As the individuals are
very prolific, and the species numerous, the
efforts of man have been limited to kecj;'»ng
them at a distance, and confining them in the

deserts

8 buffon's

deserts, whmcethej never sail v without sprctid-
ing terror, and makins: great depredations. A
single tiger issuing from the forest is sufficient
to alarm a multitude of people, and oblige
them to take up arms. What then would be
tlie consequence if these sanguinary animals
came in numbers, like wolves or jackals, to
commit their depredations ? Nature has given
this instinct to timid animals, but fortunately
denied it to the bold tribes ; they go singly,
and depend upon their courage and strength
for their safety andsupj>ort. Aristotle observ-
ed, and justly remarked, that of all animals
furnished with talons not any of them are
sociable, or go together in troops.* This ob--
gervation, which was then confined to four or
live species only, being all that were known
ill his time, is extended and verified over ten.
or twelve other sp(*c!es since discovered. Other
carnivorous animals, such as the wolf, the
fox^ the dog, the jackal, and the isatis, whose
claws are straight, go mostly in <roops, and
are all timid, and even cowardly.

B}' thus comparing every quadrnped, and
ranking ciich v/ith its proper genus, we shall
find, that the two hundred species of which we

have

* Nullum animal cui ungues aduncl, gregaiile esse per-
pcndimus. Arist.. Kist. Anim. Lib. i. Cap. i.

NATURAL HISTORY. 0

have given the history, may be reduced to a
small number of families, or principal sterns^
from which it is not impossible all the others
have derived their origin.

To place this reduction in a regular raetliod,
we shall observe that all the animals of the two
continents, as well as all those peculiar to the
Old World, may be reduced to fifteen genera,
and nine solitary species. These genera are,
first, the whole hoofed genus, properly so
called, which includes the horse, the zebra,
and the ass, with all the prolific and barren
mules. 2. The large cloverw-hoofcd with hol-
low horns, as the ox and the buffalo, with
their varieties. 3. The small cloven-hoofed
animals with hollow horns, such as the sheep,
the goat, the gazelle, the antelope, and every
other species which participates of their nature.
4. The cloven-hoofed wilh solid horns, which
are shed and renewed every year ; this family
contains the elk, the rein-deer, the stag, the
fallow-deer, the axis, and the roe-buck. 5.
Theambiguous cloven-hoofed, which is com-
posed of the wild boar, and all the varieties of
the hog, such as that of Siam, with a hanging
belly, that of Guinea, with long ears, pointed
and turned backwards, and that of the Canary
islands with thick and long tusks, &c. 6.
VOL. X. C The

10 buffon's

The very extensive race of digitated carni-
vorous animals with crooked and retractile
cla s, in which we must conipreheadthe pan-
ther, leopard, guepard, ounce, serval, and cat,
with all their varieties. 7. The digitated
carnivorous animals with straight and fixed
claws, which include the wolf, fox, jackal,
isatis, and the dog, with all their varieties. 8.
The digitated carnivorous animals with fixed
claws, and a pouch under their tails. This
consists of the hyaena, civet, zibet, badger, &c.
9. The digitated carnivorous animals with
long bodies, five toes to each foot, and the great
toe, or thumb, divided from the rest ; tliis ge-
nus is composed of the ferret, martin, pole-cat,
weasel, sable, ichneumon. Sec, 10. The nu-
merous family of digitated quadrupeds which
have two Inrge incisive teeth in each jaw, and
no bristles on their bodies ; this contains the
hare, rabbit, and e\ery kind of squirrels, dor-
mice, marmots, and rats. li. The digitated
quadrnpeds, wh ;se bodies are covered with
spiny quills, as the porcupine and hedge-hog.
12. The digitated animals covered with scales,
as the long and short-tailed raanis, or scaly li-
zards. 13. The amphibious digitated genus,
which includes the beaver, otter, musk-rats,
walrus, and seals. 14, i he tour-handed genus,

whick

NATURAIi HISTORY. H

wliich comprehends tlie apes, baboons, mon-
kies, rnakis, loris, &c. 15. The winged qua-
drupeds, which includes bats, &c. with all
their varieties. The Piine detached species are
the elephant, rhinoceros, hipp.^potanuis, gi-
raffe, camel, lion, tiger, bear, and mole, ^^ hieh
are all subject t) a greater or smaller number
of varieties.

Of those fifteen genera, and nine delaclied
species, seven genera and two species are com-
mon to both continents. The two species are,
the bear and ihe mole ; and (he seven genera
are, 1. The great cloven- hooted with hollow
horns, for the ox is found in America, under
the form of the bison. 2. The cloven- hoofed,
with solid horns, for the elk exist-, in Canada,
under the name of orignal ; the n in-decr, un-
der that of caribou ; and stag>, lallow-dccr, and
roc-bucks, are found in all the prv)vinces of
North America. 3, The digitated carnivorous
animals with fixed claws ; for ihe wolf and (ok.
are found in the New World ns well as in the
Old. 4. The digitaied animals with long
bodies, as the weasel, martin, and pole-cat,
are met with in America as well as in Europe.
5. \yc find also m America, partof the digi-
tated genus with two large inci.ive teeth in
each jaw, as the squirrels, marmots, rats, &c.

6. The

12 BUFFO n'S

6. The digitated amphibious genus, as the
walrus, seal, beaver, and otter, exist in the
North of the New Continent. 7. The winged
genus exist also in America, as the bat and
vampire.

There remains, therefore, only eight genera,
and five detached species, which are peculiar to
the Old Continent. These eight genera are,
1 . The whole-hoofed, properly so called, for
neitherthehorse, ass, zebra, nor mule, were met
with in the New Continent. 2. The small
cloven-hoofed beasts with hollow horns ; for
sheep, goats, gazelles, or antelopes existed in
America. 3. The family of hogs ; for the
species of wild boar is not to be found in
America ; and although the pecari, and its va-
rieties, are related to this family, yet they dif-
fer in a sufficient number of remarkable cha-
racters to justify their separation. 4. It is the
same with carnivorous animals with retractile
claws ; we do not meet with either the panther,
leopard, guepard, ounce, or serval, in Ame-
rica; and although the jaguar, couguar, oce-
lot, and margai, seem to belong to this family,
there is not one of these species of the New
World found in the Old, nor one of the Old to
be met with in the New. 5. The same re-
niark may be applied to the digitated qua-
drupeds

NATURAL HISTORY. 13

drupeds whose bodies are covered with prickles;
for although the coendou and the urson ap-
proach very nigh to this genus, nevertheless,
these species are very different from those of
the porcupine and hedge-hog. 6. The digi-
tated carnivorous genus "with fixed claws, and
a pouch under the tail; for the hyaena, civets,
and the badger, do not exist in America.
7. The four-lianded genus; for neither apes,
baboons, monkeys, nor makis, have ever been
seen in America. The sapajous, sagons, opos-
sums, &c. although quadrumanous, yet they
essentially differ from those of the Old Conti-
nent. S. The digitated genus whose bodies are
covered with scales ; for none of the scaly
lizards are found in America, and the ant-
eaters, to wliom they may be compared, arc
covered with hair, and differ too much from
the scaly lizards to be considered of the same
family.

Of the nine detached species, seven, namely,
the elephant, rhinoceros, hippopotamus, gi-
raffe, camel, lion, and tiger, are found only in
the Old World ; and two, viz. the bear and
mole, are common to both continents.

If we, in tlie same manner, enumerate the
animals which are peculiar to the New World,
we shall find, that there are about fifteen dif-
ferent

14 buffon's

fcrent species which may be reduced to ten
genera and four detached species. These four
species are the tapir, tlie cabiai, the lama, and
the pecari ; but there is ouly the tapir we can
absolutely term detached; for the pecari has
varieties ; and the pacos may be united to the
lama, and the Guinea hog to the cabiai. The
ten genera are, 1. Eight ] ecies of sapajous.
2. Six species of sagoii)s. 3. The opossums,
phalangers, tarsiers, &c. 4. The jaguars, coii-
guars, ocelots, raargais, &c. 5. Three or four
species of coatis. 6. Four or five species of
mouffetles. 7. The agouti genus, which com-
prehends the acouchi, the paca, the aperea,
and the tapeti. 8. That of the armadillos,
which consists of seven or eight species. 9.
Two or three species of ant-eaters; and,
ICthly, The sloth, of which we are acquainted
with but two species.

Now these ten genera, and four detached
species, to which the fifty species of animals
peculiar to the New World may be reduced,
though they differ from those of the Old Con-
tinent, nevertheless have some relations which
seem to indicate some common afiinity in their
formation, and lead us to causes of degenera-
tion, more ancient than any of the rest. We
have already made the general remark, that all

animals

NATURAL HISTORY. 15

animals of the New World were miicli smaller
than (hose of the Old. This great diniinufiofi
in size, whatever maybe the cause, is a primary
kind of dc>generation, which could not be made
without having a great influence on the figure
of the animal, and we must not lose sight of
this effect in comparing them together.

The largest is the tapir, which though not
bigger than the ass, can only be compared
with the elephant, rhinoceros, and hippopota-
mus ; he claims the first place for size in the
New Continent, as the elephant does in the
Old. Like t!ie rhinoceros, his upper lip is
muscular and projecting; and, like the hip-
popotamus, he often enters the water. Insome
respects he represents them all three, and his
figure, which partakes more of the ass than of
any other animal, seems to be as degraded as
his stature is dimini^hed. The horse, the ass,
the zebra, the elephant, the rhinoceros, and the
hippopotamus, had no existence in America;
neither was there an animal in this New Con-
tinent which could be compared with ihem^
fiiiher with respect to size or figure. The ta-
pir appears (o have some affinity to the whale,
but he is so mixer!, and approaches so Utile to
any one of them," that it is not possible to at-
tribute his origin to the degradation of any par-
ticular

15 buffon's

ticular species. And, notwitlislanding these
trifling relations Avhich he is found to have
"with the rhinoceros, the hippopotamus, and
Ihe ass, v/e must look on him not only as a pe-
culiar species, but even as a single genus.

The tapir, therefore, does not belong to any
species of the Old Continent, and scarcely
does hebear any characters which approximate
him to those animals with which we have just
been comparing him. The nature of the ca-
biai is likewise averse from our comparison :
externally he has no resemblance with any
other animal, and only approaches the Indian
hog of the same continent, by his internal
parts, and both species are absolutely diii'erent
from all those of the Old Continent.

The lama and the pacos appear to have more
significant marks of their ancient parents: the
first Avith ihe camel, and the second in the
sheep. The lama, like the camel, has a long
neck and legs, slender head, and the upper lip
divided. He resembles the latter also by
his gentle manners, servility of disposition,
endurance of thirst, and aptness for labour.
This was the first and most useful domestic
animal of the Americans : they made use of
him to carry burdens, in tlie same manner as
the Arabs do the camel. Here therefore arc

suihcidnt

NATURAL HISTORY. 17

sufficient resemblances in the nature of these
animals, to \\hich we can jet add the perma-
nent marks of labour ; for though the back of
the lama is not deformed by hunches like that
of the camel, he, nevertheless, has callosities
on liis breast, occasioned by the like habit he
is used to of resting on that part of his body.
Yet, notwithstanding all these affinities, the
lama is a very distinct and different species
from the camel. He is much smaller, not ex-
ceeding a fourth or a third part of the camel's
magnitude. The shape of his body, and the
quality and colour of his hair, are also very
different. His temperament is still more so ;
for he is a phlegmatic animal, and delights
only to live on the mountains, whereas the
camel is of a dry temperament, and willingly
inhabits the most scorching sands. On the
whole, there are more specific differences be-
tween the camel and the lama, than between
the camel and the giraffe. These three ani-
mals have many characters in common, by
which they might be referred to one genus,but5
at the same time, they differ so much in other
respects,that we cannot suppose them to be the
issue of one another; they are, therefore, only
neighbours and not relations. The height of
the giraffe is nearly double that of the camel,

VOL. X. D ^(J

18 buffon's

and the camel double that of the lama. The
two first belong to the Old Continent, and form
separate species. The lama, therefore, which
is only found in the New, must be a distinct
species from both.

It is not the same with respect to the pecari,
for though a diflferent species from the hog,
he, nevertheless, belongs to the same genus.
He resembles the hog in shape, and every ex-
ternal appearance, and only differs from it in
some trifling characters, such as the aperture
on his back, shape of the stomach, intestines,
&c. We might, therefore, be led to suppose
that this animal sprung from the same stock
as the hog, and that he formerly passed from
the Old World to the New, where, by the
influence of the soil, he had degenerated to so
great a degree as now to constitute a distinct
species.

With regard to the pacos, though it appears
to have some aflinities with the sheep, in its
wool and habit of body, yet it differs so great-
ly in every other respect, that this species
cannot be looked on either as neighbours or
allies. The pacos is rather a small lama, and
has not a single mark Avhich indicates its
Laving passed from one continent to the other.
Thus of the four detached species peculiar to
w the

NATURAL HISTORY* 19

the New World, three, namely, the tapir, the
cabiai, and the lama, with the pacos, appear
to belong originally to this continent, whereas
the pecari, which forms the fourth, seems to
be only a degenerated species of the hog,
and to have formerly derived its origin from
the Old Continent.

By examining and comparing, in the same
manner, the ten genera, to which we have
reduced the other animals peculiar to South
America, we shall discover, not only singular
relations in their nature, but marks of their
ancient origin and degeneration. The sapajous
and sagoins bear so great a resemblance to the
monkeys, that they are commonly included
under that name. We have proved, however,
tliat their species, and even their genera, are
different. Besides, it would be very difficult
to conceive how the monkeys of the Old Con-
tinent could assume in America a difierent-
shaped visage, a long, muscular, and prehensile
tail, a large partition between the nostrils, and
other characters, both specific and generic, hy
which we have distinguished and separated
them from the sapajous. But as the monkeys,
apes, and baboons, are only found in the Old
Continent, we must look upon the~ sapajous
and sagoins as their representatives in the New,

for

so buffon's

for these animals have nearly the same form,
as well externally as internally, and also have
many things in common in their natural habits
and dispositions. It is the same with respect to
the raakis, none of which are found in Ame-
rica, yet they seem to be represented there by
the opossums, or four-handed animals, with
pointed muzzles, which are found in great
numbers in the New Continent, but exist not
in the Old. We must, however, observe, that
there is much more difference between the
nature and the form of the makis, and of these
four-handed American animals, than between
the monkeys and the sapajous ; and that there
is so great a distance between the opossums and
the maki that we cannot form an idea that the
one ever proceeded from the other, without sup-
posing that degeneration can produce effects
equal to those of a new nature ; for the greatest
number of these American four-handed ani-
mals have a pouch under the belly, ten incisive
teeth in each jaw, and a prehensile tail ; whereas
the maki has a flaccid tail, no pouch under the
belly, and only four incisive teeth in the upper
jaw, and six in the lower ; therefore, though
all these animals have hands and fingers of the
same form, and also resemble each other in the
elongation of the muzzle, yet their species,

and

NATURAL HISTORY. 21

and even their genera, are so different, that we
cannot imagine them to be one and the same
issue, or that such great and general disparities
have ever been produced by degeneration.

On the other hand, the tigers of America,
which we have indicated by the names of ja-
guars, couguars, ocelots, and margais, though
different in species from the panther, leopard,
ounce, guepard, and serval, of the Old Con-
tinent, are, nevertheless, of the same genera.
All these animals greatly resemble each other,
both externally and internally ; they have
alsothe samenatural dispositions, the same fe-
rocity, the same vehement thirst for blood, and
what approximates them still nearer in genus,
those which belong tothe same continent differ
more from each other than from those of the
other Continent. For instance, the African
panther differs less from the Brasilian jaguar
than the latter does from the couguar, though
they are natives of the same country. The
Asiatic serval, and tlic margai of Guiana, like-
wise differ less from one another than from th«
species peculiar to their own continents. We,
therefore, may justly suppose, that these ani-
mals had one common origin, and that, havino-
formerlypassed from one continent to the other,
their present differences have proceeded only

from

22 buffon's

from the long influence of their new situation.
The mouffcttes, or stinkards, of America, and
the i;olecat cf Europe, seem to be of the same
genus. In general, when a genus is common
to both continents the species which compose
it are more numerous in the Old than in the
New ; but in this instance it is quite the re-
verse, for there are four or live kinds of pole-
cats in America, while we have only one, the
nature of which is inferior to that of all the
rest ; so that the New World, in its turn, seems
to have representatives in the Old ; and if we
judged only from the fact, we might think these
animals had taken the opposite road, and pas-
sed from America to Europe. It is the same
with respect to some other species. The roe-
bucks and the fallow-deer, as well as the stink-
ards, are more numerous, larger, and stronger
in the New Continent than in the Old ; ^^e
might, therefore, imagine them to be original-
ly natives of America ; but as we cannot doubt
that every animal was created in the Old Con-
tinent, we must, consequently, admit of their
migration from the Old to the New World,
and at the same time suppose, that instead of
having degenerated, like other animals, they
have improved their original nature by the in-
fluence of the soil and climate.

The

NATURAL HISTORY. 23

The ant-eaters, wliicli are sini^ular animals,
and of wliich there are three or four species in
the New World, seem also to have their repre-
sentatives in the Old. The scaly lizards re-
semble them in the pecnliar character of hav-
ing no teeth, and of being obliged to put out
their tongues and feed upon ants ; but if we
would suppose them to have one common ori-
gin, it is strange, that instead of scales, with
which they are covered in Asia, they are cloth-
ed with hair in America.

With respect to the agoutis, pacos, and other
animals of the seventh genus peculiar to the
New Continent, we can only compare them
with the hare and rabbit, from which, how-
ever, they all differ in species. What renders
their being of a common origin doubtful is,
the hare being dispersed almost over every
climate of the Old Continent, without having
imdergone any other alteration than in the co-
Jour of its hair. We cannot, Avith any founda-
tion, therefore, imagine that the climate of
America has so far changed the nature of our
hares to so great a degree as to make them ta-
petis or apereas, which have no tail ; or agbutis
with pointed muzzles, and short round ears;
or pacos, with a large head, short ears, and u
coarse hair marked with white stripes.

On

S4 kuffon's

On the whole, the coatis, the armadillos,
and the sloths, are so different, not only in
species, but also in genus, from every animal
of the Old World, that we cannot compare
them with any one ; it is also impossible to re-
fer them to any common origin, or attribute to
the effects of degeneration the prodigious dif-
ferences found in their nature from that of
every other animal.

Thus, of ten genera, and four detached
species, to which we have endeavoured to re-
duce all the animals peculiar to the New
World, there are only two, the genus of the
jiguars, ocelots, &c. and the species of the
pecari, with their varieties, which can with any
foundation be connected with the animals of
the Old Continent. The jaguars and ocelots
may be regarded as a species of the leopard or
panther, and tlie pecari as a species of hog.
After these are five genera and one detached
species, namely the species of the lama, and the
genera of sapajous, sagoins, stinkards, agoutis,
and ant-eaters,which may becompared,though
in a very distant and equivocal manner, with
the camel, monkey, polecat, hare, and scaly
lizards. There then remain four genera and
t^o detached species, namely, the opossums,
the coatis, the armadillos, the sloths, the tapir,

and

. •«* « Wk»

NATURAL HISTORY. 25

and the cabiai, wliich can neither be referred
nor compared to any grnera or species of the
Old Co iinent. This sutficien'ly proves that
the origin of these animals, peculiar to the
New world, cannot be attributed merely to
degeneration. However, great and powerful
the effects of degeneration may be supposed,
we cannot, with any appearance of reason,
persuade ourselves that these animals were
originally the same as fhose of the Old Conti-
nent. It is more reasonable to imagine that
the two continents were formerly joined, and
that those species which inhabited the New
World, because they found the climate and
soil most suitable to their nature, were sepa-
rated from the rest by the irruption of the sea
when it divided Asia from Ame» ica . This is a
tiatural cause, and similar ones might be con-
ceived which \\ould produce the same e^cct ;
for example, if the sea should make an irrup-
tion from the eastern to the w<?stem ssde of
Asia, and thus separate the southern par's of
Africa nnd Asia from the res? of the Continent,
all the animals peculiar to the southern coun-
tries, such as the elephant, the iJiinoceros,
the giraffe, the zebra, the crang-uu'ang, &c.
would be, relatively lo tlioollicrs, the same as
those of South America at present are; they
VOL, X. E would

2(5 BUFFO n's

would be entirely separated from the animals
oft lie temperate countries, and could not be
referred to an origin common to any of the
species or genera which inhabit these coun-
tries, on the sole foundation that some imper-
fect resemblances, or distant relations, might
be observed between them.

We must, therefore, to find out the origin
of these animals, turn back to the time when
the two continents were not separated, and re-
fer to the first changes which happened on
the surface of the globe. We must, at the
same time, place before our view the two hun-
dred species of quadrupeds as constituting
thirty-eight families; and although this is not
the state of nature, sucli as it is come down to
us, and as we have represented it, but, on the
contrary, a much more ancient state, which we
can only attain by inductions and relations
nearly as fugitive as time, which seems to
have effaced their traces, we Iiave endeavour-
ed, by facts and monuments still existing, to
return to those first ages of nature, and to
exhibit those cpochas which appear to be
jiaobt clearly indicated.

NATURE

NATURAL HISTORY.

27

NATURE AND PrxOPERTIES OF MINE.
RALS, VEGETABLES, &c.

LIGHT, HEAT, AND FIR£.

'^LL the powers of Nature with which we
are acquainted, may be reduced to two pri-
mitive forces; the one which causes weight,
and that which produces heat. The force of
impulsion is subordinate to thera ; it depends
on the first for its particular, and on the latter
•for its general effects. As impulsion cannot
exercise itself but by tlie means of a spring,
and the spring only acls by virtue of the force
which approximates the remote parts, it is
clear, that to perform its power it has need of
the concurrence of attraction : for if matter
ceased to attract, if bodies lost their coherence,
every spring would be destroyed, every motion
intercepted, and every impulsion void ; since
motion ca mot transmit itself from one body to
another but by elasticity , it is demonstrable,
that one body absolutely hard and inflexible,

would

is buffon's

would be absolutely immoveable, and entirely
incapable of receiving Ibe action of another.
Attraction being a general and permanent ef-
fect, impulsion, which in most bodies is neither
constant nor fixed, depends on it as a particular
effect; for, if all impulsion were destroyed,
attraction would still equally subsist and act ;
it is, therefore, this essential difference which
makes impulsion subordinate to attraction in
all inanimate and purely passive matter.

But this impulsion depends still more imme-
diately, and generally, on the power which pro-
duces heat ; for it is principally by the means
of heat, that impulsion penel rates organized
bodies ; it is by heat that they are formed,
grow, and develope themselves. We may re-
fer to attraction alone all the effects of inani-
mate matter ; and in this same power of attrac-
tion, joined to that of heat, every phenomena
of live matter. By live matter I understand
not only every thing that lives, or vegetates,
but also every living organic molecule, dis-
persed in the waste or remains of organized
bodies. In it I comprehend also light, heat,
fire, and all matter which appears to be active
in itself. Now this live matter always tends
from the ceritre to the circumference, whereas
brute or inanimate matter tends from the cir-
cumference

NATURAL HISTORY. 29

cumference to (he centre. It is an expansive
power which animates the live matier, and it
is an attractive force to which the inanimate
matter is obedient. Al hough the directions
of these two powers be diametrically opposite,
yet they balance themselves withoui ever Mng
destroyed, and from the combination of these
two powers equally active, all the phenomena
of the universe result.

But it may be said, by reducing all the powers
ofNature to attraction and expansion, without
giving the cause of either, and by rendering
impulsion, (which is the only force whose cause
is known and demonstrated to our senses) su-
bordinate to both, do you not abandon a clear
idea, and substitute two obscure hypotheses ia
its place ? To this I answer, that as we know
nothing except by comparison, v.e shall never
have an idea of what general effect will pro-
duce, because such an effect belonging to
every thing, we should be unal^le to compare
it to any, and consequently there is no hope
of ever knowing the cause or reason why all
matter attracts, although we are sensible sook
is the fact. If, on the contrary, the eflfect were
particular, like that of the atlraclion of the
loadstone and steel, we might es'pect to disco-
ver the cause, because it might be compared
to other particalar effects. To ask wliy matter

is

so uuffon's

is extended, heavy, and impenetrable, are ill*
conceived propositions, and merit not an an-
sweip; it is the same with respect to every
particular properly, when it is essential to the
subject, and we might as well be interrogated
wliy red is red ? The philosopher becomce a
child when he puts such questions ; and how-
ever much they may be forgiven to the last,
the former ought to exclude them from his
thoughts.

It is sufilcient that the forces of attraction
and expansion are two general, real, and fixed
effects, for us to receive them for causes of par-
ticular ones; and impulsion is one of these ef-
fects, which we must notlook upon as a general
cause, known and demonstrated by our senses,
since we have proved that this force of impul-
sion cannot exist nor aci, but by the means of
attraction, which docs not fall upon our senses.
Nothing is more evident, nay, certain, than
the communication of motion by impulsion ;
it is sufficient for one body to strike another to
produce this efiect. But even in this sense, is
not the cause of attraction most evident, and
that motion, in all cases, belongs more to at-
traction than impulsion ?

The first reduction being made, it might
perhaps be possible to adduce a second, and
to bring buck the power even of expansion to

that

NATURAL HISTORY. SI

that of attraction, iasomuch that all the forces
of matter would depend solely on a primilive
one ; at least this idea seems to be worthy of
that sublime simplicity with which nature
works. Now cannot we conceive that tliis
attraction changes into repulsion every time
that bodies approach near enough to rub to-
gether, or strike one against the other ? Ira-
penetrability, which we must not regard as a
force, but as a resistance essenlial to matter,
not permitting two bodies to occupy the same
place, what must happen when tw o molecules,
which attract the more powerfully as they ap-
proach nearer, suddenly strike against each
other ? Does not then this invincible resistance
of impenetrability, become an active force,
which, in the contact, drives the bodies with
as much velocity, as they liad acquired at the
moment they touched ? And from hence the
expansive force will not be a particular force
opposed to the attractive one, but an effect
derived therefrom. I own, that we must sup-
pose a perfect spring in every molecule, and
in every atom of matter, to have a clear con-
ception hoAv this change of attraction into re-
pulsion is performed. But even this is suffi-
ciently indicated by facts; the more matter is
attenuated, the more it takes a spring. Earth
and water, which are the most gross aggregates,
have a less spring than air; and fire, which is

the

52 BTJPrON*S

the most subtle of all the elements, is also that
■which has the most expai»sive force. The
smallest molecules of matter, the smallest atoms
with which we are acquainted are those of
light, and we are sensible of their being perfectly
elastic, since the angle nnder which the light is
reflected, is always equal to that under which it
comes. We may thc^refore ii fer, that all the con-
stitutive parts of matter in eneral, are a perfect
spring; and that thisspring produces all the ef*
fects of the expansive force, every time that bo-
dies strike by meeting in op^x>site directions.

We know of no other mcnns of producing
fire, but by striking or rubbing bodies toge-
ther*; since hy supposing man without any
burning glasses, and without actual fire, he
will have no other meacis of producing it;
for the fire produced by uniting the rays of
light, or by application of tire already pro-
duced, hud tl'e same origin*

Expansive force, therefore, in reality might
be only the re-action of the attractive, a re-
action which operates every time that the pri-
mitive molecules of matter, always attracted
Dne by the other, happen immediately to
touch ; for then it is necessary, that they be

repelled

* The fire, which arises fi-om the fermentation of herbs
heaped together, and which manifests itself in effervescences,
is not an exception that can be opposed to me, since th»
produciion of fire depends, like all the rest, from the action
©f the ihock of the parts of matter one againBt the other.

NATURAL mSTORY. SS

repelled with as much veloeily as they had
acquired in a contrary direction, at the mo-
vement of contact ; and when these molecules
are absolutely free from all coherence and only
obey the motion alone produced by their at-
traction, this acquired velocity is immense ia
the point of contact. Heat, light, and fire,
which are the greatest effects of expansive
force, will be produced every time that bodies
are either artificially or naturally divided into
very minute parts, and meet in opposite di-
rections ; and the heat will be so much the
more sensible, the light so much the more
bright, the fire so much the more violent, ac-
cording as the molecules are precipitated one
against the other with more velocity by their
force of mutual attraction.

trom the above it must be concluded, that
all matter may become light, heat, and fire ;
and that this matter of fire and light is not a
substance different from every other, but pre-
serves all its essential qualities; and even most
of the attributes of common matter, is evidently
proved by, first, light, though composed of
particles almost infinitely minute, is, never-
theless, still divisible, since with the prism we
separate the rays, or different coloured atoms
one from another. Secondly, light, though
in appearance endowed with a quality quite
toL. X. F opposite

54 buffon's

opposite to that of weiglit, that is, with a vola-
tility which we might thinkessential, is, never-
theless, heavy like all matter, since it bends
every time it passes near other bodies, and
finds itself inclined to their sphere of attraction .
It is very heavy, relatively to its volume,
which is very minute, since the immense velo-
city with which light moves in a direct line,
does not prevent it from feeling sufficient at-
traction near other bodies, for its direction to
incline and change in a manner very sensible
to our eyes. Thirdly, the substance of light
is not more simple than all other matter, since
it is composed of parts of unequal weight ; the
red rays are much heavier than the blue ; and
between these two extremes there are an infinity
of intermediate rays, which approach more or
less the weight of the red, or the lightness of
the blue according to their shades. All these
consequences are necessarily derived from the
phenomena of the inflection of light, and of its
refraction, which, in reality, is only an in-
flexion which operates when light passes across
transparent bodies. Fourthly, it may be de-
monstrated, that light is massive, and that it
acts, in some cases, as all other bodies act ;
for, independently of its ordinary efiect, which
is to shine before our eyes, and by its own
action, always accompanied with lustre, and

often

NATURAL HISTOIIY. 35

often with lieat, it acts by its mass when it is
condensed, and it acts to the point of putting
in motion heavy bodies placed in the focus of
a good burning glass : it turns a needle on a
pivot placed in its focus : it displaces leaves
of gold or silver before it melts or even sensibly
heats them. This action, produced by its
mass, precedes that of heat : it operates be-
tween the condensed light and the leaves of
metal in the same manner as it operates between
two other bodies which become contiguous,
and, consequently, have still this property in
common with all other matter. Fifthly, light
is a mixture, like common matter, not only of
more gross and minute parts, more or less
heavy or moveable , but also diflferently shaped .
Whoever has observed the phenomena which
Newton calls the access of easy refiection^ and
of easy transmission of light ; and on the ef-*
feels of double refraction of rock and Iceland
chrystal, must have perceived that the atoms
of light have many sides, many different sur-
faces, which, according as they present them-
selves, constantly produce different effects.

This, therefore, is suflScient to demonstrate
that light is neither particular nor different
from common matter; that its essence, and its
essential properties are the same ; and that it

differs

S6 buffon's

differs only from having undergone, in (he
point of contact, the repulsion whence its vo-
latility proceeds ; and in the same manner as
the effect of the force of attraction extends,
always decreasing as the space augments, the
effects of repuLion extend and decrease the
more, but in an inverted order, insomuch that
YPe can apply to the expansive force all that
is known of the attractive. These are two
instruments of the same nature, or rather the
same instrument, only managed in two oppo-
site directions.

AH matter will become light, for if all co-
herence were destroyed it would be divided into
molecules suflficiently minute, and these mole-
cules, being at liberty, will be determined by
their mutual attraction to rush one against the
other. In the moment of the shock the re-
pulsive force will be exercised, the molecules
will fly in all directions with an almost infinite
volatility, which, nevertheless, is not equal to
their velocity acquired in the moment of con-
tact, for the law of attraction being augmented
as the space diminishes, it is evident, that at
the contact the space is always proportionable
till the square of the distance becomes nil, and,
consequently, the velocity acquired by virtue
of the attraction must at this point become

almost

NATURAL HISTORY. 37

almost infinite : aj;d it would be perfectly so
if the contact were immediate, and, conse-
quently, tlie distance between the two bodies
void ; but there is nothing in nature entirely
nil, and nothing truly infinite ; and all that I
have observed of the infinite minuteness of the
atoms which constitute light, of their perfect
spring, and of the nil distance in the moment
of contact, must be understood only relatively.
If this metaphysical truth were doubted, a phy-
sical demonstration may begiven. It is pretty
generally known that light employs seven mi-
nutes and a half to come from the sun to the
earth ; supposing, therefore, the sun at thirty-?
six millions of miles, light darts through this
enormous distance in that short space, that is
(supposing its motion uniform), h 0,000 miles
in one second. But this velocity, although
prodigious, is yd far from being infinite, since
it is determinable by numbers. It will even
cease to appear so prodigious, when we reflect
on the celerity of the motion of the comets to
their perihelia, or even that of the planets, and
by computing that, we shvall find that the ve-
locity of those immense masses may pretty
nearly be compared to that of the atoms of
light.
So, likewise, as all matter can be converted

into

S8 BUFFO n's

into light by the division and expulsion of its
parts, when they feel a shook one against
another, we shall find that all the elements are
convertible ; and if it have been doubted whe-
ther light, which appears to be the most simple
element, may be converted into a solid sub-
stance, it is because we have not paid sufficient
attention to every phenomena, and were in-
fected with the prejudice, that being essentially
volatile it can never become fixed. But it is
plain that the fixity and volatility depend oa
the same attractive force in the first case, and
become repulsive in the second ; and from
thence are we led to think that this change of
matter into light, and from light into matter,
is one of the most frequent operations of
Nature.

Having shewn that impulsion depends on
attraction ; that the expansive force, like the
attractive, becomes negative ; that light, heat,
and fire, are only modes of the common exist-
ing matter ; in one word, tliat there exists but
one sole force, and one sole matter, ever ready
to attract or repel, according to circumstances ;
let us see how, with this single spring, and
this siiJgle subject, Nature can vary her works,
ad infinitum. In a general point of view,
light, heat, and fire, only make one object, but

NATURAL HISTORY. 39

in <i particular point of view they are three
distinct objects, which, although resembling
in a great number of properties, differ never-
theless in a few others, sufficiently essential for
us to consider them as three distinct things.

Light, and elementary fire, compose, it is
said, only one and the same thing. This may
be, but as we have not yet a clear idea of
elementary fire we shall desist from pronounc-
ing on this first point. Light and fire, such as
we are acquainted with, are two distinct sub-
stances, differently composed. Fire is, in fact,
very often luminous, but it sometimes also ex-
ists without any appearance of light. Fire,
whether luminous or obscure, never exists
without a great heat, whereas light often burns
with a noise without the least sensible heat.
Light appears to be the work of nature while
fire is only the produce of the industry of man.
Light subsists of itself, and is found diffused
in the immense space of the whole universe.
Fire cannot subsist without food, and is only
found in some parts of this space where man
preserves it, and in some parts of the profundity
of the earth, where it is also supported by
suitable food. Light when condensed and
united by the art of man, may produce fire,
but it is only as much as it lets fall on com-
bustible

40 ftUFFON's

bustlble matters. Light is therefore nomorej
and in this single instance, only the principle
of fire and notthe fire itself: even this principle
is not immediate, for it supposes the inter-
mediate one of heat, and which appears to
appertain more than light to the essence of fire.
Now heat exists as often without light as light
exists without heat : these two principles
might, therefore, appear not to bind them ne-
cessarily together ; their effects are not con*
temporary, since in certain circumstances we
feel heat long before light appears, and in
others we see light long before we feel any
heat. Hence is not heat a mode of being, a
modification of matter, which, in fact, differs
less than all the rest from that of light, but
which can be considered apart, and still more
easily conceived ? It is, nevertheless, certain,
that much fewer discoveries have been made
on the nature of heat than on that of light ;
whether man better catches what he sees
than what he feels ; whether light, presenting
itself generally as a distinct and different sub-
stance from all the rest, has appeared worthy
of a particular consideration j whereas heat, the
effect of which is the most obscure, and pre-
sents itself as a less detached and less simple
object, has not been regarded as a distinct

substance^

NATURAL HISTORY. 41

substance but as an attribute of light and
^re.

Tbe Erst thing worthy of remark, is, that
the scat of heal is quite different from that of
Jight : the hitter occupies and runs through
the void space of the universe ; heat, on the
contj*ary, is diffused through all solid matter.
The globe of the earth, and the whole matter
of which it is composed, have a considerable
Xlegree of heat. Water has its degree of heat
which it does no* lose but by losing its fluidity.
The air has also heat, which we call its tempe-
rature,and which varies much, but is never ea-
tirely lost, since its springs subsist even in the
greatest cold. Fire has also its different degrees
of heat, which appear to depend less on its own
;3ature, than on that of the aliments 'vvhich feed
it. Thus all known matter possesses warmth ;
and, hence, heat is a much more general affec-
tion than that of light.

Heat penetrates every body without excep-
iion which is ex^^osed to it, while light passes
through transparent bodies only, and is stop-
ped and in part repelled, by every opaque one.
Heat, therefore acts in a much more general and
palpable manner than light, and although the
molecules of heal are excessively minute, since
they penetrate the most compact bodies, it
voJL, X. G seems

4$ buffon's

seems, however, demonstrable, that they arc
much more gross than those of light ; for we
make heat with light, by collecting it in a great
quantity. Besides, heat acting on the sense of
feeling, it is nececssary that its action be pro-
portionate to the grossness of this sense, the
same as the delicacy of the organs of sight ap- •
pears to be to the extreme fineness of the parts
of light ; these parts move with the greatest
velocity, and act in the instant at immense dis-
tances, whefcas those of heat have but a slow
progressive motion, and only extend to small
intervals from thebodies whence they emanate.
'J'he principle of all heat seems to be the at-
trition of bodies ; all friction, that is, all con-
trary motion between solid matters produces
heat ; and if the same effect do not happen to
fluids, it is because their parts do not touch
close enough to rub one against the other ;
and that, having little adherence between
them, their resistance to the shock of other
bodies is too weak for the heat to be produced
to a sensible degree ; but we often see light
produced by an attrition of a fluid, without
feeling any heat. All bodies whether great
or little become heated as soon as they meet in
a contrary direction ; heat is, therefore, pro-
duced by the motion of all palpable matter ;

while

NATURAL HISTORY. 43

^vbile the production of light, which is also
made by motion, but in a contrary direciion,
supposes also the division of matter into very
minute parts: and as this operation of Nature
is the same with respect to both, we must con-
clude, that the atoms of light are solid of them-
selves, and are hot at the moment of their
birth . But we cannot be equally certain, that
they preserve their heat in the same degree
as their light, nor that they cease to be
hot before they cease to be luminous.

It is well known, that heat grows less, or
cold becomes greater, the higher we ascend on
the mountains. It is true that the heat which
proceeds from the terrestrial globe, is of course
sensibly less on those advanced points, than
it is on the plains ; but this cause is not pro-
portionable to the effect ; the action of heat,
which emanates from the terrestrial globe, not
being able to diminish but by the square of
the distance, it does not appear that at the
height of half a mile, which is only the three
thousandth part of the serai-diameter of tlie
globe, whose centre must be taken for the fo-
cus of heat, that this difference, which in this
supposition is only a unit and nine millions,
can produce a diminution of heat nearly so
considerable ; for the thermometer lowers at

that

44 BtJFFON'S

that height, at all time*? of the year, to the
freezina: point. It is liot probable, that this
great difFerence of heat himplj proceeds from
the difFerence of the earth ; dnd of that we
must be fully convinced, if we consider, that
at the mouih of the volcanos, where <he earth
is hott( I than in any other par( oh the surface
of the globe, the air is nearly as cold as on
other mountains of the samfe height.

It may then be supposed that the atonis of
light, though very hot at the momeilt of quit-
ting the sun, are greatly cooled during the se-
ven minutes and a half itl which they pass
from that body to the earth j and this in fact
■would be the case if they were detached ; but,
as they almost immediately succefcd each
other, and are the more confined as they are
nearer the place of their origin, the heat lost
by each atom falU on the neighbouring oiies ;
and this reciprocal communication supports
the general heat of light a longer time ; and
as their constant direction is in divergent rays,
their distance from each other increases ac-
cording to the space they run over ; and as
the heat which flies from each atom, as a cen*
tre, diminishes also in the same ratio, it fol-
lows, that the light of the solar raysj decreas-
ing in an inverted ratio from the square of the

distance,

NATURAL IIISTORV. 45

distance, that of (heir heat decreases in an in-
verted ratio of the square of the same distance.
Taking therefore the senii-diametcr of the
sun for a unif, and supposin*^ the action of
light to be as 1000 to the distance of a derai-
diameter of the surface of this planet, it will
not be more tlian as — — to the distance of

4

two demi-diameters : as ^-— to tliat of three

9

demi-diameters, hs ^°° to the distance of four
demi-diameters; and finally, Avhen it atrives
at us, who are distant from the sun thirty-six
millions of leagues, that is about two hundred
and twenty-four of its demi-diameters, the ac*
tion of liHit will be no more than as ^°"°

" 5 0 6 2 5'

that is, more than 50,00'' times weaker than
at its issuing from the sun ; and the heat of
each atom of light being also supposed 1000
at its issuing from the sun, will not be more
than as i-^^ 1^^ 1-°^ to the successive of

15^ 81 256

Ij ?, 3, demi-diameters, and, when arrived at
lis as ^ /°°° — that is. more than two

^ 25628 0O625 '

thousand tive hundred millions of times
weaker than at issuing from the sun.

If even this diminution of the heat of light
should not be admitted by reason of the squared
square of the distance to the sun, it will still
be evident that heat, in its propagation, dimi-
nishes more than li^ht. If we excite a very
strong heat, by kindling a large fire, we shall

only

40 buffon's

only feel it at a moderate distance but tvc shall
see the light at a very great one. If we bring
our hands by degrees nearer and nearer a
body excessively hot, we shall perceive that
the heat increases much more in proportion
than as the space diminislies ; for we may
warm ourselves wilh pleasure at a distance
whicli differs only by a few inches from that
at which we should be burnt. Every tiling,
therefore, appears to indicate, that heat dimi-
nishes in a greater ratio than light, in propor-
tion as both are removed from the focus
lyhence they issued.

This might lead us to imagine, that the
atoms of light would be very cold when they
came to the surface of our atmosphere; but
that by traversing (he great extent of this
transparent mass, they receive a new heat by
friction. The infinite velocity with which
the particles of light rub against those of the
air, must produce a heat so much the stronger
as the friction is more multiplied : and it is,
probably, for this reason, that the heat of the
solar rays is found much stronger in tlic lower
parts of the atmosphere, and that the coldness
of the air appears to augment as we are ele-
vated. Perliaps, likewise, as light receives
heat only by uniting, a great number of atoms
of light is required to constitute a single atom

of

NATURAL HISTORY. 47

of heat, and this may be the cause why the
feeble light of the moon, although in the at-
mosphere, like that of the sun, does not re-
ceive any sensible degree of heat. If, as M,
JBouguer says, the intensity of the light of the
sun to the surface of the earth is S00,000 times
stronger than that of the moon, the latter must
be almost insensible, even by uniting it in the
foous of the most powerful burning glasses,
which cannot condense it more than 2000
times ; subtracting the half of which for the
loss by reflexion or refraction, there remain.s
only a SOOdth part intensity to the focus of
the glass.

Thus, we must not infer that light can exist
without any heat, but only that the degrees
of this heat are very different, according io
different circumstances, and always insensible
when light is very weak. Heat, on the con-
trary, seems to exist habitually, and even to
cause itself to be strongly felt witliout light;
for in general it is only when it becomes ex-
cessive, (hat light accompanies it. But the
very essential difference between these two mo-
difications of matter is, that heat, which pene-
trates all bodies, does not appear to fix in any
one, whereas light incorporates and extin-
guishes in all those which do not reflect, or

permit

48 Bt'FFON's

permit it to pass freely ; Iieat bodies of all kinds
to any degree, in a very short time they -wili
lose the acquired heat, and return to the general
temperature. If we receive light on black or
white bodies, rude or polished, it will easily be
perceived, that some admit, and others repel
it; and that instead of being affected in a uni-
form manner as they are by heat, they are only
so relatively to their nature, colour, and po-
lish. Black will absorb more light than white,
and the rough more than the smooth. Light
once absorbed remains fixed in the body which
received it, nor quifs it like heat; wheace
we must conclude, that atoms of light may be-
come constituent parts of bodies by uniting
with the matter which composes them ; whereas
heat not fixing at all, seems to prevent the
union of every part of matter, and only acts to
keep them separate. Nevertheless, tl^ere are
instances where heat remains fixed in bodies,
and others where the light they have absorbed
re-appears, and goes out like heat.

After all there appear to be two kinds of
heat, the one luminous, of which tlie sun is the
focus; the other obscure, of which the grand"
reservoir is tlic terrestrial globe. Our body, as
maliing part of the globe, participates of this
obscure lieat : and it is for this reason, that

if

NATUltAL HISTORV. 49

it IS still obscure to us, because we do not
perceive it by any one of our senses. It is
with respect to tbis heat of the globe, as with
its motion, we are subject ^o and participate
thereof without feeling or doubting of it z from
hence it happened that physicians at first car-
ried all their views and enquiries on the heat
of the sun, without suspecting that it makes but
a very small part of what we really feel ; but
having made instruments to discover the differ-
ence of the immediate heat of the rays of the
sun, they with astonishment found that the
lieat of them was sixty-six times stronger in
summer than in winter, notwithstanding the
strongest heat of our summer differs only a
seventh from the strongest cold of our winter;
from whence they have concluded, that, inde^
pendent of the heat we receive from the sun,
there emanates another, even from this terres-
trial globe, which is much more considerable ;
insomuch, that it is at present demonstrable,
that this heat, which escapes from the bowels of
the earth, is in our climate at least twenty-nine
times in 3ummer, and four hundred times in
winter, stronger than the heat which comes to
us from thesuq.

This strong heat which resides in the in-
terior part of the globe, and which, without

voi. \, H

ceasing

50 buffon's

ceasing to emanate externally, must, like an
element, enter into the combination of all the
other elements. If the sun is the parent of
Nature, the heat of the earth must be the
mother ; they both unite to produce, support,
and animate organized beings, and to assimilate
and compose inanimate substances. This in-
ternal heat of the globe, which tends always
from the centre to the circumference, is, in
my opinion, a great agent in nature. We
can scarcely doubt but it is the principal in*
fluence on the perpendicularity of the trunks
of trees, on the phenomena of electricity, on
the eflfects of magnetism, &c. But as I do
not pretend to make a physical treatise here, I
shall confine myself to the effects of this heat
on the other elements. It is alone sufficient
to maintain the rarefaction of the air to the
degree that we breathe in : it is more than
sufficient to keep water in its state of fliiidity,
for we have lowered the thermometers to the
depth of 120 fathoms, and have found the
temperature of the water was there nearly the
same as at the like depth in the earth,
namely, ten degrees two thirds. We must not,
therefore, be surprized, especially as salt acts
as a prevention, that the sea in general does
not freeze, that fresh water freezes but to a

certain

NATURAL HlSTOnr. 51

certain thickness, and that the water at bottom
always remains liquid, even in the most intense
frosts.

But of all the elements the earth is that oa
which this internal heat must necessarily have
produced, and still produces the greatest
effects. This heat originally was doubtless
much greater than it is at present ; therefore
we must refer to it, as to the first cause, all the
sublimations, precipitations, aggregations, and
separations, which havebeen, and still continue
to be made in the internal part of the globe,
especially in the external layer which we have
penetrated, and the matter of which has been
removed by the convulsions of Nature, or by
the hands of man. The whole mass of the
globe having been melted, or liquefied, by fire,
the internal is only a concrete or discreet glass,
whose simple substance cannot receive any
alteration by heat alone : there is, therefore,
only an upper and superficial layer, which
being exposed to the action of external causes
united to that of the internal heat, will have
imdergone all the modifications, differences,
and forms, in one word, of Mineral Substances,
which their combined actions were enabled to
produce.

Fire, which at first sight appears to be only
a compound of heat and light, might also be a

modification

5'2 fitFFON's

modification of the matter, tlioiigh it Joes not
essentially differ from either, and still less frora
both (aken together. Fire never exists \yilho\it
lieat, but it can exist without light. Ilcat
alone, deprived of alt appcaranceof light, can
produce the same effects as the most violent fire ;
so can also light, when it is united. Liglit
sterns to carry a substance in itself which has
no need of fuel ; but fire cannot subsist without
absorbing the air, and it becomes more violent
in proportion to 1 lie quantity it absorbs; where-
as light, concentrated and received into a ves-
sel exhausted of air, acts as fire in air ; and
heat, confined and retained in a narrow space,
subsists and even augments with a very small
quantity of food . Tire most general difference
between fire, heat, and light, appears, there-
fore, to consist in the quantity, and perliaps
quality, of their food.

Air is the first food of fire; combustible
matters are oidy the second. It has been de-
monstrated, by experiments, thata little spark
of fire, placed in avessel well closed, in a short
time absorbs a great quantityofair,and becomes
e:5tinguished assoon as the quantity or quality,,
of this food becomes deficient. By other ex-
periments it is proved, that the most com-
bustible ma. ters' will not consume in vessels

well.

NATURAL HISTORY. 53

well closed, although exposed to the action of
the greatest fire. Air is, therefore, the first
and true food of fire, and combustible matters
would not be able to supply it withoivt tlie
assistance and mediation of this clement.

We have observed that heat is the cause of
all fluidity, and we find, by comparing some
fluids together, that more heat is requisite io
keep iron in fusion than gold ; and more to
keep gold than tin ; much less is necessary fo?
wax, for Avater less than that, and still less for
spirits of winCy and a mere trifle is sufficiejit
for mercury, since the latter goes 187 degrees
below what water can without losing its fluid-
ity ; mercury^ therefore, is the most flui4 of ail
matter, air excepted. Now this superior
fluidity in air indicates the least degree of ad-
herence possible between its constituting parts,
and supposes them of such a figure as only to
be touched at one point. It may be also ima-
gined,, that, being endowed with so little ap-
parent energy and mutual attraction, they are,
for that reason, less massive, and more light,
than those of every other body ; but that con-
clusion appears unfounded, from the compa-
rison of mercury, the next fluid body, but of
which the constituting parts appear to be more
massive and heavy than those of a!)y other

matter*

54 buffok's

matter, excepting gold. The greater or lesser
fluidity, does not, therefore, indicate that the
parts of the fluid are raore or less weighty, but
only that their adherence is so much the less,
and their separation so much the easier.

Air, therefore, of all known matter, is that
which heat divides the easiest, and is very
near the nature of fire, whose property consists
in the expansive motions of its parts ; and it
is from this similarity that air so strongly
augments the activity of fire, to which it is
the most powerful assistant, and the most in-
timate and necessary food. Even combustible
matters will not keep it alive if deprived of
air, for under this privation the most intense
fire will not burn ; but a single spark of air is
sufficient to kindle them, and in proportion as
it is supplied with that clement the fire be-
comes strong, extended, and devouring.

Artificial phosphorus, and gunpowder, seem,
at first, to be an exception, for they have no
need of the assistance of renewed air to inflame
and wholly consume them: their combustion
may be performed in the closest vessels, but
that is because those matters, which are also
the most combustible, contain the necessary
quantity of air in their substance, therefore they
have no need of tl:e assistance of foreign air.

This

NATURAL HISTORY. 55

This seems to indicate that the most essential
difference between combustible matters and
those which are not so, consists in the latter
containing only a few or none of the light,
ethereal, and oily matters susceptible of an ex-
pansive motion, or, at least, if they contain
them, that they are fixed, so that they cannot
exercise their volatility whenever the force of the
fire is not strong enough to surmount the force
of adhesion which retains them united to the
fixed parts of matter. It mjiy be said that this
induction is confirmed by a number of observa-
tions well known to chemists ; but what ap-
pears to be less so, and which, never(heless, is
a necessary consequence of it, is, that all matter
may become volatile when the expansive force
of the fire can be rendered superior to the at-
Iraclive force which holds the parts of matter
united; for though to produce afire suffi-
ciently strong it may require better constructed
mirrors than any at present known, yet we
are certain that fixity is only a relative qua-
lity, and that there is no matter absolutely so,
since heat dilates the most fixed bodies. Now
is not this dilation the index of a beginning
separation, that may be augmented with a de-
gree of heat to fusion, and with a still greater
heat to volatilisation ?

Combustion

56 BUFFON-S

Combttstioii supposes somediing more than
volattlisationi; it is not sufficient that the parts
of matter be sufficiently separated to be car-
jied off by those of heat ; they must also be of
an analogous nature to tire ; without that,
m<?rcury, being the most fluid next to air,
:\youUi also be the most combustible^ >\hereas
experience demonstrates, that though very
volatile it is not combustible. Matter is, in
general, composed of four principal subr
stances, called ekmenfSy that is , earth, water,
air, and fire. Those in which earth and water
predominate will be fixed, and will only be-
come volatile by the action of heat ; and those
which contain most air and fire will be the
only real combustibles. The great difficulty
Jhere is. clearly to conceive how air and fire,
both so volatile, can fix and become consti-
tuent parts of all bodies.

Fire, by absorbing air, destroys the spring.
Now there are but two methods of destroying
a spring, either by compressing it till it break?,
or extending it till it loses its effect. It is
l^lain tliat fire cannot destroy air by compres-
sion, &ince the least degree of heat rarefies it;
on tlie contrary, by a very strong heat the
rarefaction of llie air will be so great that it
will occupy a space thirteen times more ex-
tended than that of its general volume; and

by

NATURAL HISTORY. 5'7

by this means the spring becomes Weakened,
and it is in this state that it can become fixedj
and unite with oth«r bodies.

Light, wliich falls on bodies, is not merely
reflected, but remains in quantities oh th#
small thickness of the stirface which it strikes j
consequently it loses its mot ion, extends, is fix*
ed, and becomes a constHuent part of all t4ial
it penetrates. Let us add this light, trftfts-
formed and fixed in bodies, to the Above air5
and to both, the constant and actual heat of th*
terrestrial globe, -whose sum is much greater
than that which comes from the stin, and thdft
It will appear to be not only one of the greatesl
springs of the mechanism of Nature, but a«
element with which the whole raatteft of the
globe is penetrated.

If we consider more particularly the nature
of combustible matters, ^g shall fhid, that th^y
all proceed originally from vegetables -^^^ ani-
mals ; in a woTd, from bodies placed oti tht
surface of the globe, which the Son enlighten^,
Leats, and vivifies. Wood, bitumen, rmn^
coals, fat and oil, by espTessiOfi, 'vrax, and ^«^j
are substances ptocecding immrdiatety from
animals and Vegetables. Turf, fcfesrl. Coal,
amber, liquid, or concrete biturrreTTs, afe the
productions of their mixture, and their ^Vcem*
VOL. x\ I position.

58 buffon's

position, wbose ulterior waste forms sulphurs^
and the combustible parts of iron, tin, pyrites^
and every inflammable mineral. I know,
that this last assertion will be rejected by those
who have studied nature only by the mode of
chemistry ; but I must request Ihem to con-
sider, that their method is not that of nature,
and that it cannot even approach it without
banishing all those precarious principles,
those fictitious beings which they play upon,
without being acquainted with (hem.

But, without pressing longer on those general
considerations, let us pursue in a more direct
and particular manner the examination of fire
and its effects. The action of fire depends
much on the manner in which it is applied ;
and the effects of its motion, on similar sub-
tances, will appear different according to the
mode in which it is administered. I conceive
that fire should be considered in three different
states, first relative to its velocity ; secondly,
as to its volume ; and thirdly, as to its mass.
Under each of these points of view, this ele-
ment, so simple, and so uniform to all appear-
ance, will appear extremely different. The
velocity of fire is augmented without the ap-
parent volume being increased, every time
that in a given space and filled with com-
bustible

NATURAL HISTORY. 59^

biibtible matters, its action and expansion is
pressed by augmenting the velocity of the air
by bellows, caverns, ventilators, aspirative
tubes, &c. all of which accelerate more or less
the rapidity of the air directed on the fire.
The action of fire is augmented by its volume,
when a great quantity of combustible matters
is accumulated, and the heat and fire are
driven into the reverberatory furnaces, which
comprehend those of our glass, porcelain, and
pottery manufactories, and all those wherein
metals and minerals are melted, iron excepted.
Fire acts here by its volume, and has only its
own velocity, since the rapidity is not aug-
mented by the bellows, or other instruments
which carry air to the fire.

There are many modes of augmenting the
action of fire by its velocity or volume ; but
there is only one way of augmenting its mass ;
namely, by uniting it in the focus of a burning
glass. When we receive on the refracting,
or reflecting mirror, the rays of the sun, or
even those of a well-kindled fire, we unite
them in so much the less space, as the mirror
is longer, and the focus shorter ; for example,
by a mirror of four feet diameter, and one
inch focus, it is clear, that the quantity of
light, or fire, which falls on the four- feet mirror,

will

&f buffon's

will be united in the space ofoueincli, that is,
it will be 2SU4 times denser than it was, if all
the incident matter arrived to tliis focus with-
out any loss, and when eyen the loss is two
thirds or three fourths, the mass of fire concen-
trated in the focus of this mirror, will alwajs
besije or seven hundred times denser than on
the surface. In this, as in all other cases,
tibe mass goes by the contraction of the vo-
lume; and the fire which we thus augment
the density of, has all the properties of a mass
of matter; for, independently of the action of
heatj by which it penetiates bodies, it impels
and displaces them qs a solid moving body
which strikes another would do.

Each of these modes of administering fire,
and increasing either the velocity, volume, or
mass, often produce very different effects on
the same sHibstances ; insomuch, that no reli»
ance is to be placed on any thing that cannot
be woirked at the same time, or successively,
b^r all three. In the like manner, as I divide
in^thrcc general proceedings the administra-
Honxti this element, I divide every matter that
can be submitted toits action iato three classes.
JPassing over for the present those which are
purely combustible, and which immediately
proceed £rom aftimals and vegetables ; we

proceed

NATURAL HISTORY. 61

proceed to minerals, in the first class of which
we reckon those mineral matters, which this
action, continued for a long time, renders
lighter, as iron ; in the second, such as it ren-
ders heavier, as lead ; and in the third class,
are those matters on which, as gold, this action
of fire does not appear to produce any sen-
sible effect, since it does not at all alter their
weight. All existing matters, that is, all sub-
stances simple and compounded, will necessa-
rily be comprized under one of these three
classes ; and experiments on them by the three
proceedings, which are not difficult to be made,
and only require exactness and time, might
develope many useful discoveries, and prove
very necessary to build on real principles the
theory of chemistry, which has hitherto been
carried on by a precarious noraenclatura, and
on words the more vague as they are the more
general.

Fire is the lightest of all bodies, notwith-
standing which it has weight, and it may be
demonstrated, that even in a small volume ittS
jcally heavy, as it obeys, like all other raatters,
the general law of gravity, and consequently
must have connections or affinities with other
bodies. All matters it renders more weighty
will be those with which it has the greatest
aflittiiy. On€ €vf the effects of this affinity in

the

62 hufton's

the matters is io relaiii the sui)S)tance even of
fire, with which it is incorporated, and tli is in-
corporation supposes that lire not only lo.ses its
licat and elasticity, but even all its motion,
since it fixes itselt in these bodies, and becomes
a constituent part. From wliich it may be
irnai^ined lljat there is fire under a fixed and
concrete form in almost every body.

It is evident, that all matters, whose weight
increases by the action of fire, are endowed
with an attractive force superior to the ex*
pansive, the fiery particles of which are ani-
mated ; this bein£ij extinguished the motion
ceases, and the clastic and fugitive particles
become fixed, and take a concrete form. Thus
matters, whose weight is increased by fire, as
tin, lead, &c. are substances which, by their
affinity with fire, attract and incorporate. All
matters, on the contrary, which, like iron,
copper, &c. become lighter in proportion as
they are calcined, are substances whose at-
tractive forces, relative to the igneous parti-
cles, is less than the expansive force of fire ;
and hence tlie fire, instead of fixing in these
matters, carries ofl:' and drives away the least
adherent parts which cannot resist its impul-
sion. Those which, like gold, platina, silver,
&c. neither lose nor acquire by the application
of fire, aresubstanccswhich, having no affinity

YfitU

NATURAL IIISTORV. G3

with firCy and not being able to iini(c, cnr.no%
consequently, either re ain or accompany it
when it is carried off. It is evident that the
matters of \-\e two first classes Iiave a certain
degree of affinity with fire, since those of the
second class are loaded with fire, which ihey
retain ; and the fire loads itself with (hose of
the first class, which it carries off; whereas
the matters of ;he third class, to which it
neither lends nor borrows, have not any affinity
or attraction witli it, but are indifierent to its
action, which can neither uniiatuializc nor
even change them.

This division of every matter into three
classes, relative to the action of fire, docs not
exclude the more particular and less absolute
division of all matters into two other classes,
hitherto regarded as relative to tlieir own na-
ture, which is said to be always vitrifiable, or
calcareous. Our new division is only a more
elevated point of view, under which we must
consider them, to endeavour to deduce there-
from even the agent that is used by the rela-
tions fire can have with every substance to
which it is applied.

We might say, with naturalists, that all is
vitrifiable in Nature, excepting that which is
calcareous : that quartz, chrystals, precious

btoaes.

64 buffon's

stones, flints, granites, porphyries, agates,
gypsums, clays, lava, pumice stone, with all
metals and other minerals, are vitrifiable
either by the fire of our furnaces, or that of
mirrors; whereas marble, alabaster, stones,
chalk, marl, and other substances which pro-
ceed from the residue of shells and madrepores,
cannot be reduced into fusion by these means.
Nevertheless I am persuaded, that if the power
of our furnaces and mirrors were further in-
creased, we should be enabled to put these cal-
careous matters in fusion ; since there are a
multiplicity of reasons to conclude, that at the
bottom their substance is the same, and that
glass is the common basis of all terrestrial matter.
By my own experiments I have found, that
the most powerful glass furnaces is only a weak
fire, compared with that of bellows furnaces ;
and that fire produced in the focus of a good
mirror, is stronger than that of the most glow-
ing fire of a furnace. I have kept iron ore
for thirty -six hours in the hottest part of the
glass furnace of Rouclle, in Burgundy, without
its being melted, agglutinated, or even in any
manner changed ; whereas, in less than twelve
hours this ore runs in a forge furnace. I have
also melted, or volatilized, by a mirror many
matters which neither the fire, nor reverbera-
tor/

NATURAL niSTonir* 60

tory furnace, nor the most powerful bellows
furnace could cause to run.

It is commonly supposed, that flame is the
hottes* part of fire, yet nothing is more errone-
ous than this opinion; the contrary maybe
demonstrated by the most simple and familiar
experiments. Offer to a straw fire, or even
to the flame of alighted faggot, a cloth to dry
or heat, and treble the time will be required to
what would be necessary if presented to a bra-
sier without flame. Newton very accurately
defines flame to be a burning smoke, and this
smoke, or vapour, has never the same quanti*
iy or intensity of heat as the combustible body
from which it escapes. By being carried up-
wards a,nd extending, it lias the property of
communicating fire, and carrying it further
than the heat of the brasier, which alone might
not be, sufficient to communicate it when even
very near.

The communication of fire merits a particu-
lar attention. I found, after repeated reflec-
tions that besides the assistance of facts which
appear to have a relation to it, that experi-
ments were necessary to understand the man^
ner in which thisoperation of Nature is made.
Let us recieve two or three thousand weight of
irpn in a mould at its issuing from the furnace ;
tliismetal in ashorttimeloses its incandescence,
Vol. X, K and

66 buffon's

and ceases from its redness, according to the
thickness of the ingot. If at the moment its
redness leaves i(, it is drawn from the mold,
the under parts will be still red, but this colour
will fly off. Now so long as the redness sub-
sists, we can light combustible matters by ap-
plying tliem to the ingot ; but as soon as it has
lost its incandescent state, lliere are numbers of
matters which it will not get fire to, although
the heat which it diffuses is, perha[3S a hun-
dred times stronger than that of a straw fire,
which would inflame them.. This made me
think that fla-ne being necessary to the com-
munication of fire, there is therefore a flame in
all incandescence. The red colour seems, in
fact, to indicate it ; and indeed I am convinced,
that combustible, and even the most fixed mat-
ters, such as gold and silver, when in an in-
candescent stale, are surrounded with a dense
flame which extends only to a very short dis-
tance, and which is attached to their surface ;
and I can easily conceive, that when flame be-
comes dense to a certain degree, it ceases from
obeyifig the fluctuation of the air. This white
or red body, which issues from all bodies in
incandescence, and which strikes our eyes, is
the evaporation of tliis dense flame which sur-
rounds the body by renewisjg itself incessantly
on its surface ; aiiid even the light of the sun,

which

NATURAL HISTORY. 67

which emits such an amazino' brii>'htaess, I
presume to be only an evaporation of the dense
state that con^tantly plays on its surface ; anc|
TV'hich we must regard as a true flame, more
pure and dense than any proceeding from our
combustible matters.

It is, theref )re, by light that fire communi-
cates, and heat alone cannot produce the same
ofFect as when it becomes very strong to be iii-
jninous. Even water, that dchtruclive clement
to fire, by which aloiie we can prevent its pro-
gress, nevertheless communicates when in a
well-closed vessel, such as Papi.i's digester,
where it is penetrated with a sufficient quantity
of fire to render it luminous, and capable of
melting lead and tin, wiiereas when it is oidy
boiling, far from communicating fire, it extin-
guishes it immediately. Jt is true, that heat
alone is sufficient to prepare and dispose com-
bustible bodies for inflammation, by driving
off the humid parts from bodies ; and what is
very remarkable, this heat, which dilates all
bodies, does notdesistfVom hardening them by
drying. I have an hundred times discovered,
by examining the stones of my great furnaces,
especially the calcareous, they increased in
hardness in proportion to the time tliey had
undergone the heat, and ihcy also at the same
time became specifically heavier. From this

circumstance.

CS buffon's

circumstance, I think an induction may bo
drawn, which would prove, and fully confirm,
that heat, although in appearance always fu-
gitive and never stable in the bodies which it
penetrates, neverthelsss deposits in a positive
manner many parts which fixes there even in
greater quantities than the aqueous and other
parts which it has driven off. But what ap-
pears very difficult to be reconciled, this same
calcareous stone, which becomes specifically
heavier by the action of a moderate heat a
long time continued, becomes near a half
lighter, when submitted to a fire sufficient for
its calcination, and, at the same time, not only
loses all the hardness it had acquired by the
action of heat, but even the natural adherence
of its constituting parts.

Calcination generally received, is, with re-
spect to fixed and incombustible bodies, what
combustion is to volatile and inflammable.
Calcination, like combustion, needs the assist-
ance of air ; it operates so much the quicker,
as it is furnished with a greater quantity of
that element, without which the fiercest fire
cannot calcine nor inflame any thing, except
such matters as contain in themselves all the
air necessary for those purposes. This neces-
sity for the concurrence of air in calcination,
as in combustion, indicates, that there are more

tilings

NATURAL HISTORY. 69

tbings common between them than has been
suspected. The application of fire is the prin-
ciple of both ; that of air is the second cause,
and abiiost as necessary as the first ; but these
two causes are equally combined, according
as they act in more or less time, and with
more or less power on different substances.

Combustion operates almost instantaneously ;
calcination is sometimes so lon^:, as to be
tliought impossible ; for in proportion as mat-
ters are more incombustible, the calcinafion
is there more slowly made ; and wlien the con-
stituent parts of a substance, such as gold, are
not only incombustible, but appear so fixed as
not to be volatilized, calcination produces no
effect. They must both, therefore, be con-
sidered as effects of the same cause, whose
two extremes are delineated to us by phos-
phorus, which is the most inflammable of
all bodies, and by gold, which is the most
fixed and least combustible. All substances
comprized between these two extremes, will
be more or less subjected to tlie efiects of
combustion and calcination, according as they
approach either of tliem ; insomuch, that
in the middle points there will be found
substances that endure an almost equal degree
of both ; from which we may conclude, that
all calcination is always accopmanicd with a

little

70 buffon's

little combustion, and all combustion uiili a
little calcination. Cinders and other residue
of the most combustible matters, demonstrate
that fire has calcined all the parts it lias not
burned, and consequently, a little calcination
is found here with combustion. The small
flame which rises from most matters, tiiat are
calcined, demonstrates also that a slight
combustion is made Tlius, we must not se-
perate these two effects, if w'e would find out
the results of the action of fire on the differ-
ent sub>tances to which it is rspplied.

But it may be said, that comb u'-tion always
diminishes the volume or mass, on account of
the quantity of matter it consumes ; and that,
on the contrary, calcination increases the
•weight of many substances. Ought we then
to consider these two effects whose results are
so contrary, as effects of the same nature ?
Such an objection appears well-founded,
and deserves an answer, especially as this
is the most difficult point of the question.
For that purpose let us consider a matter in
"which we shall suppose one half to be fixed
parts, and the other volatile or combustible.
By the application of fire to this, all the vola-
tile or combustible parts will be raised up or
burnt, and consequently separated from the
whole mass ; from hence this mass or quantity

of

NATURAL HISTORY, 71

of matter ^vill be found diminished one half,
as Ave see it in calcareous stones, which lose near
half their weight in the fire. But if we con-
tinue to apply the iire for a very longtime to
the other half, composed of fixed parts, all
combustion and volatilization being ceased,
that matter, instead of continuing to lose its
mass, must increase at the expense of the air
and fire with which it is penetrated ; and (hose
are matters already calcined, and prepared by
Nature to the degree where combustion
ceases, and consequently susceptible of in-
creasing: the weisrht from the first moment of
the application. We have seen, that light
extinguishes on the surface of all bodies
which do not reflect ; and that heat, by long
residence, fixes partly in the matters which it
penetrates ; we know also that air is neces-
sary for calcination, or combustion, and the
more so for calcination as having more fixity in
the external parts of bodies, and becomes a
constituent part : hence, it is natural to ima-
gine, that this augmentation of weight pro-
ceeds only from the addition of the particles
of ligh(, heat, and air, which are a length
fixed and united to one matter, against which
they have made so many efforts, witliout being
able either to raise or burn them. This appears

clearly

72 BUFFON*S

clearly to be the fact, for if wo afterwards pre-
sent a combustible substance to them thej ^vill
quit the fixed matter, to xvhich they were only
attached through force, retake their natural
motion, elasticity, and volatility, and all de-
part with it ; frcra hence, metal, orcalcinized
matter, to which these volatile parts has been
rendered, retakes its pristine form, and its
weightis found diminished by the whole quan-
tity of fiery and airy particles which were fixed
in it, and whicli had been ju!>t raised by this
new combustion. All this is performed by the
sole law of affinities ; and their seems to be no
more difficulty to conceive how the lime of a
metal is reduced, than to understand how it is
precipitated in dissolution ; the cause is the
same, and the effects are similar. A metal dis-.
solved by an acid, will precipitate when to this
acid another substance is offered with which
it has more affinity than metal, the acid (hen
quits it and falls to the bottom. So,likewcse,
this metal calcines, tliat is, loaded with parts
of air, heat, and fire, which being fixed, keeps
it under the form of a lime, and will precipi-
tate, or be reduced, when presented to this fire
and fixed air, from the combustible matters
with which they have more affinity than with
the metal ; the latter will retake its first form

as

NAtuftAL HISTORY. 72

as soon as U is disembarrassed from tliis su^jcr-
fluous air and fire, at the ex pence of the com-
bustible matters oii'ered to it, and tlie volatile
parts it had lost.

IthinkI have nowdemonstratcdjthsit all the
litile laws of chemical afHiitlles, Vrliich ap-^
j)earcd so variable and different, are no other
llian the general laws of attraction, common
to all matter ; that this ^reat law, always
constant and the samcj appeared oidy to vary
in its expression, ^vliich cannot be the same
^vllen the figure of bodies enters, like an ele^
inent, into their distance. With this new key
we can unlock the mobt profound secrets of
Nature; we can attain the knowledge of
the figufe of the primitive parts of difil^rent
substances • assign the laws and degrees of
their affinities; determine the forms which
they take by re-uniting, &c. I think also I
have made it appear that impulsion depends
on attraction ; and thatj although it may be
considered as a different forcCj it is, notwith-
standing, a particular effect of i!ils sole and
general one. I have shewn the conmiuni-
cation of rriotion to be impossible without
a springy whence I have concluded, that
all bodies in Nature are more or less elas-
tic, and that there is not one perfectly
Vol, X. L hard 5

74 ijuffon's

hard ; that is, entirely deprived of a spring,
since all are susceptible of receiving motion.
I liave endeavoured to shew how this sole
force may change direction, and attraction
become repulsion ; and from these grand
principles, which are all founded on rational
mechanics, I have sought to deduce the prin-
cipal operations of Nature, such as the pro-
duction of light, heat, and fire, and . their
action on different substances ; this last object
%vhich interests us the most is a vast field,
but of which I can only cultivate a little spot,
yet I presume I may render some assistance,
by putting into more capable and laborious
hands the instruments I made use of. These
instruments were the three modes of making
use of fire, that is, by its velocity, volume,
and mass ; by applying it* concurrently to the
three classes of substances, which either lose,
gain, or are not affected by the application of
fire. The experiments which I had made on
the refrigeration of bodiesjon the real weight of
fire, on the nature of flame, on tlie progress of
heat, or its communication, its diperdition,i(s
conc(*nt ration, or its violent action without
flame, &c. are also so many instruments which
will spare much labour to those who choose to
avail themselves of them, and will produce an
ample harvest of knowledge .

OF

NATURAL HISTORY. 75

OF AIR, WATER, AND EARTH.

BY our former observations it appears that
air is the necessary and first food of fire, which
can neither subsist nor propagatebut by what
it assimilates, consumes, or carries off, of tliat
element, whereas of all material substances,
air is that which seems to exist the most in-
dependently of the aid or presence of fire; for
although it habitually has nearly the same heat
as other matters on the surface of the earth,
it can do without it and requires infinitely less
than any of the rest to support its fluidity,
since the most excessive cold cannot deprive
it of that. The strongest condensations are
not capable of breaking its spring ; the
active fire, in combustible matters, is the.
only agent which can alter its nature by rare-
fying and extending its spring to the point of
rendering it ineff^^ctual, and thus destroying its
elasticity. In this state, and in all the links
which precede, the air is capable of re-assuming
its elasticity, in proportion as the vapours of
combustible matters evaporate and separate
from it. But if the spring have been totally

weakened

/^^^ BUFFON'S

Avcakcned and extended that it cannot re-instate
itself, from having lost all its elastic power, the
air, volatile as it might before have been, be-
comes a fixed substance Avhich incorporates
■with the other substances, and forms a consti-
tuent part of all those to which it unites by con-
tact. Under this new form it can no longer
forsake the fire, except to unite, like fixed
matter, to other fixed matters; and if there
remain some parts insCj a able from fire, they
tlien make a portion of that element serve
it for a base, and are deposited with it in the
subetance tliey heat and penetrate together.
This efi'ect is manifested in all calcinations,
and is the more sensible as the heat is longer ;
but combustion demands only a small time
to completely effectuate the same. If we
wish to hasten calcination the use of bellows
may be necessary, not so much to augment
the heat of the fire as to establish a current
of air on the surface of the matters ; yet it is
not requisite for the fire to be very fierce to
deprive air of its elaslicity, for a very mode^
rate heat, when constantly applied on a small
quantity, is sufficient to destroy the spring ;
and for this air, without spring, to fix it-
self afterwards in bodies, there is oidy a little
more or less time required, according to the
afl&nity it may have under tliis new form, with

the

NATURAL HISTORY. 77

the matters to Tvhich it unites. The heat of
the body of animals, and even vegetables, is
sufficiently powerful to produce this effect.
The degrees of heat are different in different
lands of animals : birds are the hottest, from
M'hicli we pass successively to quadrupeds,
man, cetaceous animals, reptiles, fish, insects,
and, lastlj>,to vegetables, whose heat is so tri-
fling as to have made some naturalists declare
they had not any, although it is very apparent,
and in wijiter surpasses that of the atmosphere.
I have frequently observed in trees that were
cut in cold weather, that their internal part
was sensibly warm, and that this heat remained
for many minutes. This heat is only moderate
while the tree is young and sound, but as soon
as it grows old the heart heats by the fermen-
tation of the pith, which no longer circulates
there with the same freedom ; and as soon as
this heat begins the centre receives a red tint,
which is the first index of the perishing state
of the tree, and the disorganization of the
wood. The reason naturalists have not found
there was a difference between the temperature
of the air, and the heat of vegetables is, be-
cause they have made their obseryations at a
bad time of the year, and not paid attention,
that in the summer the heat of the air exceeds

that

"78 buffoxn's

that of the internal part of a tree; whereas in
winter it is quite the contrary. They have not
. remembered that the roots have constantly the
deicree of heat which surrounds them, and
that this heat of the internal part of the earth
is, daring all winter, considerably greater than
that of the air, and the surface of the earth.
.They did not consider that the motion alone of
the pith, already warm, is a necessary cause of
heat, and that this motion, increasing by the
action of the sun, or by an external heat, that
of vegetables must be so much the greater as
the motion of their pith is more accelerated,
&c.

Here the air contributes to the animal and
vital heat, as we have seen that it does to the
action of fire in combustible and calcinable
matters. Animals, which have lungs, and
which consequently respire the air, have
more heat than those deprived of them ; and
the more the internal surface of the lungs
is extended, and ramified in a greater num-
ber of cells, the more it presents greater su-
perficies to the air which the animal draws by-
inspiration; the more also its blood becomes
hotter, the more it communicates heat to
all parts of the body it nourishes, and this
proportion takes place in all known animals.

Birds,

WATURAL HISTORY. 79

Birds, relatively to the volume of their body,
have lungs considerably more extended than
man or quadrupeds. Reptiles, even those with
a voice, as frogs, instead of lungs have a
simple bladder. Insects which have little or
no blood breathe the air only by some pipes,
&c. Thus taking the degree of the temperature
of the earth for the term of comparison, I have
observed that this heat being supposed ten de-
grees, that of birds was nearly thirty-lhree,
that of some quadrupeds more than thirty-one
and a half, that of man thirty and a half, or
thirty-one, whereas that of frogs is only fifteen
or sixteen, and that of fishes and insects only
eleven or twelve, which is nearly the same as
that of vegetables. Thus the degree of heat
in man and animals depends on the force and
extent of the lungs; these are the bellows of
the animal machine : the only difficulty is to
conceive ho.v they carry the air on (he fire
"which animates us, a fire whose focus seems
to be indeterminate ; a fire that has not even
been qualified with this name, because it is
without flame or any apparent smoke, and its
heat is only moderate and uniform. How-
ever, if we consider that heat and fire are ef-
fects, and even elements of the same class ;
that heat rarefies air, and, by extending its

spring,

so BUFFOS ^$

spring, it may render it without effect ; wd
may imagine, tbat I be air drawn by our lungs
being greatly rarefied, loses its spring in
the bronchiae and little vesicles, where it is
soon destroyed by the arterial and venous
blood, for these blood-vessels are separated
from the pulmonary vesicles by such thin di*
visions that the air easily parses into the
blood, where it produces the same effect as
upon common fire, because the heat of this
blood is more than sufficient to destroy the
elasticity of the particles of air, and to drag
them under this new form into all the roa^s
of circulation. The fire of the animal bbay
differs from common fire only in more or
less ; the degree pf heat is less, hence there is
no flame, because the vapours, which represent
the smoke, have not heat enough to inflame ;
every other effect is the same : the respiration
of a young animalabsorbs as much air as the
light of a candle, for if inclosed in vessels of
equal capacities, the animal dies in the same
time as the candle extinaruishes : nothini^ can
more evidently demonstrate that the fire of
the animal a|id that of the candle are not of
the same class but of the same nature, and to
which the assistance of the air is equally ne-
ccssarv.

TegetableSj

NATURAL HISTORY. 81

Vegetables, and most insects, instead of
lungs, have only aspiratory tubes, by which
they pump up the air that is necessary for
them ; it passes in very sensible balls into the
pith of the vine. This air is not only pumped
up by the roots but often even by the leaves,
and forms a very essential part of the food of
the vegetable which assimilates, fixes, and
preserves it. Experience fully confirms all
we have advanced on this subject, a.nd that all
combustible matters contain a considerable
quantity of fixed air, as do also all animals
and vegetables, and all their parts, and the
waste which proceeds therefrom ; and that the
greatest number likewise include a certain
quantity of elastic air. And, notwithstanding
the chimerical ideas of so me chem ists, respecting
phlogiston, tliere does not remain the smallest
doubt but that fire or light produces, with the
assistance of air, all tiie efiects thereof.

Minerals, which like sulphur and pyrites,
contain in their substance a quantity of the ul-
terior waste of animals and vegc(ables, con-
tain thence combustible matters, which, like
all other, contain more or less fixed air, but
always much less than the purely animal or
vegetable substances. Tliis fixed air can be
equally removed by combustion. In animal
and vegetable matters it is disengaged by
VOL. X. M simpk-

S^ buffon's

simple fermentation, wliicli, like conibuhtion,
has always need of air for its operation. Sul-
phurs and pyrites are not the only minerals
which must be looked upon as combustible,
there are many others which I shall not here
enumerate, because it is sufficient to remark,
^heir degree of combustion depends commonly
on the quantity of sulphur which they contain.
AH coml)Ustible minerals originally derive this
property either from the mixture of animal or
vegetable parts which are incorporated with
them, or from the particles of light, heat, and
air, which, by the lapse of time, are fixed in
their internal part. Nothing, according to
my opinion, is combustible but that which has
been formed by a gentle heat, that is, by these
same elements combined in all the substances
which the sun brightens and vivifies, or in
that which the internal heat of the earth fo-
ments and unites. «

The internal heat of the globe of the earth
must be regarded as the true elementary fire ;
it is always subsisting and constant ; it enters,
like an clement, inio all the combinations of
the other elements, and is more than sufficient
to produce the same effi^cts on air as actual
fire on animal heat; consequently this internal
heat of the earth will destroy the elasticity of the
air, and render it fixed, which being divided

into

NATURAL HISTORY. S3

into minute parts \vill enter into a great num*
ber of substances, from hence they will contain
articles of fixed air and fire, which are the first
principles of combustibility ; but they will be
found in difierent quantities, according to their
degree of affinity witli the substance, and this
degree will greatly depcnil on the quantity
these substances contain of animal and vege-
table parts, which appear to be the base of ail
combustible matter. Most metallic mineral,
and even metals, contain great quantities of
combustible parts; zinc, antimony, iron, cop-
per, &c. burn and produce a very brisk flame,
as long as the combustion of these inflammable
parts remains, after which, if the fire be con-!-
tinued, the calcination begins, during whicli
there enters into them new parts of air and
heat, which fixes, and cannot be disengaged
but by presenting to them combustible matters,
with which they have a greater affinity than
with those of the mineral, witli which they
are only united by the effort of calcination.
It appears to me, that the conversion of me-
tallic substances into dross, and their repro-
duction, might be very clearly understood
Avithout applying to secondary principles, or
arbitrary hypotheses, for their explanation.

Having considered tlje action of fixed air in
,lhe most secret operations of nature, let us take

a yipw

a view of it when it resides in bodies under an
elastic form ; its effects are then as variable as
the degrees of its elasticity, and its action,
though always the same, seems to give different
products in different substances. To bring this
consideration back to a general point of view,
we "will compare it with water and earth, as
"we have already compared it with fire ; the
results of this comparison between the four
elements will afterwards be easily applied to
every substance, since they are all composed
merely of these four real principles.

The greatest cold that is known, cannot de-
stroy the spring of the air, and the least heat is
sufficient for that purpose, especially when this
fluid is divided into very small particles.
But it must be observed, that between its state
of fixity, and tliat of perfect elasticity, there are
all the links of the intermediate states, in
one of which it always resides in earth and
water, and all the substances which are com-
posed of them ; for example, water, which ap-
pears so simple a substance, contains a certain
quantity of air, which is neitlier fixed nor
elastic, as is plain from its congulation, ebul-
lition, and rcsistence to all compression, &c.
Experimental philosophy demonstrates, that
water is incompressible, for instead of shrink-
ing and entering into itself when pressed, it

passes

NATURAL HISTORY. 85

passes tlirou<?li the most solid and tliickest
vessels^; which could not be the case if the
air it contained were in a state of full elasti-
city. The air contained therefore in Avater,
is not simply mixed therewith, but is united
in a state where its spring is not sensibly ex-
ercised ; yet the spring is not entirely de-
stroyed, for if we expose water to congelation,
the air issues from its internal part, and unites
on its surface in elastic bubbles. This alone
suffices to prove, that air is not contained in
water under its common form, since being spe-
cifically 850 times lighter, it would be forced
to issue out by the sole necessity of the prepon-
derance of water; neither under an affixed
form, but only in a medium state, from whence
it can easily retake its spring, and separate
more easily than from every other matter.

It may, with some justice, be objected that
cold and heat never operate in the same
m6de, and that if one of these causes gives to
air its elasticity, the otlier must destroy it,
and I own that in general it is so, but in this
particular they produce the same effect. It
is well known that water, frozen or boiled,
reabsorbs the air it had lost as soon as it is
liquefied or cooled . The degree of affinity of
air with water, depends, therefore, in a great
measure, on its temperature, Mhich in its li-
quid

B6 buffon's

^quid state; is nearly the same as that of the
general heat, to the surface of the earth : the
air with which it has much affinity penetrates
it as soon as it is divided into small parts, yet
the degree of elementary and general heat,
"weakens their spring so as to render them in-
effectual as long as the water preserves this
temperature ; but if the cold penetrate, or this
degree of heat diminish, then its spring will
be re-established by the cold, and the elastic
bubbles will rise jto the surface of the water
ready to freeze; if, on the contrary, the tem-
perature of the water is increased by an exr
ternal heat, the integrant parts become too
much divided, they are rendered volatile, and.
the air with which they are united, rises an4
escapes with them. Water and air have much
greater connections between them than oppor
site properties, and as I am well persuaded,
tliat all matter is convertible, and that the ele-
ments may be transformed, I am inclined to
believe, that water can change into air when
sufficiently rarefied to raise up in vapours, for
the spring of the vapour of the water is evei^
more pow erful than the spring of the air.

Experience has taught me that the vapours
of water can increase the fire in the same
manner as- common air ; and this air, which
we may regard as pure, is always mixed with

a very

NATURAL HISTORY. S7

a very great quantity of water ; but it must
be remarked, as an observation of much im-
portance, thiit the proportions of the mixtures
are not nearly the same in these two elements.
It may be said in general that there is much
less air in water than water in air. In consi-
dering this proportion we must refer to the
volume and mass. If we estimate the quantity
of air contarinedin water by the volume it will
appear nil, since the volume is not in the least
increased. Thus it is not to the volume that
"we must relate this proportion, it is alone to
the mass, that is, to the real quantity of mat-
ter in one and the other of these two elements
that we mubt compare that of their mixture,
by which we shall percelre that the air is much
more aqueous than the water is aerial^ perhaps
in proportion of the mass, that is, eight hun-
dred and fifty times. Be this estimation eit^ier
too strong or too weak we can derive this in-
duction from it, that water must change more
easily into air than air can transform into
water. The parts of air, although susceptible
of being extremely 'divided, appear to be
more gross than those of water, since the
latter passes through many filtres which air
cannot penetrate ; since the vapours of water
are only raised to a certain height in the air ;
and, in short, since air seems to imbibe water

like

83 buffon's

like a sponge, to contaia it in a large quantij,
and that the container is certainly greater than
the contained.

In the order of the conversion of the ele-
ments it appears to me, that water is to air
what air is to fire, and that all the transforma-
tions of nature depend on them. Air, like
the food of fire, assimilates with it, and is
transformed into this first element. Water,
rarefied by heat, is transformed into a kind of
air capable of feeding the fire like common air.
Thus fire hasa double fund of certain subsist-
ence ; if it consume much air it can also pro-
duce much by the rarefaction of water, and
thus repair, in the mass of atmosphere, all the
quantity it destroyed, ivhile ulteriorly it con-
verts itself with air into fixed matter in the
terrestrial substances which it penetrates by its
heat or by its light. And so, likewise, as
water is converted into air, or into vapours, as
volatile as air, by its rarefaction, it is also,
converted into a solid substance by a kind of
condensation. Every fluid israreficd by heat and
condensed by cold. Water follows this com-
mon law, and condenses as it grows cold. Let
a p-lass tube be filled three parts full and it will
descend in proportion as the cold increases,
l)nt some time before congelation it will ascend

above

NATUHAL HISTORY. 89

above the point of three fourths of the height
of the tube, and increase still more considera-
bly by being frozen. But if the tube be well
stopped, and perfectly at rest, the water will
continue to descend, and will not freeze, al-
though the degree of cold be six, eight, or teii
degrees below the freezing point ; congelation,
therefore, presents, in an inverted manner, the
same phenomena as inflammation. A heat,
however great, shut up in a well-closed vessel,
will not produce inflammation unless touched
with an inflamed matter ; so, likewise, to what-
soever degree a fluid is cooled, it will not
freeze unless it touch something already frozen,
and this is what happens when the tube is
shaken or uncorked; the particles of water,
which are frozen in the external air, or in the
air contained in the tube, strike the surface of
the water, and communicate their ice to it.
In inflammation, the air, at first very much
rarefied by heat, loses its volume, and fixes it-
self suddenly. In congelation, water, at first
condensed by the cold, takes a larger volume,
and fixes itself likewise, for ice is a solid sub-
stance, lighter than water, and would preserve
its solidity if the cold continued the same; and
I am inclined to believe that wc may attain
the point of fixing mercury at a less degree
VOL. X. N of

90 buffon's

of coldj by sublimalin^ it info vapours in a
very cold air; and also that water, which
only owes its liquidity to. heat, would become
a substance much more solid and fusible, as
.it would endure a stronger and a longer time
the rigour of the cold.

But without stopping upon this subject,
that is, without admitting or excluding the
possibilily of the conversion of the ice into in-
fusible matter, or fixed and solid earth, let us
pass on to more extensive views on the modes
.which Nature makes use of for the transfor-
mation of water. The most powerful of all and
the most evident is the animal filter. The
body of shell-animals, by feeding on the par-
ticles of water, labours, at the same time, on
the substance to the point of unnaturalizing it.
The shell is certainly a terrestrial substance, a
true stone, from which all the stones called
calcareous^ and many other matters, derive
their origin. This shell appears to make the
constitutive part of the animal it covers, since
it is perpetuated by generation, for it is on
thesraall shell-animal just come into existence
as well as on those which have arrived at their
full growth ; but this is no less a terrestrial
substance, formed by the secretion or exuda-
t^ion of the body, for it increases and thickens

NATUIIaL IllSTORV. 91

by rings and layers in proportion as the ani-
mal grows ; and stony matter often exceeds
fifty or sixty times the mass of the body whicli
produces it. hot us, for a moment, reflect on
the number of the kind of shell-animals, or ra_
Iher of those animals with a stony transuda-
tion ; they, possibly, arc more numerous in the
sea than (he insect kind are upon earth. Lei
us afterwards represent their full growth, their
prodigious multiplication, and the shortness
of their lives, which we may suppose does
not excee<l ten years ; let us then consider that
"we must multiply by fifty or sixty the almost
imniense number of the individuals of this class
to form an idea of ail the stonj' matter pro-
duced in ten years; then that this block must
be augmented with as many similar blocks as
there are as many times ten in all the ages
from the beginning of the world, and by this
means we shall conceive, that all our coral,
rocks of calcareous stone, marble, chalk, &c.
originally proceeded alone from the cast-otf
coats of those little animals.

SaltSj bitumeUj oil, and the grease of the
sea, enter little or none into the composition
of the shell; neither does the calcareous stone
contain any of those matters; this stone is,
therefore, only water hansformed, joined to
«Dme little portion of vitrifiable earth, and to a

great

92 buffon's

great quantity of fixed air, which may be dis-
engaged by calcination. This operation pro-
duces the same effect on the shells taken in the
sea as upon those drawn out of quarries ; they
both form lime, with only a little difference in
their quality. Lime, made with oyster or
other shells, is weaker than that made with
marble or hard stone; but the process of Na-
ture is the same, as are the results of its opera-
tion. Both shells and stones, lose nearly half
their weight by the action of fire in calcination;
the water issues first, after which the fixed air
is disengaged, and then the fixed water, of
which these stony substances are composed , re-
sumes its primitive nature, is elevated into va-
pours, drove off and rarefied by the fire, so that
there remains only the most fixed parts of this
air and water, which, perhaps, are so strongly
united in themselves, and to the small quantity
of the fixed earth of the stone, that the fire cannot
separate them ; the mass, therefore, is reduced
nearly a half, and would probably be still
more if submitted to a stronger fire. And what
appears to me to prove that this matter, driven
out of the stone by the fire, is nothing else than
air and water, is the avidity with which cal-
cined stone sucks up the water given to it, and
the force with which it draws water from the
atmosphere. Lime, by exposure either in air

or

NAtUttAL HISTORY. 93

or water, in a great measure regains the mass{
it had lost by calcination ; the water, with the
air it contains, replaces that which the stone
contained before. Stone then retakes its first
nature, for in mixing lime with the remains of
other stones, a mortar is made which hardens,
aiid becomes a solid substance, like those from
which it is composed.

Thus, then, we see on the one hand all the
calcareous malters, the origin of which we
must refer to animals ; and on the other, all the
combustible matters proceeding from animal
or vegetable substances; they occupy together
a great space on the earth ; yet, however great
their number may be, they only form a small
part of the terrestrial globe, the principal
foundation of which, and the greatest quan-
tity consisis in one matter of the nature of
glass ; a matter we must look upon as ter-
restrial element, to the exclusion of all other
substances, to which it serves as a base, like
earth, when it forms vegetables by the means,
or remains of animals, and by the transforma-
tion of the other elements ; and it is also the
ulterior term to which we can return or reduce
them all .

It appears that the animal filter converts
water into stone ; the vegetable filtre can also'
transform it, when all the circumstances are

found

94l buffon^s

found to be the same. The heat of vegetables
and the organs of life being less powerful (haii
those of shell animals, the vegetables can pro-
duce only a small quantity of stones, which
are frequently found in its fruits ; but it can
and does convert a great quantity of air, and a
still greater of water into its substance. It
may be asserted, without fear of contradiction,
that the fixed earth it appropriates, and which
serves as a base to these two elements, does not
make the hundredth part of its mass; hence,
the vegetable is almost entirely composed of
air and water, transformed into wood, or a
solid substance, which is afterwards reduced
into earth by combustion and putrefaction.
The same may be said of animals ; they not
only fix and transform air and water, but fire^
and in a much greater quantity than vege-
tables. It appears, therefore, to me, that the
functions of organized bodies are the most
powerful means made use of by Nature for the
conversion of the elements. We may regard
each animal, or vegetable, as a small particular
centre of heat or fire that appropriates to itself
the air and water which surround it, assimilates
hem to vegetate or nourish, and live on the
productions of the earth, which are themselves
only air and water previously fixed. It also^
appropriates to itself a small quantity of earth ,

and

NATURAL HISTORY. 95

and reccivini^ the impressions of liglit, the heat
of the sun and terrestrial globe, it converts into
its substance all these different elements;
works, combines, unites, and opposes them,
till they have undergone the necessary form
towards its support of life, and the growth of
organization, the mold of which once given,
models every matter it admits, and from inani-
mate renders it organized.

Water, which so readily coalesces and enters
with air into organizcdbodies, unites also with
some solid matters, such as salts ; audit is often
by their means that it enters into the com-
position of minerals. Salt at first appears to
be only an earth soluble in water, and of a
sharp flavour, but chemists have perfectly
discovered, that it principally consists in the
union of what they term the earthlj/ and the
aqueous principle. The experijp.ent of the
nitrous acid, which after combustion leaves
only a small quantity of earth and water, has
caused them to think, that salt was composed
only of these two elements ; yet I think it
is easily to be demonstrated, that air and fire
also enter their composition ; since nitre pro-
duces a great quantity of air in combustion,
and this fixed air supposes fixed fire which dis-
engages at the same time : besides all the expla-
nations given of the dissolution cannot be sup-
ported,

96 buffon's

ported, and it would be against all analogy,
that salt should be composed only of these
two elements, while all other substances are
composed of four. Hence we must not re-
ceive literally what those great chemists
Messrs. Stalil and Macquer have said on this
subject ; the experiments of Mr. Hales de-
monstrate, that vitriol and marine salt contain
much fixed air ; that nitre contains still more,
even to the eighth of its weight ; and that salt
of tartar contains still more than these. It
may, therefore, be asserted that air enters as a
principle into the composition of all salts ;
but this does not support the idea that salt is
the mediate substance between earth and water;
these two elements enter in different propor-
tions into the different salts or saline sub-
stances, whose variety and number are so great,
as not to be enumerated ; but which, generally
presented under the denomination of acids and
alkalis, shews us, that there is in general
more earth than water in the last, and more
water than earth in the first.

Nevertheless, water, although it may be
intimately mixed with salts, is neither fixed
nor united there by a sufficient force to
transform it into a solid matter like calcareous
stone ; it resides in salt or acid under its pri-
mitive form, and the best concentrated acid,

or

NATURAL HISTORY. 9t

or ihe most deprived of water, which might be
looked II pon as liquid earlb, only owes its liquir
dity to the quantity of (he air and fire it con-
tains; and it is no less certain, tliat they are in-
debted for their savour to the same principles.
An experiment which I have frequently tried,
has fully convinced mo, that alkali is produced
by fire. Lime made according to <he common
mode, and put upon the tongue, even before
slacked by air or water, has a savour which
indicates the presence of a certain quantity of
alkali. If the fire be continued^ this lime by
longer calcination, becomes more poignant ;
and that drawn from furnaces, where the cal-
cination has subsisted for five or six months to-
gether, is still more so. Now this salt was not
contained in the stone before its calcination ;
it augmented in proportion to the strength and
continuance of the fire ; it is therefore evi-
dent, that it is the immediate product of the
fire and air, which incorporate in thesubbtance
during its calcination, and which, by this
means, are become fixed parts of it, and from
which they have driven most of the watry
molecules it before contained . This alone ap-
peared to me sufficient to pronounce that fire
is the principal of the formation of the mineral
alkali ; and we may conclude, by analogy, that
other alkalis owe their formation to the con-
voL. X. O stant

9$ BUFFOI^'S

stant beat of the animal and vegetable fronr
which they are drawn.

With respect to acids^ although the demon-
stration of their formation by fire and fixed air,
is not So Immediate as that of alkalis, yet it
does not appear less certain. We have proved ,
that nitre and phosphorus draw their origin
from vegetable and animal matters : that vitriol
comes from pyrites, sulphur and other combus-
tibles . It is likewise certain that acids, whether
vitriolic, nitrous, or phosphoric, always con-
tain a certain quantity of alkali ; we must, there-
fore, refer their formation and savour to the
same principle, and by reducing the varieties of
both to one of each, bring back all salts to one
common origin : those which contain most of
the active principles of air and fire, will necessa-
rily have the most power and taste. I under-
stand by power the force with which salts ap-
pear animated to dissolve other substances.
Dissolution supposes fluidity, and as it never
operates between two dry or solid matters, it
also supposes the principle of fluidity in the dis-
solvent, that is, fire ; the power of the dissolvent
will be, therefore, so much the greater, as on
one part it contains more of this active princi-
ple; and, on the other hand, its aqueous and
terrene parts will have more aflinity with those
of the same kind contained in the substances-

i9

NATURAL HISTORY. 99

to dissolve; and, as the degrees ofaffinity vary,
we must not be surprized at different salts va-
rying in their action on different substances ;
their active principle is the same, their dissolv-
ing power the same ; but they remain without
exercise when the substance presented repels
that of the dissolvent, or has no deo^ree of
affinity with \i ; but the contrary is the case
when there is sufficient force of affinity to con-
quer that of the coherence; that is, when the
active principles, contained in the dissolvent,
under the form of air and fire, are found more
powerfully attracted by the substance to be
dissolved, than they are by the earth and wa-
ter they contain. Newton is the first who has
assigned affinities as the causes of chemical
precipitation ; Stahl adopted this idea and
transmitted it to all the other chemists ; and it
appears to be at present universally received
as a truth. But neither Newton nor Stahl
saw that all these affinities, so different in ap-
pearance, are only particular effects of the ge-
neral force of universal attraction : and, for
want of this knowledge, their theory cannot
-be either luminous or complete, because they
were obliged to suppose as many trivial laws
of different affinities, as there were different
phenomena ; instead of which there is in fact

only

100 BUFrox's

only on6 law of affiuityj a law which is pre-,
cisely the same as that of universal attraction.
Salts concur in many operations of Nuture
by the power they have of dissolvhig other sub-
stances ; for, although it is commonly said^
that water dissolves snK, it is easy to be per-
ceived, that in reality, when there is a dissolu-
tion, both are active, and may be alike called
dissolvents. Regarding- salt as only a dissol-
vent, the body to be dissolved may be either
liquid or solid; and, provided the parts of the
salt be sufficiently divided to touch immediate-
ly those of the other substances, they will act
and produce all the effects of dissolution, ^y
this we see how much the action of salts, and
the action of the element of water which con-
tains them, must have influence on the com-
position of mineral matters. Nature may
produce hy this mode, all that our arts
produce by that of fire. Time only is require
ed for salts and water to produce on the most
compact and hard substances, the most com-^
plete division and attenuation of their parts,
$o as to render them capable of uniting with
all analagous substances, and to separate from
all others; but this time, which to Natnre is
never wanting, is, of all things, that which is
the most deficient tons : the greatest ofall our
arts., therefore, is that of abridging time, that

is.

NATURAL HISTORY, 101

is, to effect that in one day, which nature takes
an age to perform. However vain tliis prc-
icnsioji may appear, we must not entirely re-
nounce it, for has not man drscovered the
mode of creating ure, of applying it to his use,
and by (he means of tliis element (o suddenly
dissolve those bodies by fusion which would
require a considerable period by any other
means ?

We must not, however, conclude that Na*
ture really performs by the means of water all
4hat we do by fire. The decomposition of
£very substance is ouly to be made by division,
and the greater this division the more the de-
.composition will be complete. Fire seems io
divide as much as possible those matters which
it fuses ; nevertheless it may be doubted whe-
ther those which water and acids keep in dis^
solution are not still more divided, and the
Vapours raised by heat contain matters still
further attenuated, in the bowels of the carth>,
?then, by the means of the heat it includes, and
the water which insinuates, there is made an
infinity of sublimations; distillation , chrys-
tallizatlons, aggregations, and disjunctions, of
every kind. By time all substances may be
compounded and decompounded by these
means; water may divide and attenuate the
parts more than fire when it melts them, and

iliosfc

102 BUFFO n's

those attenuated parts will join in the same
manner as those of fused metal unite by cooU
ing. Crystallization, of whicli the salts have
given us an idea, is never performed but Avhen
a substance, being disengaged from every
other, is much divided and sustained by a
fluid, which having little or no affinity with it,
permits it to unite and form by virtue of its
force of attraction, masses of a figure nearly
similar to its primitive parts. This operation,
which supposes all the above circumstances,
may be done by the intermediate aid of fire as
well as by that of water, and is often accom-
plished by the concurrence of both, because
all this exacts but one division of matter suffi-
ciently great for its primitive parts to be able
to form, by uniting figured bodies like them-
selves. Now fire can bring many substances
to this state much belter than any other dis-
solvent, as observation demonstrates to us in
asbestos, and other productions of fire, whose
figures are regular, and which must be looked
upon as true crystallizations. Yet this de-
gree of division, necessary to crystallization,
is not the greatest possible, since in this state
the small parts of matter are still sufficiently
large to constitute a mass, which like other
masses, is only obedient to the sole attractive
force, and the volumes of which, only touch?
ing in points, cannot acquire the rcsultive

force

BUFFO N*S 105

farce that a much greater division might per-
form by a more immediate contact, and this
is what we see happen in eftervescences, where
at once, heat and light are produced bj the
mixture of two cold liquors.

Light, heat, fire, air, water, and salts, are
steps by which we descend from the top of
Nature's ladder to its base, which is fixed
earth . And these are at the same time the
only principles that we must admit and com-
bine for the explanation of all phenomena.
These principles are real, independently of
all hypotheses and all method, as are also
their conversion and transformation, which
are demonstrated by experience. It is the
same with the element of earth, it can convert
itself by volatilizing and taking the form of
the other elements, as those take that of earth
in fixing ; it, therefore, appears quite useless
to seek for a substance of pure earth in terres-
trial matters. The transparent lustre of the
diamond dazzled the sight of our chemists,
when they considered that stone as a pure ele-
mentary fire ; they might have said with as
much foundation, that it is pure water, all the
parts of which are fixed to compose a solid
diaphanous substance. When we would de-
fine Nature, the large masses should alone be
considered, and those elements have been well
t^ken notice of by even the most ancient philo-
sophers.

104 BUFFO n's

soplicrs. Tbc sun, atmosphere, earlh, sea, &c.
are all great masses on which they establisiied
all their conclusions ; and ifthere ever had ex-
isted a planet of phlogiston, an atmosphere
of alkali, an ocean of acid, or a mountain of
diamonds, such might have been looked upon
as the general and real principles of all bodies,
but they are only particular substances, pro-
duced, like all the rest, by the combinations
of true elements • and ideas to the contrary
"vvould never have been started but upon the
supposition that the earth was neither more
simple nor less convertible than either of the
other elements.

In the great mass of solid matter^ which the
earth represents, the superficial is the least
pure. All the matter deposited by the sea, in
form of sediment, all stones produced by shell-
animals, all substances composed by the com-
binations of the waste of tlic animal or vege-
table kingdom, and all those which have beea
changed by the fires of volcanos, or subli-
mated by the internal heat of tlie globe, are
mixed and transformed substances ; and al-
though they compose great masses they do not
clearly represent to us the element of earlh.
They are vitrifiable matters, whose mass must be
Considered as 100,000 limes more considerable
than all those other substances, which should
be regarded as the true basis of this element-
It

KAtURAL HISTORY. 105

It is front this common foundation that all
other substances have derived the origin of
their solidity, for all fixed matter, however
much decomposed, subsides finally into glass
by the sole action of fire : it resumes its first na-
ture, when dis«ngaged from the fluid, or vola-
tile matters, which were united with it ; and
this glass, or virtreous matter, which compo-
ses the mass of our globe^ represents so much
the better the element of earth j as it has nei-
ther colour, smell, taste, liquidity, nor fluidity,
qualities which all proceed from the other ele-
ments, or belong to them*

If glass be not precisely the element of earth,
it is at least the most ancient substance of it ;
metals are more recent, and less dignified ;
and most other minerals form within our sight.
Nature produces glass only in the particular
focus of its volcanos, whereas every day she
forms other substances by the combination
of glass with the other elements. If v/e would
form to ourselves a just idea of her formation
of the globe, we must first consider her proces-
ses, which demonstrate that it has been melted
or liquefied by fire ; tliat from this iramenss
heat it successively passed to its present de-
cree ; that in the first moments, ^\here its sur-
face began to take conbistencCi inequalities
YOL. X. P must

lOG BUFFO w'*

must be formed, sucli as we see on the surface
of racUed matters grown cold : that the high-
est mountains, all composed of vitrifiable
matters, existed and take their date from that
moment, vvhich is also that of the seperation of
the great masses of air, water, and earth ; that
afterwards, during the long space of lime
which the diminution of the heat of the globe
to the point of present temperature supposes,
there were made in these mountains, which.
T\ere tlie parts most exposed io the action
of external causes, an inftnity of fusions, sub-»
limatioris, aggregations, and transformations,
by the fire of the sun, and all the o her causes
vhich this great heat rendered more active^
than they at present are, and that consequently
we must refer back to this date the format iort
of metals and minerals which we find in great
masses, and in thick and continued veins. The
violent fire of inflamed earth, after having
raised up and reduced into vapours all that
was volatile, after having driven off from its
internal parts the matters which compose the
atmosphere and the sea, and at the same time
sublimated all the least fixed parts of the earth,
raised them up and deposited them in every
void space, in all the cavities which formed on
the surface in proportion as it cooled ; this,
then, is the origin and the gradation of the

situation

NATURAL HISTDRV. 107

sitttntioh nhd formation of vitrifinble matters
■which fire lias dividct], formed andsubUmated

After this first establishment (and ^vhich
still subsists) of vitrifiable matters and minerals
into a gt-eat mnss, whicli can be attributed to
the action of fir(3 alone, water which till then
formed with Air only a vast volume of vapours,
begiin to take its present slate ; it collected
and covered the greatest part of the surface of
the earth, on which, finding itself agitated
by a cohtiliualflux aud reflirx, by the action bf
^Viiids arid heat, it began to act on thfe works
of fire: it changed, by degrees, the superfici^
of vitrifiable matters ; it transported the wrecks
rtnd deposited them in the form of sediments ; it
nourished shell-ahiraals,it collected their shells,
produced calcareous stones, formed hills and
mountains, which becoming afterwards dry,
received in their cavities all the mineral mat-
ters they could dissolve or contain.

To establish a general theory on the for-
mation of Minerals, we must begin then by
distinguishing with the greatest attention, first,
those which have been prod need by the pri-
tnttive fire of the earth while it was burning
witli heat ; secondly, those which have been
farmed (torn the waste ofthe first by the means
pf water; and thirdly, those which in vol-

cafio^i

103 buffon's

canosj or other subsequent conflagration^
have a second time undergone the proof of a
violent heat. These three objects arc very
distinct, and comprehend all the mineral
kingdom; by not losing sight of them, and by
connecting each substance, we pan scarcely be
deceived in its origin, or even in the degrees
of its formation. All minerals which are found
in masses, or large veins in our high moun-
tains, must be referred to the sublimation of
the primitive fire ; all those which are found
in small ramifactions, in threads or in vegeta-
tions, have been formed only from the waste
of the first hurried away by the stillation of
■waters. We are evidently convinced of this,
hy comparing the matter of the iron mines
of Sweden with that of our own. These
are the immediate work of water, and we see
them formed before our eyes ; they are not at-
tracted by the load stone ; they do not contain
any sulphur,and are found only dispersed in the
earth ; the restare all more or less sulphureous,
all attracted by the load stone, which alone sup-
poses that they have undergone the action of
fire ; they are disposed in great, liard, and solid
masses: and their substance is mixed with a
quantity of asbestos, another index of the
action of fire. Iti^the same with other metals:
their ancient foundation comes from fire, and

all

NATURAJL IIISTORY. 109

all their great masses have been united by its
action ; but all their crystallizations, vegeta=
tions, granulations, &c. are due to the second-
ary causes, in which water is the primary

assent.

EXPERIMENTS ON THE PROGRESS OF HEAT
IN MINERAL SUBSTANCES.

I CAUSED ten bullets to be made of forged
and beaten iron ; the first, of half-inch diame-
ter; the second, of an inch; and soon pro-
gressively to five inches : and as all the bullets
were made of iron of the same forg^e, their
weights were found nearly proportionable to
their volumes.

The bullet of half an inch weighed 190
gr(iins, Paris weight ; that of an inch, 1522
grains; that of an inch and a half, bl36
grains; that of two inches, 12173 grains;
that of two inches and an half, 23781 grains ;
that of three inches, 41085 grains ; that of
three inches and a half, 65':^5ii grains; that of
four inches, 97S88 grains ; that of ftnir inches

an4

IK) buffok's

a^d an half, i^8179 grains; and that of five
inches, 190211 grains. All these weights
were taken with very good scales, and those
bnllets which were found too heavy, were
filed.

While these bullets were making, the ther-
mometer exposed to the open air was at the
freezing point, or some degrees below ; but \n
the pit where the bullets w^ere suffered (o cool,
the thermonicler was nearly ten degrees above
that point ; that is to say, to the degree of tem-
perature of the pits of the observatory, and it
is this defirree which! liave here taken for that
of tlie actual temperature of the earth. To
know the exact moment of their cooling to
this actual temperature, other bullets of the
same matters, diameters, and not heated, were
juadc use of for comparison, and which were
felt at the same time as the others. By the ira*
mediate touch of the hand, or two hands, on
the two bullets, we could judge of the moment
yfhcn they were equally cold; and as the
greater or less smoothness or roughness of
bodies makes a great difference to the touch ;
(a smooth body, w^hether hot or cold, ap-
pearing much more so than a rough body,
even of the same matter, although they are
both equally so) I took care that the cold bul-

lets

NATURAL HISTORY. Ill

lets were rou^gh, and like those \vhich bad
been heated, \^ hose surfaces w<ire sprinkled over
with little eminences produced by the fire.

EXPERIMENTS.

I. The bullet of half an inch was healed
"white in two minutes, cooled so as to be heUl
in the hand in V2y and to the actual tcmpem-
ture in 39 minutes.

II. That of an inch, heated white in fi\re
minutes and a half, cooled so as to be held in
the hand, in 35^ minutes, and to the actual
teiuperature in one hour and 2,5 minutes,

III. That of an inch and an half, heated
white in nine minutes, cooled so as to be hekl
in the hand in 5S minutes, and to the actaal
temperature in two hours and 35 minutes.

IV. That of two inches heated white in 13
minutes, cooled so as to be held in the hand
in one hour 20 minutes, and to the actual
temperature in three hours 16 minutes.

V. That bullet of two inches and an half
heated white in 16 minutes, cooled so as to be
held in the hand in one hour 42 minutes, and
to the actual temperature in four hours SO
minutes.

VI. That bullet of three inches heated white^
in 191 minutes, cooled so as to be held in the
hand in t ^o hours seven minutes, and to (he
actual ^empcratuie in five hours eiijht minutes,

VIL

112 BUFFO n's

VII. Tlmt of three inched aHcl a half beafecl
\vhite in 2S| minutes, cooled so as to be held
in the hand in two hours 36 minutes, and to
theactual temperature in five hours 56 minutes.

VIII. That of four inches heated white in
27 minutes and a half, cooled so as to be
held in the hand in lliree hours two minutes,
and to the actual temperature in six hours 55
minutes.

IX. That of four inches and a half heated
white in SI minutes, cooled so as to be held in
the hand in three hours and 25 minutes, and
to the actual temperature in seven hours 46
minutes.

X. That of five inches heated white in S4
minutes, cooledj so as to be held in the hand,
in three hours 52 minutes, and to the actual
temperature in eight hotirs 42 minutes.

The most constant difference that can be
taken between each of the terms which express
the time of cooling, from the instant the bullets
were drawn from the fire, to that when we can
touch them unhurt, is fouild to be about 24
minutes, for, by supposing each term to in-
crease 24, we shall have 12, 36, 60, 84, 108,
IS2, J56, 180,204, 228 minutes. And the
continuation of the real time of these coolings
are, 12, 351, 58, 80, 102, 127, 156, 182, 205,.
232 minutes, which approach the first as

nearly

NATURAL HISTORY. tl3

nearly as experiment can approach calcula-
tion.

So, likewise, the most constant difference to
be found between each of the terms of coolins:
to actual temperature is found to be 5i minutes,
for by .supposing each term to increase 54, we
shall have 3>J, 93, 147, 201, 255, S09, 363,
417, 471, 5:5 minutes, and the continuation
of the real lime of this cooling is found, by the
preceding experiments, to be 39, 93, 145, 196j
248, 308, 356, 415, 466, 522 minutes, which
approaches also nearest to the first*

I made the like experiments upon the same
bullets twice or thrice, but found I could only
rely on the first, because each time the bullets
were heated they lost a considerable part of
their weight, which was occasioned not only
by the falling off of the parts of the surface
reduced into scoria, but also by a kind of dry-
ing, or internal calcination, which diminishes
the weight of the constituent parts, insomuch
that it appears a strong fire renders the iron
specifically lighter each time it is heated; and
I have found, by subsequent experiments, tfiat
this diminution of weight varies much, ac-
cording to the different quality of the iron.
Experience has also confirmed me in the opi-
nion, that the duration of heat, or the time
VOL. x» Q taken

IM buffon's

taken up in cooling of iron, is not in a smaller,
as stated in a passage of Newton, but in a
larger ratio than that of the diameter.

Now if we would enquire how long it would
require for a globe as large as the earth to cool,
"we should find, after the preceding experi-
ments, that instead of 50,000 jears, which
Newton assigns for the earth to cool to the pre-
sent temperature, it would take 42,964 years,
221 days, to cool only to the point where it
would cease to burn, and 86,667 years and 132
days, to cool to the present temperature.

It might only be supposed, that the refrige-
ration of the earth should be considerably in-
creased, because we imagine that refrigeration
is performed by the contact of the air, and
that there is a great difference between the
time of refrigeration in the air and in vacuo;
and supposing that the earth and air cool in
the same time in vacuo, this surplus of tim«
should be reckoned. But, in fact, this dif-
ference of time is very inconsiderable, for
though the density of the medium, in which
a body cools, makes something on the dura-
tion of the refrigeration, yet this effect is much
less than might he imagined, since in mercury,
which is eleven thousand times denser than air,
it is only requisite to plunge bodies into it

about

NATURAL HISTORY. |15

about nirre times as often as is required to pro-
duce the same refrigeration in air. The prin-
cipal cause of refrigeration is not, therefore,
the contact of the ambient medium, but the
expansive force which animates the parts of
heat and fire, which drives them out of the
bodies wherein they reside, and impels them
directly from the centre to the circumference.
By comparing the time employed in the
preceding experiments to heat the iron globes,
with that requisite to co(A them, ^^e find that
they may be heated till they become white in
one sixth part and a half of the time they take
to cool, so as to be held in the hand, and about
one fifteenth and a half of that to cool to ac-
tual temperature, so that there is a great error
in the estimate which Newton made on the
heat communicated by the sun to the comet of
1680, for that comet having been exposed to
the violent heat of the sun but a short time,
could receive it only in proportion thereto,
and not only in so great a degree as that au-
thor supposes. Indeed, in the passage alluded
to, he considers the heat of red-hot iron much
less than in fact it is, and he himself states it
to be, in a Memoir, entitled, The Scale of
Heat, published in the Philosophical Trans-
actions of 1701, which was many years after

116 buffon's

the publication of h'ls prwcjples. We see in
that excellent Memoir, which includes the
germ of all the ideas on which thermometers
have since been constructed; that Newton,
after very exact experiments, makes the heat of
boiling water to be three times greater than
that of the sun in the height of summer ; that
of melted tin, six times greater ; that of melted
lead, eight times; that of melted rogulus,
twelve times; and that of a common culinary
fire, sixteen or seventeen times ; hence we may
conclude, that the heat of iron, when heated
so as to become white, is still greater, since it
requires a fire continually animated by tho
bellows to heat it to that degree. Newton
seems to be sensible of this, for he says, that
the heat of iron in that state seems to be seven
or eight times greater than that of boiling
water. This diminishes lialfthe heat of this
comet, compared to that of liot iron.

But this diminution, which is only relative,
is nothing in itself, nor nothing in comparison
with that real and very great diminution which
results from our first consideration. For the
comet to have received this heat a thousand
times greater than that of red-hot iron, it must
have remained a very long time in the vicinity
©f the sun, whereas it only passed very rapidly

at

NATURAL IIISTOHY. 117

at a small distance. It was on the Stli of De-
cember, 16S0, at ~oo distance from the earth
to the centre of the sun ; but 24 hours before,
and as many after, it was at a distance six
times greater, and where the heat was consc"
quently 36 times less.

To know then the quantity of this heat com-
municated to the comet by the sun, we here
find how we should make this estimation tole-
rably just, and, at ihc same time, make tlie
comparison with hot iron by the means of my
experiments.

We shall suppose, as a fact, that this comet
took up 666 hours to descend from the point
where it then was, and which point was at an
equal distance as the earth is from the sun,
consequently it received an equal heat to what
the earth receives from that luminary, and
which I here take for unity ; we shall likewise
suppose that the comet took 666 hours more
to ascend from the lowest point of its perihe-
lium to this same distance; and supposing
also its motion uniform, we shall perceive,
that the comet being at the lowest point of its
perihelium, that is, to yoVo ^^ the distance
from the earth to the sun, the heat it received
in that motion was 27,766 times greater than
that the earth receives. By giving to this
Hiotion a duration of 80 minutes, viz. 40 for its

descent.

118 UUi'FON's

descent, and 40 for its ascent, we sball have,
at 6 distance, 27,776 heat duvini^ 80 minutes
at 7 distance 20,408 heat also during 80 mi-
nutes, and at S distance 13,625 heat during
80 minutes, and thus, successively, to the
distance of 1000, where the heat is one. By
summing up the quantity of heat at each dis-
tance we shall find ^63,110 to be the total of
the heat the comet has received from the sun,
as much in descending as in ascending, which
must be multiplied by the time, that is, by
four thirds of an hour; we shall then have
484,547, which divided by 2,000 represents
the solid heat the earth received in this time
of 1332 hours, since the distance is always
1,300, and the heat always equals one. Thus
we sliall have 242, aV^ for the heat the comet
received more than the earth during the wliole
time of its perihelium instead of 28,000, as
Newton supposed it, because he took only
the extreme point, and paid no attention to the
very small duration of time. And this heat
must still be diminished 242,^^, because the
comet ran, by its acceleration, as much more
way in the same as it was nearer the sun.
But by neglecting this diminution, and ad-
mitting that the comet received a heat nearly
242 times greater than that of our summer's
sun, and, consequently 177 times greater ^^^an

that

NATURAL HISTORY. 119^

fhat of hot iron, according to Newton's esti-
mation, or only ten minutes greater according
to this estimation ; it must be supposed, that
give a heat ten times greater than that of red
Lot iron, it required ten times more time ; that
is to say, 1332; consequently, we may compare
the comet to a globe of iron heated by a
forge fire for 13320 hours, to lieat it to a
whiteness.

Now we find by calculation from ray expe-
riments, that with a forge fire, we can heat to a
whiteness a globe whose diameter is 228342 J
inches in 799200 minutes, and, consequently,
the whole mass of the comet to be heated to the
point of iron to a whiteness, during the short
time it was exposed to the heat of the sun, could
only be 2233421 inches in diameter ; and even
then it must have been struck on all sides, and
at the same time, by the light of the sun.
Thus comets, when they approach the sun, do
Jiot receive an immense nor a very durable
heat, as Newton says, and as we at the first
view might be inclined to believe. Their stay
is so short in the vicinity of the sun, that their
masses have not time to be heated, and besides
only part of their surface is exposed to it ;
this part is burnt by the extreme heat, which

by

120 buffom's

by calcining and volatilizing the matter of this
surfkce, drives it outwardly in vapours and
dust from the opposite side to the sun ; and
what is called the tail of the comet, is nothing
else than the light of the sun rendered visible,
as in a dark room, by those atoms which the
heat lengthens as it is more violent.

But another consideration very different and
infinitely more important, is, that to apply
the result of our experiments and calculation
to the comet and earth, we must suppose them
composed of matters which would demand as
much time as iron to cool: whereas, in reality,
the principal matters of which the terrestrial
globe is composed, such as clay, stones, &c.
cannot possibly take so long.

To satisfy myself on this point, I caused
globes of clay and marl to be made, and having
heated them at the same forge until white, I
found that the clay balls of two inches, cooled
inSS minutes so as to be held in thehand ; those
of two inches and an half, in 48 minutes ; and
those of three inches, in 60 minutes ; w liich
being compared with tlie time of the refri-
geration of iron bullets of the same diameters,
give 38 to 80 for two inches, 48 to 102 for
two inches and a half, and 60 to 127 for

three

NATURAL HISTORY. 1^1

three ihclies ; so that only half the time is re-
quired for the refrigeration of clay, to what is
necessary for iron.

I found also, that lumps of clay, or marl^
of two inches, refrigerated so as to be held in
the hand in 45 minutes ; those of two inches
and a half in 58 ; and those of three inches in
75, which being compared with the time of
refrigeration of iron bullets of the same dia-
meters, gives 46 to SO for two inches, 58 to
102 for two inches and a half, and 75 to 127
for three inches, which nearly form the ratio
of 9 to 5 ; so that for the refrigeration of
clay, more than half the time is required than
for iron.

It is necessary to observe, that globes of clay
iieated white, lost more of their weight than
iron bullets, even to the ninth or tenth part of
their weight : whereas marl heated in the same
jfire, lost scarcely any thing, although the
whole surface was covered over with scales,
and reduced into glass. As this appeared sin-
gular, I repeated the experiment several times,
increasing the fire, and continuing it longer
than for iron ; and although it scarcely requir-
ed a third of the time to redden marl, to what
it did to redden iron, I kept them in the fire
thrice as long as was requisite, io sec if they
would lose more, but I found very trifling di-
TOL. X. R miziulions ;

129 BUFFO N*S

mwiutions ; for fhe globe of two inches lieated
foe eight minutes, which weighed seven ounces^
two drachms, and thirty grains, before it was
put in tlie fire, lost only forty-one grains,
which docs not make a hundredth part of its
weight ; and that of three in ches,wliich weighed
twenly-four ounces, five drachms, and thirteen
grains, having been heated by the fire for
eighteen minutes, that is nearlj^ as much as
iron^, l©st only seventy-eight grains, which
does riot make the hundredth and eighty-first
part of its weight. These losses are so trifling,
that it may be looked upon, in general, as cer**
taialhat pure clay loses nothing of its weight
in the fire ; for those trifling diminutions were
certainly occasioned by the ferruginous parts
wliich were found in the clay, and which were
in part destroyed by the fire. It is also worthy"
of observation, that the duration of heat in
difierenLmatters exposed to the same fire for an
equal time, is always in the same proijortion,
whether tlie degree of heat begreatt?ror smaller.
, I have made similar experiments on globes
of maib)e, stone, lead^ and tin, by a heat only
strong enough to melt tin, and I found, that
iron refrigerated in eighteen minutes, so as to
be able to liold it in the hand, marble refri-
gerated to the same degree in twelve minutes,
stone iu eleven, lead in nine, and tin in eiglit.

It

JfATURAL HISTORY. 125

it is not, therefore, in proportion to their den-
tsitj, as is commonly supposed, that bodies
receive and lose more or less heat, but iti an
inverse ratio of their solidity; that is, of their
greater or lesser non JIuid'df/ ; so that, by the
game heat, less time is requisite to Iteiit or cool
the most dense fluid.

To prevent the suspicion of vainly dwelling
upon assertion, I think it necessary to remark
iipon what foundation I build this theory ; I
have found that bodies which should heat in
ratio of their diameters, could be only those
which were perfectly permeable to heat, and
would heat or cool in the same time ; hence,
I concluded that fluids, whose par(s are only
held together by a slight connection, might
approach nearer to this perfect permeability
than solids, whose parts have more cohesion.
In consequence of this, I made ex[3eriments,
by which I found, that with the same heat all
fluids, however dense they might be, heat and
cool more readily than any solids, howev»er
light, so that mercury, for example, heats
much more readily than wood, although it
be fifteen or sixteen times more dense.

This made me perceive that the progress of
heat in bodies cannot, in any case, be made
relatively io their density ; and I have found

by

124 buffon's

by experience, that this progress, sis well in
solids as fluids, is made rather by reason of
their fluidity, or in an inverse ratio of their so-
lidity. I mean by solidili/ the quality oppo-
site to fluidity ; and I say, that it is in an in-
verse ratio of this quality that the progress
of heat is made in both bodies ; and that they
lieat or cool so much the faster as they are the
more fluid, and so much the slower as thoy arc
more solid, every otlier circumstance being
equal.

To prove that solidity, taken in this sense,
is perfectly independent of density, I have
found, by experience, that the most or least
dense matters, heat or cool more readily than
other more or less dense matters, for example,
gold or lead, which are much more dense than
iron and copper, heat and cool much quicker ;
while tin and marble, which are not so dense,
heat and cool much faster than iron and cop-
per ; and there arc likewise many other mat-
ters which come under the same description ;
so that density is in no manner relative to the
scale of the progress of heat in solid bodies.

It is likewise the same in fluids, for I have
observed, that quicksilver, which is thirteen or
fourteen times more dense than water, never-
theless heats and cools in less time than water ;

and

NATURAL HISTORY. 125

and spirit of wine, which is less dense than
water, heats and cools much quicker ; so that
generally the progress of heat in bodies, as well
witli regard to tlie ingress as egress, has no
affinity with their density, and is principally
made in the ratio of their fluitlity, by extend-
ing the fluidity to a solid ; from hence I con-
cluded, that wc should know thereat degree of
fluidity in bodies, by heating them to the same
heat ; for their fluidity would be in a like ratio
as that of the time during which they would
receive and lose this heat ; and that it would
be the same with solid bodies. They will bo
so much the more solid, that is tosay, so much
the more nonjluids^ as they require more time
to receive and lose this heat, and that almost
generally to what I presume; for I have al-
ready tried these experiments on a gr^at num-
ber of different matters, and from them I have
made a table, which I have endeavoured to
render as complete and exact as possible.

I caused several globes to be made of an
inch diameter witli the greatest possible pre-
cision, from the following matters, which
nearly represent the Mineral kingdom.

M. Tillet, of the Academy of Sciences,
made the globe of refined gold at my particu-
lar

i2Q buffon's

lar request, and the whole of tjiem weighed
as follows :

oz. d. gr.

jGoM - - J 6 2 17

I.ead - - - 3 6 28

Pure silver - - 3 3 22

Bismuth - - - 3 0 3

€opper-red - - 2 7 56

Iron . - - 2 5 10

Tin - - - 2 3 48

Antimony melted, and which had

small cavities on its surface 2 1 34

Fine - - - 2 12

Emery - - - 1 2 24f

White marble - - 1 0 25

Pure clay - - 0 7 24

Marble common of Montbard 0 7 20

White gypsum, improperly called

Alabaster - - 0 6 3Q

Calcareous white stone of the quarry

of Aiiicres, near Dijon - 6 6 6
Rock chry&tal : it was a little too
small, and had many defects. I
presume that without them it

would have weighed - 0 6 22

Common glass - - 0 6 21

Pure

OZ. (

0
0

d. gr.
6 16
5 9

fa-
0
0

5 2i
4 49

NATURAL HISTORY. 1:27

Pure earth, very dry

Olver

Porcelain of the Court de Laura-

guais
White chalk
Cherry wood, i^feicli although lighter
than most other woods, is that
which takes in the least fire 0 1 59
1 must here observe, that a positive conclii"
sion must not be made of the exact specific
weight of each matter from the preceding
table, for notwithstanding t lie precaution thai
was taken to render the globes equal, yet, as
I was obliged to employ different workmen ^
some were too large, and others too small.
Those which were more than an inch diameter
were diminished, but those of rock chrystal,
glass and porcelain, which were rather too
small, we suffered to remain, and only rejected
those of agate, jasper, and porphyry, which
were sensibly so. This precision in size was
however not absolutely necessary, for it could
very little alter the result of my experiments.
Previously to ordering these globes, I exposed
to a like degree of fire, a square mass of iron^
and another of lead of two inches diameter,and
found, by reiterated essays, that lead lieated

and

123 bttffon's

and cooled in much less time tlian iron. I made
the same experiment on red copperj and that
TCt]uircd more time to heat and cool than lead,
and less than iron. So that of these three mat-
ters, iron appeared the least accessible to hcaf,
and, at the same time, that Avhich retained
it the longest. From which I learn that the
law of the progress of heat in bodies was not
proportionable to their density, since lead,
which is more dense than iron or copper, ne-
vertheless heats and cools in less time than
either. As this object appeared important, I
was induced to have these globes made, and to
be more perfectly satisfied of the progress of
heat in a great number of different matters, I
always placed the globes at an inch distance
from each other, before the same fire, or in the
same oven, 2, 3, 4, or 5, together w ith a globe
of tin in the midst of them. In most of my ex-
periments I suffered them to be exposed to the
same active fire till the globe of tin began to
melt, and at that instant they were all remov-
ed, and placed on a table in small cases. I
suffered them to cool without moving, often
trying whether I could touch them, and the
moment they left offburning,and I could hold
them in my hands half a second, I marked the
time which had passed since I drew them from

the

JfATURAL HISTORY. 159

the fire. I afterwards suflfered them to cool to
the actual temperature, of whicli I endeavoured
to judge by means of touching other small
globes of the same matters that had not been
heated. Of all the matters which I put to the
trial, there was only sulphur which melted ina
less degree of heat than tin, and notwithstand-
ing its disagreeeble smell I should have taken
it for a term of comparison, but being a brittle
matter which diminishes by friction, I pre-
ferred tin, although it required nearly double
the heat to melt.

Having heated together bullets of iron, cop-
per, lead, tin, gres, arid Moiitbard marble,
they cooled in the following order :

So as to be held in the hand for

To actual temperature.

half a second.

Min.

Min,

Tin in - - 6|

In

-

-

- 16

Lead in - - S

In

-

-

- 17

Gresin - - D

In

-

-

- 19

Common marble in 10

In

-

-

- 21

Copper in - l\\

In

-

-

- 30

Iron in - - IS

In

-

.

- SS

l^y a second experiment with a fiercer fire,
sufficient to melt the tin bullet, the five others
cooled .
VOL. X, S So

130

BUJFFON S

So as to he

hddinthe hand.

To

' actual tefii pet afar

e.

Min.

Min'

Lead in

•

m

In

-

-

-

42

Gres in

-

m

In

-

-

-

46

Common

marble

m

In

-

-

-

50

Copper

-

m

In

-

-

-

51

Iron

.

231

In

-

.

-

54

By a third experiment, with a less degree
of fire than the preceding, the same bullets
with a fresh tin buUetj cooled in the following
maimer.

So as to be held in

the hand.

To actual

' temperature.

Min.

Mitt.

Tin in

'• n

In

-

-

- 25

Lead in

' n

In

-

-

- 25

Gres in

- lOi

In

-

-

. 37

Common marble 12

In

-

-

- S9

Copper

- 14

In

-

-

- 44

Iron

- 17

In

-

-

- 50

From these experiments, which I made with
as much precision as possible, we may con-
clude, first, that the time of refrigeration of
iron, so as to be held in the hand, is to that of
copper : : 53| : 45, and so to the point of
temperature : : 142 : 125.

2dly, That the time of refrigeration of iron,
so as to be held in the hand, is to that of the
first refrigeration of common marble : : 5S| :
35f and their entire refrigeration « : 142 : 110.

Sdly,

NATURAL HISTORY. 131

Sdly, that the time of Tefrigeration of iron,
to that of gres, so as to be held in the hand, is
: : 53| : S2 and : : 142 : 102^, for their en-
tire refrigeration.

4thly, That the time of refrigeration of
iron <o that of lead, so as to be held in the
hand, is : : 531 ' 27 and li^ ; QU for their
entire re fri operation.

In an oven hot enough to melt tin, although
all the coals and cinders were drawn out, I
placed, on a piece of iron wire, five bullets,
distant from one another about nine lines, after
which the oven was shut, and haying drawn
them out, in about 18 minutes they cooled,

So as to be hdd in

the hand.

To actual

temperature.

Min.

Mm

Melted tin in

- 8

In

-

-

- 24

Silver in

- 14

In

-

-

- 40

Gold in

- 15

In

-

-

- 46

Copper in -

.- \6\

In

-

-

- 50

Iron in

- 18

In

.

.

. 56

In the same oven, but with a slower heat,
the same bullets with an other bullet of tin,
cooled.

So as to be held in

the hand.

To actual temperature.

Min.

Mirj.

Tin in

- 7

In - - - 20

Silver in -

- 11

In - - - 56

Gold

13S

BUPFO?^'^

Gold in

- \2\

In -

- - 40

Copper in -

' 14

In -

- - 43

Iron in

- 16i

In - .

■ - 47

In thesameoven, but wiilia still less degree

of heat, the

same bullets cooled,

So as to ie held in tbs hand.

To attuai

I temferatut;e.

Min.

Min.

1 m in

- 6

hi .

- - 17

Silver in -

- 9

In -

- - 26

Gold in .

- 91

In -

- - 28

Copper in

. 10

In -

- - 31

Iron in

- 11

In -

- - 35

Having placed in the same oven five other
bullets, placed the same and separated from
each other, their refrigei*ation was in the fol-
lowing pioporlions.

^ So as to be held in

the

hand.
Min.

To Mctual

' tempi

atture

Min

Antimony in

'

6i

In

-

-

-

25.

Bismuth in

-

7

In

-

-

r

2G

Lead in

-

8

In

-

-

-

27

jL'mic in

-

101

In

-

-

-

30

Emery in

_-

IH

In

-

-

-

38

In the same oven, and in the same manner,
another nullet of Bismuth was placed, with
six oilier bullets, which cooled.

So as to be held in the band. To actual temperature.

Min. Min

Anii^iiony in - 6 In . - - - 23
Bismuth in - 6 In - - - 25

Lead

NATURAL HISTORY. 133

. - - - 28

.... so

. - - - 32
. - - - 34
- - r - 39

There was put in the same oven a bullet of
glass, another of tin, one of copper, and one
of iron, and they cooled,

Lead in

■ 7i

In

Silver in f

- 9f

In

Zinc in

- lOi

In

Gold in

- Hi

In

Emery in -

- m

In

S« ai to be held in the hand.

To actual temperature.

Miu.

MIn,

Tin in - - 8

In

- - - . 27

Glass in - - 8^

In

- - - - 22

Copper in - - 14

In

- - - - 42

Iron in - - 16

In

- . - - 50

Bullets of gold, glass, porcelain, gypsum,
and grcs, were heated together, and cooled,

So as to be held in the band.

To

actual temperature.

Min.

Min.

Gypsum in - - 8

In

- -

- - 24

Porcelain in- - Sf

In

«

- - 25

Glass in - - 2

In

- -

- - 26

Gres in - - 10

In

-

- - 32

Gold in - - 141

In

- -

- - 45

Bullets of silver, common marble, hard

stone, white marble, and soft calcareous stone

of Aniercs, near Dijon, were heated like the

former, and cooled,

So

134: BUFFON S

So as to be held in the hand. To

actual

temperature.

Min.

Mm.

Syoft calcareous slone in 8

In

-

- 25

Hard stone in - - - 10

In

-

- 34

Common marble in - 11

In

'

- 35

White marble in - - 12

In

-

- 36

Silver in - - - - 13f

In

-

- 40

The whole of these experiments were made
-vvitb the utmost care and attention, not only
by myself but in the presence of several per-
soiis, who also endeavoured to judge of the
first degree of temperature by holding the bul-
lets for half a iecond in their hands, and the
relations of which are more exact than those
of the actual temperature, because that being
variable the result must sometimes vary also.

With a view to avoid that proxility which
would necessarily attend the continual repeti-
tion in a comparative statement of the refrige-
ration of these diflerent bodies, we have con-
nected them iii a general table, and taking
10,000 for the st^mdard of comparison, their
diflfences mny be seen at one vicAV.

A TABLE

STATURAL HISTOHT. J^

A TABLE

OP THE

J^elations of different Mineral Substances',

IRON^ Tvith

First Entir*
■Refrig. Refrig-,

-Emery - . 10000 fo 9117— 9020

popper - to 8512—8702

yP^d - - to8J60— 8148

^i^^c - - to 7653—6020

Silver . - . . to 7619— 7423

Marble White - to 6774—6704

Marble common - to 66.36— 6746

Stone calcareous hard • to 6617 6274

J.^»*-'s - - -to 5596— 6926

y^ass - - to D^76^bS05

}.\^^^ - - to 5143—6482

^^» - - to 4898— 4921

Mone calcareous soft - — — to 4194—4659

^l^y - - to 4198—4490

^|s«iuth - . , fo 3580-4081

^"alk - . to 3086-3878

Cxum - - to 2325— 2817

V\ ood - . . to 1890—1594

I umice-stonc - to 1627 1268

EMREY

iBQ BVTFoas

EMERY, Tvilli

First Entire
Refrig. Refrig.

Copper - - 10000 to 8519— 8148

Gold - - - to 8513—8560

Zinc - - to 8S90— 7693

7458

Silver - - to 7778— 7895

S(one calcareous hard - to 7304 — 6963

Gres - - to 6552— 6517

Glass • - to 5862— 5506

Lead - - to 5718— 6643

Zinc - - to 5658—6000

Clay - - 10 5185—5185

Bismuth - - to 4949— 6060

Antimony - to 4540— 5S27

Oker - - to 4259— 3827

Chalk - - to 3684— 4105

Gypsum''"^- - to 2368—2947

Wood ^ - - to 1552—3146

COPPER, Avith

Gold - - 10000 to 9136—9194

Zinc - - to 8571— 9250

7619

Silver - - to 8395— 7823

Marble common - to 7639—8019

Gres - . - to 7333— 8160

Glass - - to 6667— 6567

Lead - - to 61 79— 7367

Tin

NATURAL HISTORY.

137

First Entire
Re frig

Tin - 10000^0 5716'
Stone calcareous tender to 516-^-

Clay

Bismuth

Aniimony

Oker

Chalk

to 5652

to 5686

to 5130

to 5003

to 4068— 436S

Refrig.

6916
-5633
-6363
'5959

-5808

-4 or

GOLD, wiih

Zinc

Silver

Mir'le white

Marble common

Stone calcareous hard

Gres

Glass

Lead

Tin

Stone calcareous soft

Clay -

Bismuth

P(;rcelain

Antimony

Oker

Chalk

Gypsum

10000 to 2474-9304

8452
to 8956

toS^O^-

to 7342

■ to 7383

8686
7863
7^34

7516

lo 7368—7627

to 7103—5232

to 6526—7500

t. 6324-6051

. to 6087—5811

to 5S It— 5077

to 5658—7043

to 5526 - 5593

to 5395—6348

to 5349- 4462

to 4571—4452

to 2989—3293

YOL. X.

ZINC,

138

BUFFON S

ZINC, with

Silver

Marble white

Gres -

Lead

Tin

Stone calcareous soft

Ciaj

Bismuth

Antimony

Chalk

Gypsum

First Entire
Refrig^. Refrig.

lOOOO to 8904—8990
10015
to 8S05— 8424

7194
to 6242—7333

5838
to 6051—7947

4940
to 6777—6240

5666
to 5536—7719

4425
to 5484—7458

4373
to 5343—7547

4232
to 5246—6608

4135
to 3729—5862

2618
to 3409—4261

2298

SILVER, with

Marble white
Marble common
Stone calcareous hard
Gres

10000 to 8681—9200

to 7912—9040

to 7436—8580

to 7361—7767

Glass

NATURAL HISTORY. 139

First Entire
Refrig. Refrig.

Glass - - 10000 to 7930— 7212

Lead - - to 7154— 9184

Tin - - to 6176—6289

Stone calcareous soft to 6 1 78 — 6289

Clay - - to 6034— 6710

Bismuth - to 6308—8877

Porcelain - - to 5536— 5242

Antimony - to 5692—7653

Oker - to 5000—5668

Chalk - - to 4310— 5000

Gypsum - to 2879—3366

Wood - to 2253—1864

Pumice-stone to 2059 — 1525

WHITE MARBLE, with

Marble common 10000 to 8992—9405

Stone hard - to 8594—9130

Gres - to 8286—8990

Lead - - to 7604— 5555

Tin - - to 7143— 6792

Stone calcareous soft to 6792—7281

Clay . - to 6400— 6286

Antimony - to 6286—6792

Oker - - to 5400—5571

Gypsum * - to 4920— 5116

Wood - to 2200—2857

COMMON

140 bupfon's

COMMON MARBLE, with

First Entire
Refrig. Refrig,

Stone hard - 10000 to 9483—9665

Gres - - to 8767— 9273

Lead - (o 7671—8590

Tin - - to 7424— 6666

Si one soft - - to 7327— 7 &59

Clay - to 7272— 7213

Antniiony - to 6279—8333

Oker - to 6136-6393

Chnlk. - - to 5581— 6333

Wood - - . to 2500— 327^

HARD CALCAREOUS STONE, with

Gres - - 10000 to 9268— 9355

Glass . - to 8710—8352

Lead - - ■ to 8571— 7^31:

Tin - - 1 1095—7931

S?one soft - to 80 -0—8. 95

Clay - - to 6190—6897

Oker - - to4762— 55i7

Wood - . 10 2195—4516

GRES, with

GIrss - - lO'^OO to 9324— 79^9

Lead - to 856 1 —8950

Tin - - to 7667— 7633

Stone soft - to 7644—7 !93

Porcelain - to 7c>64 — 7059

Antimony

NjlTUIlAL HISTORV*

Ml

Antimony

Gvpsum

Wood

First Entire
Refrig. Reirig.

10000 fo 73 >s— 6 ro

to 4368—5000

to 2368—4828

GLASS, ^Tith

Lead

Tin

Clay

Porcelain

Oker

Chalk

Gvpsum

Wood

10000 tof^SIS— 8548

to9 07— 86"9

to 7938—7643

to 7^.fJ2— 8863

- — to 628^>— 6500

to 6104—6195

to 4160—6011

to 2647—5514

Tin

Stone soft

Clay

Bismuth

Antimony

Oker

Chalk

Gypsum

LEAD, with

8ooa

10000 to 8695

to 8437—7192

-— to 7878—8536

to 8698—8750

to 8241—8201

to 6060—7073

to 5714—6111

to 4736—5714

Clay
Bismuth
Antimony
Oker

TIN, with

10000 to 8823—9524

. to 8889—9400

to 8710—9156

to 5882—7619

Chalk

14S

buffon's

Chalk
Gypsum

First Entire
Refrig. Refrig.

10000 to 6394 6842
to 4090 4912

STONE CALCAREOUS SOFT, ^ith

Antimony

Chalk

Gypsum

10000 to 7742—9342

r to 7288—7312

to 4182—5211

CLAY, with

15ismutb

Oker

Chalk

Gypsum

AYood

10000 (o 8870— 94J6

— _ to 8400—8571

to 7701 8000

to 5186- 8055

to 3437 4545

BISMUTH, ^ilh

A ntimony

Oker

Chalk

10004 to 9349—9572
to 8846 7380
to 8020—9500

PORCELAIN, with

Gj^psura

lOOOO to 5301 6500

ANTIMONY, with

Chalk
Gypsum

10000 to 8431—7391
to 3833 5476

OKER, with

Chalk

Gypsum

^yood

10000 to 8954—8889

— _ to 6364—9062

■- — to 4074—5128

CHALK,

NATURAL IIISTORT. 113

First Entire
Refrig. Refri^.

CHALK, with

Gypsum - - lOOOO to 6667— 7920

GYPSUM, with

Wood - - 10000 to 8000 ---5260
Pumice-stone - to 7009—4560

WOOD, with
Pumice-stone - 10000 to 8730—8182

Notwithstanding the assiduity I used in my
experiments, aiid the care I took (o render the
relations exact, I own there are still some im-
perfections in the foregoing table ; but the de-
fects are trivial, and do not much influence the
general results ; for example, it will easily be
perceived, that (he relation of zinc to lead
being 10,0000 to 6,0,51, that of zinc to tin
should be less than 6,000, whereas it is found
6,777 in the table. It is tlie same with respect
of silver to bismuth, which ought to be less
than 6,308, and also with regard of lead to
clay, which ought to be more than 8,000, but
in the table is only 7,878. This difference
proceeded from the leaden and bismuth bullets
not being always the same ; they melted, as
well as those of tin and antimony, and, there-
fore, could not fail to produce variations, the

S:reatest

144; buffon's

greatest of wbicli are the three I have just re-
marked. It was not possible for me to do
better; the different bullets of lead, tin, bis-
muth, and aniimony, ^vJiich I successively
made use of, were made in the same manner,
bul the matter of each might be somewliat dif-
ferci'.t, according; to the quantity of the alloy in
the lead and tin, for I liad pure tin only tor
the two first bullets; besides, there remains
very often a small cavity in the melted bullet,
and these little causes are sufficient to produce
the litlle differences which may be remarked
in the table.

On the whole, to draw from these experi-
ments all the profit that can be expected, the
matters which compose their object mustbcdi-
vided into four classes, viz. 1. Metals. 2 Se-
mi-metals and Metallic Minerals. 3. Vitreous
and Vitrescible Substances. And 4. Calca-
reous andCalcinable substances. Afterwards
the matters of each class mu t be compared
between themselves to discover the cause, or
causes, or the order w hic!i folio .vs the progress
of heat in each, and ihen with each other, in
order to deduce some general results.

First. The order of ihc six metals, accord-
ing to their densiU/, is tin, iron, copper, silver,
lead, and gold; v.hereas the order in which

they

NATURAL HISTORY. 145

tliey receive and lose their heat is tin, lead, sil-
ver, gold, copper, and iron ; so that in tin
alone it retains its place.

The progress and duration of heat in metals
<ioes not then follow the order of their density,
except in tin, which being the least dense, is
also that which soonest loses its heat ; but the
order of the five other metals demonstrates that
it is in relation to their fusibility that they all
receive and loose heat ; for iron is more diffi-
cult to melt than copper, copper more than
gold, gold more than silver, silver more than
lead, lead more than tin ; and therefore we
may conclude that it is only by chance if the
density and fusibility of tin be found so unitea
as to place it in the last rank. Nevertheless,
it would be advancing too much to pretend
that we must attribute all to fusibility, and no-
thing to density. Nature never deprives her-
self of one of her properties in favour of ano-
ther in an absolute manner ; that is to say, in
a mode that the first has not any influence on
the second. Thus,' density may be of some
weight in the progress of heat ; but we may
safely aflirm, that in the six metals it has very
little comparatively with fusibility.

This fact was neither known to chemists nor
naturalists ; they did not even imagine that
gold which is more than twice as dense as iron,
VOL. X. U nevertheless

146 . BUrF0N*9

nevertheless loses its heat near a thiird soonefi
It is the same with lead,. silver, and copper,
■which are all more depse than iron, and Avhich,
like gold, hept and cool more readily ; for
thou;^li the object of this second memoir -vvas
only refrigeration, yet the experiments of the
one that preceded it demonstrate, that there is
ingress and egress of heat in bodies, and that
those which receive it most quickly also lose
it- the soonest.

. . if we reflect on the real principles of density,
and the cause of fusibility, we shall perceive,
tliatdensity depends absolutely on the quantity
of matter which Nature places in a given space.;
that the more she can make it enter therein, the
more density there will be, and that gold, in this
respect, is of all substances, that which con-
tains the most matter relatively to its volume.
It is for this reason that it has been hitherto
thought, that more time is required to heat or
cool gold than other metals ; and it is natu-
ral enough to suppose, that containing double
ortreble the matterinthe same volume, double
or treble time would be required to penetrate
it with heat ; nay this would be true, if in
every substance the constituent parts were of
the same figure and ranged the same. But in
the most dense the molecules of matter arc,
probably, of a figure sufficiently regular not to
leave very void places between them 3 in others

which

NATURAL HIStORV. 147'

wbichare not so dense, andtbeir iignres more
irregular, more vacuities are left, and in tlie
lifijhest, llie molecules being few, and most
likely of a very irregular figure, a tbousand
times more void is found than plenitude ; for it
may be demonstrated by other experiments,
tbat the volume of even the most dense sub-
stance contains more void space thanfull matter.

Now, the principal cause of fusibility is the
facility which the particles of Jieat find in se-
parating these molecules of full matter from
each other ; let the sum of the vacuities be
greater or less, which causes density or light-
ness, it is indifferent to the separation of the
molecules which constitute the plenitude;
and tlie greater or less fusibility depends en-
tirely on the power of coherence which retains
the massive parts united, and opposes itself
more or less to their separation. The dilata-
tion of the total volume is the first degree of
the action of heat ; and in different metals it is
made in the same order as the fusion of the
mass, which is performed by a greater degree
of heat or fire. Tin, which melts the most rea-
dily, is also that which dilates the quickest ;
and iron, which is the most difBcultof all to
melt, is likewise that whose dilatation is the
slowest.

After these general positions, which appear
clear, precise, and founded on experiments

tlwt

143 buifok's

tliat nothing can contradict, it might be iiiia'sr
gincd that ductility would follow the order of
fusibility, because the greater or less ductility
seems to depend on (he greater or less adhesion
of ihe parts in each metal ; neyerlheh ss, ducti-
lity seems iohaveasmuch connection with the
order of density, as with that of their fusibility.
I would even afhrra that it is in a ratio com-
posed of the two others, but that would be only
by estimation, and a presumption which is,'per-
haps not founded ; for it is not so easy to ex-
actly determine the different degrees of fusibi-
lity, as those of density ; and as ductility parti-
cipates of both, and varies accordir)g to cir-
cumstances, we have not as yet acquired the
necessary knowledge topronounceaffirmativcr
ly o this subject, though it is most certainly
of sufficient importance to merit particular
researches. The same metal when cold gives
very different results to what it does when
Lot, although treated in the same man-
ner. Malleability is the first mark of duc-
tility ; but that gives only an iraj^crfect idea
of the point to which ductility may extend ;
nor can simple lead, the most malleable
metal, be diawn into such fine threads as
gold, or even as iron, which is the least mal-
leable. Besides we must assist the ducti-
lity of metals with the addition of fire, with-
out

KATUnAL HISTORY. 149

out \vhich the J become brittle : even iron, al-r
thoug-h the raost robust, is brittle like the rest.
Thus the ductility of one metal, and the ex-
tent of continuity ^vhich it can support, dc^
pcnd not only on its density and fusibility,
but also on the manner and space in which it
is treated, and of the addition of heat or fire
T^hich is properly given to it,

II. By comparing those substances which
we term semi-metals and metallic jninerals^
which want ductility, we shall perceive, that
the order of their density is emery, zinc, an-
timony and bismuth, and that in which they
receive and lose heat, is antimony, bismuth,
zinc, and emery ; and which does not in any
measure follow the order of their density, but
rather that of their fusibility. Emery, which
is a ferruginous mineral, although as dense
again as bismuth, retains heat longer. Zinc
which is lighter than antimony or bismuth,
retains heat longer than either. Antimony
and bismuth, receive and keep it nearly alike.
There are, therefore, semi-metals, and metallic
minerals, whicli, like metals, receive and lose
heat nearly in the same relation as their fusi-
bility, and partake very little of their density.

But by joining the six metals, and the fotir
^f^mi- metals, or nietallic minerals, which I have

tried,

150 BUFFOX^S

ii'lcdy we siiall find the order of the densities of
lliese ten mineral substances to be emery, zinc,
antimony, tiii, iron, copper, bismuth, silver,'
lead and gold. And that tlie order in which
these subsl*inces heat and cool, is antimony,
bismulh, tin, lead, silver, zinc, gold, copper,
emery and iron, in which there aretwothings
that do not appear to perfectly agree with the
order of fiidbilily.

First, Antimony, which, according to New-
ton, should heat and cool slower than lead,
since by his experiments it requires ten degrees
of the same heat to fuse, of which eight are suf-.
ficicnt for lead ; whereas by my experiments
antimony is found to heat and cool quicker;
than lead. But it should be observed that
]J»'ew(on made use of the regulus of antimony,
and that I employed only melted antimony in
experiments. Now this regulus of antimony,
or native antimony, is much more difficult to
fuse than antmiony which has already under-
ffone a first fusion, therefore that does not make
an exception to the rule. On the whole, I do
not know Avhut relation native antimony, or
Fegulus of antimony, may have with the other
matters I have heated and cooled ; but I pre-.
sume, from the experiments of Newton, that
it heats and cools slower than lead.

Secondly,

NATURAL mSTQUr. 151

Secondly, it is pretended, that zinc fuses
more easily than silver, consequently it should
be found before silver in the ordei indicated
by experiments, if this order were in all cases
relative to that of fusibility ; and I own that this
semi-metal seems, at the first glance, to make
an exception to the law which is followed by
all the others ; but it must be observed, tliat the
ditference given by my experiments betweea
zinc and silver is very trifling. The small
globe of silver which I made use of was of th^
purest silver, without the least mixture of cop-
per ; but I had my doubts whether that of zinc
were entirely free from copper, or some other
metal less fusible; and therefore, after all my
experiments, I returned the globe of zinc to
M. Rouelle, a celebrated professor of chc-^
mistry, requesting him carefully to examine
it, which having done, afier several trials, he
found a pretty considerable quantity of iron,
or saffron of sleel in it.

I have, therefore, had the satisfaction of
seeing that not only my own supposition was
well founded, but also that my experiments
have been made with sufhcient precision to
evince a mixture. Thus zinc exactly follows
the order of fusibility, like the other metals and
semi-metals, in the progress of heat, and does
not piake any exception to the rule, li caa»

not.

l52 RUFFON^S

not (Iierefbre, in general, be said tliat the proi
gross of heat in metals, semi-metals, and me-
tallic minerals, is in the same ratio, or even
nearly to that of their fasibility.

III. The Vitrescible and Vitreous Matters,
which I tried, beiivg ranged according to their
density, are, pumice-stone, porcelaine, oker,
clay, glass, rock-chrystal, and gres, for I
must observe, that although chrystal is not
set down in the table of the weight of each
matter but for six drachms 22 grains, it must
be supposed one drachm heavier, because it
was sensibly too small; and it was for this
reason that I excluded it from the general table
of relations; nevertheless, as the general result
agrees with the rest, I can present the follow-
ing as the order in which these different sub-
stances are cooled :

Pumice-stone, oker, porcelain, clay, glass,
crystal and gres, is according to that of theit
density, for the oker is here before the porcelain
only because, being a fusible matter, it dimi-
nished by the friction it underwent in the ex-
periments, and, besides, their density differs so
little that they may be looked upon as equal.

Thus the law of the progress of heat in
vitrescible and vitreous matters is relative to
the order of their density, and has little or no re-
lation with their fusibility but by the heat re-
quired

NATURAL HISTORY. 153

quired to fuse th^se substances being in an
almost equal degree, and the particular degree
. of their different fusibility being so near each
other that an order of distinct terms cannot }3e
made ; thus their almost equal fusibility mak-
ing only one terra, which is the extreme of this
order, we must not be astonished that the pro-
gress of heat here follows the order ofdensity,
, and that these different substances, which are
.all equally difjScult to fuse, heat and copl
more or less quick in proportion to. the matter
they contain.

It may be objected to rae that glass fuses
more easily than , clay, porcelain, oker, aod

pumice-stone, which, nevertheless, heat and
cool in less tinie than glass ; but the objection

will fail when we reflect, that to fuse glass it is
requisite to have a very fierce fire, the heat of
which is so remote from the degrees which
glass receives in our experiments on r<?frigera-
tion, that it cannot have any influenot on them.
Besides, by powdering clay, porcelain, and
pumice-stone, and by giving them their analo-
gous fusers, as we give to sand to convert it
into glass, it is more than probable that we
should fuse all the matters in the same degree
of fire, and that, consequently we must look
upon it as equal; or almost equal, with their
TOL. X. X resistanet

IM BUFFO n'^^

tesistance to fusion ; and it is for this reasott
that the law of the pron^ress of heat in these
matters is found proportionable to the order
of their density.

ly. Calcareous matters, ranged according*
to the order of their density, are, chalk, scft
stone, hard stone, common marble, and white
marble, which is the same as that of their den-
sity. The fusibility is not here of any weight,
because it requires at first a very great degree
of fire to calcine them; and although the cal-
cination divides the parts, we must look upon
the effect only as a first degree and not as a
complete fusion. The whole power of the
best burning mirrors is scarcely sufficient to
perform it. I have melted and reduced into
a kind of glass some of these calcareous mat-
ters; and i am convinced that these matters
may, like all the rest, be reduced ulteriorly
into glass, without employing for this purpose
any fusfng matter, and only by the force of a
fire superior to that of our furnaces ; conse-
quently the common term of their fusibility is
still more remote, and more extreme, than that
of vitreous matlers, and it is for this reason
that they also follow more exactly the order of
density in the progress of heat.
White gypsum, improperly called alabaster,

is

NATURAL HISTORY. 155

is a mat/er which calcines like all other plasters
fej a more modera<e heat than that which is
necessary for the calcination of calcareous
matters, and it follows tlie order of density in
the progress of heat which it receives or loses,
for although much more dense than chalk, and
a little more so than v/hite calcareous stone, it
Jieats and cools more readily than either of
those matters. This demonstrates that the
more or less easy calcination and fusion pro-
duces the same effects relatively to the pro-
gress of heat. Gypsous matters do not require
so much fire to calcine as calcareous^ and it is
for this reason that, although more dense,
they heat and cool much quicker.

Thus it may be concluded, that, in general,
the progress of heat in all Mineral Substances
is alwaj/s nearly in a ratio of their greater or
less facility to calcine, or melt : but that when
their calcination, or their fusion, are equallj/
dijficidt'i and that thei/ require a degree ofeX"
treme heaty then the progress of heat is made
according to the order of their densiii/,

I have deposited in the Royal Cabinet the
globes of gold, silver, and of all the other
metallic and mineral substances Tvhich served
far the preceding experiments, that if the truth
pf their results^ and the general consequences

which

156 buffon's

whicli 1 have deduced, be doubtiedy there may
be an opportunity of rendering them more
authentic.

OBSERVATIONS ON THE NATURE OF PLATINA.

WE have already seen, that of all the Mi-
neral substances which I subjected to trial it
was not the most dense, but the least fusible,
which required the longest time to receive and
lose heat. Iron and emery, ^vhich are the
most difficult matters to fuse, are, at the
same time, those that heat and cool the
slowest. There is nothing except platina
that is accessible to heat, which retains it
longer than iron. This mineral, (which has
not long been publicly mentioned) appears,
however, to be more difficult to fuse ; the fire
of the best furnaces is not fierce enough to prc-
duce that effect, nor even to agglutinate the
small grains, which are all angular, hard,
and similar in form to the thick scale of iron,
but of a 3^ellowish colour ; and although we can
fuse them without any addition, and reduce
them into a mass by a mirror, platina seems to
require more heal than the ore and scales of iron

which

NATURAL HISTORY. 15T

wtich we easily fuse in our forge furnaces.
In other respects, the density of piatina being
much greater than that of iron, the two quan-
tities of density and non-fusibility unite here to
retider this matter the least accessible to the
progress of beat. I presume, therefore, that
piatina would have been at the head of my table
if I had put it to (he experiment; but I was
not able to procure a globe of it of an ir.ch dia-
meter, it being only found in grains* ; and that
which is in the mass is not pure, it being ne-
cessary, in order to fuse it, to mix it with other
matters, which alter its nature. The Comte
de Billarderie d'Angivilliers, who often at-
tended my experiments, led me to examine
this rare metallic substance, not yet suQiciently
known. Chemists who have employed their
time in plutir.a, have looked upon it as a new,
|>erfect, proper, and particular metal, different
from all the rest ; they have asserted, tliat i(s
specific weight was nearly equ^l to that of gold; •
Ijut that it essentially differed in other respects
from gold, having neither ductility nor fusibi-
lity. I own I am of a quite contrary opinion ;
because a matter which has neither ductility
nor fusibility, cannot rank in the number of

metals,

* I have been assured, however, by a person of the first
respectability, that piatina is sometimes found in masses,
and that he himself saw a piece that weighed twenty
pounds, pure as it was extracted from the mine.

loS BUFFO n's

Kielals, whose essential and common pro»
periies are to be ductile and fusible. JNeithcr,
aitcr a very careful examiuationj did pl.iiina
appear (o nie a new metal different from every
olker, but rather an alloj of iron and gold
formed by Nature, in which the quantity of
gold predominated over the iron ; ai.d J found*
ed this Oj7inion on tlie following facts :

Of S ounces 85 grains of plutina, furnished
mc by Comied'AngiviilitTs, yvhich 1 presented
to a fetrong loadbtane, there remained only 1
©ujice, i dram, awd 98 grains, all ihe rest was
taken avvay by the loadstone ; tii ere fore, nearly
six-scvcmiis ot the whole was attracted by thq
loadstene, \Yliich is so considerable a quantity,
that it is iiriposbibte to suppose that iron is not
contained intheintimaie substance of platiiia,
b«t that it is even there in a very great quan-
tity. I am convinced it contains much more,
for ii 1 had not been weary of these experi-
naents, which took me up several days, I should
have attracted a great part of the remainder
of the 8 ounces by my loadstone, for to the
last it continued to draw some grains one by
one, and sometimes two. l here is, therefore,
iMuch iron in platina, and it is not simply
jMixed with il, as with a foreign matter, but in-
limately united and making part of it» bubf

stance i

NATURAL HISTORY. I^

stance; or, if this is denied, it must be sup-
posed, that there exists a second matter m
Nature which like iron may be attracted by
the loadstone.

All the platina I have had an opportunity of
examining, has appeared to be mixed with two
different matters, the one black, and very at-
tractable by the loadstone ; iha other in larger
grains, of a pale yellow, and much less mag-
netic than the first. Between tliese two mat-
ters, which are the two extremes, are found all
the intermediate links, whether with respect-
to magnetism, colour, or size of the grains.
The most magnetic, which are at tlie same
time the blackest and smallest, reduce easily
into jwwder by a very slight friction, and leaye
on white papier the same marks as lead. Seven
leaves of paper which were .successively made
use of to expose the platina to the action of
the loadstone, were blackened over the whole
extent occupied by it ; the la»t left less tlian the
first, in proportion as the grains which remain-
ed were less black and magnetic ; the largest
grains, which are yellow, and least magnetic,
instead of crumbling into powder like the
small black grains, are very hard, and resist all
' trituration ; nevertheless, tlicy are SLi>ceplit)ie
of extension in an agate mort;tr, under tlie
reiterated strokes of a pestle of the same mat-
ter.

]60 buffon's

ter, and I flaUened and extended many grains
to the double or treble cxtoiit of tbcir surface :
this part of platina, therefore, has a certain
degree of malleabiiitj', and duclility, whereas
the black part appears to be neither malleable
nor ductile. The intermediate grains parti-
cipate of the qualities of the two extremes :
they are brittle and hard, tliey break or ex-
tend under the strokes of the pestle, and afford
a little powder not so black as the £rst.

Having collected this black powder and the
most magnetic grains that the loadstone at
first attracted, I discovered that the whole
A^as iron, but in a different state from common
iron. The latter reduced into powder and
filings contracts moisture, and rusts very
readily ; in proportion as the rust increases, it
becomes less magnciic, and absolutely loses
this magnetical quality when entirely and in-
timately rusted; whereas this iron powder, or
ferruginous sand found in Iheplatina, is inac-
cesssible to rust, how long soever it may be
exposed to the air and humidity; it is also
more infusible and much less dissoluble than
common iron; but is, nevertheless, an iron
V, liich appears to differ only from common iron
by a greater purity. This sand is, in fact, iron
divested of all llie combustible matter and all
terrene paits wliich are found in common iron,

and

NATURAL HISTORY. 161

and rven in stx^el. It appears endowed and co-
vered with a Wtreous varnish which defends
it from all injury. What is very rcnarkable,
this pure iroR sand does not exclusively belong
to the platinaore; for I have found it, although
always in small quantities, in many par(s where
theiron ore has been dug, and which consumed
in my forges. As I submilted to several trials
all the ores I had, before I used ihem in rny
t;xpcrimen(s, I was surprised to find in some
of them, which were in grains, parlicles of
iron, somewhat rounded and shining, like the
tilings of iron, and perfectly resembling the
ferruginous sand of the platina ; they were all
as magnetic, all as little fusible, and all as dif-
ficult of solution. Such was the result of the
comparison I made on the sand of platina,
and of the sand found in both my iron ores, at
the depth of three feei, in earths where wa-
ter easily ]3enctrated. 1 was puzzled to conceive
whejice these particles of iron could proceed,
how they had been defended against rust for
the ages they were exposed to the humidify
of the earth, and how this very magnetical
iron had been produced in veins of mines,
which had not the smallest degree of that qua-
lify. I called experience to my aid, and became
at lengfh satisfed upon these points. I was
TOI-- X. Y well

1C2 buffon's

well convinced that none of our iron ores in
grain were tractable by the loadstone, and
well persuaded that all iron ores, which are
magnetical, have acquired that property only
by the action of fire : that the mines of the
north, which are so raagnelical as lobe sought
after by the compass, must owe their origin to
.fire, and are formed by the means, or the inter-
medium of water; from which I was induced
to suppose that this ferruginous and magnetic
sand, that I found in a small quantity in my
iron mines, must owe its origin to fire, and
having examined the place I was confirmed in
this idea. This magneticul sand is found in a
wood, where, from time immemorial, they
have made, and still continue to make, coal
furnaces. It is likewise more than probable that
there were formerly considerable fires here.
Coal and burnt wood produce iron dross,
whicli includes the most fixed parts of iron
that vegetables contain ; it is this fixed iron
which forms tlie sand here spoken of, when thtf
dross is decomposed by the action of the air,
sun, and rain, for then these pure iron parti-
cles, which arc not subject to rust, nor to any
otlier kind of alteration, suffer themselves to be
carried away by tlie water, and penetrate with
it some feet deep into the earth. What I here

advance

NATURAL IIISTORf r 163

advance may be verified by grinding the dross
well burnt, and there will be found a small
quantify of this pure iron, which, having re-
sisted the action of tlie fire, equally resists that
of the solvents, and does not rust at all.

Being satisfied on this head, and having
sufficiently compared the sand and dross ta-
ken from th« iron ores with that of the platina,
so as to have no doubt of their identity, it was
not long before I was led to conclude, consi-
dering the specific gravity of platina, that if
this pure iron sand, (proceeding from the de-
composition of dross) instead of being in an
iron mine, was found near to a gold one, it
might, by uniting with tliat metal, form an al-
loy which would be absolutely of the same na-
ture as platina. Gold and iron have a great
affinity ; and it is well-known that most iron
mines contain a small quantity of gold ; it is
also known how to give to gold the tint, co-
lour, and even the brittleness of iron, by fusing
them together. This iron-coloured gold is
used on difl:erent golden jewels to vary the co-
lours ; and this gold mixed witli iron is more
or less grey, and more or less tempered, accord-
ing to the quantity of iron which enters the
mixture. I have seen it of a tint absolutely
like the colour of platina ; and having enquir-
ed

164 buffon's

cd of a goldsmith the proportion of gold anej
iron (herein, he informed rac, (hat in a piece
of 'i4 carats, there were no more than 18 gold,
consequently a fourth p irt was iron, which is
nearly the propartion found in (he natural pla-
tina, if we judge of it by the specific weight;
and this gold made with iron is harder and
specifically less weighty than pure gold. All
these agreements and common qualities with
platina, have persuaded me, that this pretend-
ed metal is, in fact, only an alloy of gold and
iron, a!)d not a particular substance, a new
and perfect metal different from every other,
as cbeinis(s have supposed.

It is well known \hal alloy makes all me(ais
brittle, and that when there is a penetration,
that is, an augmentation in the specific gravity j
the alloy is so much the more tempered as the
penetration is the greater, and the mixture be-
comes the more intimate, as is {perceived in the
alloy crdled bell-metal, although it be com-
posed of two very ductile metals. Now no-
thing is more tempered, nor heavier than pla-
tina, which alone ought io make us conclude
that it is only an alloy made by Nature, a
mixture of iron and gold, owing in part its
fpecific gravity to this last, and, perliaps, al-
so, in a great part, to the i>enet ration of the
two matters of which it is composed.

As

NATUR^Ii HISTORY. 1G5

As this matter, heated alone and without
any addition, is very difScult to reduce into a
mass, as by the fire of a burning mirror we caa
obtain only very snaall masses, and as fhe hy-
drostaticnl experiments made on small vo-
lumes are so defective, that we can not conclude
any thing therefrom, it appears to me that the
chemists bave been deceived in their estima-
tion of the specific gravity of this mineral. I
put some powder of gold in alitde quill, whicli
I weighed very exactly ; I put in the same
quill an equal yolume of platina, and it weigh-
ed nearly . a tenth less ; but this gold powder
was much too fine in comparison of the pla-
tina. M. Tiiiet, who besides a profound know-
ledge of metals, possessed the talent of mak-
ing experiments with the greatest precision,
repeated, at my request, this experiment up-
on the s|)ecific weight of the platina, com pared
to pure gold; for tliis purpose, he, like me,
made use of a quill, and cut gold of 24 c:irats,
reduced as much as possible to the size of the
grains of platina, and he found, by eight ex-
periments, that the weight of platina differed
from that of pure gold very near a fifteenth?
but we both observed that the grains of gold
had much sh a per angles than the platina: all
the angles of the latter were blunt, and even
soft, whereas the grains of this gold had sharp

and

I^ buffon's

and culting angles, so that they could not
adjust themselves, nor heap one on the other
as easily as those of platina. The gold pow-
der I had before made use of Tyas such as is
found in river sand, whose grains adjust them-
selves much better one anjainst the otlier, and
I found a about a tenth difference between the
specific weight of thoic and platina ; neverthe-
less, those are not pure gold, more than tw^o or
three carats beinsc often wantinrr, which must
diminish the specific weight in the same rela-
tion. Thus we have thongl^t we might main-
tain, from the result of my experiments, that
platina in grains;, and such as Nature produces
if, is, at least, an eleventh, or twelfth, lighter
than gold. There is every reason to presume
that the error on tlie density of platina, pro-
ceeded from is not having been weighed in its
natural state, but only after it had been re-
duced into a mass ; and as this fusion cannot
be made but by the addition of other matters,
and a very fierce fire, it is no longer pure pla-
tina, but a composition in which fusing mat-
ters are entered, and from which fire has taken
the lightest parts.

Platina, therefore,insteadofbeing of a density
almost equal to that of pure gold, as has been
asserted, is onlj^ density between that of gold

and

NATUHAL IIISTORY. 167

and iron, anclonly !>earer this :first metal than
the last. For supposing that the cube foot of
gold weighed 13:-61b and that of iron 280, that
of platina in grains will be found to weigh
about 11911b. which supposes more than | of
gold to 5 of iron in this alloy, if there is no
penetration ; but as we extract | by the load-
stone, it might be thought, that there is more
than I iron therein : especially as by conti-
nuing this experiment, I am persuaded, we
should be able, wit h a strong loadstone to bring
away all the platina even to the last grain.
Nevcrtlieless, we must not conclude that iron
is contained therein in sogreat a quantity; for
when it is mixed by the fusion with gold, the
mass Xvhich results from this alloy is attractable
by the loadstone, although the iron is in no
great quantify therein. M. Baume had a piece
of this alloy weigliingGG grains, in which was
only entered 6 grains, that is, ^\- of iron, and
this button was easily taken up by the load--
stone. Hence the platina might possibly con-
tain only yV i**on, or fi gold, and yet be at-
tracted entirely by the loadstone; and this per-
fectly agrees with the specific weight which is
^V less than gold.

.But what makv?s me presume, that plitina
contains more than -^j of iron, or ff of gold,

is

t6S ijgpfon's

is, that the alloy from fhis proportion is slill
t)f the gold colour, and much yellower Ihaft
the highest coloured platina, and that | iron,
or I gold is requisite for the alloy to be pre*
ciscly of the natural colour of platma. lam,
therefore, greatly inclined to think that there
might possibly be this quantity of | iron in
platina. We were assured by many experi-
wicnts, that Uic sand of this pure iron which
contained platina, is heavier than the filings
of common iron. Tlius, this cause, added to
the efil'ct of penetration, is suflficient for th^
reason of this gre^it quantify of iron contained
under the small volume indicated by the spe-
cific weight of platina.

On tlie whole, it is very possible that I may
be deceived in some of the consequences which
I have drawn from my observations on this
metallic substance : for I ha\'e not been able
to make so profound an examination as I
cotildwish; and wha.t I say is only what I
Iiave observed, which may perhaps serve as
a stimulus to other and better researches.

Chance led me to tell my ideas to Contc de
Milly, who declared himself nearly of my opi-
nion. I gave him the preceding remarks to
inspect, and two days after he favoured me

wit U

NATURAL HISTORY. 169

with the following observations, and which he
iias permitted me to publish.

" I weighed exactly thirty-six grains of
platina ; I laid them on a sheet of white paper
that I might observe them the better with a
-magnifying glass : I perceived three different
substances; the first had the metallic lustre,
and was the most abundant ; the second, draw-
ing a LuIq on the black, very nearly resembled
a ferruginous metallic matter, which could
undergo a considerable degree of fire, such
as the scoria of iron, vulgarly called mackefer:
the third less abundant than the two first, i. e.
sand, where the yellow, or topaz colour, is
ih.6 most predominant. Each grain of sand,
considered separate, offered (o the sight regu-
lar chrystals of different colours. I remarked
some in an hexagon form, terminating in
pyramids like rock chrystal ; and this sand
seems to be no otlier than a detritus of chrys-
tal, or quartz of different colours*

'' I resolved On separating, as exactly as
possible,these different sub^ances, by means of
the loadstone, and to put aside the parts most
attractable by the Loadstone, from those which
were less, and both from those which were not
so at all ; then to examine each substance par«
ticularly, and to submit them to different che-
mical and mechanical heats,
^'OL. X. Z ^'l sepa-

170 buffom's

'^ I separated these par(s of the platina
which were briskly attracted at the distance of
two or three lines ; that is to say, without the
contact of the loadstone ; and for this experi-
ment I made use of a good fictious magnet; I
afterwards touched the metal with this mag*
net, and carried ofFall that would yield to the
magnctical ft.rce. Being scarcely any longer
attractable, I weighed what remained, and
whicli I shall call No. 4 ; it was twenty-four
grains; No. 1, which was the most sensible to
the magnet, weighed four grains; No. 2
weighed the same ; and No. 3, five grains

" No. i , examined by the magnifying glass^
presented only a mixture of metallic parts, a
white sand bordering on the greyish, flat and
round, or black vitriform sand, resembling
pounded scoria, in which very rusty parts are
perceptible : in short, such as the scoria of
iron presents after having been exposed to
moisture.

'' No. 2 presented nearly the same, except-
ing that the metallic parts predominated, and
that there were very few rusty particles.

" No. 3 was the same, but the metallic parts
were more voluminous ; they resembled melted
metal which had been thrown into water to be
granulated ; they were flat, and of all sorts of
figures, rounded on the corners.

No. 4,

NATURAL HISTORY. 171

*^ No. 4, which had not been carrieJ off by
the magnet (but some parts of which still af-
forded marks of sensibility to magnetism , when
the magnet was moved under the paper where
they were in), was a mixture of sand, metallic
parts, and real scoria, friable between the fin-
gers, and which blackened in the same manner
as common scoria. The sand seemed to be
composed of small rock, (opaz, and cornelian
chryslals. I broke some on a steel, and the
powder was like varnish, reduced into powder ;
I did the same to the scoria ; it broke with the
greatest facility, and presented a black powder
which blackened the paper like the common,

*' The metallic parts of this last (So. 4) ap-
peared more ductile under the hammer than
those of No. 1, which made me imagine they
contained less iron than the first : from whence
it follows, that platina may possibly be no more
than a mixture of iron and gold made by Na*
ture, or perhaps by the hands of men.

'' I endeavoured to examine, by every pos-
sible means, the nature of platina: to assure
myself of the presence of iron of platina by
chemical means, I took No. 1, which was
very attractable by the magnet, and No. 4,
which was not; I sprinkled them with fuming
spirit of nitre ; I immediately observed it with
the microscope, but perceived nocfiorvcsccnce?

I added

172 buffon's

I added distilled water thereon, and it still
made no motion, but the metallic parts ac-
quired new brilliancy, like silver : I let this
mixture rest for ^ve or six minutes, and hav-
ing still added water, I threw some drops of
alkaline liquor saturated with the colouring
matter of Prussian blue, and very fine Prus-
sian blue was afforded me on the first.

^* No. 4, treated in the same manner, gave
the same result. There are two things very
singular to remark in these experiments ; first,
that it passes current among chemists who
have treated on the platina, that aquafortis, or
spirit of nitre, has no action on it. Yet, as I
have just observed, it dissolves it sufficiently,
though without effervescence, to afford Prus-
sian blue, when we add the alkaline liquor
phlogisticated and saturated with the colour-
ing matter, which, as is known, participates
iron into Prussian blue.

^' Secondly, Platina, which is not sensible.
to the magnet, does not contain less iron, since
spirits of nitre dissolves it enough, and without
effervescence, to make Prussian blue. Whence
it follows^ that this substance, winch modern
chemists, perhaps toogreedy of the marvellous,
and too willing to give something novel, have
considered as a ninth metal, may possibly be
only a mixture of gold and iron.

'' Without

NATURAL HISTORY. 175

<< Without doubt there still require many
experiments to determine bow this mixture has
taken place, if it be the work of Nature or the
effects of some volcano, or simply the produce
of the Spaniards' kbours in the New World to
acquire gold in the mines of Peru.

" If we rub platina on white linen it black-
ens it like common scoria, which made me
suspect that it was the parts of iron reduced
into scoria which are found in Uiis platina, and
give it this colour, and which seem, in this
slate, only to have undergone the action of a
violent fire. Besides, having a second time
examined platina with ray lens, I perceived
therein different globules of liquid mercury,
which made me suppose that platina might
be the produce of the hands of man, in the
follov/ing manner : — Platina, as I have been
told, is taken out of the oldest mines in Peru,
which the Spaniards explored after the con-
quest of tlie New World. In those dark times
only two methods were kriown of extracting
gold from the sands wiiich contained it ; first,
by an amalgarna with mercury ; secondly, by
drying it. The golden sand was triturated
with quicksilver, and when that was judged
to be loaded with the greatest part of the gold,
the sand was thrown away, which was named
crass e, as useless and of i\Q value.

"The

174 BUFFOX'S

" The otber method was adopted with as little
judgment ; <o extract it they began by minera-
lising auriferous metals by means of sulphur,
which has no action on gold, the specific weight
being greater than that of other metals : but to
facilitate its precipitation iron was added, which
loaded itself with the superabundant sulphur,
and this method is still followed. The force
of fire vitrifies one part of the iron, the other
combines itself with a small portion of the gold,
or even silver, which mixes with the scoria,
from whence it cannot be drawn but by strong
fusions, and being well instructed in the suit-
able intermediums which are made use of. Che-
mistry, which is now arrived to great perfec-
tion, affords, in fact, means to extract the
greatest part of this gold and silver : but at the
lime when the Spaniards explored the mines of
Peru, they were, doubtless, ignorant of the art
of mining with the greatest profit ; besides,
they had such great riches at their disposal that
they, probably, neglected the means which
would have cost them trouble, care, and time ;
there is much reason therefore to conclude that
they contented themselves with a first fusion,
and threw away the scoria as useless, as well as
the sand which had escaped thequicksil ver,and
perhaps they made a mere heap of these two
mixtures; which Ihey regarded as of no value,

'' Thcs#

NATURAL HISTORir. 175

** These scoria contained goW. and silver,
iron under different states, and that in different
proportions unknown to us, but which, per-
haps, are those that gave origin to the platina.
The globules of quicksilver which I observed,
and those of gold which I distinctly saw,
with the assistance of a good lens, in the plati-
na I had in my hands, have given birth to the
ideas which I have written on the origin of
this mineral; but I only give them as ha-
zardous conjectures. To acquire some cer-
tainty we must know precisely where the pla-
tina mines arc situated, and examine if they
have been anciently explored, whether it be
extracted from a new soil, or if the mines bo
only rubbish,and to what depth thej are found ;
and, lastly, if they have any appearance of
being placed by the hands of man there or not,
which alone can verify or destroy the conjec-
tures I have advanced." *

These observations of Comte de Milly con-
firm mine in almost every point. Nature is the
same, and presents herself always the same to
those who know how to observe her : thus we

must

* Baron Siekengen, minister of the elector Palatine,
told M. de. Milly, that he had then in his possession two
memoirs whic'i had been given to him by M. Kellner, che-
mist and metallurgist in the service of the Prince of Birc-
kenfeld, at Manheim, and which oft'cred to the court of
Spain to return nearly as much gold as they vyould send
him platina.

176 buffon's

must not be surprized that, without any com-
munication, we observed the siinie things, and
deduced the same consequence therefrom ; that
platina is not anew metal, different from every
other, but a mixture of iron and gold. To re-
concile his observations still more with mine,
and to enlighten, at the same time, the doubts
which remain on the origin and formation of
platina, I have thought it necessary to add the
ibllowing remarks :

1. The Comte de Milly distinguishes three
kinds of matters in platina, namely ,two, metal-
lic, and the third, non-metallic, of a chrystal-
line form and substance. He observed, as well
as I, that one of the metallic matters is very
attractable by the magnet, and ihe other but
Utile, or not at all. I mentioned these two mat-
ters as well as he, but I did not speak of the
third, which is not metallic, because there was
none, or very little, on the platina on which I
made my observations. It is possible that
the platina which the Comte m.adc use of
was not so pure as mine, which, I observ-
ed with the greatest care, and in which I saw
only some small transparent globules, like
white melted glass, which were united to the
particles of platina, or ferruginous sand, and
which were carried any where by the magnet*

fhcs-e

NATURAL

'iii'sTORY. '177

' ^li^sb'ti-alfsparVnt g^of3iil(^s were very" lew, "and
in eiglit Ounces'of platinaSvliicIi I h'tirr6\vly
inspected ivitli a very strong' lens, I ne\er
ipcrceiycd regular crystals. It rather appeared
to' me "t L at ' al 1 ili e t rahs p a re n f pa r t ib^ cs were

' gio%uToii'5, like mel-eVf glass, aiivi all attnctied'to

' niefallic parts ; nevertheress, as 1 (litt'not in tlio

least doub't the veracity 'of the Comte de Slitly 's

obserValibn, who observed crystalline parlicies

"of 6. f&guiar form, anri in a' groat nnhilDer, in

'Hisptatinn, I thought 1 ought' liot to'con^ne
myseffsoldy to the examination of lliat p'latina
of which r have spoken ; hnd finding some m
the king*s cabinet, M. Dnubeiiton and T ex-
amined it togc^tlier : tiiis appeared to be riiucli
less pure thaii tliat we had 'before made our
experiments on ; and in it we remarked a

' great number of small prismatic and transparent
crystals, some of a ruby 'colour, others ofa

* topaz, and others perfectly wliite, whicfi con-
vinced us of the correctness of the Comte
de Milly in his observations; but this only
proves that there are some mines of platina
much more pure than others, and that iii tllose
which are the most so, none of these foreign
bodies are found. M. l)aubcnton also re-
marked some grains flat at bottom andrough at
tbp, like melted metal cooled on a plain, and I
VOL. X. A a very

1T8 buffon's

very distinctly saw one of these hemispherical
grains, which might indicate that platina is a
matter that has been melted by the fire ; but it
is very singular, that in this matter, if melted
by fire, small crystals, topaz, and rubies, are
found ; and I know not whether we ought
not to suspect fraud ia those who supplied this
platina, who, to increase the quantity, mixed
it with these crystalline sands, for I never met
with these crystals but in one half pound of
platina given me by the Comte de AngilUviers.
2. 1, as well as Comte de Milly, found gold
sand in platina ; it is readily discovered by its
colour, and because it is not magnet ical ; but
I own that I never perceived the globules of
mercury which he states to have done ; yet I
do not mean therefore to deny their exist-
ence, only that it appears to me that the sand
of gold meeting with the globules of mercury,
in the same matter, they might be soon amal-
gamated, and not retain the colour of gold,
which Ihaveremarked in all the gold sand that
I could find in half a pound of platina ; besides,
the transparent globules, which I have just
spoken of, resemble greatly the globules of live
and shining mercury, insomuch that at the
tkbt glance it is easy to be deceived in them.

3. There

NATURAL HISTORY. 170

3. There were by no means so may tar-
nisbed and rusty partsin my first platina asin
that of Comte de Milly's. nor was it properly
a rust which covered the surface of those fer-
ruginous particles, but a black substance pro-
duced by fire, and perfectly similar to tbat
which covers the surface of burnt iron. But
my second platina, that which I had from the
royal cabinet,had a mixture of some ferruginous
parts, which under the hammer were reduced
into a yellow powder,and had all the characters
of rust. This platina therefore of the royal
cabinet,andthat of Comte deMilly, resembling
in every respect, it is probable that thoy pro-
ceeded from the same part, and by the same
road. I even suspect that both had been so-
phisticated and mixed nearly one half with
foreign crystalline and fenuginous rusty mat-
ters, which are not to be met with in the natu-
ral platina.

4. The production of Prussian blue by pla-
tina appears evidently to prove the presence
of iron in those parts even of this mineral which
are the least attractable to the magnet, and at
the same time confirms what I have advanced
on the intimate mixture of iron in its substance.
The flowing of platina by spirits of nitre, also
proves that although it has no sensible efferves-
cence, this acid attracts the platina in an evident

manner ;

j&0 bvfjfon's

irqiimcr ; and the authors who have asserted
the contrary, have followed their common
track, which consists in looking on all actions
as iiiill which jdonot produce an cfFervcscence.
These second experiments of the Conitc de,
D.Iilly would appear to me very important, if
they succeeded always alike.

5., We mutt however admit that many es-
sential points of inforrnat ion are wanting to pro-
Tiounce affirrnativciv on the origin of platina.
We know nothing of the natural history of
his mineral, and we cannot top greatly exhort
those wlio are able to examine it on the spot,
to make known their observations; and until
that is done we must confine ourselves to con-
jectures, some of which appear only more pro-
bable than oi hers. For example, I donotima-
gine platina to be the work of man. The
Mexicans and Peruvians knew how to ca^t
and work gold before the arrival of the Spa-
niards, and ihey were nut acquainted with iron,
which nevertheless they must have employed
in ^ great quantify. The Spuniards theiuj^ei V:es
d'li^ not establish furnaces in tius countrywheii
they first inhabited it to fuse iron. There
is, therefore, every reason to conclude5 that
th^y did not make use of the filings of iron
for the separation qi gold, at least in the be-

NATURATv HISTOHY. !8l

ginning of Iheir labours, v/hich does not go
above two centuries and ^ halfback; a time
much too short for so plentiful a production
as platina, -which is found in large quantities
in many places.

Besides, uhen gold is mixed with iron, by
fusing them together, we ma v always, by a
chemical process, separate then), and extract
the gold : Avhercas, hiihc-rto, chenaists have
not been able to make this separation in pla-
tina, nor determine the quantity of gold con-
tained in this mineral. This seems to prove,
tliat gold is united w ith it in a more intimate
manner than the common alloy, and that iron
is also in it, in a different state from that of
common iron. Flatinn, therefore, appears to
me to be the production of nature, and I am
greatly inclined to think, that it owes it's first
origin to the fire of volcanos. Burnt iron,
intimately united Avithgoldby sublimation, or
fusion, may have produced this mineral, whicli
haying been at first formed by the action of the
fiercest fire, will afterwards have felt tiie im-
pression of water, and reiteraieil frictions,
which have given it the form of blunt angles.
But water alone might have produced platina ;
for supposing gold and iron divided as much as
possible by the humid mode, their molecules,

by

1S2 buffonV

bj unltin£^, will have formed the ^ains whicli
compose it, and which from the heaviest to the
lightest contain gold and iron ; the proposition
of the chemist who offers to render nearly as
much gold as they shall furnish him witlipla-
tina, seems to indicate, that there is, in fact,
only tV of iron to yt of gold in this mineral,
or possibly less. But the nearly of this che-
mist is perhaps a fifth, or fourth, and indeed,
if he could realize his promise to a fourtli, it
would be doing a great deal, and no vain boast.

Being at Dijon the summer of 1773, the
Academy of Sciences and Belles Letters, of
which I have the honour to be a member, ex-
pressed a desire of hearing my observations on
platina ; and having complied, M. de Mor-
veau resolved to make some exiK^riments on
this mineral; for which purpose I gave him
a portion of that which I had attracted by the
loadstone, and also some which I had found
insensible to magnetism, requesting him to ex-
pose it to the strongest fire he could possibly
make. Some time after, he sent me the fol-
lowing experiments, which he was pleased to
subjoin to mine.

'*" Monsieur the Comtede Buffon, in a jour-
ney to Dijon, in the summer of 1773, having
caused me to remark in half a drachm of plati-
na.

NATURAL HISTORY. 1S3

na, which M. de Baume had sent hira in 17GS,
grains in form of buttons, others flatter, and
some black and scaly ; and having separated
by the loadstone those which are attractable
from those which appeared not so, I tried to
form Prussian blue with botli. I sprinkled the
fumin«: nitrous acid on the non-attractable
parts, which weighed 2^ grains. Six hours
after I put distilled water on the acid, and
sprinkled alkaline liquor, saturated with a co-
louring matter; however there was not a
single atom of blue, the platina had only a
little more brightness. I alike sprinkled the
fuming acid on t!ie remaining platina, partof
w hich was attractable, the same Prussian alkali
precipitated a blue feculency, which covered
the bottom of a pretty large bason. The pla-
tina-, after this operation, shewed like the first.
I washed and dried it, and found it had not lost
I of a grain, or -^^-^ part ; having examined it
in this state I perceived a grain of beautiful,
yellow, which was pure gold.

*' M. de Fourcy had lately told the world,
that the dissolution of gold was thrown down
in a blue precipitate by the Prussian alkali,
and had placed this circumstance in a table of
alfmity ; I was tempted to repeat this experi-

mentj

184 SUFFON***

menf, and si3iinkled, in consequence, tlic
plitogisticated alkaline liquor in fhe dissolution
of gold, but the colour of this dissolution did
not change, which made me suspect that the
dissolution of gold made use of bj M. de
Fourcy might possibly not have been so pure.
" At the same time the Comte de Buffbn
Laving given me a sufficient quantity of platina
to make further assays, I undertook to separate
it from all foreign bodies by a good front ; and
I have here subjoined the processes and their
results.

EXPERIMENTS.

*^ I. Having put a drachm of platina, in a
cupel, into a furnace, I kept up the fire two
hours, when the covers sunk down, the sup-
porters having run, nevertheless the platina was
only agglutinated ; it stuck to the cupel, and
had left spots of a rusty colour. The pla-
tina was then tarnished, even a little black,
and had only augmented a quarter of a
grain in weight; a quantity very small in
comparison with that which other chemists
have observed. AYhat surprised me still
more was, that this drachm of platina, as well
as that I used for other experiments, bad
been successively carried away by the load-
stone

NATURAL HISTORY. 185

Uone, and made a portion of 4. of eight ounces,
of \yhich the Comte dc Buiibn has before
spoken .

"II. II al f a d racli m of tlie same pi .itina , ex-
posed to tlie same fire iii a cupel, wascilso ag-
glutinated ; I adhered to thecnpel, on which it
bad left soolsofa rusty colour; the augmenta-
tion of weiglit was found to be nearly in the
saniicproportioii, and the surface as black.

*' iil. I put this half drachm into a new
cupel, but ir.slead ot a cover I placed over it a
leaden crucible. This I kept in the most ex-
treme ijcat for four hours; y^hcti il was cooled
I found tile crucible soldered to the supporf,
and having broken it I perceived that nothing
had peneirated into the internal part of the
crucible, which appeared to be only more
glossy than Uioie. The cupel had preserved
its form and position ; it was a litile cracked,
but not enough lo admit of any penetration ;
the plalina was also not adherent to it, thouo-h
agglutinated, but in a much more intimate
manner than in the first experiments ; the
grains were less angular, the colour more clear,
^nd the brilliancy more metallic. But what
was the most remarkable during the opera! ion
there issued from its surface, probably in the
first momenjts of its refrigeratioir, three drops
VOL. X. B b ,,/

186 BUFFON*S

of water, one of wliich, that arose perfectly
spherical, v/as carried up on a small pedicle of
the vitreous and transparent matter. It was of
an uniform colour, with a slight tint of red,
which did not deprive it of any transparency ;
the smallest of the other ( wo drops had likewise
a pedicle, and the other none, hut was only at-
tached to the plalina by its cxlcr:;ai surface.

'' ly. I endeavoured to assay tlie platina,
and for that intent put a drachm of the grains
taken up by the loadstone into a cupel, with
two drachms of lead. After havin<jc kept up
a very strorig tire for two hours, I found an ad-
herent butfon, covered with a yellowish and
spungeous crust of two drachms twelve grains
weight, which announces thattJie platina had
retained one drachm twelve grains of lead. I
put this button into another cupel in the same
furnace, observii^g to turn it, by which it only
lost twelve grains in two hours ; its colour and
form were very little changed. The same
piece of platina was put into Macquer's
furnace, and a fire kept up for three hours,
when 1 was obliged to take it out, because the
bricks began to run. The platina was become
more metallic, but it, nevertheless, adhered to
the cupel, 'ud this time it lost 34 grains. I
threw it into the fuming nitrous acid to assay it,

and

NATURAL HJSTOliY. 1S7

and (here arising a li.tle cfFcrvcscpnce, I added
distilled water (hereon. The platina lost two
grains, and I remarked some small holes, like
those which its flyinsf off might occasion.

" There then remained only 22 grains of
lead in the platina. I began lo form a hope of
vitrifying this remaining portion of lend, for
which purpose I put the s:ime piece of platina
into a new cupel, and by the care I took for
the admission of air. and other precautions,
the activity of the fire Avas so greatly aug-
mented that it required a supply every eleyen
minutes; to this degree of heat we kept for
four hours, and then permitted it to cool.

" I perceived the next morning that the
leaden crucible had resisted, and that the sup-
})or<ers were only glazed by the cinders. I
found a piece in the cupel, hot adhering, of
a uniform colour, approaching more the colour
of tin than any other metal, but only a little
ragged. It weighed exactly one drachm. All,
therefore, announced that this platina had en-
dured an absolute fusion, and that it was per-
fectly pure, for if we suppose it still contained
lead, we must then admit that it had lost ex-
actly as much of its substance as it had gained
of foreign matter; and such a precision can-
not be the effect of pure chance.

" I passed

1S8 kuffon's

" I passed several days ^villl M. BufTon,
whose company has the same charms as lib
style, and whose conversation is as complete as
his books : I took a pleasure in presenting him
with the production of onr essays ; reexamined
them together, and observed, First, that the
drachm of platina, agglutinated by these ex-
periments, was not attractable by the load-
stone; that, nevertheless, the magnetical bar
had an action on the grains that were loosened
from it.

'' 2, The half drachm of the third experi-
ment was not only attractable in the mass, but
the grains of gold separated therefrom did not
themselves give any signs of magnetism.

" 3. The platina of the fourth experiment
was absolutely insensible to the loadstone.

" 4. The specific weight of this piece was
determined by a good hydroslatical balance,
and being, for the greater certainty, compared
to coined and to other very pure gold, used
by M. BufFon in his experiments, their density
was found, with water, in which they were
plunged,

Pure gold - 19 V
Coin gold - 17 i
Platina - 14 f

" 5. This piece of platina was put upon

s(eel

NATURAL HISTORY. 1S9

etcel to try its dudability ; it supported the
hammer verv well for a few strokes ; its sur-
face because fiat and even, a little smooth in
the parts which were struck, but it split soon
after, and nearly a sixth part separated . The
fracture presented many cavities, some of
winch had the whiteness and brilliancy of
silver, and in others we remarked several
points like chrystalization ; the tops of these
points examined with the lens, was a globule
absolutely similar to that of the third experi-
ment. All the other parts of this piece of
platina were compact, the grain finer and
closer than the best brass, which it resembled
in colour. We offered several of these pieces
to the loadstone, but not one was attracted
thereby. We powdered them again in an
ngate mortar, and then remarked that the
magnetical bar raised up some of the smallcbt
every time ihey are placed under it.

" This new appearance of magnetism was
so much the more surprising,as the grains were
detached from the agglutin tied mass of the se-
cond experiment, which seemed to have lost all
sensibility at the approach and contact of the
loadstone. In consequence we again took sonic
of these grains, which were alike powdered, and
soon perceived the smallest parts sensibly at-
tach themselves to the magnetic bar. It is im-
possible

190 BUFFO n's

possible to attribute this effect to the smdotfi-^
ness of the bar, or to any other cause foreign
to magnetism. Apiece of smooth iron, ap-
plied in the same manner on tlie parts of this
platina did not raise up a single grain.

" By tlyese experiments, and tlie observa-
tions whicli ha ve arisen therefrom, we may judge
of the diflFicuity of determining the nature of
platina. It is very certain that it contains some
parts which are vitrifiableeven without the ad-
dition of a fierce fire ; it is also certain that all
platina contains iron and attractable parts ; but
ifthePrussian alkali never affords blue but with
tlie grains which the loadsfone attracts, we
should conclude, that those which resist it arc
pure platina, which of itself hns no magnetical
virtue, and of vvliich iron does not make an
essential part* Wc must suppose that a suffi-
cient fusion, or perfect cupcllation, might de-
cide the question; at least, these operations
appear to have, in fact, deprived it of every
magnetic virtue, by separating it from all
foreign bodies; but the last observation proves,
in an incontrovertible manner, that this mag-
netic property was, in realily, only weaken-
ed, and perhaps masked or buried, since it re-
appeared when it was ground.''

From these experiments of M. dc ivTorvean
there results, 1. That we may expect to meet

platina

NATURAL HISTORY. 191

^latina without addition, by applying the
fire of it several times successively, because the
best crucibles might not resist the action of so
fierce afire during the whole time that the
complete operation would require.

2. That by molting it with lead, and assay-
ing them several times, we should in tlie end
vitrify all the lead and the platina; and that
this experiment would be able to purge it
from a part of the ibrcign matters it contains.

3. That by melting without any addition,
it seems to purge itself partly into the vilres-
cible matters it includes, since it emits to its
surface sinall drops of glass, which form pretty
considerable masses, and which we can easily
sepamle after refrigeration.

4. That by making experiments on Prussian
blue with the grains of platina, which appeared
to be most insensible to the lo-tdstone, v.e were
not always certain of obtaining it ; a circum-
stance which never fails with grains that have
more or less sensibility to magnetism.

5. It appears that neither fusion norcupella-
tion can destroy all the iron with which platina
is intimately penetrated; the pieces melted or
assayed, appeared, in reality , equally insensible
to the action of the load&tone; but having
pounded them in a mortar, we found nurgnetical

parts ;

parts ; so mucbtlie more abwrrdaiit as the pla«
tina was reduced to a fino powdtT. The first
ptecr, whose grains were only aggUitinaled,
b^ing ^^round, re»(]erecl many iiiiOic magrietical
parts than tjie second and third, the grains of
which hud undergone a stronger fusion ; but,
ncvcrthek'ss, being both ground, they furnished
magrtctical parts ; insomuch that it cannot be
doubted liiat there is iron in platina, after it
iias undergone the fiercest efilbrts of fire, and
Ihse devouring actions of the heat in tlie cupel.
This demoasirates, that this miuerdl is really
an intiiBate mixture of gold and iron, whkli
hitherto has not been able to separate.

6. I made another observation with M. Mor-
veau on melted, and afterwards on ground
platina ; namely, that it takes in grinding pre-
ctbely the same ibrm as it had before it had been
iiielled ; all i he grains of this iiioKcd and ground
platina are similar to those of the natural, as
well in form as variety of size ; and they ap^
pear to differ only because the smallest alo»«4?
jiufler themselves to be raised by ^he load.^tone,
and in so much the less quantity as the platina
has endured the nre. This seems also to prove,
iluit, al hough the fire has been strowg enough
itot oidy to l>in tvand vitrify, J>ut even to drive
t)iiii \hiii of th^j iron^with other vitrescible

nialtcr

iifATURAL HISTORY. 193

mafter wliich it contains ; the fusion, never-
theless, is not so complete as that of other per-
fect metals, since, in grinding, it retakes the
same figure as it had before fusion.

EXPERIMENTS ON LIGHT, AND ON THE
HEAT IT MAY PRODUCE.

INVENTION OF MIRRORS TO BURN AT GREAT
DISTANCES.

THE story of the burning glasses of Archi-
medes is famous ; he is said to have invented
them for the defence of his country ; and he
threw, say the ancients, the fire of the sun with
such force on the enemy ^^ fleet, as to reduce
it into ashes as it approached the ramparts of
Syracuse. But this story, Avhich, for fifteen or
sixteen centuries, was never doubled, lias been
contradicted, and treated as fabulous in these
latter ages. Descartes, with the authority of
a master, has attacked this talent attributed to
Archimedes; he has denied the possibility of
the invention, nnd his opinion has prevailed
VOL. X. C c over

194; buffon's

over the testimonies and credit of llicancienls.
Modern naturalists, either through a respect
for their philosopher, or through complaisance
for their contemporaries, have adopted the
same opinion. Nothing is allowed (o the an-
cients but what cannot be avoided. Deter-
nained, perhaps, by these motives, of ^vhich
self-love too often is the abettor, have we not
naturally too much inclination to refuse what
is due to our predecessors? and if, in our
time, more is refused than was in any other,
is it not that, by being more enlightened, we
think we have more right to fame, and more
pretensions to superiority ?

Be that as it may, this invention was the
cause of many other discovoi i( s of antiquity
which are at present unknown, because the
facility of denying them has been preferred to
the trouble of finding them out ; and the
burning glasses of Archimedes have been so
decried, that it does not appear possible to re-
establish their reputation ; for, to call the
the judgment of Descartes in question, some-
thing more is required than assertions, and there
only remained one sure decisive mode, but at
the same time difficult nnd bold, which was
to undertake to discover glasses that might
produce the like effects.

Tliough

NATURAL HISTOllY. 195

Though I had conceived the idea, I was for
a long time deterred from making the experi-
ment, from the dread of the difficulty which
might attend it; at length, however, I deter-
mined to search after the mode of makins:
mirrors to burn at a great distance, as from 100
to 500 feet. I knew, in general, that the power
of reflecting mirrors, never extended farther
than 15 or 20 feet, and with refringent, the dis-
tance was still siiortcr : and I perceived it
was impossible in practice to form a metal, or
glass mirror, with such exactness as to burn at
these great distances. To have sufhcient pow-
er for that, the sphere, for example, must be
800 feet diameter ; therefore, we could hope
for nothing of that kind in the common mode
of working glasses ; and I perceived also that
if we could even find a new method to give to
large pieces of glass, or metal, a curve suffi-
ciently slight, there would still result but a
very inconsiderable advantage.

But to proceed regularly, it was necessary
first to see how much light the sun loses by re-
flection at different distances, and what are
the matters which reflect it the stron^^^fst; I
first found, ihii glasses when they are pjlished
"with care, reflect the light more powiTlully
than the best polished metals, aijd even bet-
ter

1D6 buffon's

tcr tlian tho compounded metal with which
■telescope mirrors are made ; and that although
tliere are two reflectors in the glasses, they
yet give a brighter and more clear light than
metal. Secondly, by receiving the light of
the sun in a dark place, and by comparing it
w ith this light of the sun reflectpd by a glass, I
found, that at small distances, as four or five
feet, it only lost about half by reflection,
%vhich I judged by letting a second reflected
light fall on the first ; for the briskness of these
two reflected lights appeared to be equal to
ilmt of direct light. Thirdly, having received
at the distances of 100, 200, and SOO feet, this
light reflected by great glasses, I perceived
that it did not lose any of its strength by
the thickness of the air it had to pass
through.

I afterwards tried the same experiments on
thelight of candles ; and to assure myself more
exactly of the quantity of Aveakness that re-
flection causes to »Iiis light, I made the follow-
ing experiments .

1 seated myself opi:oite a glass mirror with
a book in mv hand, in a room where the dark-
ness of the night would not permit me to dis-
tinguish a single object. In an adjoining room
I had a lighted candle placed at about 40 feet

distance :

NATURAL HISTORY- 197

x3istance ; this I approached nearer and nearer,
till I could read the book, when the distance
.was about 24 feet. Afterwards turning the
book, I endeavoured to read by the reflected
light, having by a parchment intercepted the
part of the light which did not fall on the
mirror, in order to have only the reflected
light on my book. To do so I was obliged to
approach the candle nearer, which I did by
degrees, till I could read the same characters
clearly by the same light, and then the distance
from the candle, comprehending tliatofthe
book to the mirror, which was only half a
foot, I found to be in all 15 feet. I repeated
this several times, and had always nearly the
same results; from whence I concluded, that
the strength, or quantity, of direct light is to
that of reflected light, as 576 to 225 ; there-
fore, the liglit of five candles reflected by a
flat glass, is nearly equal to that of the direct
light of two.

The light of a candle, therefore, loses more
by reflection than by the light of the sun ; and
this difference proceeds from the rays of the
former falling more obliquely on the mirror
than the rays of the sun, which conic almost
parallel. This experiment confirmed what I
jbad at first found, and 1 hold it ccrtiiin, that

(he

irS buffon's

the H:;lit of the sun loses only half by ils ic-
flection on a glass mirror.

This first information being acquired, I af-
terwards sought what became of the images of
the sun when received at great distances. To be
perfectly understood we mustnot,as is generally
done, consider the rays of the sun as parallel ;
and it must also be remembered, that the
body of the sun occupies an extent of about
32 minutes ; that consequently the raj^
which issue from the upper edge of the disk,
falling on a point of a reflecting surface, the
ravs wliich i.%sue from the lower edfi:e falling
albo on the same point of this surface, they
form between them an angle of 32 minutes in
the incidence, and afterwards in the reflection,
and that, consequently, the image must in-
crease in size in proportion as it is farther dis-
tant. Atirntion must likewise be paid to the
figure of those images ; for example, a plain
square glass of half a foot, exposed to the rays
of the sun, will form a square image of six
inches, when this image is received at the dis-
tance of a few feet ; by removing farther and
farther off, the image is seen to increase, after-
wards to become deformed, then round, in
which state it remains still increasing in size,
in proportion as we are more distant from the
mirror. Thj^ image is composed of as many

of

NATURAL HISTORY. 1G9

of the sun's disks as there are physical points
in the reflecting surface; the middle point
forms an image of the disk, (he adjoining points
form the like, and of the same size, •which ex-
ceed a little the middle disk: it is the same
with the other points, and the image is com-
posed of an infinity of disks, ^vhich surmount-
ing regularly, and anticipating circularly one
over the other, form the reflected image, of
which the middle point of the glass is the cen-
tre.

If the image composed of all these disks is
received at a small distance, then their extent
being soraewnat larger than that of the glass,
this image is of the same figure and nearly of
the same extent as the glass ; but when the
image is received at a great distance from the
glass, where the extent of the disks is much
greater <han that of the glass, the image no^
longer retains the same figure as the glass, but
becomes necessarily circular. To find the
point of distance where the image loses its
square figure, we have only to seek for the dis-
tance wliere the glass appears under an angle
equal to that the sun forms to our sight, i. e.
an angrc of 32 minutes, and this di-tance will
be that Vihere the image will lose its square
ficnre, and become round, for the disks having

al ways

200 buffon's

always an equal line to the semi-circle, whicK
measures an ans^le of S2 minutes for a diame-
ter, we shall find by this rule that a square
glass of six inches loses its square figure at the
distance of about 60 feet, and tliat a glass of
a foot square loses it at 120 feet, and so on of
the rest.

By reflecting a li< tie on this theory we shall
no longer be astonished to find, that at very
great distances a large and small glass afford
an image of nearly the same size, and which
only differs by the intensity of the light ; we
shall no longer be surprised that a round,
square, long, or triangular glass, or any other
figure, always yields round images* ; and we
shall evidently see that images do not increase
and lessen by the dispersion of light, or by
any loss in passing- through the air, as some
naturalists have imagined ; but that, on the
contrary, it is occasioned by the augmentation
of the disks, which always occupy a space of 52
minutes to whatever distance they are removed .

So, likewise, we shall be convinced, by
the simple exposition of this theory, that
curves, of any kind, cannot be used with ad-
van! age

* This is the Treason that the small images which pass
betwixt the leaves of high and full trees, and which falling
•n the walk* are all oval or round.

T^ATURAL history; 201

vantage to bum at a great distance, because the
diameter of the focus can never be smaller than
the chord, which measures an angle of 32 mi-
nutes, and that, consequently, tlie most perfect
concave mirror, whose diameter is equal to
this chord, will never produce double the ef*
feet of a plane mirror of the same surface ; and
if the diameter of a curved mirror were less
than the chord, it would scarcely have more
effect than a plane mirror of the same surface.
Wlien I had well considered the above I had
no longer a doubt that Archimedes could not
burn at a distance but with plane mirrors, for,
independently of the impossibility they then
felf, and which we feel at pleasure, of making /ifijlAi^
concave mirrors with so large a focus, I was
well aware that the reflection I have just made
could not have escaped this great raathemati-
< ian . Besides, there is every reason to suppose
that the ancients did not know how to make
large masses of glass ; that tbey were ignorant
of the art of burning it to make large glasses,
possessing only the method of blowing it, and
making bottles and vases; from which consi-
deration I was led to conclude, that it was
with plane mirrors of polished metals, and by
the reflections of the sun, that Archimedes had
been enabled to burn at a distance. But as I
VOL. X. D d perceived

202 ; buffon's

perceived iliat glass mirrors reflected the
light more powerfully than the most polished
mirrors, I thought to construct a machine to
coincide iu the same point the reflected images
by a great number of these plane glasses, be-
ing well convinced that this was the soic
mode of succeeding.

Nevertheless, I had still some doubts re-
maining, which appeared to me well founded,
for thus I reasoned. Supposing the burning
distance to be 240 feet, I perceived clearly
that the focus of ray mirror could not have a
less than two feet diameter; in which case
what would be the extent I should be obliged
to give to my assemblage of plane mirrors to
produce a fire in so great a focus ? It might be
so great that the thing would be impracticable
in the execution, for, by comparing the dia-
meter of the focus to the diameter of the mir-
ror, hi the best reflecting mirrors, I observed
that the diameter of the Academy's mirror,
which is three feet, was 108 times bigger than
its focus, which was no more than four lines ;
and I concluded, that io burn as strong at
240 feet it was necessary that my assemblage
of mirrors should be 216 feet diameter tohavea
focus of two feet; now a mirror of 216 feet
diameter was certainly an impossible thing.

Thig

NATURAL HISTORV. 203

This mirror of Uiree feet diamcier burnt
strong enough to melt gold, and I wasdcsiroa
to see how much I should gain -by reducing
its action to the burning of wood. For this
purpose I used circular zones of paper on the
mirrors to diminisli the diameter, and I fuund
that there was no longer power enough to in-
flame dry wood when its diameter was reduced
to Kttle more than four inches ; therefore, tak-
ing five inches, or sixty lines, for the diameter
necessary to burn with a focus of four lines,
it appeared, that to burn equally at 210 feet,
where the focus should necessarily bave two
feet diameter, I should require a mirror of 30
feet diameter, which appeared still as impossi-
ble, or at least impracticable.

To such positive conclusions, and which
others would have regarded as demonstrations
of the impossibility of the mirror, I had only a
supposition to oppose; but an old supposi-
tion, on which the more I reflected the morei
was persuaded that it was not without founda-
tion ; namely, that the effects of heat might
possibly not be in proportion to the quantity
of light, or, what amounts to the same, that
at an equal intensity of light large focuses
must burn brisker than the small.
By estimating heat mathematically, it is not

to

204 BUFFO n's

to be doubted but that the power of a focus of
the same length is in proportion to the surface
of the mirror. A mirror whose surface is dou-
ble that of another, must have the same sized
focus, and this focus must contain double the
quantity of light which the first contained ;
and in the supposition, that eftects are always
in proportion to their causes, it might be pre-
sumed that the heat of this second focus should
be double that of the first. ^

So likewise, and by the same mathe^aticiil
estimation, it has always been thought, that at
an equal intensity of light, a small focus ought
to burn as much as a large one, and that the
eifect of the heat ought (o be in proportion to
this intensity of light : insomuch (says Des-
cartes J that glasses^ or extremely small mirrors,
may he made^ which will burn with as muchxio-
lence as the large, I at first thought tliat this
conclusion, drawn from mathematical theory,
might be found false in practice, because heat
being a physical quality, of the action and
propagation of which we know not the laws,
it seemed to me, that there was some kind of
temerity in thus estimating its effects by a sim-
ple speculation.

I had, therefore, once more, recourse to
experiments. I took metal mirrors of differ-
ent

NATURAL HISTOEY, ^5

cnt focuses and dificrent dei^rees of polisb, and
by compnrins; the diffiirent actions on (he
same fusible or combustible raniters, I foujtJ,
that at an equal intensify of ii:rh/, large focuses
constantly have more effect than small, and I
discovered the same to be the case ^yiih refract-
ing mirrors.

It is easy to assign the reason of this differ-
ence, if we consider that hcai coninsunica^cs
nearer and nearer, and disperses, if I rsiay
so speak, when it is even applied on the same
point: for example, if wc let the focus of a
burning glass f:dl on the cenfrc of a crown
piece, and that this focus was only a line in
diameter, the heat produced on the centre
disperses and extcn(!s over and throughout the
whole piece : thus alt the heat, although used
at first to the centre of the crown, does not stop
there, and consequently cannot produce so
great an eff'^ct cis if it did. Bat if, iiisiead of
a focus of aline v.^hich falls upon the centre of
the crov/n, we let tall a focus of equal intensity
on the whole crown, every jjart being alike
heated, then instead of experiencing the less
heat, it acquires an augmentation ; for the
middle profiting of the heat with the other
points which surround i(, the crown piece

will

206 BUFFO n'^S

will be melted in this laltercasc, "while in the
first, it will only be slightly heated.

After these experiments and reflections, I
began to entertain sanguine hopes of making
mirrors to burn at a great distance; for I no
ionger dreaded as before, ihc great extent of
the focus; I was persuaded, on the contrary,
that a focus of a considerable breadth, as4\^
feet, and which in the intensity of the light
would not be near so great as in a small
focus of four lines, might, nevertheless, pro-
duce inflammation, and with more power ;
and that, consequently, this mirror, which,
hy mathematical theory, ought to iiave at
least thirty feet diameter, would be reduced
to one of eight or ten feet at most, which was
not only a possible, but even a very practical
ble thing.

I then thought seriously of executing my
project: I had at first a design of trying to
burn at iOO or 300 feet distance with circular
or hexagonal glasses of a square foot in surface,
and I was desirous of having four iron car-
riages for them, with screws to each to move
them, and a spring to adjust tliem; but the
considerable expense that this required made
roe quit that idea, and I took two common
glasses of six inches by eight, and a wooden

adjustment,

NATURAL HISTORY. 207

atljustment, which, in fact, was less solid and
precise, but the expence was more consistent
with a mere experiment : the mechanism of
"which was executed by M. Passement.

It is sufficient to say, that it was at first
composed of 168 glasses of six inches by
eight each, about four lines distant from
each other; these glasses moved in all direc-
tions, and the four lines of space between them
not only served for the freedom of this motion,
but also to let the operator see the place where
lie was to conduct his images. By means of
this construction, 168 images could be thrown
on one point, and, consequently, burn at se-
veral distances, as at 20, SO, and to 150 feet.
By increasing the size of the mirror, or by
imiking other mirrors like the first, we are cer-
tain of throwing fire to still greater distances,
or to increase as much as we please the force
or activity of those first distances.

It is only to be observed, that the motion
here spoken of is not very easy to be executed,
and that also there is a very great choice to be
made in the glasses ; for they are not all equally
good, though they appear so at the first in-
spection. I was obliged to pick out of more
than 500 the 168 I made use of. The method
of tr} ing thera is to receive at 150 feet distance
j^c reflected image of the sun, as a vertical

plane ;

SOS BUFFO N'S

plane ; we must select those wliiclj give a round
and terminated image, and reject those,
•whose thickncvsscs being unequal in difFerent
parts, or the surface a little concave or con-
vex, have images badly terminated, double,
treble, oblong, &c. according to the different
defects found in the glasses.

Bj the first experiment which I made the
23d of March, 1747, at noon, I set fire to a
plauk of fir at 6(ifeet distance, with 40 glasses
only, about a quarter of the mirror. It must
be observed (hat not being yet mounted, it was
very disadvantageously placed, forming an
angle with the sun of twenty degrees declina-
tion, and another of more than ten degrees in-
clination.

Tlie same day I set fire to a pitchy and sul-
phureous plank at 126 feet distance, with
eighty-eight glasses, tlie mirror being s(iU
placed disadvantageously. It is well known,
that to burn with the greatest advantage tlie
mirror should be directly opposed to the sun,
as well as the matters to be inflamed ; so that,
by supposing a perpendicular plane on the
plane of the mirror, it must pass by the sun,
and, at Ihc same time, through the midst of
combustible matters.

The 3d cf ^\pril, at four o^clock in the af-
ternoon, the mirror being mounted, produced

a sliiiht

NATURAL HISTORY* S09

tt slight inflaramad'on on a plank covered with
pilch at 138 feet distance, although the sun
"was weak and the light pale. Great care
must be taken, when we approach the spot
where the combustible matters are, not to
look on the mirror ; for if, unfortunately, the
eyes should meet the focus, inevitable blind-
ness will ensue*

The 4th of April, at cloven in the morning,
although the sun appeared watery, and the sky
cloudy, yet it produced, with 154 glasses, so
considerable a heat at 158 feet, that in less than
two minutes it made a deal plank smoke^
and ^vhich wouldccrtainiy have flamed, if the
sun had not suddenly disappeared .

The ensuing day, the 5th of April, at three
o'clock in the afteraoon, we set fire, in a minute
a'ld a half,at 150 feet distance, to a plank sul-
phured and mixed with coals. with 154 glasses.
When the sun is powerful, only a few seconds
is required to produce inflammation.

The lOih of April in the afternoon, the sun
being bright, we set fire to a fir plank at ]oQ
feet distance, with only 128 glasses : the in-
flammation was very sudden, and made in all
the extent of the focus, which was about six-
teen inches diameter at this distance.

The same day, at half past t vo o'clock, W0-
threw the fire on another plank, partly pitched
VOL. X. E e ?ii

210 BUfFO>f s

and covered with sulphur in some places : the
infla'ramation was made very suddenly; it be-
gan by the parts of the wood whi^h were un-
covered, and the fire was so violent, that the
plahk was obliged to be dipt in water to ex-
tinguish it : there were 148 glasses at 150 feet
distance.

The eleventh of April, the focus being only
20 feet distant from the mirror, it only required
12 glasses to inflame small combustible matters;
with 21 glasses we set fire to another plank
which had already been partly burnt ; with
45 glasses we melted a block of tin of 61b.
weight ; and with 117 glasses we melted thin
pieces of silver, and reddened an iron plate ;
imd I am also persuaded, that by using all the
glasses of the mirror we should have been en-
abled to have melted metals at 50 feet dis*
tance ; and as the focus at this distance was
six or seven inches broad, we should be aWe to
make trials on all metals, which it was not
possible to do with common mirrors, whose
focus is either very weak or 100 times smaller
than that of mine. I have remarked, (that me^
tals, and especially silver, smoke much before
they melt ; the smoke was so striking that it
shaded the ground, and it was there I looked
on it attentively, for it is not possible tdlook a
moment on the focus when it falls on the me-

NATURAL HISTORY. Sll

taij (he lustre being much more dazzling tliaii
that of the sun.

Tiie experiments which I have here related,
^nd which were made immediately after the
invention of the mirrors, have been followed
by a great number of others, which confirm
them. I liave set fire to wood at 210 feet dis-
tance with this mirror, by (he sun in summer ;
and I am certiiin, that with lour similar mir-
rors I could buri at 400 feet, and, perliaps,
at a greater di4rince. I have likewise,melt-
ed all metals, and metallic minerals, at S5,
SO, and 40 feei. We sliall find, in the course
of this article, tlje uses to which these mirrors
can be applied, and the limits that must be
assigned to their power for calcination, com-
bustion, fusion, &c.*

This mirror burns according to the different
inclination given it, and what gave it this ad-
vantage over the common reflecting mirrors
was that its focus was very distant, and had
so little curvature, that it was almost imper-
ceptible : it was seven fe»t broad by eight
feet high, which makes about the IjOlh part
of the circumference of the sphere, when we
burn at 150 feet distance.

The

* It requires about half an hour to mount the mirror and
to make all the images fall on the same point ; but wJien
this is once adjusted, it may be used at all times by simply
drawings curtain.

212 buffonV

- The reason (liat detcrminccl me to prefer
glasses of six inches broad by eight inches
high to square glasses of six or eight inches,
^vas, th;it it is much more commodious to
make experiments npon a horizontal and level
ground than otherwise, and that with this fi-
gure,thc height of which exceeded the breadth,
the images were rounder ; whereas with square
glasses they would be shortened, especially at
small distaucrs, in a horizontal situation.

This discovery furnishes us with many useful
hints for physic, and periiaps for tlie arts. We
know that v.Jiat renders common reflecting
mirrors most useless for experiments is, that
they burn almost always upwards, and tliat we
are greatly cmbarrafsed to find means to sus-
pend or !juppoit to their focus matters to be
melted or c^dcined. By means of my mirror we
burn concave mirrors downwards, and with so
great an advantage that we have what degree
of heat v/e please ; for example, by opposing
to my mirror a concave one of a foot square in
the surface, the lieat produced to this last mir»
ror, by using 154 glasses only, will be upwards
of 12 i lines greater than that generally pro-
duced, and the viWct will be the same as if 12
suns existed instead of one, or rather as if t!ic
sun had 12 times more heat,

Secondly,

NATURAL HISTORY. 213

Seconclly, By means of my miiTor we shall
bave the true scale of tiic augmentation of heat,
and make a real thermometer, whose divisions
will be no lonsjer arbitrary, from the tempera-
ture of the air to what degree of heat we chiise,
by letting fall, successively, the images of the
jBun one on the other, and by graduating the
intervals, whether by means of an expansive
liquor, or a machine of dilatation, and from
that we shall know, in fact, what a double,
treblc.quadruple, &c. augmentation of heat is,
and shallfind out matters whose expansion, or
other effects, will be the most suitaJjie to mea-
sure the augmentations of heat.

Thirdly, We shall exactly know how many
limes is required for the heat of the sun to
burn, melt, or calcine different matters, which
was hitherto only known in a vague and very
indefinite lyauner ; and shall be in a state tr>
make precise compariisons of the activity of our
fires with that of the sun, and have exact rela-
tions and fixed and invariable measures. In
short, those who examine my theory, and shall
^avcseen the effect of my mirror. I think will
be convinced the mode I have used was the
only one possible to succeed to burn f^r off,
^or, inJependant of the physical difticulty of

makinij

making large concave, spherical; parabolical
mirrors, or of any atUer curvature whatsoeverj
regular enough to burn at 150 feet distance,
we shall easily be convinced that they would
not produce but nearly as rmich effect as mine,
because the focus would be almost as broad ;
that besides, these curved n)irrors, if even it
should be possibl to make them, would have
the very great disadvanlagc to burn only at a
mgh distance, whereas mine burns at all dis-
tances ; and, consequently, we shall abandon
the scheme of making mirrors to burn at a
^reat distance by means of curves, which has
uselessly employed a great number of mathe-
maticians and artists, who were always de-
ceived,because they considered the rays of Ih©
sun as parallel, w hereas they should be consi-
dered as they are, namely, as forming angles of
all sizes, from 0 to 32 minutes, which makes
it impossible, wliatsoevcr curve is given to a
mirror, to render the diameter of the focus
smaller than the chord, which measures S2
minutes. Thus, even if we could nmke a
concave mirror to burn at a great distance ;
for exam pie, at 150 feet, by employing all its
points on a sphere of COO f^ci diameter, and
by employing an uncommon mass ofghiss or

metal,

NATITtlA r. HISTORY. £15

metal, it is evident that we shall have a little
more advantage than by using, as I have done,
only small plane mirrors.

On(!ic whole, alflunugh this mirror is sus-
ceptible of a very gre:;! perfection, both for
the adjustment, and many other particulars,
and though I think I shall be able to make
another, whose effects will be superior, yet, as
every thing has its limits, it must not be ex-
pected that every one can be formed to bur a
at extreme distances ; to burn, for e:5ample,
at the distance of half a mile, a mirror 200
times larger would be required ; and I am of
opinion that more will never be effected thaa
to burn at the distance of 8 or 900 feet. The
focus, whose motion is always correspondent
to that of the sun, moves so much the quicker
as it is farther distant from the mirror ; and at
90 feet it would move about six feet a minute.

[lowever, as I have given an account of my
discovery, and the success of my experiments,
I should render to Archimedes, and the an-
cients, the glory that is their due. It is certain
that Archimedes could |">erforin witii metal
mirrors what I have done with glass, and that,
consequently, I cannot refuse him the title of
the first inventor of these mirrors, and !he op-
portunity he had of using them rendered him,

without

SI 6 BUFFO N^gr

without doubt, more celebrated than the merti
t)f the thing itself.

Many advanlagcs may be derived from the
use of these mirrors ; by an assemblage of
small mirrors^ with hexagonal planes, and po-*
lished steel, which will have more solidity than,
glasses, and which would not be subject to the
alterations which the liglit of ihe sun may
cause, we may produce very useful effects,
and which would amply repay the expences
of the construction of the mirror^

" For all evaporations of salt waters, wliere
great quantities of wood and coal are consumed^
or structures raised for the purpose of carrying
the waters off, which cost more than the con-
struction of many mirrors, such as I mention >
for the evaporation of salt waters, only an as-
semblage of twelve plane mirrors of a square
foot each is necessary. The heat reflected by
their focuses, although directed below their
level, and at tifteea or sixteen feet distance, will
be still great enough to boil water, and conse-
quently produce a quick evaporation : for the
lieat of boiling water is only treble the heat of
the sun in summer; and as the reflection of a
well polished plane surface only diminishes the
heat one half, only six mirrors are required to
produce at the focus a heat equal to boiling

water j

NATURAL HISTORY. 217

^ater ; but I shall double the number to make
the heat communicate quicker; and likewise by
reason of the loss occasioned by the obliquity,
under which the light falls on the surface of the
water to be evaporated, and because salt water
heats slower than fresh. This mirror, whose
assemblage would form only a square four feet
broad by three high, would be easy to be
managed ; and if it were required to double or
treble the effects in the same time, it would be
better to make so many similar mirrors, than
to augment the scale of them; for water can
only receive a certain quantity of heat, and we
should not gain any thing by increasing this
degree; whereas, by making two focuses with
two equal mirrors, we should double the effect
of the evaporation, and treble it by three mir-
rors, whose focuses would fall separately one
from the other on the surface of the water to
be evaporated . We cannot avoid the loss caus-
ed by the obliquity ; nor can it be remedied
but by suffering a still greater, that is, by re-
ceiving the rays of the sun on a large glass,
which would reflect them broken on the mirror;
for then it would burn at bottom instead of the
top, but it would lose half the heat by the first
reflection, and half of the remainder by the
second ; so that instead of six small mirrors, it
VOL. X. F f ^ould

218 buffon's

\vould require a dozen to obtain a lieat equaf
to boiling water. For the evaporation to be
made with more success, we ought to diminish
the thickness of the water as much as possible ;
a mass of water a foot deep will not eva*
|)Grate nearly so quick as the same mass re-
duced to six inches, and increased to double the
superfices. Besides, the bottom being nearer
the surface, it heats quicker, and this heat,
which the bottom of the vessel receives, con-
tributes still more to the celerity of fhe eva-
poration.

2. These mirrors may be used with advan-
tage to calcine plaislcrs, and even calcareous
stones, but they would require to be larger, and
the matters placed in an elevated situation, that
nothing might be lost by the obliquity of the
light. It has already been observed that gyp-
sum heats as soon again as soft calcareous stone,
and nearly twice as quick as marble, or hard
calcareous stone ; their calcination, therefore,
Jnust be in a respective ratio. I have found
by an experiment repeated three times, that
very little more heat is required to calcine
white gypsum, called alabaster, than to melt
ieati. Now the heat necessary to melt lead is,
according to the experimentsof Newton, eight
limes stronger than the heat of the summer
^un ; it therefore would require at least six-
teen

NATURAL HISTORY.

dl9

teen small mirrors to calcine gypsum ; and
because of the losses thereby occasioned, as
:weU by the obliquity of the light as by the
inequality of the focus, which is not removed
above fifteen feet, I presume it would require
twenty, and perhaps twenty-four mirrors of a
foot square each, to calcine gypsum in a short
4ime, consequently it would require an assem-
blage of forty -eight small mirrors to calcine
^he softest calcareous stone, and seventy-two
of a foot square to calcine hard calcareous
stones. Now a mirror twelve feet broad by
«ix feet high, would be a large and cumber-
some machine ; yet we might conquer these
difficulties if the product of the calcination
were considerable enough to surpass the ex-
pense of the consumption of wood. To as-
certain this, we ought to begin by calcining
plaister with a mirror of twenty-four pieces,
and if that succeeded, to malce two other si-
milar mirrors, instead of making a large one
of seventy-two pieces ; for by coinciding ihe
focuses of these three mirrors of twenty-four
pieces, we should produce an equal heat,
strono- enough to calcine marlie or hard stone.
But a very essential matter remains doubtful,
that is, to know how much time would be re-
quisite, for example, to calcine a cubical foot
^ matter, especially if that foot were struck

with

220 BUFFO n's

with llie heat only in one part. Some time
would pass before the heat penetrated its thick-
ness; during this time, a great part of the
heat would be lost, and which would issue
from this piece of matter after it had entered
it. I fear, therefore, much that the stone not
being touched by the heat on every side at
once, the calcination would be slower, and the
produce less. Experience alone can decide
this, but it would be at least necessary to at-
tempt it on gypsous matters, whose calcina-
tion is as quick again as calcareous stone.

By concentrating this heat of the sun in a
kiln, which has no other opening than what
admits the light, a great part of the heat
would be prevented from flying off, and by
mixing with calcareous stone a small quan-
tity of coal dust, which is the cheapest of all
combustible matters, this slight supply of food
would suffice to feed and augment the quan-
tity of heat, which would produce a more
ample and quick calcination, and at very little
expense.

3. These mirrors of Archimedes might be,
in fact, used to set fire to the sails of vessels,
and even to pitched wood at more than 150
feet distance ; they might also be used against
the enemy, by burning tbe grain and other
productions of tlie earth ; this eifcct would be

no

NATURAL HISTORY. 221

no less sudden than destructive ; but we will
not dwell on the means of doing mischief,
conceiving it to be more our duty to think on
those which may do some real service to man-
kind.

4. These mirrors furnish the sole means of
exactly measuring heat. It is evident that U\o
mirrors, whose luminous images unite, produce
double heat in all tiie points of their surfaces,
that three, four, five, or more mirrors, will
also give a treble, quadruple, quintuple, &c.
Leaf, and that, consequently, by this mode we
can make a thermometer whose divisions w ill
not be too arbitrary, and the scales different,
like those of tlic present thermometers. The
only arbitrary thing which would enter into
the composition of the thermometer, would be
the supposition of the total number of the parts
of the quicksilver by quitting the degree of
absolute cold: but bv takins; it to lOO'uO be^
low the congelation of water, instead of 1000,
as in our common thermometers, we should
approach greatly towards reality, especially
by chusing the coldest day in winter to mark
the thermometers, for then every image of the
sun would give it a degree of heat above the
temperature of ice. The point to which the
mercury rises by the first image of the sun,
•would be marked 1, and so on to the highest,

which

222 BUFFO n's

which might be extended to 35 degrees. * At
this degree we should have an augmentation of
heat, thirty-six times greater than that of the
first, eighteen times greater than that of the
second, twelve times greater than that of the
third, nine times greater than that of the
fourth, and soon ; this augmentation of thirty-
six of heat above that of ice would be sufficient
to melt lead; and there is every appearance
to think that mercury, which volatilizes by a
much less heat, would by its vapour break the
thermometer. We cannot therefore, at most,
extt^nd the division farther than twelve, and
perhaps not farther than nine degrees, if mer-
cury be used for these thermometers, and by
these means we shall have only nine degrees of
the augmentation of heat. This is one of the
reasons which induced Newton to make use of
linseed oil instead of quicksilver; and, in fact^
hy making use of this liquor, we can extend
the division not only to twelve degrees, bot as
far as to make this oil boil. I do not pro-
pose spirits of wine, because that liquor de?
composes in a very short time, and cannot be
used for experiments of a strong heat.*

When

• Many travellers have tol4 and written to me, that Reau-
mur's thermometers of spirit of wine, became quite useless
to th€m, because this liquid lost its colour, and became
charged with a sort ©f mud in a very short time.

NATURAL HISTORY. 223

%Vhen on the scale of these thermometers
filled with oil or mercury, the first divisions
1, 2, 3, 4, &c. are marked to indicate the
double, treble, quadruple, &c. augmentations
of heat, we must search after the aliquot parts
of each division ; for example, of the point 1|,
^i, SI, &c. or I|, 2f , Sf, &c. and 1|, 2|, Sf,
and which will be obtained in an easy manner,
by covering the |,|, or |, of the superficesof
one of those small mirrors ; for then the image
-which it reflects, will contain only the |, |, or f ,
of the heat which the whole ima<re will con-
tain, and, consequently, the division of the
aliquot parts will be as exact as those of the
whole numbers.

If once we succeed in this real thermometer,
Tvhich I call real, because it actually marks
the proportion of the heat, every other thermo-
meter whose scale is arbitrary and different,
will become not only superfluous, but even
inimical, in many cases, to the precision of na-
tural truths sought after by these means.

5. By means of three mirrors we may easily
collect in their entire purity, the volatile parts
of gold, silver, and other metals and minerals ;
for, by exposing to the large focus of those
mirrors a large piece of metal, as a dish, or
silver plate, we shall see smoke is-^ue from it

in

224 BUFFOK*S

in great abundance, and for a considerable
time, till the metal is in fusion ; and by giving
only a smaller heat than what fusion requires,
we shall evaporate the metal so as to diminish
the weiglit considorably.

I am certain of this circumstance, which
also elucidates the intimate composition of
metals. I was desirous of collecting this plen-
tiful vapour, which the pure fire of the sun
causes to issue from metal, but I had not the
necessary instruments, and I can only recom-
mend to chemibts and naturalists to follow this
important experiment, the results of which
would be as much less equivocal as the metallic
vapour is pure ; whereas, in all like operations
made with common fire, the metallic vapour is
necessarily mixed with other vaj:ours proceed-
ing from combustible matters, which serve for
food to this fire.

Besides, this means is the only one we have
to volatilize fixed metals, such as gold and sil-
ver ; for I presume that this vapour, which I
have seen rise in such great quantities from
these fixed metals, heated in the large focus of
my mirror, is neither of water, nor of any
other liquor, but of the parts even of the me-
tal which tile heat detaches by volatilizing
them. By receiving these vapours of different

metals,

NATURAL insTonv. 225

metals J and thus mixing them together, more
intimate and pure alloys would be made thaa
can be by fusion, and the mixture of these me-
tals when melted, which never perfeclly unites
on account of the inequality of their specific
weight, and many other circumstances which
are opposed to the intimate and perfect equality
of the mixture. As the constituent parts of
the melallic vapours are in a much greater
state of division than fusion, th-y would join
and unite closer and more readily. In shorty
we should attain the knowledge of a general
fact by this mode, and which, for many rea-
sons, I have a long time sust ec(ed, that there is
penetration in all alloys made in this manner,
and that their specific weight would be alwavs
greater than the sum of the specific > eights of
the matters of which they are composed : for
penetration is only a greater degree of inti-
macy; every thing equal in other respects will
be so much the greater as matters will be in a
more perfect state of division.

By reflecting on the vessels used to receive
and collect these metallic vapours, I was
struck with an idea, which apjeared to me to
be of too great utility not to publish ; i( isako
easy enougli to be realized by good able che-
mists ; I have even communicated it to some
VOL. X. G g of

^26 buffon's

of them, wbo appeared lo be quite satisfied
■with it. This idea is to freeze mercury in this
climate, and with a much less degree of cold
than that of the experiments of Petcrsburgh
or Siberia. For this purpose the vapour of
mercury is only required (o be received, and
"which is the mercury itself volatilized by a
very moderate heat in a crucible, or vessel^ to
which we give a certain degree of artificial
cold. This vapour, or this mercury, minutely
divided, will offer, to the action of the cold,
surfaces so large, and masses so small, that in-
stead of 187 degrees of cold requisite to freeze
mercury, possibly 18 or 20 will be sufficient,
and perhaps even less to freeze it when in va-?
pour. I recommend this important experi-
ment to all those T\ho endeavour earnestly for
the advancement of the sciences.

To these principal uses of the mirror of
Archimedes, I could add many other particular
ones; but L have confined myselfto those only
which appeared the most useful, and the least
difficult to be put in practice ; neyertheless I
have subjoined some experiments that I made
on thetransmission of light through transparent
bodies, to give some new ideas on the means of
seeing objects at a distance witli the raked eye,
pr with a mirror, like lluit spoken of by the an^

cientSj

NATURAL HISTORY. 227

cientsi and hyihe eifectof vvliicli vessels could
be perceiv ed from the port of Alexander, as
far as the curvature of the earth would permit.
Naturalists at present know, that there are
three causes which prevent the light from
uniting in a point, when its rays have passed
the objective glass of a common mirror. The
first is the spherical curve of this glass, wliicli
disperses a part of the rays in a space termi-
nated by a curve. Tlie second is the angle
under which the object appears to the naked
eye : for the breadth of the focus of the ob-
jective glass has a diameter nearly equal to
the chord of which this angle measures. The
third is the different refrangibility of the light ;
for the most refrangible rays do not collect in
the same place with the lesser.

The first cause may be remedied by substi-
tuting, as Descartes has proposed, elliptical, or
liypcrbolical, glasses to the spherical. The
second is to be remedied by a second glass,
placed to the focus of the objective, whose
diameter is nearly equal the breadth of this
focus, and whose surface is worked on a sphere
of a very short ray. The third has been found
to be remedied, by making telescopes, called
Acromatics, which are composed of two sorts
of glasses, which disperse the coloured rays

differently 5

$28 BUFFON*S

differently : so that the dispersion of the one
is corrected by tlic other, without the general
refraction, which constitutes the mirror, being
destroyed. A telescope Sf feet long, made on
this principle, is in effect equivalent to the old
telescopes of 25 feet.

But the remedy of the first cause is perfectly
useless Jit this time, because the effect of the
last being much more considerable, has such
great influence on the whole effect, that nothing
can be gained by substituting hyperbolical, or
elliptical glasses to spherical, and this substi-
tution could not become advantageous, but in
the case where the meaiis of correcting the
effect of the different refrangibility of the rays
of light might be found ; it seems, therefore,
tliat we should do well to combine tlie two
means, and to substitute, in acromatic teles-
copes, elliptical glasses.

To render this more obvious, let us suppose
the object observed to be a luminous point
wilhout extent, as a fixed star is to us. It is
certain, that with an objective glass, for ex-
ample, of SO feci focus, all the images of this
luminous point will extend in the form of a
curve to this focus, if it be worked on a sphere;
and, on tlie contrary, ihcy will unite in one
pi'intif this gla^s be hyperbolical : but if the

object

NATURAL HISTORY. 229

object observed have a certain extent, as the
moon, which occupies half a degree of space
1o our eyes, then the image of this object will
occupy a space of three inches diameter in the
focus of the objective glass of thirty feet ; and
the aberration caused by the sphericity pro-
ducing a confusion in any luminous point, it
produces the same on every luminous point of
the moon's disk, and, consequently, wholly
disfigures it. There would be, then, much
disadvantage in making use of elliptical glasses
or long telescopes, since the means have been
found, in a great measure, to correct the effect
produced by the different refrangibility of the
rays of light.

From this it follows, that if we would make
a telescope of SO feet, to observe the moon,
and see it completely, the ocular glass must be
at least three inches diameter, to collect the
whole image which the objective glass pro-
duces to its focus ; and if we would observe this
planet with a telescope of 60 feet, the ocular
glass must be at least six inches diameter, be-
cause the chord which the angle measures
under which the moon appears to us, is, in
this case, nearly six inches; therefore astro-
nomers never make use of telescopes that in-
clude the whole disk of the moon, because
they would magnify but very little. But if

We

550 BUFFO n's

we would observe the planet Yen us witli a te-
lescope of 60 het^ as the angle under which it
appears to us is only CO secondsj the ocular
glass can only have four lines diameter ; and
if we make use of an objective of 120 feet, an
ocular glass of eight lines diameter would suf-
fice to unite the whole image which the ob-
jective forms to its focus.

Hence we see, that even if the rnjs of light
were equally refrangible we could not make
such strong telescopes to see the moon with as
to see the other planets, and that the smaller a
planet appears to our sight the more we can
augment the length of the telescope, with
which wc can see it wholly. Hence it may be
well conceived, that in this supposition of the
rays, equally refrangible, there must be a cer-
tain length more advantageously determined
than any ether for each different planet, and
that this length of the telescope depends not
only on the angle under whicli the planet ap-
pears to our sight, but also on the quantity of
li£:ht with which it is brightened.

In common telescopes the rays of light being
difTeiently refrangible, all that could be done
in this mode to give them perfection would be
of very little advantage, because, that under
whatever angle the object, or planet, appears
to our sight, and whatever intensity of light it

may

NATURAL HISTORY. 231

may liavo, the rays will never collect in the
same part ; the longer the telescope the more
interval it will have between the focus of the
red and violet rays, and consequently the more
confused the image of the object observed.

Refracting telescopes, therefore, can be
rendered perfect only by seeking for the means
of correcting this eftect of the different refran-
gibility, either by composing telescopes of dif-
ferent densities, or by other particular means,
which would be different according to different
objects and circumstances. Suppose, for ex-
ample, a short telescope, composed of two
glasses, one convex and the other concave; it
is certain that this telescope might be reduced
to another whose two glasses would be plain
on one side, and on the other bordering on
spheres, whose rays would be shorter than that
on the spheres on which the glasses of the first
telescopes have been constructed. However,
to avoid a great part of the effect of the dif-
ferent refrangibility of the rays, the second te-
lescope may be made with one single piece of
massive glass, as I had it done with two pieces
of white glass, one of two inches and a half
in lengtli, and the other one inch and a
half; but then the loss of transparency is a
greater inconvenience than the different re--

frangibility

232 uuffon's

frangibilify wliicb it corrects, for these two
small massive telescopes of glass are more
obscure than a small common telescope of the
same glass and dimensions ; they indeed give
less iris, but are not better; for in massive
glass the light, after having crossed this thick-
Bess of glass, would no longer have a suffi-
cient force to take in the image of the object
to our eye. So to make telescopes 10 or 23
feet long, I find nothing but water that has
sufficient transparency to suffer the light to
pass through this great thickness. By using,
therefore, water to fill up the intervals be-
tween the objective and the ocular glass, we
should in part diminish the effect of the dif-
ferent refrangibility, because water approaches
nearer to glass than air, and if we could, by
loading tlie water with different salts, give it
the same rcfringent degree of power as glass,
it is not to be doubted, that we should correct
still more, by this means, the different refran-
gibility of the rays. A transparent liquor
should, therefore, be used, which would have
nearly the same refrangible power as glass, for
then it would be certain that the two glasses,
with their liquor between them, would in
part correct the effect of the diflerent refran-
gibility of the rays, in the same mode as it

is

NATURAL HISTORY. 233

is ^corrected in the small massive telescope
which I speak of.

According to the experiments of M. Bon-
guer, the thicknes^s of aline of glass destroys ■§.
of light, and consequently the diminution
would be made in tlie following proportion :

Thickness, .1, 2, 3, 4, 5, 6 lines

lillttlUllUII, 7 -^Y "34 3" "24 oT 16 8 0 7 lT7S^49

So that by the sum of these six terms we
should find, that the light which passes Ihrough
six lines of glass would lose tttIttj ^^^^ ^^5
about If^ of its quantity. But it must be con-
sidered, that M. Bouguer makes use of glasses
which are but little transparent, since he has
observed, that the thickness of a line of these
glasses destroys |. of the light. By the experi-
ments which I have made on different kinds of
white glass, it has appeared to me that the
light diminishes much less. These experi-
ments are easy to be made, and are what all the
world may repeat.

In a dark chamber, whose walls were black-
ened, and which I made use of for optical ex-
periments, I had a candle lighted of five (a
the pound ; the room was very large and the
candle the only light in it; I then tried at what
distance I could read by this light, and found
that I read very easily at 24 feet four inches
VOL. X. H h from

234: buf^'on's

from the candle. Afterwards, bavlng placed a
piece of glass, about a line tliick, before it, at
two inches distance, I found that I still read
very plainly at 22 feet nine inches ; and sub-
stituting to this glass another piece of two lines
in thickness and of the same glass, I read at
21 feet distance from the candle. Two 6f the
same glasses joined one to the other, and
placed before the candle diminished the light
so much that I could only read at 17| feet dis-
tance; and at length, with three glasses, I
could only read at 15 feet. Now the lisrht of
a candle diminishing as the square of the dis-
tance augments, its diminution should have
been in the following progression, if glasses
had not been interposed : 2 — 2^•. 2 — 22|
2__2J. 2— 17i. 2— 15, or 592^. 517^441.
S06|. 225. Therefore the loss of the light,
by the interposition of the glasses, is in the
following progression: 84t4V' 151. 2h5^.
367 i.

From hence it may be concluded, that the
thickness of a line of this glass diminishes only
tVt o^ iJ^'^lj or about -f ; that two lines dimi-
nishes m, not quite ^ and three glasses of
two lines l^l, i. e. less than l.

As this result is very different from that of
M. Bouguer, and as I was cautious of sus-
pect ing

NATURAL HISTORY. 235

pecting the truth of his experiments, I re-
peated mine uith common glass. For long
telescopes water alone can be used ; and it is
still to be feared that an inconveniency will
subsist, from the opacity resulting from the
quantity of liquor which fills the interval be-
tween the two glasses.

The longer the telescope the greater loss of
light will ensue : so that it appears at first sight
that this mode cannot be used, especially for
'iong telescopes ; for following what M. Bou-
guer says in his Optical Essay, on the gradation
of liglit, nijie feet seven inches sea-water di-
minishes the lisfht in a relation of 14 to 5 ;
therefore these long telescopes, filled with wa-
ter, cannot be used for observing the sun, and
the stars would not have light enough to be
perceived across a thickness of 2>) or SO feet of
intermediate liquor.

Nevertheless, if we consider, that by allow-
ing]: onlv an inch, or an inch and a half, for
the bore of an objective of SO (eei, we shall
very distinctly perceive the planets in the com-
mon telescopes of this length; we may sup-
pose that by allowing a greater diameter to the
o!)jective we should augment the quantity of
light in the ratio of the square of this diameter,
and, consequently, if an inch before suffices to
see a star distinctly, in a common telescope,

Ibrco

^^^ buppon's

llir^e iiicbes bore would be sufficient to see it
distinctly through a thickness of 10 feet water,
and that with a glass of three inches diameter
We should easilj see it through a thickness of
20 feet water, and so on. It appears, therefore,
that we might hope to meet with success in
constructing a telescope on these principles ;
for, bybicreasing the diameter of the objec-
tive, we parlly regain the light lost by the de-
feet of the transparency of the liquor.

But ir appears to me certain that a telescope
constructed on this mode would be very useful
for observing the sun ; for supposing it even
the leuglh of 100 feet, the light of that lumi-
nary would not be too strong after having tra-
versed this thickness of water, and we should
be enabled to observe its surface easily, and at
•leisure, without the need of making use of
smoked glasses, or of receiving the image on
pasteboard ; an ad vantage we cannot possibly
derive from any other telescope.

There would require only some tri /ling dif-
ference in the construction of this solaAele-
scope, if we wanted the whole face of the sun
presented ; forsupposing it the length of 100
feet, in this case, the ocular glass must be ten
inches diameter; because the sun, taking up
more than half a celesti;d degree, the image
formed by t he object veto its focus at ICO feel,

will

NATURAL HISTORY. ^^J

will at least have this length of ten inches;
and (o unite it wholly, it will require an ocul
lar glass of this breadth, to whicli only twenty
inches of focus should be given to render it as
strong as possible. It is necessary that the ob-
jective, as well as the ocular glass, should be
ten inches in diameter, in "order that the
image of the sun, and the image of the bore
of the telescope, be of an equal size with the
focus.

If this telescope, which I propose, should
only serve to observe tlie sun exactly, it would
be of great service; for example, it would be
very curious to be able to discover wheiher
there beany luminous parts larger than others
in (he sun ; if there be inequalities on its sur*
face; and of what kind; ifthe spots float on its
surface; or whether they be fixed tliere, &c. The
brightness of its light prevents us from observ-
ing this luminary with the naked eye, and the
different refrangibility of its rays, renders its
image confused when received in the focus of
an objective glass, or on pasteboard, so that the
surface of the sun is less known to us than that
of any of the planets. The different r.fran-
gibility o£ its rays would be but little corrected
in this Jong telescope filled with water; but
if the liquor could, by the addition of salts.

2S8 buipfon's

he rciiflcred as dense as glass, it woulct then ha
ihe same as if there were onlj^ one glass to pass
throngli; and it appears to me that infinitely
jnore advantage would result from making
use of these telescopes filled with water, than
from the common telescopes with smoked
glasses. ^

Whether that would or would not be the
fact, this lioweveris certain, that to observe the
sun, a telescope quite different is required from
those that we make use of for the different
planets ; and it is also certain, that a particular
telescope is necessary for each planet, propor-
tionate totheirintensity of light, that is, to the
real quantity of light with which they appear
to be enlightened. In all telescopes the ob-
jectives arc required as large, and the ocular
glass as strong, as possible, and, at the same
time, the distance of the focus proportioned to
the intensity of the light of each planet. To
do this with the greatest advantage, it is requi-
site to use only an objective glass so much tlie
larger, and a focus so much the shorter, accordr
ing to the light of the planet. Why has there
not hitherto been made objectiveglassesof 243
feet diameter ? The aberration oftherays, occa-
sioned by the sphericity of the glasses, is the
fcolc cause of the confusion, which is as the

square

NATURAL HI ST our. :?39

, square of the diameter of the tube; and it is
for this reason that spherical glasses, with a
small bore, are of no value when enlarged ; we
have more iighJ, but less distinction and clear-
ness. Nevertheless, broad spherical glasses are
very good for night telescopes. The Englisk
#lave constructed telescopes of this nature, and
they make use of them very advantageously
to see vessels at a great distance in dark nights
But at present, that we know, in a great mea-
sure, how to correct the effects of the different
rcfrangibility of the rays, it seems, that we
should make elliptical or hyperbolical glasses,
which would not produce the alteration caused
by sphericity, and which, consequently, would
he three or four times broader than spherical
glasses. There is only this mode of augment-
ing to our sight the quantity of light sent io
us from the planets, for we cannot put an ad-
ditional light on them, as we do on objects
which we observe with the microscope, but
must at least employ to the greatest possible
advantage, the quantity of light with which
they are illumined, by receiving it on as great
a surface as possible. This hyperbolical tele-
scope, which would be composed only of one
single large objective glass, and of an oculir
one proportionate, would require matter of the
greatest transparency; and we should unite

by

sis BUFFO N'S

by this means all the advantages possible, that
is, those of the acromatic to that of the ellipti-
cal or hyperbolical telescopes, and we should
profit by all the quantity of light each planet
reflecis to our sight. I may be deceived ; but
what I propose appears to be sufficiently
founded to recommend i!s execution to per-
sons zealously attached to the advancement of
the sciences.

Employing myself thus on these reveries,
some of which may one day be realized, and
in which hope I publish them, I thought of
(he Alexandrian mirror, spoken of by some an-
cient authors, and by means of which vessels
were seen at a great distance on the sea. The
most positive passage which I have met with
is the following.

^' Alexandria .... in Pharo vero erat specu-
*' lum e ferro sinico. Per quod a longe vide-
*' bantur naves Graecorum advenientes ; sed
*' paulo postquara Islamismusinvaluit, scilicet
*' tempore califatus Walidfil: Abdi-I-melec,
^' Christiani,fraude adhibita illud deleverunt.
*' Abu-1-feda, &c. Dcscriptio iEgypti."

Having dwelt for some time on this, I
have thought, 1. That such a mirror was
possible to be made. 2. That even without
a mirror or telescope, we might by certain

disposstions

NATTJilAL HISTORY. 211

dispositions obtain the same effect, a^d see ves-
sels from land, as far, perhaps, astlic curvature
of tlie earth would permit. We have already
observed that persons whose sight was very
good, have perceived objects illumined by the
sun at more than 3400 times their diameter,
and at the same timt we hrwe remarked, that the
intermediate light was of such great hurt to
that of distant objects, that by night a lumi-
minous object is perceived at ten, twenty, and
perhaps a hundred times greater distance than
during the day. We know that at the bottom
of very deep pits, stars may be seen in the day-
time* ; why therefore should we not see ves-
sels illumined by the rays of the sun, by
placing one's self at the end of a very long
dark gallery, situated on the seashore, in such
a manner as to receive no other than that of
the distant sea, and the vessels which miglit be
on it? This gallery would be only a hi ri-
zoiital pit, which wotdd have the same effect
with respect to ships as the vertical pit has
with respect to the stars ; and it appears to
me so simple, that I am astonished it has never
before been thought of and tried. It seems to
me, that by taking the time of the day for our
VOL. X. I i observations

* Aristotle is, I believe, the first that ever mentioned this
observation.

242 BUFFO n's

observations wlien the sun slioiild be behind
the <]:allerv, we miffht sec them from the dark
end of it ten times at least better than in the
open light. Now a man on liorseback is easily
distinoruished at a mile distance, when the
rays of the sun shine on him, and by sup-
pressing the intermediate liglit which sur-
rounds us, and dPtrkening our sight, we should
see him at least ten times farther ; that is to
say, ten miles. Ships, therefore, being much
larger, would be seen as far as the curvature of
the earth would permit, without any other in*-
stniment than the naked eye.

But a concave mirror, of a great diameter,
and of any focus, placed at the end of a long
black tube, would Jiave nearly the same effect
as our great objective glasses of the same dia-
meter and form would have during the night,
and it was probably one of these concave mir*
Tors of polished steel that was established at
the port of Alexandria*. If this steel mirror
did really exist, we cannot refuse to the an-
cients the glory of the first invention, for this
mirror can only be effective by as much as the

light

* From time immemorial the Chinese, and particularly
the Japanese, have possessed the art of working in steel
both in large and small bodies; and hence I have thought
that the words eferro sinico in the preceding quotation should
be understood as applying to polished steel.

NATURAL HISTORY. 2 IS

light reflected by its surface was collected by
another concave mirror placed at its ft)cus,
aiid in this consists the essence of the telescope
and the merit of its construction. Neverthe-
less this does not deprive the great Ncwtnn of
any glory, who first renewed the almost-forgot-
ten invention. As the rays of light are by their
nature differently refrangible, he was inclined
to think there were no means of correcting this
effect, or, if he had perceived those means, he
judged them so difhcult that he chose rather to
turn his views another way, and produce, by
means of the reflection of the rays, the great
effects which he could not obtain by their re-
fraction ; he, therefore, constructed his telc-
•scQpe, the reflection of which is infinitely su-
perior to those that were in common use. The
best telescopes are always dark in comparison
of the acromatic, and this obscurity does not
proceed only from the defect of the polish, or
the colour of the metal of mirrors, but from the
nature even of light, the rays of which being
differently refrangible are also differentlj^ re-
flexible, although in much less unequal degrees.
It still remains, therefore, to bring the tele-
scope to perfection, and to find the manner of
compensating ihia different reflexibility, as we

have

SM BUFFO n'S

hav€ discovered that of compensating the dif-
ferent rcfrangibility.

After all, I imagine that it will be well per-
ceived tbata verj'goodday-gl»'^s may be made,
withoui using either glasses or mirrors, and
simply by suppressing the siirrounding light,
by means of a tube 150 or ^50 feet long, and by
placing ourselves in an obscure place. The
brighter the day is, the greater will be the ef-
fect. I am persuaded that we should be able
io see at 15, and perhaps 20 miles distance.
The only difference between this long tube,
and the dark gallery, which I have spoken of,
is, that the field, or the space seen, would be
smaller,and precisely in the ratio of the square
of the bore of the tube to that of the gallery.

OBSERVATIONS

NATURAL HISTORV. QiS

OBSERVATIONS AND EXPERIMENTS ON TREES
AND OTHER VEGETABLES.

THE physical study of Ycgetables is one of
those sciences which require a multiplicity of
observations and experiments bej^ond the ca-
pacity of one man, and must consequently be
a work of time ; even the observations them-
selves are seldom of much value till they have
been repeatedly made, and compared in dif-
ferent places and seasons, and by different per-
gons of similar ideas. It was for this purpose
that Buffon united with M. Dii Ilarael, to la-
bour, in co:icert for the illustration of a num-
ber of henomena, whicii appeared difficult to
explain, in the vegetable kingdom, and from
the knowledge of which may result an infinity
of useful matters in the practice of agriculture.

The frost is sometimes so intense during
wit.tcr, that it destroys almost all vegetables,
and the scarcity in the year 1709 was a melan-
choly proof of its cruel effects. Seeds, and
some kinds of trees, entirely perished, while

others

^6 15ufpon's

others, as olives, and almost all fruit-trees, sliar-
^d a milder fate, shooting forth their leaves,
tlreir roots not having been hurt; and manjr
large trees, which were more vigorous, shot
forth every branch in spring, and did not ap-
pear to have suffered any material injury. We
shall, nevertheless, remark on the real and ir-
jcparablc damage this winter occasioned them.

Frost, which can deprive us of the most ne-
cessary articles of life, destroys many kinds of
useful trees, and which scarcely ever leaves
one insensible of its rigour, is certainly one of
the most formidable misfortunes of human na-
ture; we have therefore every reason to dread
intense frosts, which might reduce us to the
last extremities if their severities v/cre frequent ;
but fortunately we can quote only two or tliree
winters which have produced so great and ge-
neral a calamity as that in 1709.

The greatest spring frosts, although they
damage the grain, and principally barley^
when it is but just eared, never occasion great
scarcities. They do not affect the trunks or
branches of (rees, but they totally destroy tlieir
productions, deprive us of the harvest of the
vines and orchards, and by the suppression of
new buds cause a considerable damage to
forests.

AUhouirh

NATURAL HISTORY. 247

Although there are some examples of ^vinter
frosts having reduced us to a scarcity of bread,
and deprived us of vegetables,thcdamage which
spring frosts occasion becomes still more im-
portant, because tliey afflict us more frequcnt-
Ij, and their effects are felt almost every year*

To consider frost even very superficially,
we must perceive that the effects produced by
the sharp frosts of winter are very different
from what are occasioned by those in spring,
since the one attacks (he body and most solid
parts of trees, whereas the other simj^y destroys
4heir productions, and opposes their growth .;
at the same time they act under quite different
circumstances ; and it is not always the ground
|n which the winter frosts produce the greatest;
disorders, as that generally suffers most fron;i
those in the spring frosts.

It was from a great number of observations
that we have been able to make this distinctioa
on the effects of frost, and which we hope will
not be simply curious, but prove of utility,
and be profitabl(? to agriculture ; and should
they not wholly enable us to escape from the
evils occasioned by frost, they will afford us
a means to guard against them. We shall,
therefore, enter upon the detail, beginning
•with that ^^hich regards the sharp frosts of

wii.tcr :

243 BUFFO n's

"winter : of these, however, we cnnnot reason
with so great a certainty as on those of spring,
because, as we have already observed, we are
seldom subjected to their tragical effects.

Most trees during wi;iler being deprived of
blossoms, fruits, and leaves, have generally
their buds hardened so as to be capable of sup-
porting very sharp frosts, unless the preceding
summer was cool, in which case the buds not
being arrived to that degree of maturity , which
gardeners call crow/cs*, they are not in a state
of resisting the moderate frosts of winter; but
this seldom happens, the buds commonly rip-
ening before winter, and the trees end are
the rigour of that season without being damag-
ed, unless excessive cold weather ensue, join-
ed to the circumstances hereafter mentioned.

We have, nevertheless, met with many trees
in foresis with considerable def('cts,whichhave
certainly been produced by the sharp frosts,
and which will never be effaced.

These defects are, 1st, chaps or chinks,
which follow the direction of the fibres. 2. .1
])ortion of dead wood included in the good ;
and lastly, the double sap, which is an entire
crown of imperfect wood. We must dwell

a little

* Ripened or filled vrith sap.

NATURAL HTSTORY. S45

a little on these defects to trace the causes
whence they proceed.

The sappy part of trees- is^ as is well known,
a crown or circle of white or imperfect wood
of a greater or less thickness, and which in
almost all trees is easily distinguished from the
sound wood, called the^ear^, by the difference
of its colour and hardness ; it is found imme*
diately under the bark, and surrounds the per-
fect wood, which in sound trees is nearly of (he
same colour, from the circumference to the
centre. But in those we now speak of, the per-
fect wood was separated by another circle of
white wood, so that on cutting the trunks of
them we saw alternately circles of sap and
perfect wood, and afterwards a clump of the
latter, which was more or less considerable,
according to the different soils and situations ;
in strong and forest earth it is more scarce tliaa
in glades and light earth.

By the mere inspection of these cinctures of
white wood, which we in future shall terra
false sap, we could perceive it to be of bad
quality; nevertheless, to be certain of it, we
had several planks sawed two feet in length,
by nine to ten inches square, and having the
like made from the true sap, we had both
loaded in the middle, and those of the false sap
VOL. X. K k alv/ays

250 buffon'^s

always brolie under a less \veigl)t than (li(E)se of
the (rue, though (he strength of the true sap
is very trivial in comparison with that of
formed wood.

We aficr wards took several pieces of these
two kinds of sap, and weighed them both in
th€ air anil water, by which we discovered that
the specific weight of the natural sap was al-
ways greater than that of the false. We then
made a like experiment with tlie wood of the
centre of the same trees, to compare it with
that of the cincture which is found between
these two saps, and we discovered that the dif-
ference was nearly the same as is usual between
the weight of the wood of the centre of all
trees and that of the circumference ; thus all
that is become perfect wood in these defective
trees is found nearly in the common order. But
it is not the same with respect to the false sap,
for, as these experiments prove, it is weaker,
bofter, and lighter tlian the true sap, although
formed 20, nay 25 years befole, which we dis-
covered to be the fact, by counting the annual
cirdes, as well of the sap as of the wood which
covered it; and this observation, which wc
have repeated on a number of trees, Lncon-
testibly proves that these defects had been
caused by the hard frost of 1709, notwith-
standing

NATURAL HISTORY.

251

stand Lnsr til at the number of some of their coals
was less than the years which had passed since
that period ; and at which we must not be
surprised, not only because we can never, by
the number of li^i»eous coats, find the age of
trees within three or four years, but also be-
cause the first ligneous coats, formed after
that frost, were so thin and confined, that we
cannot very exactly distinguish them.

It is also certain, that it was the portion of
the trees that were in sap in the hard frost of
i709, which instead of coming to perfection,
and converting itself into wood, became more
faulty. Besides, it is more natural to suppose,
thatthe faulty part raustsufFer more from sharp
frosts than sound wood : because it is not only
at the external part of the tree, and therefore
more exposed to the weather, but also because
the fibres are more tender and delicate than the
wood. All this at first appears to wear but
little diflficulty, yet the objections related in
the history of the Academy of Sciences, 1710,
might be here adduced ; by these objections
it appears that in 1709, the young trees en-
dured the hard frost much better than old.
But as these facts are certain, there mnst be
some difference between the organic parts, the
vessels, the fibres, &c. of the sappy part of

the

55S buffon's

the old trees and that of the young ; they per-
haps will be more supple, so that a power
which will be capable of causing the oue to
break, will only dilate the other.

But as these are conjectures with which the
mind remains but little satisfied, we shall pass
sligh'ly over them, and content ourselves with
the particulars we have well observed. That
this sappy part suffered greatly from the frost
is an incontestible fact, but has it been en-
tirely disorganized? This might happeii
without the death of the tree ensuin^g, pro-
vided the bark remained sound ; and even ve-
getation might continue. Willows and limes
frequently subsist only by their bark, and the
same thing has beerv seen at the nursery of
Roule in an orange tree. But we do not think
that the false sap is dead, because it always
apj>eared to lis in quite a different state from
the sap found in trees, which had a portion of
dead wood included in the sound ; besides, if
it had been disorganized, as it extends over
the whole cbcumference, it would have inter-
rupted the lateral motion of the sap, and the
wood of the centre, not being able to vegetate,
would have ali / perished and altered, which
was not the case, and which I could confirm by
a number of experiments ; however, it is not

easily

NATURAL HISTORY, S53

easily conceivable iiow tliis sappy part of wood
has been changed so far as not to become
■wood, and that far from lacing dead, it was
even in a state of supplying the ligneous coat^
wiUi sap, whicli are formed fro^n above in a
state of perfection, and which may be com-
pared to the wood of trees that have suffered
no accident. This must nevertlieless have
been done by the hard winter, which caused an
incurable malady to this part of the tree; for if
it were dead, as well as the bark which cloathed
it, there can be no doubt that tlie tree would
have entirely perished, which happened in
.1709 to many trees whose bark was detached
from them, and which by the remaininir sap in
their trunk, shot forth their buds in spring, but
died through weakness before autumn, for want
of receiving sufficient nutriment to subsist on.
We have met with some of these false sappy
.part of' trees which are thicker on oiic side
than the other, and which surprisingly agrees
with the most general state of the sap. Wc
have also seen others very thin, so that appa-
rently there were only the outer coats injured.
These were not all of the same colour, had not
undergone an equal alteration,norwer;e equally
affected, which agrees with what we have be-
fore advanced. At length, we dug at the

foot

254 buffon's

foot of some of these trees, to sec if tLe defect
existed also in the roots, but we found them
sound: therefore, it is probable that the earlh
which covered them had repaired the injury
done by the frost.

Here then we see one of the most dreadful
effects ofwinter frosts, which though locked up
within the tree, is not less to be feared, since
it renders the trees attacked by them almost
useless; but besides this, it is very difficult to
meet with trees totally exemjjt from these in-
juries ; and indeed all those whose wood is not
of a deeper colour at the centre, growing
somewhat lighter towards the sap, may be sus-
pected of having some defects, andouglit not
to be made use of in any matter of consequence.

By horizontally sawing the bottom of trees,
wc sometimes perceive apiece of dead sap or
dried bark, entirely covered by the live wood :
this dead sap occupies nearly half of the cir-
cumference in the parts of the trunk where it
is found : it is sometimes browner than good
wood, and at others almost white. From the
depth also where this sap is found in the trunk,
it appears to have been occasioned by the sharp
frost in winter, by which a portion of the sap
and bark perished, and wasaftcrwards covered
hy the new wood ; for this sap is almost always

found

NATURAL HISTORY. 255

found exposed to llie south, where the sun
melting the ice, a humidity results, which
again freezes soon after the sun disappears, and
that forms a true ice, which is well known to
cause a considerable prejudice to trees. This
defect does not always appear throughout the
whole length of the trunk, for we have seen
many square pieces which seemed perfectly
exempt from all defects, nor were the injuries
of the frost discovered until they were slit into
planks. It is, nevertheless easily to be con-
ceived, how such a disorder, in their internal
parts, must diminish their strength, and assist
their perishing.

In forests, or woods, we meet with trees
which strong winter frosts have split accord-
ing to the direction of their fibres; these are
marked with a ridge formed by the cicatrice
that covers the cracks, but which remain
within the trees without uniting again, because
a re-union is never formed in the ligneous
fibres when they have been divided or broken ;
nor can it be doubted, that the sap, which in-
creases in volume when it freezes, as all liquors
do, may produce many of these cracks. But
we also suppose that there are some which are
independent of the frost, and which have been
occasioned by a too great abundance of sap.

Be

25S buffon's

Be this as it may, the fact is, we have found
defects of (his kind in all soils, and mall ex-
Jmsitions, but most frequeiUly in wet ground
and in nortliern and western expositions ; the
letter may perhaps proceed in cases whert
the cold is more intense, in such expositions ;
and in the other, from the trees which are in
marshy grounds, having the tissue of their lig-
neous fibres weaker, and because their sap is
more abundant and aqueous- tlmn in dry land;*
which may be the cause that the effect of the
rarefaction of liquors by the pores is more per-*
ccptible, and more in a state of diminishing
the ligneous fibres, as they bring less resist-
ance thereto.

This reasoning seems io be confirmed by
anotlicr observation ; namely, that resinous
trees, as the fir,aveseldom injured by the sharp
frosts of winter, evidently from their sap bein^
more resinous : for we know that oils do not
perfectly freeze, and that instead of augment-
ing in volume, like water, in frosty weather,
they diminish when they congeal.

Dr. Hales says in his Vegetable Sialics, p. 16,
that the plants which transpire the least, arc
those which best resist the winter; because they
have need of only a small quantity of nu-
triment to preserve themselves. He says,
likewise in the same part, that the plants,

Ivhich

NATURAL HISTORY. 257

"Hbicli preserve their leaves during winter, are
those ^vhich trcanspire the least ; nevertheless,
we know that the orange tree, the myrtle, and
still more the jessamine of Arabia, &c. are
very sensible to frost, although these trees pre-
serve their leaves during winter; we must,
therefore, have recourse to another cause to
explain why certain trees which do not shed-
their leaves in winter, so well support the
sharj^est frosts.

We have sawed many trees which were at-
tacked with this malady, and have almost al-
ways found, under (he prominent cicatrice, a
deposit of sap or rotten wood, and they are ea-
sily distinguished from what are called in the
forest terms, sinks or gutters, because the de-
fects which proceed from an alteration of the
ligneous fibres, which is internally produced,
occasion no cicatrice to change the external
form of the trees, whereas the cliinks produc-
ed by frosts, w hich proceed from a cleft after-
wards covered by a cicatrice, make a ridge or
eminence in the form of a cord, which an-
nounces the internal defect.

The sharp winter frosts produce, without
doubt, many oilier injuries to trees, and we
Jiave remarked many defects, which we might
attribute to them with great probability ; but,
as we have not been able to verify the fact, we
VOL. X. I, 1 ^]i^ll

358 BUFFO n's

shall pass on to the effects of the advantages and
disadvantages of different expositions with rc^.
spect to frost ; for this question is too interesting
to agriculture not to attempt its elucidation,
especially as various authors have supported an
opposition of sentiment more capable of breed-
ing doub:s than increasing our knowledge.
Some have insisted that tlie frost is felt more
strongly at the northern exposition, while
others assert it is more sensible to the south or
vrest, and all these opinions are founded on a
single observation. We nevertheless perceive
what has caused thisdiversity of opinion, and
we are therefore enabled to reconcile them.
But, before we relate the observations and ex-
periments which have led us therelo, it is but
just we should give a more exact idea or the
question.

It is not doubted that the grcalest cold pro-
ceeds from the north, for that is in the shade
of the sun, which alone, in sharp frosts, tem-
pers the rigour of the cold ; besides, a situation
to tlie north, is exposed to the north-east, and
north-west winds, which are clearly the most
intense, whether we judge from the effects
which Lhose winds produce, or from the liquor
of the thermometers, whose decision is much
more certain. It may also be observed along
the espaliers, that the earth is often frozen and

hardened

NATUJlAL HISTORY* 259

hardened all the day towards the north, while
it may be worked upon towards the south.
Moreover when a strong frost succeeds in the
night, it is evident, that it must be much colder
in the part where it is already formed, than ia
that where the earth is warmed by the sun ; this
is also the reason why, even in hot countries,
we find snow in tlie northern exposition, on
the back of lofly mountains : besides, the li-
quor of the thermometer is alwaj^s lower at
the northern exposition, than in that of the
south ; therefore, it is incontestible, that it is
colder there, and freezes stronger.

It is therefore certain, that all the accidents
which depend solelj^on the power of the frost,
will be found more frequently at the northern
expo>iUon than elsewhere. But yet it is not al-
ways the great power of the frost which injures
trees, for there are particular accidents, which
cause a moderatcfrost to do them more preju-
dice than the mucii sharper, when they happen
in favourable circumstances. Of this we have
already given an example in speaking of that
part of dead wood included in the good, which
is producj^d by the hoar frost, and is found
most frequently intlie expositions to ihe south ;
and it is also to be observed, that great part of
the disorders produced in the winter of i 709,

are

^60 buffon's

are to be attributed to a false thaw, w!iicli was
followed by a frost still sharper than what had
preceded ; but the observations which we
have made on the eiTectsof spring frosts sup-
ply us with many similar examples, which
i neon test ibly prove it is not in the expositions
where it freezes the strongest, that the frost
commits the greatest injuries to vegetables,
^ot to dwell upon assertions,we shall proccc.l
to a detail of facts, which will render these
general positions clear and apparent.

In the winter 1734 we caused a coppice in
my wood,, near Montbard in Burgundy, to be
cut,which measured one hundred and fifty-four
feet, situated in a dry place, on a Hat ground,
surrounded on all sides widi cultivated land.
In this wood we left many small square pieces
without felling them, and in a manner that each
equally faced east, west, noilh and south. Af-
ter having well cleared the part that was cut,
we observed carefully in spring the growth of
the young buds ; the renewed tops on the 2jih
of April, had sensibly shot out in the parts ex-
posed to the soutli, and which consequently
•were sheltered from the north by the tufted
tops ; these were the first bucis that appeared,
and were the most vigorous ; those exposed to
the east appeared next ; then those of the

west,

NATURAL IIISTOR'T. 261

west, and lastly those of the northern exposi-
tion. On the 28th of April the ff^st \vas very
sharp in the morning accompanied by anortli
wind ; the .sky was clear, and the air very diy ,
and in whicb manner it continued for throe
dajs. At the end of which I went to sec iu
what slate the buds were about the cluinps,
and found them absoiiitcly blacliei'.cd in all the
parts exposed to the south and sheltered from
the north wind, wherciis those wliich were ex-
posed to the cold north wind, which still
Wowed, were only slightly injured; and with
resiDcctto the eastern and western expositions,
they were that day nearly alike ifijured.

The 14th, 15th, and 22d of May, it froze
pretty sharply, accompanied by the north and
north-west winds, and I then likewise observed
that ali those sheltered from the wind were very
much injured, but that all those which were
exposed thereto had sufllrcd but very little.
This experiment appeared decisive, and show*
ed that although it froze most strong in p;irts
exposed to the north wind, yet the frost in that
-aitnationdid the least injury to vegetabics.

This circumstance is certainly opposed to
common prejudice ; but it is not less the fact,
atid is even easy to be explained ; for this p.u-
jK«M\ it h 'sufficient topay attcnlio;i tocirciun-

g(j2 buffom's

stances in wTiich frost acts, and we shall dis-
cover that humidity is the principal cause of
its effects, so thatall which occasions humidity
renders, at the same time, the frost dangerous
to vegetaljles, and all that dissipates humidity,
evenlf it should be done by increasing the cold
(for every thing 'hat dries diminishes the dis-
asters ofa fro.t) acts towards their preservation.
We have often remarked, that iu low places,
where mists and fogs reign, frost is felt n»ore
sharoly, and oftener than elsewhere. For in-
stance, in autumn and spring we have seen de-
licate plants frozen in a kitchen-garden, in a
low situation, while the like plants were pre-
served sound in another kitchen-garden situated
on an eminence. So, likewise, in vallies and
low forests the wood is never of a beautuul
vein, nor of good quality, although the vallies
are often by much the best soil . The coppice
wood is never go.d in low places, although it
shoots forth th6re later than upon high places,
and which is occasioned by a freshness that is
always concentered therein. When I walked
H nioht in the wood I felt almost as much
heat "on eminences as in the open plains, but
in the vallies 1 experienced a sharp a,.d un-
comfortable cold. Though the trees shoot out
the latest in those parts, yet the shoots arc stil

injurcu

NATURAL HISTORY. 263

injured by <Iie frost, which spoiling the prin-
cipalbudsobligesthe trees toshoot forth lateral
branches, and thus prevents their ever becom-
ing straight and handsome Irees fit for ser-
vice. What we have just advanced must not
be understood only of deep vallies, which
are liable to those inconveniencies from nor-
thern expositions, or those inclosed on the
southern side in the form of an alley, in which
it often freezes the whole year, but also of the
smallest vallics, so that by a little custom we
can discover the bad figure of the shoots from
the inclination of the earth ; this Ipaiticularly
observed on the 2Sth of April, 1734; on that
day the buds of all the trees, from cnc year up
to six or seven, were Aozcn in all the lower
places; whereas in the high and uncovered
places there were only the shoots near the earth
which were so ; tlie earth was then very dry,
and the humidity of the air did not appear
to have greatly contributed to this injury.
Neither vines, nor the trees of the plain, arc
subject to frost, which might lead us to sup-
pose they are less delicate than the oak ; but
we think tliis must be atlributcd to the humi-
dity, which is always greater in the woods than
in the rest of the plains, for we have observed
that oaks are often very much injured from

frosts

^2G'i buffon's

frosts in forests, wliile those \vl5ic1i are in (he
plains arc not hurt in t];c least.

JjiAYge timbers, even on ennnenccs, may
cause the young' trees near them to be in the
sanoc state as if at tlie bottom of a valley. We
Lave also remarked, that the young wood near
large trees is often more injured by (he frost
than in parts remote from them, as in the
midst of such woods, where a great number of
branches are left, it is felt with more force than
in ihoic which are o{3{'n. Now all these dis»
orders are most considerable in such places, for
as the wind and sun cannot di^sipate the tran-
spiration of the earth and plants, there remains
a considerable humidity, which causes a very
great prejudice to plants.

We have also remarked, that the frost is
never more to be dreaded, with respect to the
vine flowers, buds of trees, &c. than when it
succeeds mists, or even rain, however slight,
for they are all capable of enduring a very coUf
siderable degree of cold without being damagr
cd, when i( lias not rained for some time, ant}
the earth is dry.

Frosts likewise act more powerfully in places

newly cultivated than in others, because the

vapours, which conlinually risefrom the earth,

, transpire more freely and abundantly from that

which

NATURAL HISTORY. 205

which is newly cultivated. To this reason we
mus(, however, subjoin the fact, that plants,
newly set, shoot foith more vigorously than
others, which renders them more sensible and
liable (o (he effects of fro&t. So also in light
and sandy soil the frost does more injury than
in strong land, even though of equal dryness,
because more exhalations escape from the first
kind of earths than from the latter; and if a
vine newly dunged is most subject to the frost,
it arises from the humidity whicfi escapes from
it. A furrow of vine which lies ah)ng a field
of sainfoin, pea>, &c. is often all destroyed by
the frost, while the rest of the vine is quite
healthy, and this is undoubtedly, to be attri*
buted to the transpiration of the sainfoin, or
other plants, which bring a humidity on the
shoots of the vine. In the vine also, the
branches that are strong and cut are always
less injured th:m the stock; especially when
not attached tothe props, as they are then agi-
tated by the wind which dries them.

The same thing is remarked of limber, and
I have seen in copses all the buds entirely de-
stroyed by the frost, while the upper shoo s had
not received the least damage ; indeed it always
appeared that the frost did most injury nearest
to the earth, commonly within one or two feet,
VOL. X. Mm insomuch

S66 BUFFO n's

insomiicli that it must be very violent to de-
stroy the buds higher than four.

All these observations, which may be re-
garded as very constant, agree to prove that in
general it is not the sharpest frosts which do
the greatest injury to plants, but that they are
affected in proportion as they are loaded with
humidity, which perfectly explains why the
frost causes so many disorders in the southern
exposition, although it should be less cold than
that of the north, and likewise why the frost
causes more injury to the northern exposition,
when after a rain proceeding from a westerly
wind the wind veers to the north towards sun-
set, as often happens in spring, or when, by
an easterly wind, a cold moist air arises before
sun-rise, which, however, is not so common.

There are likewise circumstances where the
frostdoes most injury to the eastern exposition ;
but as we have many observations on that sub-
ject, we shall first relate those which we made
in the spring frost in 1736, which occasioned
so much damage. It having been very dry
previously, it froze for a long time before it in-
jured the vines ; but it was not so in the forests,
apparently because they contained more hu-
midity. In Burgundy it was the same as in
the forest of Orleans, the underwood was in-
jured

KATURAL HISTORY. 267

jurcd very earij. At last the frost increased
so greatly that all the vines were destroyed,
notwithstanding the dryness still continued ;
but instead of this frost doing much damage
under thesheltcr of the wind, those parts which
were sheltered were the only ones preserved,
insomuch, that in many closes surrounded by
walls the stocks along the southern exposition
were very green, while all the rest remained
dry ; and in two quarters the vines were saved,
tlie one by being sheltered from the north by
a nursery of ash-trees, and the other because
the vineyard was stocked with a number of
fruil -trees.

But this effect is very rare, and this hap-
pened only because the season had been dry,
and because the vines had resisted the wea--
ther till the plants had became so strong, from
the time of the year, that the frost could not
injure them, independently of the external hu-
midity and other particular circumstances.

But there are other causes to be assigned
v/hy frost produces injury more frequently to
the east than to the west, and which are drawn
from the following observations :

A sharp frost causes no prejudice to plants
when it goes off before the sun comes upon
them : let it freeze at night, if the morning be

cloudy,

268 bupfon's

cloudy, or a slight rain fall, or, in a word, if
by any cause whatever the ice melt gently,
and independently of (he action of the sun, it
seldom does Any injury ; and we have very
often saved very delicate plants, which had by
chance remained exposed to ihe frosts, by re-
turning them into the green-house before sun-
rise, or by simply covering them before the sun
' had shone upon them.

One time in particular a very sharp frost
happened in autumn while our orange-lrecs
were out of the green-house, and as it rained
part of the night they were all covered with
icicles: but this accident was prevented from
doing any injury by covering them with cloths
before the sun rose, so that there was only the
young fruit and the most tender shoots injured,
and we are persuaded they would all have
been saved if the covering had been thicker.

Another time oxxr geraniums ^ and many other
plants which cannot bear the frost, were out,
when suddenly the wind, which was south-
west, veered to the north, and became so cold
that the rain, which fell abundantly, was
frozen, and in almost a moment all that were
exposed to the air were covered with ice ;
we thought, therefore, that all our plants were
irrecoverably destroyed ; nevertheless we had

then

NATURAL HISTORY. 269

them carried to the furthermost part of the
green-house, shut up the windows, and by
that means they sustained but little damage.

This kintl of precaution is always observed
with regard to animals ; whcnlhey are stricken
with cold, or have a limb frozen, great care
is taken not to expose them hastily to heat, but
they are rubbed with snow, dipped in water,
or burned in dung; in one word, the greates^t
attention is paid that they shall gradually be
brought to warmth. It is almost certain, with
respect to fruit which may be frozen, that if
thawed with precipitation it invariably j3e-
rishes, whereas it suffers but little if thawed
gradually.

In order to explain how the sun produces
so manj^ disorders in frozen plants, some have
imagined that the ice, by melting, is reduced
into small spherical drops of water, which
form so many small burning mirrors when the
sun shines upon them. But however small
the form of a mirror may be, it can only pro-
duce heat at a distance, and can have no effect
on a body it touches ; besides, the side of the
drop of water which is on the leaf of a plant
is flat, wliich removes its focus to a greater
distance. In short, if these drops of water
could produce this effect why should not the

dew-

§70 buffon's

dew-drops, which are also splierical, produce
the same ? Perhaps, it may he tliought that
the most spirituous and volatile parts of the sap
meitini^ the first, they evaporate before the
rest are in a state of moving in the vessels of
the plant, which might decompose the sap.

But in general it may be said, that the frost
increasing the volume of fluids, dilates the ves-
sels of plants, and that the thaw cannot be
performed without the parts which compose
the frozen fluid enter into motion. This
change may be made with suflicicnt gentleness
not to break the most delicate vessels of plants,
which will by degrees return to their natural
tone, and then the plants will not suffer any
injury; but, if it be done with precipitation,
these vessels will not be able to resume their na-
tural tone so soon after having suflbred a vio-
lent extension, the liquors will evaporate and
the plant remain dry.

Although we might conclude wilh these
conjectures, wi;h which I am not myself per-
fectly satisfied, yet the following data are irre-
vocably constant.

1. That it seldom happens with regard to
fruit, ei'.her in spring or winter, that the plants
are injured simply by the force of the frost and
independently of any particular circumstances,

and

NATURAL HISTORY. 271

and when it does, it is at the northern exposi-
tion that plants meet with the greatest injur^^.
2. In frosty weather, which lasts several days,
the heat of the sun melts the ice in some places
for a few liours ; for it often fieezcs again be-
fore sun-set, whicli forms an ice very preju-
dicial to plants, and it is observable that the
southern exposition is more subject to this in-
convenience than all the rest.

3. It has been observed, that spring frosts
principally disorder those plants where there is
humidity, the soils which transpire much, the
bottoms of vallies, and in general all phices
which cannot be dried by the wind and sua
are the most injured.

• In short, if, in spring, the sun which shines
on frozen plants occasion a more considerable
damage to them, it is clear that it will be the
eastern exposition, and those next the south
which will suffer most.

But it may be said, if this be the case, we
must no longer plant tothe souihern expositijn
en a-dos (which are slopes, or borders of earth,
thrown up in kitchen gardens or along espa-
liers) gilliflowcrs, cabbages, winter lettuces,
green peas, and such othc'r delicate plants as
we would have stand the winter, and preserve
for an early crop in spring : and that it is t'3

the

272 supfon's

the northern exposition alone that we must in
future plant peach and olher delicate trees.
It is proper to destroy these objections, and
shew that Ihey are false consequences of what
we have advanced.

Different objects are proposed when we set
plants to pass through the winter in shelters
exposed to the south, and sometimes it is to
expedite vegetation: it is, for example, with
this intention, that along espaliers we plant
ranges of lettuces, which for that reason are
termed winter-hiiuces ; these will tolerably
well resist the frost in whatever part we plant
them, but are always most forward in this ex-»
position ; at other times, it is to preserve them
from the rigour of this season, with an inten-
tion of replanting them early in the spring.
This practice is also followed in winter cab-
bages, which are sown in this season along an
espalier border. These kind of cabbages,
like brocoli, are tender and cannot endure the
frost, and would often perish in these shelters,
if care were not taken to cover them durin<r
the sharp frosts with straw or dung supported
on frames.

To forward the vegetation of some plants
which will not bear the frost, as green peas, &c.
it is usual for that purpose to plant them on

borders

NATURAL HISTORY. 273

borders exposed to Ihe south, besides ^vhich,
they are defended from sharp frosts \vhc:i the
weather requires it.

It is well known, without being compelletl
to dwell any longer on this point, that the
southern exposition is more proper than all
the rest to accelerate vegetation, and we have
shewn that this is also what is princip:\lly
proposed when some plants are set in that ex-
position to pass through the w inter, since, in
addition, we are aUo obliged to make use of
coverings to guard those plants which are very
delicate from the frost. But we must add,
tliat if there be some circumstances wherein
the frost causes more disorders to the southern
than toother expositions, there arcaLo many
cases which are favourable to this exposition :
for exaniple, in winter, when there is any
t!)ing to tear from tiic ice. it freqtiently
happens that the heat of ilie sun, increased by
the reflection of the wall, has sufncienl force to
dissipate all the li uni id ity, and tlien tl:e jlants
are almost perfectly scciue against the cold.
Besides, dry frosts oncn happen, Nvhich uncea-
singly act tovvards the north, and wliich are
{scarcely ever felt towards the south . In spring,
likewise, we perceive that after a raiii which
proceeds from the sonth-wcst, or south-east, if
the wind chang;* to the r.orti), t'lc southerji
vol.. X. rs n o?-. nailer

274 buffon's

espalier being under the shelter of the wind^
will suffer more than the rest ; but these cases
are very rare, and most often it is after rains,
which come from the north-east or north-west
that the wind changes to the north, and then
the southern espalier having been under shelter
from the rain by the wall, the plants there wiU
have less to suffer than (he rest, not only be-
cause it will have received lets rain, but also
because there is always less cold here, than in
other expositions. It is likewise to be ob-
served that as the sun dries much earth along
the espaliers which are to the soutli, the earth
transpires there less than elsewhere.

It is well known that what we have just ad-
vanced must be considered as applying also
to peach and apricot trees, which it is custo-
mary to put in this exposition and in that of
the east. AVe shall only add, that it is not
unusual to see peach trees frozen in the east
and southern expositions, while those are not
so which stand in the west or north ; but not-
withstanding this we can never rely on having
many, nor good peaches in this last exposition,
for great quantities of blossoms fall oft' entirely
without setting; others, after having set fall
from the trees, and those Avhich remain with
difficulty arrive to maturity. I have an
espalier of peach-trees in a western exposition,

a little

NATURAL HISTORY* 273

a little declining to the north, which scarcely
^vcr produce any fruit, although the trees are
liandsomer than those to the southern and
northern. We cannot, therefore, avoid the
inconveniences of the frost with respect to the.
southern exposition without feeling others that
are worse.

All delicate trees, as fig. laurel, &c. must be
set to the south, and great care taken to cover
them ; it is only requisite to remark that dry
dung is preferable for this purpose to straw,
because the latter not only does not so exactly
.cover them, but also from its always retaining
some grain which attracts moles and rats, who
sometimes eat the bark of trees to quench their
tliirst in frosty weather, when they can meet
with no water to drink, nor herb to feed upon ;
and however singular this may appear, it is a
circumstance which lias happened to us several
times ; but Avhen dung is made use of it must
be dry, without which it will heat and make
the young branches grow mouldy.

All these precautions are, nevertheless, very
inferior to the espaliers in niches, as in that
manner plants are sheltered from all winds,
except the south, which cannot hurt them ;
the sun, which warms these places during the
&i\yy prevents the cold from being so violent
during the iiiglit ; and over tistse defended

pince^

~/U BUFFON S

places v/e mny put a slight coveriiii^ wiili great
facilKy, wliicli ^vill liolcl the plants there in a
state of dryness, it) finitely proper to prevent
all ihe accidents which (lie spring frosts and
ice rnig!)t produce ; and most plants will not
Rnfirr from being deprived of their external
Iiuriiidity, because they scarcely transpire in
the winter, or in the beginning of spring, so
that the humidity of the air is sufficient for
their supply.

But since tlie dew renders plants so suscep-
tible of (he spring frost, might we not liope,
fhat from the researclies of Messrs. Musschen-
brorck and Fay, some inferences may be de-
duced wirlch may turn to the advantage of
agriculture ? for since there are some bodies
whicli seem to attract dew, while others evi-
dently repel if, if we could paint, plaster, or
wa-h the walls witli some matter which would
have tlie latter effect, it is certain we should
have room to expect a more fortunate success
tlia'i from the juecaution taken to j lace a
plank in form of a roof over the espaliers,
which cannot prevent the abundancc'of dew
from resting on trees, since Fay has proved
(hat it very ofien does not fall perpendicularly
like rain, but floats in the air, and attaches
iiselfto those bodies it encounters ; so that fre-
cjuendy as much dew is amassed under a roof

as

NATURAL HISTORY. 2/7

as m places entirely open. It would be easy
ibr us to recapitulate all our observations, and
continue to deduce useful consequences, but
•what we have said must be sufficient to shew
the necessity of rooting up all trees which
prevent the wind from dissipating mists.

Since b}^ cultivating the earth we cause more
exhalations to issue, great attention should be
paid not to cultivate them in critical times.

We must expressly declare against sowing
kitchen-plants on vinc-furrow's, as by their
transpiration they hurt the vine.

Props sliould be put to the vines as late as
possible. The hedges, which border thera on
the north side, should be kept lower than the
rest. It is preferable to improve vines with
mould rather than dung. And in choosing a
soil we should avoid those whicli are in bot-
toms and grounds which transpire much.

A part of these precautions may be also
usefully employed for fruit-trees; with res-
pect, for example, to plants which gardeners
are forward to put at the feet of their bushes
and along their espaliers.

If there are some parts high and others low
in a garden, Ave should pny attention to sow-
spring and delicate plants on elevated parts, at
least if we do not design to cover them witii
glasses^ &c. but in cases where humidily can-
not

278 bufI'On's

not hurt them it might be often advantageous to
choose low places, where they might be shcU
tered from tlie north and north-west winds.

Wc may also profit from what has been said
1o the advantage of forests, for if we mean to
make a reserve of any of the trees, it should
never be in parls wliere the frost is severe ; and
in planting we should pay attention to put in
vallies those trees which can endure the frost
better than the oak.

When any coui^iderable fall of timber is
made wc should make tljeni in roads, beginning
always on the north side, in order that the
v,-ind, which generally blows in frosty weather,
may dissipate that humidity which is so pre-
judicial to the underwood.

There might be also many other useful con*
sequences drawn from our ol>servati{)ns ; but
\ye shall content ourselves with having briefly
adverted to some, because the ingenious man
may supply what we have omitted by paying a
little attention to the observations we have
mentioned. We are well convinced there are
a great number of further experiments to be
made on this matter ; and perhaps even ihose
•which we have related will engage Fome per-^
€ons to work on the same subject, and from
our hints general and useful advantages may
be derived.

NATURAL HISTORY. 279

ON THE TEMPERATURE OF THE PLANETS.

MAN newly created, and even the igno-
rant man at this day beholds the extent and
nature of the universe only by the simple organ
of light : to him the earth is but a solid body,
whose volume is unbounded, and whose ex-
tent is without limits, of which he can only
survey small superficial spaces : while the sun
and planets seem to be luminous points, of
which the sun and moon appear to be the only
objects worthy regard in the immensity of th^
heavens. To this false idea on the extent of
^^ature and the proportions of the universe is
joined the still more disproportionate sentiment
of superiority. Man, by comparing himself
with other terrestrial beings, feels that lie ranks
the first, and hence he presumes that all was
made for him ; that the earth was created only
to serve for his habitation, and the heavens for
a spectacle; and in short the whole universe
ought to yield to his necessities, and even his
pleasures. But in proportion as he makes use
of that divine light, which alonie ennobles hi*

being;

280 BUFFON*S

being ; in proportion as he obtains instruction^
he is forced to abate his pretensions ; he finds
himself lessened in proportion as the universe
increases in his ideas, and it becomes demon-
strable to him, that the earth, which forms all
his domain, and on which unfortunately he
cannot subsist without trouble and sorrow, is as
small with respect to the universe, as he is with
respect to the Creator. In short, from study
and application, he finds that there does not
remain a possible doubt, that this earth, large
and extensive as it may seem to him, is but a
moderate sized planet, a small mass of matter,
which, with others, has a regular course round
the sun : for as it appears our globe is at the
distance of at least 33 millions of leagues, and
the planet Saturn at Si3 millions, the natural
conclusion is, that the extent of the sun's em-
pire is a sphere, whose diameter is 627 millions
of leagues, and that the earth, relative to this
space, is not more than a grain of sand to the
volume of the globe.

However, the planet Saturn, altliough the
furtliest from the sun, is not by uny means near
the confines of his empire: his limits extend
m'lch further, since comets ])ass over spaces
beyond that distance, as n)ay be estimated by
the time of their revolutions : a comet which

like

NATURAL HISTORY. SSl

like that ofthe jear 1680 revolves round the
i^im in 575 years must be 15 times more remote
from him than Saturn ; for the great axis of
its orbit is 138 times greater than the distance
from the earth to the sun. Hence we must still
augment the extent of the solar power 15 times
the distance from the sun to Saturn, so thatall
the space in which the planets are included is
only a small province of his domain, whose
bounds should be placed at least 138 times his
distance from the earth.

What immensity of space ! What quantity of
matter ! For independently ofthe planets, there
is a probability ofthe existence of 400 or 500
comets, perhaps larger than the earth, which
run over the different regions of this vast
sphere of which the terrestrial globe only con-
stituting a part, a unity on 191, 201, 612, 9S5y
514, 272, 000, a quantity represented by num-
bers, which imagination cannot attain or com-*
prehend.

Nevertheless, this enormous extent, this vast
sphere, is yet only a very small space in the im-
mensity of the heavens; each fixed star is a sun,
a center of a sphere equally as extensive ; and
as we reckon more than 2O0O of these fixed
stars perceived by the naked eye^and as with
telescopes we can discover so much the greater
number as these instruments are more powerful ;
voB. X. O a the

282 buffon's

the extent of tlic universe appears lobe \vit1i»
out bounds and the solar system forms only a
province of the universal empire of the Crea-
tor ; an infinite empire like himself.

Sirius, the most brilliant fixed star^and which
for that reason may be regarded as the nearest
sun to our's, affords to our sight only a second
of annual parrallax on the whole diameter of the
earth's orbit, and is therefore at the distance of
6, 771, 770, millions of leagues distant from
us, that is, 6, 767, 216 millions of leagues
from the limits of the solar system, such as we
have assigned it after the depth to which the
comets immerse. Supposing then, there is an
equal space from Sirius to that which belong*
to our sun , we shall perceive that we must ex-
tend the limits of our solar system 742 times
more than it is at present, as for as the aphe-
lion of the comet, ivhose enormous distance
from the sun is nevertheless only a unit on 742
of the total diameter of the solar system.

Leagues.

Distance from the earth to the Sun - - 33,000,000

Distance from Saturn to the Sun - - 3l3,OOO,CC0i

Distance from the aphehon of the Comet to

the Sun - - - 4,554,000,000

Distance from Sirius to the Sun - 6,771,770,000,000

Distance of Sirius to the point of the aphe-
lion of the Comet, supposing that in as-
cending; from the sun the comet point-
ed directly towards Sirius (a supposition

whick

NATURAL lUSTOIlY. 283

which diminishes the distance as much as

possible) - - 6,767^16,030,000

Oue half the distance from Sirius to the

Sun, or the depth of the solar and sircin

system - - 3,385,S85,0(X),OCO

Extent beyond the Hmits of the comet's

aphelion - - 3,331,331,000,000

Which being divided by the distance of the

comet's aphelion, gives about - 742§

We can form another idea of our immense
distance from Sirius, by recollecting that the
sun's disk formstooursisrht an'ancrle of 32 mi-
nutes, wliereas that of Sirius forms only that of
a second ; and Sirius being- a sun like ours,
■wliich we shall suppose of equal magnitude,
since there is no reason to conceive it larger or
smaller, it would appear to lis as large as the
sun, if it were but a like dislance. Taking
therefore two numbers proportional to the
square of 32 minutes, and to the square of a
second, we shall have 3,686,4000 for the dis-
tance of the earth to Sirius, and one for its
dibtuncc to the sun ; and as this unit is equal
to c3 millions of leagues, we see how many
millions of leagues Sirius is distant from us,
since we must multiply these 33 millions by
3,686,400 ; and if we divide the space between
these two reighbouring suns, althougli at so
great a distance, we shall sec that the comets
might be removed to a distance 1.800,000 times

£!Tcater

2iS4 BUFFO n's

ffrcaler Mian (hat of the earth to (he sun withr
out quittinfi^ the limits of (he solar universe,
and without bcingsulrjectcd to other laws than
that of our sun, and lieuce it may be concluded
that the solar system for its dianie(er has an
extent, which, although prodigious, never-
theless, forms on! J a very small portion of the
licavcns ; and we must infer a truth therefrom
but little known, namely, that from the sun,
the earlh and all the other planets, the sky
must appear the same.

When in a serene and clear night we con-
template all those stars nith which the celestial
vault is illuminated, it might be imagined that
by being conveyed into another planet more
remote from the sun, we should see these glitter-
ing stars larger, and emitting a brighter light,
since we siiould be so much nearer to them.
Nevertheless, the calculation we have just
made demonstrates that if we were placed in
Saturn, which is 300 millions of leagues nearer
Sirius, it would appear only an ]9i,021st
part bigger, an augmentation absolutely insen-
sible ; from which it must be concluded, that
the heaven, with respect to all the planets, lias
the same aspect as it has lo the ear(h. There-
fore if even there should exist comets whose
periods of revolution might be double, or

(rebk

NATURAL HISTORY. ^^5

4veble the period of 575 yrars, tlie longest
known to us ; if even tlic comets in coiisct*
qiieiice thereof, immerse at a depth ten times
greater, there would still he a space 74 or 75
times deeper j to reach the iast coniincs,as well
of the solar system, as of the sirian ; so that
by allowing" Sirius as much magnitude as our
sun has, and supposing in !iis system as muny
or more cometary bodies than tiMere are comets
existing in the solar, Sirius will govern them
as the sun governs his, and tJiere will renuiin
an immense interval between the coniines of
the two enipires; an interval which appears
to be no more than a desart in the vast space,
and which must give a suspicion t!)at cometa-
ry bodies do exist, whose periods are longcT,and
which are to a muchgreaterdistance than we.
can determine by our actual knowledge. Sirius
may also be a sun much l.uger and more
powerful than ours ; and if ihvd is tlie case, it
must throw the borders of his doinain so much
the further back by approaching them to us,
and at the same time retrench the circumfe-
rence of the sun.

I cannot avoid presuming, that in tin's great
number of fixed stiirs, which are all so many
suns, there are some greater and others smaller
than ours; others more or less luminous, some

i)(.<irer.

2SG buffon's

nearer, wliich are represented to us bj those
stars called by astronomers, stars of Ute first
magm'ltide, and many oliiers more remote,
which for that reason appear Jo us smaller.
The stars called iuhulous seem to "want light
and fire, a:id io be only half lighted ; those
which appear and disappear alternately are,
perhaps, of a form flattened by ihc violence of
the centrifugal force in their motion of rotation,
and are perceiveableonly when they are in the
full, disappearing when they are sideways. In
this grand order of things, and in the nature of
the stars, there arc the same varieties, and ihe
same differences, in number, size, space, ma*
tion, form, and duration; the same relation,
the same degrees, and the same coimection, as
are found in all the other orders of the creation.
Each of the suns being endowed like ours,
and like all matter, with an attractive power,
which extends to an indefinite distance, and
decreases, as the space increases, analogy leads
us to imagine that within each of their spheres
there exists a great number of opaque bodies,
planelSjOr comets, which circulate round them,
but which bcinof much smaller than the suns
which serve them for heat, they are beyond
the reach of our si"ht.

It

NATURAL HISTORY. 287

It might be imagined that comets pass from
one system to the other, and that if they hap-
pened to approach the confines of the two em-
pires they would be attracted by the prepon^
derating power, and forced to obey tlic laws
of a new master. Biii, by the immensity of
space which is beyond (he aphelion of our co-
mets, it appears that the Sovereign Ruler has
separated each system by immense dcsarts, a
thousand and a thousand times larger than all
the extent of known spaces. These desarts,
which numbers cannot fathom the depth of,
are external and invincible barriers, that ail
the powers of created nature cannot surmount.
To form a communication from one system to
the other, and for the subjects of one to pass
into the other, it would be requisite that the
centre was not immoveable, for the sun, the
head of the system, changing place, would
draw with it in its course all the bodies which
depend thereon, and hence might approach
and invade another demesne. If its rout were
directed towards a weaker star, it would com-
mence by carrying off the subjects of its most
distant provinces, afterwards those more inte-
rior, and would oblige them all to increase its
train by revolving round it ; and its neiglibour
thus deprived of its subjects, no longer liaving
planets nor comets, would lose both its h'ght

and

^S8 liUFFON's

and fire, which their motion alone can excite*
and support; hence this detached star, being
no longer maintained in its place by the equili-
brium of its farces, would be obliged to change
nutrition, by changing nature, and becoming
an obscure body, would, like the rest, obey the
power of the conqueror, whose fire would in-*
crease in proportion to the number of its con-
quests*

For what can be said on the nature of the
junbut that it is a body of prodigious volume^
an enormous mass of matter penetrated by
fire, which appears to subsist without aliment,
and which resembles a metal or a solid body in
incandescence ? And from whence can this con-
stant state of incandescence, this continually re-
newed production of fire proceed, whose con-
sumption does not appear to be supported by
any aliment, and whose deperdition is at least
insensible, although constant for such a great
number of years ? Is there, or can there be,
any other cause of the production of this per-
manent fire, but the rapid motion from the
strong pressure of all bodies, wliich revolve
round this common heat, and wliich heats and
sets fire to it, like a wheel r.ipidly turned round
its axis ? The pressure, wliich tliey exercise by
virtue of iheir weight is equivalent to the fric-*
tioii, and even more powerful, because this^

presbuie

NATURAL HISTORY. 289

pressure is a penetrating power, which not only
rubs the external surface but all the internal
parts of the mass : the rapidity of their raotioa
is so great tliat the friction acquires a force al-
most infinite, and consequently sets the whole
mass of tlie axis in a state of incandescence, of
light, of lieat, and of fire, which hence has no
need of aliment to be supported, and which,
in spite of the deperdition each day made by
the emission of light, may remain for ever
without any sensible alteration, other suns ren-
dering as much light to ours as it sends to them,
and no part of the smallest atom of fire, or any
otlier matter, being lost in a system wliere all is
attracted.

If from this sketch of the great table of the
heavens, and in wliich I have only attempted to
represent to myself the proportion of the spaces,
and that of the motion of bodies which travel
over them ; if from this point of view, to which
I only raised myself to see how greatly nature
must be multiplied in the difierent regions of
the universe, we d<?scend to that proportion of
space which we are better acquainted with,
and in which the sun exercises its power, we
shall discover, that although it governs all
bodies therein, it, nevertheless, has not the
yoL. X. P p power

I'tower of vivifying thera, nor even that of sup-^
porting life and vegetation.

Mercury, which is the nearest to the sun,
nevertheless receives only a heat 400 times*
stronger than that of the earth, and this heat,
so far from being burning, as it has alwaj's
been supposed, v. ould not be strong enough of
itself to support animated nature, for the actual
heat of the sun on the earth being only -^ part
of the heat of the terrestrial globe, that of the
sun on Mercury consequently is only \ part of
the actual heat of the earth. Now if | parts
were subtracted from the heat which is at pre*
sennt the temperature of the earth, it is certain
animated nature would be checked, if not en^
tirely extinguished. Since the sun alone can-
not maintain organised nature in the nearest
planet, how much more aid must it require to
animate those at a greater distance ? To Venus
it only sends a heat -^ times stronger than that
it sends to the earth, which instead of being
strong enough to support animated nature,
would no; certainly suffice to maintain the li-
quidity of water, nor perhaps even the fluidity
of air, since our actual temperature would be
refrigerated to ^^ which is very near the term
■^j we have given as tha external limit of the

slightest

$?ATUItAvL HISTORY. ^i

siiscbtest heat, relative to living' nature. And
with respect to Mcvrs, Jupiter, Saturn, and all
their satellites, the quantity of hoot which the
sun sends to them, in comparison with that
-which is necessary for the support of nature,
which may be looked upon as of little cllect^
<especially in the two larger planets, which, ne-
vertheless, appear to be the essenlialobjects of
the solar system,.

All the planets, tlierefore, hav^ always been
volumes (as large as useless) of matter more
than dead, profoundly frozen, and consequent-.
>ly places uninhabited and 41 n in habit able fox
ever, if they do not include within themselves
treasures of heat much superior to what they
receive from the sun. The heat wiiich our
globe possesses of itself, and which is 50 times
greater than that which comes to it from the
sun, is, in fact, the treasure of nature, the true
fund which animates us as well as every being :
it is this internal heat of the earth which causes
all things to germinate and to develope; it is
that which constitutes the element of fire,
properly called an element, which alone gives
motion to other elements, and which if it was
reduced to -^ could not conquer -their rcsist-
ftnce,but would itself fall into an inertia. Now
4hls element, this sole active power, whicli

may

292 buffon's

may render the air fluid, the water liquid, and
the earth penetrable, might it not have been
given to the terrestrial globe alone ? Does ana-
^^gy permit us to doubt that the other planets
do not likewise contain a quantity of heat,
which belongs to them alone, and which must
render them capable of receiving and support-
ing living nature ? Is it not greater and more
worthy the idea we ought to haveof the Creator,
to suppose that there every where exists beings
who acknowledge his power and celebrate his
glory, than to depopulate all the universe, ex-
cepting the earth, and to despoil it of all be-
ings, by reducing it to a profound solitude, in
which we should only find a desart space, and
frightful masses of inanimate matter.

Since the heat of the sun is so small on the
earth, and other planets, it is necessarj^ that
they should possess a heat belonging solely to
themselves, and our enquiry must be to see
whence this heat proceeds which alone can
constitute in them this element of fire. Now
where shall we be able to discover this ffreat
quantity of heat if it be not in the source itself,
in the sun alone ? for the matter of which the
planets have been formed and projected by a
like impulsion will have preserved their mo-
tion in the same direction, and their heat in

proportion

NATURAL HISTORV. 203

proportion to their magnitude and density,
Whoever weighs these a lalogics, and con-r
ccives the power cf their relations, will not
doubt that the planets have issued from the
sun by the stroke of a comet, because in the
solar system comets oidy could have power
and sufficient motion, to communicate a
similar impulsion to the masses of matter which
compose the planets. If to all these circum-
stances we unite that of the innate heat of the
earth, and of the insufficiency of the sun to
support nature, we must rest persuaded, that
in the time of their formation the planets and
earth were in a state of liquefaction, afterwards
in a state of incandescence, and ,at last in a
successive state of heat, always decreasing
from incandescence to actual temperature, for
there is no other mode of conceiving the origin
and duration of this heat peculiar to the earth.
It is difficult to imagine that the fire, termt^d
central, can subsist at the bottom of the globe
without air (that is, v/ilhout its first aliment,
and from whence this fire should proceed,
which is supposed to be shut up in the centre
of the globe), because what origin, what
source shall we then find for it ? Descarles has
imagined the earth and planets were only small
incrusted suns ; in other words, suns entirely

cxtinguislicd.

^S)i: BUFFO n's

exlinguislied . Leibnitz has not besiiated to prOi-
nouncetbat the terrestrial globe owes its source,
and the consistence of its matters, to the elcr
jinent of fire: yei these two great philosophers
had not the assistance of these nnmeroiis cir-
ciiiTistances and observations which have been
acquired and collected in our days, and whick
are so well established that it ap j)ears more than
probable that the earth, as well as the planets,
•(v^ere projected out of ihx" sun, and being con-
sequently of a like matter, which was at first in
a sta(e of liqucfacticm they obeyed the centri-
fugal power, at the same time that it c6llec(cd
itself together by that of attraction, which has
^iven a round form to all the planets under the
equator, and flattened under the poles, on ac-
count of the variety of their rotation ; that af-
terwarcfethis fire being gradually dissipated,
the benign temperature, suitable to organized
Jiature, succeeded in difl"erent planets accord-
ing to the difference of their thickness or den-
sity. If there should be other particular
causes of heat assigned for the earth and pLi-
liets, which might combine with those whose
<:rffects we have calculated, our results are not
less curious, nor less usefid to the advancement
of science; and we shall here only observe,
that those particular causes may prolong the
4ime of the refrigeration of the globe, and the

duration

NATURAL HiSTGRY. 2fe

dnralian of living nature, bejoncl the terms we
have indicated.

But I may be asked is this Tlieorj equally as
well founded in every point %vhic]i serves far
its basis ; is it certain, according to your ex-
periments, that a globe, as large as the earth,
and composed of the same matters, cannot re-
frigerate from incandescence to actual tempc-*
rature in less than 74,000 years, and that in
order to become heated to the point of incan-*
descencc a 15th of this time, that isdOOO years,
would be required : and also that it should be
surrounded all that time by the most violent
fire ; if so, there are as you say strong presump-
tions tliat this great heat of the earth could not
have been communicated to it from a disttince,
and that consequently the terrestrial matter
formerly made a part of the mass of the sun ;
but it does not appear equally proved that i\iQ
heat of this body on the earth is at present but
•^ part of the heat of the glgbe. The testimony
of our senses seems to refute this opinion,
which you lay down as a certain truth, for al-
though we cannot doubt that the earth has an
innate heat, which is demonstrated by its al-
ways equal temperature, iii all deep places
where the coldness of the air cannot communi-
cate; yet does it result that this heat, ^vhicli

appears-

^d6 liu Frog's

appears of moderate temperature, is gre^tcf
than that of the sun which seerns to burn us?

To all these objections I can give full satis-
faction, but let us first reflect on the nature of
our sensations. A very slight, and often im-
perceptible, difterence in the causes which
affect us, produces considerable ones in their
effects. Is there any thing which comes nearer
to extreme pleasure than grief? and who can!
assign the distance between the lively irritation
by which we are moved witli delight, and the
friction which gives us pain ? between the fire
"which warms and that which burns ? between
the light which is agreeable to our sight and
tliat which blinds us? between the savour
Tvhich pleases our taste and that which is dis-
agreeable ? between the smell of which a small
quantily will at first be agreeable and yet
soon after create nausea ? We must therefore
cease from being astonished that a small aug-
mentation of heat, such as ^^ should appear
so striking.

I do not pretend positively to assert that the
innate heat of the earth is really 49 times
greater than that wdiicli comes to it from the
su!i : for as the heat of the globe belongs to all
terrestrial matter, we liave no means of
separating it, nor consequently any sensi-
bly

NATURAL HISTORY* 297

ble and real limits to wlrich wemidit relate it.
But even if ihe solar heat be grealer or smaller
than we have supposed, relative to the terres-
trial heat, our theory would only alter thp. pro-
portion of tlie results.

For ei^ample, if we include the whole extent
of our sensations of the greatest heat to the
greatest cold, within the limits given by the
observations of M. Amontons, that is, between
seven and eight, and at the same time suppose
that the heat of the sun can alone produce this
difierence of our sensations, we shall from
thence have the proportion of 8 to 1 of the in-
nate heat of the terrestrial globe to that which
proceeds from the sun ; and consequently the
compensation which this heat of the sun ac-
tually makes on the earth, would be |- and the
compensation which it made in the time of in-
candescence will have been _a^: adding toge-
ther these two terms, we have -^ which mul-
tiplied by 12f, the half of the sum of all the
terms of the diminution of heat, gives |^J or
-J for the total compensation made by the sun's
heat during the the period of 74047 years of
tlie refrigeration of the earth to actual tempe-
rature. And as the total loss of the innate
beat is to tlie total compensation in the same
ratio as the time of the period of refrigeration,
roL. X. Q q ^c

S98 BUFFON S

we shall have 25 : 1 » : ; 74047 : 4813 ^\, so
that the refrigeration of the globe of the earth
instead of having been prolonged only 770
years, would have been 4813 ^ years ; which
joined to the longest prolongation, the lieat of
the moon would also produce in this supposi-
tion, would give more than 50OO years.

If we adopt the limits laid down by M. dc
Marian, which are from 31 to 32, and suppose
that the solar heat is no more than -jV of that
of the earth, ue shall have only \ of this pro-
longation, about 1250 years, insfead of 770,
which gives the supposition of -5^ which we
have adopted.

But if we suppose that the sun's heat is only
^^ of that of the earth, as appears to result
from the observations made at Paris, we should
have for the compensation of the incandescence
^^^and ^1^ for the compensation to the end
of the period of 7407 years of the refrigeration
of the terrestrial globe to actual temperature,
and we should find ^jj for the total compensa-
tion made by the heat of the sun during this
period, which would give only 154 years, or
the 5th part of 770 years for the time of the
prolongation of refrigeration. And likewise,
if in the place of ^ we suppose that the solar
heat was -^^ of the terrestrial, we should find

that

NATURAL HTSTORT. 999

that the time of prolongation would be five
times longer, that is 3850 years ; so that the
more we endeavour to increase the heat ^vhich
comes to us from the sun relative to that which
emanates from the earth, the more we shall ex-
tend the duration of nature, and date the an-
tiquity of the earth further back; for by sup-
posing the heat of the sun was equal to the in-
nate of the globe, we should find that the time
of prolongation would be S8504 years, which
consequently gives the earth a greater antiquity
of38 or 39000 years.

If we cast our eye on the table which M. de
Mairan has calculated with great exactness,
and in which he gives the proportion of the
heat which comes to us from the sun, to that
which emanates from the earth in all climates,
we shall discover a well attested fact, which is,
that in all climates where observations'havc
been made, the summers are equal, whereas
the winters are prodigiously unequal ; this
learned naturalist, attributes this constant equa-
lity of the intensity of heat in summer in all
climates to the reciprocal compensation of the
solar heat, and from the l»eat of the emana-
tions of the central fire.

All naturalists who have employed them-
selves

30O BUFFOIV'S

selres on this subject agree with me that the
terrestrial globe possesses of itself a heat inde-
pendently of that which comes from the sun.
Is it not evident that this innate heat should be
equal at every place on the surface of the globe,
and that there is no other difference in this re-
spect than that whicli results from the swelling
of the earth at the equator, and of its flatness
under the poles ? A difference, which being in
the same ratio nearly as the two diameters,
does not exceed yto^ so that the innate heat of
the terrestrial spheriod must be ^-^ times
greater under the cqua'or than under the poles.
The depcrdition which is made, and the time
of refrigeration must, therefore, have been
quicker, or more sudden, in the northern cli-
mates, where the thickness of the globe is not
so great as in the southern climates, but this
difference of -2 |o cnnnot produce that of the in-
equality of the central emanations, whose rela-
tion to the heat of the sun in winter being
equal 50 to 1 in the adjacent climates to tlie
equator, is found double to the 27th degree,
triple to the SSth, quadruple to the 40Lh, ten-
fold to the 49th, and 35 time§ greater to the
60th degree of latitude. This cause, which
presents itself, contributes to the cold of (he

northern

NATURATi HISTORY. SOI

novtlicrn climafcs, but it is insufficient for tbe
effect of the inequality of the winters, since
this effect would be S5 times ^eater than its
cause to the 60th degree, and even excessive in
climates nearer the poles ; at the same time it
would in no part be proportional to this same
cause.

On the other hand there is not any founda-
tion for supposing" that in a globe which has re-
ceived, or which possesses a certain di^grce ef
Jieat, there might he some parts of it much col-
der than others. We are sufficiently acqtiaint-
«d with the progress of heat and the pheno-
mena of its communication, to be convinced
that it is every Avhere distributed alike, since
by placing a cold body on one thai is hot, the
latter will communicate to the other sufficient
heat to render heat of the same degree of tem-
perature in a short time. It must not, there-
fore, be supposed that towards the polesthere
are strata of colder matters less permeable to
the heat than in other climates, for of whatever
uature (hey may be supposed to be, experience
has demonstrated that in a very shovi tunc
they would become as hot as the rest.

It is evident that great cold in the north does
not proceed from tliese pretended obstacles
which might oppose t!i em selves to the issue of
heat, nor from the slight difference which that

of

S02 BUFFOW's

oftlie diameters of the terrestrial spheroid must
produce ; but it appears to me, after much rc-
lleciion upon it, that we ought to attribute the
equality of the summers, and the great inequa-
lity ofthe winters to a much more simple cauf-e,
but which, notwithstanding, has escaped the
notice of all naturalists.

it is certain that as the native heat of the
earth is much greater than that which comes
to it from the sun, the summers ought to appear
nearly equal every where, because this same
heat from the sun makes only a small augmen-
tation to the stock of real heat which the earth
possesses ; and consequently if this heat issu-
ing from the sun, be only * ofthe native heat
of the globe, the greater or less stay of it on the
horizon, its greater or less obliquity on the cli-
mate, and even its total absence, would only
produce one-fiftieth difference on the tempera-
ture of the climate, and hence the summers
must appear, and are, in fact, nearly equal in
all the climates of the earth. But what makes
the winters so very unequal is the emanations
of this internal heat of the globe being in a
great measure suppressed as soon as the cold
and frost bind and consolidate the surface of
the earth and waters.

This heat which issues from the globe, de-
creases in the air in proportion, and in the

same

NATURAL HISTORY. SC5

same ratio as the space increases, and the sole
COHdensation of the air by this cause is sufficient
to produce cold winds, which acting against
the surface of the earth, bind and freeze it.
As long as this confinement of the external
strata of the earth remains, the emanations of
the internal beat are retained, and the cold ap-
pears to be, nay in fact is, very considerably
increased by this suppression of a part of this
heat: but as soon as the air becomes milder, and
the superficial strata of the globe loses its ri-
gidity, tlie heat, retained all the time of the
frost, issues out in greater abundance than in
climates where it doet not freeze, so that the
sura of the emanations of the heat becomes
equal and every where alike ; and this is the
reason that plants vegetate quicker, and the
harvest is reaped in much less time in northern
countries ; and for the same reason it is, that
often at the beginning of summer we feel sucfe
considerable heats.

If there were any doubt of the suppression of
the emanations of the internal heat by the ef-
fect of frost, we might easily be convinced of
the fact ; for it is a circumstance universally
known, that after a frost, we may perceive
snow to thaw in pits, acqueducts, cisterns,
quarries, subterraneous vaults or mines, wlien
even these depths, pits or cisterns, contain no

water s

30i BVFFOa^S

water; the emanations of the earth having
their free issue through these kinds of vents,
the ground which covers tliis top is never fro-
zen so strong as the open land; to the emana-
tions, it permits their general course, and their
heat is sufficient io melt the snow, especially in
hollow places, at the same time that it remains
on all the rest of the surface where the earth is
not excavated.

This suppression ofthe emanations of die na-
tive heat of the earth h not only made by the
frost, but likewise by the simple binding of the
ear 111, often occasioned by a less degree of cold
thau that which is necessary to freeze the sur-
face ; there are very few countries where it
freezes in the plains beyond the 35th degree la-
titude, particularly in the northern hemisphere.
It appears, therefore, that from the equator, as
far as the 35th degree, the emanations of the
terrestrial heat having always their free issue,
there ought to be in that part little or no dif-
ference between winter and summer, since this
diflbrence proceeds only from two causes, both
too slight to produce any sensible effect. The
iirst cause is the difference of the solar action,
but as this action is itself much smaller than
that of the terrestrial heat, its difference is too
inconsiderable to be regarded as any thing.
The second cause is the thickness of the globe,

which

NATURAL HISTORY. S05

\\luch towards the Soth degree, is near -^lotli
part less than at the equator, but even this dif-.
ferencecan only produce a very slight effect,
since at 35 degrees the relation of the emana-
tions of the terrestrial to the solar heat is in
summer from 33 to 1, and in winter from 153
to 1, which gives 186 to 2 or 93 to 1. From
hence it can only be owing to the consolidation
of the earth occasioned by the cold, or even to
the cold produced by the durable rains -which
fall in these climates, that wc can attribute this
difference between winter and summer ; the
binding of the earth by cold suppresses a part
of the emanations of the internal heat, and the
cold, always renewed by the fall of rain, di-
minishes its intensity ; these two causes, there-
fore, together produce the difference between
winter and summer.

After having proved that the heat which
comes to us from the sun is gready inferior to
the native heat of our globe ; after having ex-
plained that, by supposing it only -^Jg^ part, the
refrigeration of the globe to actual tem.perature
cannot be made but in 75,832 years ; after
having demonstrated that the time of this re-
frigeration would still be longer, if the heat
sent from the sun to tlie earth were in a greater
relation, namely, of J5. or-j^ instead of ^Vj ^ve
VOL. X. R r cannot

503 uufpon's

cannot Ijeblamed for having adopted that pi*o-
portion which appears the most plausible from
physical reasonings, and at the same time the
most probaHe, as it does not extend too fer
back the time of the commencement of nature,
which we l3a\'« fixed at 37 or 38,000 years,
dating itfrom the first day.

1 nevertheless acknowledge that this time,
all considerable as it is, does not appear suffi-
ciently long for certain changes, certain suc-
cessive alteiations, which Natural History de-
monstrates to have taken place, and which
seem to have required a still longer course of
centuries ; and from which I should be inclined
to imagine, that, in reality, this time would be
increased perhaps double if every phenomena
were completely investigated ; but 1 have con-
fined myself to the least terms, and restrained
the limits of time as much as possible, with-
out contradicting facts and experiments.

This theory, perhaps, may be attacked by
another objection, which it is right to guard
against. It may be told me that I have sup-
posed, after Newton, the heat of boiling water
to be three times greater than that of the sun
in sTtmmer,and iron heated red-hot eight times
greater ih&n boiling water, that is, 24 or 2a
times greater than that of tlie adtml tempera-
lure

NATURAL HISTORY. 307

ture of the earth, and that there is EometUing
hypothetical in this supposition, on which I
have founded tlie second basis of my calcula-
tions, whose results would be, without doubt,
very different if this red heat of iron, or glass
in incandescence, instead of bein^, in il^ct, 25
times greater than the actual heat of the
globe, were, for example only 5 or Q times
as great.

The better to feel the force of this gbjectiou,
let us make a calculation of the refrigeration
of the earth, upon the supposition that in the
time of incandescence it was only five times
hotter than it is according to our calculations ;
this solar heat, instead of a compensation of
5V would have only made the compensation
of -5^1^ in the time of incandescence, these two
terms added together gives ■^-^, which multi-
plied by 2|, the half of the sum of all the
terms of the diminution of heat, gives ^ for
the toktal compensation which the heat of the
sun has made during the whole period of the
deperdition of the innate heat of the globe,
which is 74047 years : therefore we shall have
: ^^^ : : 74047 : S$8 44 from which we see
that the prolongation of refrigeration, which
for a heat 28 times greater than actual tempe-
rature, has been only 770 years, should have

308 buffon's

been 888 |4j i" ^'^e supposition that this first
lieat should have been only fivie times greater
thsfn this actual temperature. This alone
shews us that if we even suppose this primitive
heat below 25, there would only be a longer
prolongation of the refrigeration of the globe,
and that alone appears to me sufficient to
satisfy the objection.

It may likewise be said, " you have calcu-
lated the duration 6f the refrigeration of the
planets, not only by the inverted ratio of their
diameters, but also by the inverted ratio of
their density ; this might be well founded if we
could imagine that in fact there exists matter
whose density is as different from that of our
globe : but does it exist? What, for example,
willbethe matter of which Saturn is composed,
since its density is more than five times less
than that of the earth ?

To this I answer, that it would be very easy
to find, in the vegetable class, matters five or
six times less dense than a mass of iron, mar-
ble, hard calcareous stone, &c. of which we
liuow that the earth is principally composed ;
but without quitingthemineralkingdom, and
considering the density of these five matters,
we have 21 f| for iron, 8yf for white marble,
forgres 7 14, for common marble and calcare-
ous stone 7 f|; taking the mean term of the

densities

NATURAL HISTORY. 509

densities of these five matters, of Vyhic)i the
terrestrial globe is principally composed, we
find its density to be 10y\.. It is therefore rcr
quired to find a matter Avhose density is in the
relation of 189 to 1000 density, Avhicli is the
same as that between Saturn and tlie Earth.
Now this matter might be a kind of pumice
stone, somewhat less dense than common pu-
mice stone, whose relative density inhere ly| ;
whence it appears that Saturn is principally
composed of a light matter similar to pumice
stone.

So likewise the density of the Earth being
to that of Jupiter as 1000 to 292, we must
suppose that Jupiter is composed of a more
dense matter than pumice stone, but much less
dense than chalk.

The density of the Earth being to that of the
Moon as 1000 to 702, this secondary planet
appears composed of a matter whose density-
is not quite so great as that of hard calcareous
stone, but more so than soff.

The densitj' of the Earth being to that of
Mars as lOOO to 730, this planet must be com-
posed of a matter somewhat more dense than
that of gres, and not bO great as that of white
marble.

But the density of the Earth being to that of
Yenus as lOOO to 12700, it may be supposed

that

310 buffon's

that this planet is chiefly composed of a more
dense matter than emery, and less dense than
zinc.

Finally, tlie density of tlie Earth being to
that of Mercury : : 1000 : 2040, or : : 10^ :

^SOjI^I^I, it must be thought that this planet is
composed of a matter less den^se than iron but
more so than tin.

To the question, how can animated nature,
which you suppose every >vhere established,
exist in planets ofiron, emery, or pumice stone?
I shall answer, by the same causes, and by the
same means as it exists on the terrestrial globe,
although composed of stone, grcs, marble,
iron, and glass. There are other planets like
our globe, v/hose principalis one of these mat-
ters ; but the external causes will soon have
altered its superficial strata, and according to
the different degrees of heat or cold, dryness or
humidity, they will have converted this matter
into a fertile earth proper to receive the seeds
of organized nature, which only needs heat and
moisture to develope itself.

Having answered the most obvious objec-
tions, it is necessary now to explain the facts,
and observations, by which we are assured that
the sun is only an accessory to the real heat,
which continually emanates from the globe of

NATURAL HISTORY. 311

(be earth; and it will be just, at the same
time, to see how comparable thermometers
have taught us in a certain manner that the
heat in summer is equal in all the climates of
the earth, excepting Senegal, and some other
parts of Africa, where (he heat is greater than
elsewhere.

It may be incontcslibly demonstrated, that
the light, and consequently the heat of the
sun, emitted on the earth in the summer, is
very great, comparatively with (hat emitted by
the same body in winter; and yet, by very
exact and reiterated observations, thediiFerence
of the real heat of the sun in summer is very
small. This alone would be sufficient to prove
that the heat of the sun makes only a small
part of that of the terrestrial globe; but in ad-
dition io this M. Amontons, by receiving the
rays of the sun on the same thermometer in
summer and winter, observed that the greatest
heat in summer in our climate differs from the
cold in winter, when the water congeals, as
only 7 differs from 6 ; whereas it can be de-
monstrated that the action of the sun in sum-
mer is about 6C) times greater than that of th«
sun in winter ; it therefore cannot be doubted,
that there is a fund of very great heat in the
terrestrial globe, on which, as a basis, the de-
grees

512 buffon's

grccs of heat iirise, and that at the surface it
docs not give a greater quantity of heat than
that which comes from the sun.

If it be asked, how we can then assert that
the heat in summer is 66 times grater than that
in winter in our climate? I cannot give a bet-
ter answer than by referring to the memoirs
given by the late M. de Mairanin 1719, 1722,
and 1765, and inserted in those of the Aca-
demy, where he examines, with a scrupulous
altention, the vicissitudes of summers in dif-
ferent climates ; the various causes for which
may be reduced to four principal ones : 1 . The
inclination under which the light of the sun
falls according to the different height of (he
sun on the horizon ; 2Jly. The greater or less
intensify of light in proportion us its passage
in the atmosphere is more or less oblique ;
,*^dly. The diffbrent distance of the earth
to the sun in summer and winter; and
4thly. The inequalities of the length of days
in diiferent climates. By the principle that
lieat is proportional to the action of light it
will be easily demonstrated^ that these four
united causes, combined and compared,'
diminish with respect to our climate, this
action of the sun's heat in a ratio of about
66 to 1 between the summer and the winter

solstice ;

NATURAL HISTORY. 313

solstice ; and this theoretical truth may be re-
garded as certain, as the second truth from
experience, and which demonstrates, by the
observations of ihe thermometer, immediately
exposed to the sun's rays in winter and sum-
mer, that the diiference of real heat in these
two is, nevertheless, at most only from 7 to 6;
I say at most, for this determination given by
M. Amontons is not nearly so exact as that
which has been made by M. de Mairan, who,
after a great number of final observations,
proves that this relation is only as 32 to 31.
What, therefore, must indicate this prodigious
inequality between these two relations of the
action of the soldr heat^ in summer and winter,
which is from 66 to 1 ; and of that of the real
heaty which is only from 32 to 3i ? Is it not
evident that the innate heat of the globe of the
earth is considerably greater than that which
comes to us from the sun ? It appears, in fact,
that in the climate of Paris this heat of the
earth is 29 times greater in summer, and 491
times greater in winter than thatof ths sun, as
M. de Mairan has determined it. But I have
already said that we must not conclude, from
these two combined relations, tho real one of
the beat of iht globe of the earth to that
which comes from the sun, and I have firiven
reasons which hr\ve determined rae io suppose
VOL. X. Ss that

SI^ buffon's

that we may estimate this heat of the sun 49*
times less than the heat which emanates from
the earth.

From the year ITOl to 1756 inclusive, a
variety of observations were made with ther-
mometers, and the following were the results .
The greatest degree of heat, and of cold, which
was experienced at Paris in each year was col-
lected ; a total of these was made, and it was
found that the mean estimate, in all the ther-
mometers, reduced to Rheaumur's division,
was 1026, for the greatest heat in summer, that
is 26 degrees above the freezing point ; and
that the mean degree of cold in winter, during
those 56 years, was 994, or 6 degrees below
the freezing point of water, whence we con-
cluded that the greatest heat in our summers
at Paris differs from the greatest cold of our
winters only •g?^, since 994 : 1026 : : 31 : 32;
and it was on this foundation that we stated
the latter to be the relation of the greatest heat
to the greatest cold. But it may be objected
against the precision of this valuation, the de-
fect of the construction of the thermometer,
and Rheaumur's division (to which we have
here reduced the scale of all the rest); and
this defect is extending only 1000 degrees be-
low that of ice, as if 1000 degrees were in fact,
that of absolute cold, whereas absolute cold

doe

NATURAL HISTOHY. 315

does not exist in nature ; and that of the smallest
heat should be supposed 10,000 instead of
1000, which would alter the thermometer's
gradation. It may likewise be said that it is
possible all our sensations between the greatest
heat and the greatest cold are comprised in as
small an interval as that of a unit on 32 of heat,
but that the voice of judgment seems to be
raised against this opinion, and tells us this
limit is too confined, and that it is much easier
to reduce this interval than to give it an eighth,
or a seventh instead of a thirty-second.

But be this valuation as it may, there can
be no doubt of the truth of these facts which
we have drawn from our observations, for in
the same manner as we found, from the com-
parison of oQ successive years, the heat of sum-
mer at Paris 1026, or 2o degrees above the
freezing point, we also found, with the same
thermometers, that the heat in summer was
1026 in every climate of the earth, from the
equator to the polar circle ;* at Madagascar, in
the islands of France and Bourbon, Roderigo,
Siam, and the East-Indies ; at Algiers, Malta,
Cadiz, Monlpelier, Lyons, Amsterdam, Upsal,
Petcrsburgh, and as far as Lapland, near the

polar

* See the Memoirs of Rheaumur In those of the Aca-
demy (year 1735 and 1741), and also of the Memoirs of
M. de Mairan in thvseof the year 1765, p. 213.

316 BUFFO N'S

polar circle. At Cayenne, Peru, Martinica,
Carthag^nain America; at Panama; m short,
in all the climates of tlie two hemispheres and
continents Tvhere observations could be made,
it has been constantly found that the liquor of
the thermometer rose equally to 25, 26, or 27 de-
grees in the hottest days in summer ; and hence
ensues the incontestible fact of the equality of
beat in summer in all climates of the earth.
There are indeed some exceptions, for at Sene-
gal, and some few other places, the thermo-
meter rises 5 or 6 degrees higher, to 31 or 32
degrees; but that arises from accidental and
local causes, which do not alter the truth of the
observations, nor the certainty of the general
fact, Vvhich alone might demonstrate to ns, that
there really exists a very great heat in the ter-
restrial globe, that the effect, or the emana-
tions, of which are nearly equal in all the
points of its surface, and that the sun, very far
from being the only sphere of heat which ani-
mates nature, is at best only the regulator.
This important fact, which we consign to pos-
terity, will enable it to discover the real pro-
gression of the diminution of the heat of the
terrestrial globe, which we have been only able
to determine in a hypothetical manner. In a
few centuries, I am confident it will be found

thii^

NATURAL HISTORY. 317

that the greatest beat of summer, insteail of
raising the liquor of the tliermometer to 26,
will not raise it to more than 25, or 24 ; and
from this eilect, which is the result of all the
combined causes, a judgment may be formed
of the value of each of the particular causes,
which produce the total effect of heat oi\ the
surfiice of the globe ; for the heat which be-
longs to the earth, and which it has possessed
from the time of incadescence, has very con-
siderably diminished, and will continue to di-
minish with the course of time: this heat is
independent of that whicli comes from the sun;
the latter may be looked upon as cuiistant, and
consequently in futurity will make a greater
compensation than at present. To the loss of
this innate heat of the globe there are two
other particular causes, which may add a con-
siderable quantity of heat to the effect of the
two first, tlie only ones we have as yet taken
notice of.

One of these particuhtr causes proceeds, in
some measure, from the iirst general cause, and
may add something to it. It is certain Ih^it
during the time of incadescence, aiRl indeed
all the subsequent tig^^s till that of the refrige-
ration of the eartli, not any of the volatile
matters could reside at the surface, or even in

the

5iS buffon's

the internal part, of the globe ; (hey were
raised and dispersed in the form of vapours,ancl
could not deposit themselves but successively
in jiroportion as it cooledjby which means some
of these matters have penetrated through the
clefts and crevices of the earth to great depths,
in an infinity of places; and this is the primitive
foundation of volcanos, which are all found in
lofty mountains, were the clefts of the earth
are so much the greater as these points of the
globe are more projecting and isolated. This
deposit of the volatile combustible matters of
the first ages will have been greatly augmented
by the addition of every combustible matter
which has been subsequently formed. Pyrites,
sulphurs, coal, bitumen, &c. have penetrated
into the principal cavities of the earth, and
produced almost every where great masses of
inflammable matters, and often conflagrations,
■which have been manifested by earthquakes,
crruptions of volcanos, and by the hot springs
which flow from mountains, or run internally
in the cavities of theearth. It may, therefore,
be presumed that these subterraneous fires,
some of which burn without explosion, and
others with great noise and violence, somewhat
increase the general heat of the globe. Never-
theless this adiiition of heat can be only very

slight.

NATURAL HISTORY. 31^

slight, for it has been observed that it is nearly
as cold on the top of volcanos as on the top of
other mountains of the same height, except at
the very time when the volcano throws out in-
flamed vapours or burning matters.

The second cause, which seems not to have
been thought of, is the motion of the moon
round the earth. This secondary planet per-
forms its evolution round the earth in 27 days
and one third, and being 85.3^5 leagues dis-
tance, it goes over a circumference of 536,329
leagues in this space of time, which makes a
motion of 817 leagues in an hour, or from 13
to 14 leagues in a minute. Although this rout
is, perhaps, the slowest of all the celestial bo-
dies, yet it is rapid enough to produce on the
earth, which serves for the axis or pivot to this
motion, a considerable heat by the friction
which results from the weight and velocity of
this planet. But it is not possible to estimate
the quantity of heat produced by this exterior
cause, because hitherto we have had nothing
which might serve us for a term of comparison.
But if we ever can discover tlie number, mag-
nitude, and velocity, of all tlie planets which
circulate round the sun, we s^IialUhen be able
to judge of the quantity of iieat wliich the
moon can give to tlic earth, by the much

greater

390 buffon's

grealer quantity of fire which all these vast bo«*
dies excite in the sun. For my own part I am
greatly inclined to think that the heat produc-
ed by this cause in the globe of the earth,
forms a verj' considerable part of its own heat :
and that, in consequence, we mast still extend
the limits of time for the duration of nature.
But let us return to our principal object.

We have observed that the summers are very
nearly equal in all climates of the earth, and
that this truth is founded on incontestible
facts ; but it is not the same with respect to
winters ; they are very unequal, and vary in
different climates, as we remove further from
that of the equator, where the heat in winter
and summer is nearly the same. I think I
have already explained in a satisfactory man-
ner the cause of this, viz, the suppression of the
terrestrial heat. This suJ)pression is, as I
have said, occasioned by the cold winds, which
fall from the air, bind the earth, freeze the
waters, and shut up the emanations of the
terrestrial heat during the time the frosts re-
main ; so that it is not at all surprising that the
cold in winter is in fact so much the greater
as we advance further towards the climates
where the mass of air, receiving the rays

of

STATURAL HISTORY. 3^1

of the sun more obliquely is for that reason
colder.

But with respect to the cold as well as to
the heat, there are some countries which are an
exception to the general rule. At Senegal,
Guinea, Angola, and probably in every
country where the natives are black, as in
Nubia, the country of the Papons, New Gui-
nea, &c. it is certain that the heat is greater
there than in any other part of the earth ; but
this arises from local causes and therefore in
those particular climates where the east wind
reigns during the whole year, passes over a
very considerable track of land, and receives
a scorching heat before it arrives to them, it is
not surprising that the heat is found 5, 6, and
even 7 degrees greater tlian it is elsewhere.
The excessive colds of Siberia, are also to be
attributed to that part of the surface of the
globe being much higher than that which sur-
rounds it. " The northern Asiatic countries
(says the Baron Strahlenberg in his description
of the Russian Empire) are considerably more
elevated than the European. They are like
a table, in comparison of the bed on which
they appear so be placed ; for on coming from
the west and leaving Russia, we pass to the
east by the mountains Ripha and Rymnikas
VOL. X. T t to

322 BUFFO. \'S

to enlcr Siberia, and constantly advance to an
ascent." " There are many places in Siberia,
says i\I. Gmelin, which arc not less elevated
above the rest of the earth, nor less remote
from its centre, than are many high moun-
tains in many other regions." Tliese plains of
Siberia, appear, in fact, to be as high as the
summit of theRiphean mountains, on which
the ice and snow do not wholly melt during
summer ; and if the same effect do not hap-
pen in the plains of Siberia, it is because they
are less detached, for this local circumstance
also adds much to the duration and to the in-
tensity of cold and heat. A vast plain once
made hot will retain its heat longer than a de-
tached mountain, though both are alike ele-
vated ; and for the same reason the mountain
once cooled will retain its snow or ice lon-
ger than the plain.

But if we compare the excess of heat with
that of cold produced by these particular and
local causes, we shall be surprized to find, that
in Senegal, &c. where the heat is greatest, it ne-
ver exceeds seven degrees beyond the summer
heat in other countries, which is 26 degrees
above the freezing point, while on the contra-
ry, the colds of Siberia sometimes reach 60 or
70 degrees below it, and that at Petersburg!),

Upsal,

NATURAL HISTORY. 323

Upsal, &c. under the same latitude as Siberia,
the greatest cold is not more than to 25 or 26
degrees below tbe freezing point ; therefore,
we must conclude, that these local causes have
much more influence in cold than in hot cli-
mates. Although we cannot pretend to deter-
mine what this great difference in the excess
of cold and heat may produce,yet by reflecting
on it, it appears that we may easily conceive
the reason of this difference. The auirmenta-
tion of the heat in such a climate as Senegal
can only proceed from the action of the air^
the nature of the soil, and the depression of
■the ground; forthis country being alnwst on a
level with the sea, it is in a great measure co-
vered with scorching sands, over which an
jeasterly wind continually blows ; this, instead
of refreshing the air, only renders it more burn-
ings because it traverses over more than 2000
leagues of land in its way, and consequently
acquires a considerable degree of heat. But
in such countries as Siberia, where the plains
are elevated like the summits of mountains
above tbe level of the rest of the eaith, this
sole diftbrence of elevation must produce an ef-
fect proportionally greater than the depression
of the ground of Senegal, which cannot be
s,upposed more than that of the level of the

324: • buffon's

sea ; for if the plains of Siberia be only elevate
ed 4 or 500 fathoms above Ibe level of Upsal,
or Petersburgh, we must cease from being as-
tonished that the excess of cold is so great
there ; sine? the heat which emanates from the
earth, decreases at each point as the space in*
creases, and this elevation of tlie ground alone
suffices to explain this great difference of cold
under the same latitude.

On this point there remainsonly oneinterest-
ing question. Men animals, and plants, may,
for some time, support the rigour of this cold,
which is 60 degrees below the freezing point ;
but could theyalso support a heat which should
be CO degrees above it ? To tliis we answer,
yes, provided we knew as well how to guard
airainst the heal as we do to shelter ourselves
from the cold ; and if the air could, during the
remainder of the year, refresh the earth, in the
same manner as the emanations of the heat of
the globe warms the air in cold countries. We
know of plants, insects, and fish, which live
and grow in baths of 45, 50, and even 60 de-
grees of heat ; there are, therefore, species in
living nature which can support this degree
of heat ; and as the negroes are in the human
race those whom a strong heat the least in^
commodes, might we not conclude, according

tci

NATURAL HISTORY. 325

to this hypothesis, that the earth has continued
to decline from its original heat, and that the
race of negroes are more ancient than that of
white people?

GENERAL VIEWS OF NATURE.

FIRST VIEW.

NATURE is that system of laws established
by the Creator for regulating the existence of
bodies and the succession of beings. Nature
is therefore not a body, for if it were so, it
would comprehend every thing; neither is it a
being, for in that case it would necessarily be
God. We must rather consider Nature as an
immense living power, which is in subordina-
tion to the Supreme Being, and by his com-
mand animates the universe, and whose actions
are dependent on, and continued by, his con-
currence or consent. This power is that part
of Divine omnipotence which is manifested to

mankind ;

526 BUFFON S

mankiiid : it is the cause and eflfcct, tho mode
and substance, the design and execution. Ex-
tremely different from all human art, whose
productions are inanimate. Nature is herself a
Mork perpetually alive, an active, an unceas-
ing operator, who knows how to make use of
every material, and whose power, though al-
ways employed on the same invariable plan, in-
stead of suffering dirainulion, is perfectly in-
exhaustible : time, space, and matter, are her
means ; the universe her object ; and motion
and life her end.

Every object in the universe is the effect of
this power. Those springs which she makes
use of are active forces which time and space
can only limit but can never destroy; forces
which unite, balance, and oppose, but areinca-r
pable of annihilating each other. Some pcr
netrate and connect bodies, others heat and
animate them. It is principally by attrac-
tion and impulsion, that this power acts
upon brute matter, while beats and organic
molecules are her chief active agents, which
she employs in the formation and exj an-
sion of organized beings. Aided by such in-
struments, how can the operations of Nature
be limited ? She only wants the additional
power to create and annihilate to become omni-
potent. But these two extremes the Almighty

has

NATURAL IIISTOIIY. 327

has reserved to himself alone ; the power of
creating and annihilating are his peculiar at-
tributes; while that of changing, destroying-,
unfolding, renewing, and producing, are th€
only privileges he has conferred on this or any
other agent. Nature, the minister of his irrc^
"cocahle commands, the depositary of his immU'
table decrees, never deviates from the laws he
has prescribed to her ; she never changes any
part of his original plan, but in all her opera-
tions she exhibits the will and design of the
eternal Lord of the universe. This grand de-
sign, this unalterable impression of all exist-
ence, is the model upon which she invariably
acts; a model of which all the features are so
strongly impressed, that they can never be
effaced; a model which the infinite number
of copies, instead of impairing', only serve t(3
renew.

We may therefore affirm that every thing
has been created, but nothing annihilated;
Naiure acts between the two without ever
reaching either the one or the other. It is in
some points of this vast space, which she haj»
filled and traversed from the beginning of ages,
that we must endeavour to lay hold of her (o
bring her inio view.

Whatan infinity of objects, comprehending
jin infinity of matter, which would liave beeu

creatwl

o28 BUFFO n'S

created in vain, had it not been divided info
portions, separated from each other by almost
inconceivable spaces ! Myriads of luminous
globes, placed at immense distances, are the
bases which support the fabric of the universe,
and millions of opaque globes, which circu-
late round them, constitute the moving order of
its architecture. By two primitive forces, each
of which are in continual action, these masess
are revolved and carried through the immen-
sity of space ; and their combined efforts pro-
duce the zones of the celestial spheres, and in
the midst of vacuity establish fixed stations, and
regular routes and orbits.. From motion pro-
ceeds the equilibrium of worlds, and the repose
of the universe. The first of these forces is
equally divided, but the second is separated in
unequal proportions. Every atom of matter
contains the same degree of attractive forcc^
while every individual globe has a different
quantity of impulsive force assigned to each.
Of the stars, some are fixed and others wan-
dering ; some globes appear formed to attract,
and others to impel or be impelled. Some
spheres have received a common impulsion in
the same direction, and others a particular
impulsion. Some stars are alone, and others
are attended by satellites ; some are luminous,

aiul

NATURAL HISTORY. ^9

E^nd others opaque masses. There are planpt^
whose different parts successively enjoy a bor-
rowed light, and there are comets which, after
being lost in the immensity of space for several
ages, return to receive the influence of the solar
heat. There are some suns which appear and
disappear as if they were alternately kindled
and extinguished ; and there are others which
n^erely shew themselves and then are seen no
ipore. Heaven abounds with great events,
which the human eye is scarcely able to per-
ceive. A sun which expires and annihilates
a world, or system of worlds, has no other
effect upon the eyes of man than an i^ms-
fatuus, which gives a transitory bla?;e and
then vanishes for ever. Mao, confined to the
terrestrial atom on which he vegetates, cpn^
aiders this atom as a world, and loojks upoi;
pther worlds as atoms.

This earth which we inhabit js scarcely dis-
tinguishable among the other globes, and per-
fectly invisibl,e to the distant spheres ; it is at
least a million times smaller than the sun by
which it is illuminated, and even a thousancj.
times less tlian some of the planets which, by
its influence, the sun compels to ciiculate
round him. Saturn? Jupiter, Mai^j the Earthy
Yenus, Mercury, an,d the Sun, occupy that
\oh. X. U u small

330. BUFFO n's

small portion of the heavens which we tertrj^
our Universe. These planets, with their sa-
tellites, moving with amazing celerity in the
same direction, and almost in the same plane,
compose a wheel of an immense diameter,
whose axis supports the whole weight, and
which by the rapidity of its own rotation must
inflame and diffuse heat and light throughout
the whole circumference. As long as this re-
gular motion continues (and which will be
eternal, unless the Divine Mover exert the
same force to destroy as He thought necessary to
create them) the sun will burn and illuminate
all the spheres of this universe with his splen-
dor; and as, in a system where the whole of
the bodies mutuatly attract each other, nothing
can be lost or removed without being return-
ed, the quantity of matter must always remain
the same ; this great source of light and life
can never be extinguished or exhausted, for
other suns, which also continually dart forth
their fires, constantly restore to our sun as
much light as they take from him. Comets
are more numerous than planets, and like
them depend on the power of the sun ; they
also press on the common focus, and by aug-
menting the weight increase the inflammation.
They may also be said to form a part of our

universe.

NATURAL HISTORY. 331

liHi verse, for, like the planets, they are subject
to the attraction of the sun. But in their pro-
jectile and impelled motions they have nothing
iji common either with each other or with the
planets. Every one of them circulates in a
different plane, and they each describe orbits
in different periods of time ; for some perform
their revolutions in a few years, while others
require several centuries. The sun, simply
moving round his own centre, remains, as
it were at rest in the midst, and, at the same
time, serves as a torch, a focus, and an axis,
to all and every part of this w onderful ma-
chine.

That the sun continues immoveable, and re-
gulates the motions of the other globes, is to be
ascribed to his magnitude alone. The force
of attraction being in proportion to the mass of
matter; as the sun is so considerably larger
than any of the comets, and contains above a
thousand times more matter than the most ex-
tensive planet, they can neither derange him
nor diminish his influence, which extending to
immense distances keeps the whole within the
bounds of his power, and thus at particular
periods recals those which have stretched fur-
thest into the regions of space. Some of these
en being brought back, approach so near the

sua,

utjffon's

siin, that after Tiavin^^ cooled for ages they re-
ceive an inconceivable degree of beat. From
experiencing- the^ alternate extremes of heat
artd cold, they ate subject to singular vicissi-
ttides, as Well as from the ineCfiialities of theur
tridtioTis, which at sortie titnes are most incon-
ceivably rapid, and at others so amazingly
^loiv as to be scarel}^ perceptible. In compari-
S6n with the planets the comets may be consi-
dered fes ivorlds in disorder, for to them the
orbits of the planets are re'gtilar, their move-
ments equal, their temperature always the
sanle ; they appear to be places of rest, where,
every thing being permanent, Nature, has the
power of establishing a uniform plan of opera-
tion, and successively to mature her various
productions. Among the planets the Earth,
which we inhabit, seems to possess peculiar ad*
Vantages ; from being less distant from the ^un
than Saturn, Jupiter, and Mars, it does not ex-
perience that excess of cold ; nor is it so
scorched as Venus and Mercury, which appear
to revolve in an orbit too near the body of that
luminary. Besides, what a peculiar magnifi-
cence from Nature does the earth enjoy? A
pure light, gridunlly extending ftom east to
west, alternately gilds both hemispheres of this
globe; which is also surrounded with a pune

transparent

NATURAL HISTORY. 333

transparent element. By a mild and fertile
heat all (he germs ofexistence are animated and
nnfolded, and they are nourished and supported
by a plentiful supply of excellent waters. Con-
siderable eminences dispersed over the surface
of the land, not oaly check, bnt collect the
moist vapours which float in the air, and give
rise to perpetual fountains. Immense cavi-
ties evidently formed for the reception of those
waters, separate islands and continents. The
sea in extent is equal to that of the land : nor
is this a cold and barren element, but a new
empire, no less rich and no less furnished with
inhabitants. By the finger of the Almighty
the limits of the waters are marked out. If
the sea encroach on the western shores, it re-
treats from those of the cast. This great
mass of water, though inactive of itself, is agi-
tated, and put in motion by the influence of
the celestial bodies, whence arise its regular
and const-Hit flux and reflux ; it rises and falls
with the course of the moon, and is always at
the highest when the action of the sun and
moon concurs ; it is from these causes uniting
at the time of the equinoxes, that the tides arc
then higher tiian at any other time ; and this
is certainly the strongest mark of the connec-
tion of this globe with the heavens. These

general

S34 buffon's

general and constant motions are the cause of
many variable and particular circumstances ;
it is by those that the removals of earth are
occasioned, which falling in the form of sedi-
ment, produce mountains at the bottom of the
sea, similar to those which are on the surface
of the land; they also give rise to currents,
which following the direction of these chains
of mountains, bestow On them a figure, whose
Singles correspond, and maintain a course in
the midst of the waves as waters run upon
land ; they may in fact, be considered as sea*-
rivcrs.

The Air being lighter and more fluid than
water, is subject to the influence of a greater
number of powers. It is constantly agitated
by the effects of the sun and moon, by the
immediate action of the sea, and by the rare-
faction and condensation of heat and cold. The
winds arc, as it may be said, its currents ; they
force and collect the clouds, they give rise to
meteors, and transport the moist vapours of
the ocean to the surfuces of islands and conti-
nents ; from them proceed storms, and they
diffuse and distribute the fertile dews and rains
over the land ; they interfere with the regular
motions ot the sea, agitate the waters, some-
times stop, and at others precipitate the cur-
rents,

NATURAL HISTORY. S3a

rents, elevate the waves, and excite dreadful
storms and tempests. Forced by them the
troubled ocean rises towards the heavens, and
with a tremendous noise and violence, rushes
against those immoveable barriers, which it
can neither destroy nor surmount.

The earth being elevated above the level of
the sea, it is thus defended against its irrup-
tions. Its surface is beautifully enamelled
with various flowers, and a constant renewing
verdure ; it is inhabited by numberless species
of inhabitants, among which, man, placed to
assist the intentions of Nature, presides over
every other being, finds a place of perfect re--
pose, and a delightful habitation. He alone is
endowed witli knowledge, and dignified witli
the fiiculty of admiration ; the Almighty has
rendered him capable of distinguishing the
wonders of the universe, and a witness of his
increasing miracles. Animated by a ray of
divinity, he participates the mysteries of the
Deity. It is by this ray tliat he is enabled io
think and reflect, and that he perceives and un-
derstands the wonderful works of his Creator.

The external throne of the Divine mag-
nificence is Nature ; and man, by contem-
plating her, advances by degrees to the internal
throne of the Almighty. He is formed to

adore

$$6. buffon's

udore his Creator, and to h^ve dominion ovef
every other creature; he is the vassal of heaven,
and the lord of the earth ; by hina this nether
globe is peopled, enobled, and enriched ; he
f{>tablishcs order, subordination, and harmony
among living beings, and even to Nature her-
self he gives polish, extension, cultivation, ^nd
embellishment ; for he cuts down the thistle
und the bramble, and, by his care, multiplies
the vine and the rose. In those dreary desarts
vhere man has not inhabited, we find then>
ever-run wi<h thorns and briars ; the trees de-
formed, broken and corrupted, and the seeds
T^hich ought to renew and embellish the scene,
Rfechaaked by surrounding rubbish, and ret
dnced to sterility. Nature, whom we find ir^
other situations adorned with the splendour of
youth, has here the appearance ofoldageand
eiccrepitude. Here the earth , overloaded with
the spoils of its produciipns, instead pf pre*
senting a scene of beautiful verdure, exhibit?
only a rude mass of coarse herbage, and trees
Joided with parasitical plants, as lichens, aga*
ri&s, and other impure and corrupted fruits ;
the low grounds are covered with putrid and
§<agnant waters ; these miry lands being nei^
ther solid nor'fluid, arc not only impassable bujt
ere entirely useless to the inhabitants of j)qi\}.

land

NATURAL HISTORY. 337

land and ^ater ; and the marshes abounding
with stinking aquatic plants, serve only to nou-
rish venomous insectSjand to harbour infectious
animals. There is, indeed, between the pu-
trid marshes of the low ground, and the de-
cayed forests of the high parts of the country, a
species of lands, or savannas, but which are
very different from our meadows ; for in them
there is an abundance of noxious herbs which
spring up and check the growth of the useful
kinds : instead of that delicate enamelled turf,
which may be considered as the down of the
earth, they are covered over with coarse vege-
tables and hard prickly plants, which are so
interwoven, that they appear to have more con-
nection with each other, than with the soil ;
and by a constant and successive generation at
length form a kind of rough mat several feet
thick* In these uncultivated and desolate re-
gions,there is no road, no communication, and
no vestige of intelligence. Man, when seek-
ing to destroy the wild beasts, is compelled to
follow their tracks, and to be constantly on
the watch, lest he should become a victim to
their savage fury ; alarmed and terrified by
their frequent roarings, and even awed by the
profound silence of those dreary solitudes, he
shrinks backhand exclaims ; '• Uncultivated
yoL% X. X X Nature

^^ Nature is bideoiis and onflounsliing ; it is
" I alone Vihty can render her agreeable and
*' vivacious. Let us drain the marslies, and
'* jSrive animation to the waters, by converting
" them into brooks and canals ; let us make
*' use of that active and devouring element,
** whose po'wer we have discovered ; let us
** apply fire to this burthensome load of vege-
** tables, and to those decaying forests which
*' are already half destroyed ; let us complete
*' the work by destroying w4th iron what can-
*' not be removed by fire ; and then instead
" of coarse reeds and water-lilies, from which
*' the toa<l is said to extract his poison, we
" shall soon behold the ranunculus, truffles,
^' and other mild and salutary herbs spring up ;
*^ that land, which was formerly impassable,
" will become a flourishing pasture for flocks
•* of cattle, where they will find plenty of
" food, and where, by the excellence of their
^' sustenance, they will increase and multiply,
*^ and thus reward us for our labours and the
'' protection we have given them. Let us go
*^ still further, and subjectthe ox totlie yoke ;
''let his strength and weight of body be em-
^' ployed to plough the ground, which ac-
*' quires fresli vigour from culture. Thus
♦'will lh« operations.of Nature be assisted,

'' and

NATURAL UI6T0EY* 330

^^ and acquire double strength and splendor
^' from the skill and industry of man."

How beautiful is cultivated Nature I How
lovelj does she appear when decorated by the
iiand of man ! He is himself her chief orna-
ment, her noblest production, and by multi-
plying his own species he increases the most
precious of her works. She even seems to
multiply in proportion to his attention, for
by his art hedevelopes all that she has conceal-
ed in her bosom. What a source of unknown
treasures has been brought to light ! flowers,
fruits and grains, matured to perfection, and
xnaltiplied to infinity ; the usual species of
animals transported, propagated and increased,
-without number ; the noxious and destructive
kinds diminished and driven from the habita-
tions of men ; gold, and iron a more useful
metal, extracted from the bowels of the earth ;
torrents restrained, rivers directed in their
courses and confined within their banks, and
even the ocean itself subdued, investigated and
traversed from one hemisphere to the other; the
earth rendered active, fertile, and accesible, in
every part 5 the vallies and plains changed into
blooming meadows, rich pastures, and culti-
.y^ted §dd& ; tbe hills SHUounded with vines

and

310 BUFFON'f

and fruits, and their summKs crowned with
useful trees ; the desarts converted into popu-
lous cities, whose inhabitants spread from its
Centre (o its utmost extremities; roads and com-
munications opened, established 5 and frequent-
ed, as so many proofs of the union and strength
of society. There are besides a thousand other
monuments of power and glory ^ which clearly
demonstrate that man is the lord of the earth ;
that he has changed and improved its surface;
and that from the earliest periods of time he
alone has divided the empire of the world be-
tween him and Nature.

It is by the right of conquest, however, that
he reigns ; he rather enjoys than possesses,
and it is by perpetual activity and vigilance
that he preserves his advantage ; if those are
neglected every thing languishes, changes,
and returns to the absolute dominion of Na-
ture, she resumes her power, and destroys the
operations of man ; envelopes with moss and
dust his most pompous monuments, and in
the progress of time entirely effaces them, leav-
ing him to regret having lost by his negligence
what his ancestors had acquired by their in-
dustry. Those periods in which man loses
his empire, those ages in which every thing va-
Ittable perishes, commence with war, and are

completed

NATURAL HISTORY. 341

completed by famine and depopulation. Al-
though the strength of man depends solely upon
the union of numbers, and his happiness is de-
rived from peace, he is, nevertheless, so regard-
less of his own comforts as to take up arms and
to ^ght^ which are never-failing sources of
ruin and misery. Incited by insatiable avarice,
or blind ambition, which is still more insa-
tiable, he becomes callous to the feelings of
humanity ; regardless of his own welfare, his
whole thoughts turn upon the destruction of
his own species, which he soon accomplishes.
The days of blood and carnage over, and the
intoxicating fumes of glory dispelled, he be-
holds, with a melancholy eye, the earth deso-
lated, the arts buried, nations dispersed, aa
enfeebled people, the ruins of his own happi-
ness, and the loss of his real power.

Omnipotent God ! by whoisc presence Nature
is supported, and harmony among the laws of
the universe maintained ; who seest from thy
immoveable throne in the empyrean all the ce-
lestial spheres rolling under thy feet without
deviation or disorder; who, from the bosom
of repose, every instant renewest their vast
movements, and who alo:.e governs in profound
peace an infinite number of heavens and of
earths, restore, restore tranquillity to a troubled

world !

S42 BUFFO n's

■world ! Let the earth be silent ! Let the pre»
snmptaons tunmlts of waranti discon^ Ix^dis*
pelled by the sound oi thy voice I Merciful
God I aotbor of ail beiu^, whose . aternal re-
gards extend to everj created object, and to
man, thy principal favourite ; thou ba«t illu-
mined his miad v ith a ray of thy immortal
light ; penetrate also his heart Wr h a shaft of
thy love ; thy divine sentiment, when univer-
sally diffused, viill unite the most hostile
spirits ; man will no L nger dread the sight of
man, nor will bis hand any longer coitinue to
feearmed with murdering steel ; the devouring
iSames of war "will no longer stop the sources of
generations; the humaa species, -which are
BOW weakened, mutilated, and prematurely
mowed down, will germinate anew, and mul-
tiply without number. Nature, groaning un-
tier the pressure erf calamity, sterile and aban-
defied, will soon resume with additional vigour
her former fecundity ; and we, beneficent God \
%ha\\ aid, cultivate, and incessantly contem-
plate her operations, that we, at every mo-
ment, may be enabled to offer thee a fresh tri*
bute of gratitude and admiration*

SECONBt

HATUItAt HISTORY. S43

SECOND VIEW.

Individuals of whatever kind, or however
numerous, are of no estimation in (he universe ;
i«t is species alone that are existences in Nature,
for they are as ancient and pennancnt as her-
self. To have a clear and distinct idea of this
subject we must not consider a species as a
collection or succession of similar individuals,
but as a whole, independently of number or
time, always active, and always the same ; a
whole which was considered but as one in the
works of the creation, and therefore constitutes
only a unit in Nature. Of these units the hu-
man species is to be placed in the first rank ;
all the others, from the elephant to the mite,
from the cedar to the hyssop, belong to the se-
cond and third orders. Notwithstanding that
theviirediiFerentin form, substance, and even
life, yet each sustains its appointed destination,
and subsists independently of others, while the
whole, in a general view, represents animated
Natu»*e, who has hitherto supported, and will
continue to support, herself in the same man-
ner as she is seen at present. Her duration is

not

544

BUFFON S

not to be estimated by a day, a year, an age,
iior any given period of time, for time it-
self relates only (o individuals, to beings whose
existence is limited. It is not so with respect
to species, for their existence is constant ; their
permanence produces duration, and their dif-
ferences give rise to number. It is in th is
light that we must consider species, and give
to each an equal right to the indulgence and
support of Nature ; for so she has certainly
considered them, by bestowing on each the
means of existing as long as herself.

Let us now consider the species as having
changed places with the individual. In our
preceding observations we have seen the
relation which Nature holds in respect to
man ; let us now then take a view in what light
she would appear to a being who represented
the whole human species. We perceive that
in the spring the fields renew their ver-
dure, the buds and flowers expand, the
bees revive from their state of torpor, the
swallows return to our climates, the night-
ingale chaunts her song of love, the lamb
frisks, and the bull laws with desire, and
all animated creatures are eager to unite
and multiply their species ; and we can
then have no ideas but those of repro-

ductioD

NATURAL HISTORY. 34:5

duction and the increase of life. But whea
the dark season of cold and frost approaches,
these same beings become indifferent to and
avoid each other ; many of the feathered race
desert our clime, and the inhabitants of the
waters lose their freedom under tlie massy con-
gelations of ice ; various animals dig retreats
for themselves in the ground, where they fall
into a state of torpor ; the earth becomes hard,
the plants wither, and the trees, deprived of
their foliage, are covered with frost and snow ;
every object excites the idea of languor and
annihilation. These apj^arances, however,
of renovation and destruction, images, as it
were, of life and death, although they se^m
general, are only individual and particular.
Man, as an individual, concludes in this man-
ner, but tlie being whom we have supposed as
a representative of the species, thinks and
judges in a manner more exalted and general ;
in that constant succession of destruction and
renovation, and in those various vicissitudes, he
perceives only permanence and duration. The
different seasons in one year appear to him the
same as those of the preceding, the same as
those of millions of ages. The animal which
may be the thousandth in the order of genera-
tion is the same to him as the first. In a
vot. X. Y y word,

346 buffon's

word, if man had no period to Lis existence,
and if all the beings by which he is surrounded
existed in the same manner as they do at pre-
sent, the idea of time would vanish and the in-
dividual would in fact become the species.

het us then consider Nature for a few mo-
ments under this new aspect. Man certainly
comes into the world enveloped in darkness.
His mind is equally naked with his body ; he
is born without knowledge and without de-
fence, and brings nothing with him but passive
qualities. He is compelled to receive the impres-
sions of objects on his organs ; even the light
shines on his eyes long before he is able to
recognize it. To Nature he is at first indebt-
ed for every thing, without making her any
return. No sooner, however, do his senses
acquire strength and activity, and he can
compare his sensations, than he reflects upon
the universe ; he forms ideas, which he retains,
extends, and combines. Man, after receiving
instruction, is no longer a simple individual,
for he then, in a great measure, represents the
whole human species. He receives from his
parents the knowledge which had been trans-
mitted to them from their forefathers ; and
thus, by the divine arts of writing and print-
ing, the present age, in some sort, becomes

identified

NATURAL HISTORY, 3i7

identified with those that are past. This
accumulation of experience in one man, al-
most extends the limits of his being to infini-
ty. He is born no more than a simple indi-
vidual, like other animals, capable only of at-
tending to present sensations ; but he becomes
afterwards nearly the being which we sup-
posed to represent the whole species ; he reads
what has past, sees the present, and judges of
the future ; and in the torrent of time, which
carries off and absorbs all the individuals of
the universe, he perceives that the species are
permanent, and Nature invariable. As the
relations of objects are always the same, to him
the order of time appears to be nothing ; he
considers the laws^ of renovation as only
counterbalancing those of permanency. An
uninterrupted succession of similar beings, is,
in effect, only equivalent to the perpetual
existence of one of them.

What purposes then are gained by this im-
mense train of generations, this profusion of
germs, many thousands of which are abortive
for one that is brought into life ? Does not this
perpetual propagation of beings, which are
alternately destroyed and renewed, uniformly
exhibit the same scene, and occupy the same
proportion in Nature ? From what cause pro-
ceed

S48 BUFPON^S

ceed all these changes of life and death, these
laws of growth and decay, all these individual
vicissitudes, and reiterated representations of
the same identical thing ? They certainly arise
from the very essence of Nature, and depend
on the first establishment of the universal ma-
chine ; the whole of which is fixed and stable,
but each of its parts being endowed with the
power of motion, the general movements of
the celestial bodies have produced the parti*
calar ones of this terrestrial globe. The pene-
trating forces by which these immense bodies
are animated, and by which they act recipro»
cally upon each other at a distance, at the
same time animate every particle of matter ;
and this strong propensity, which every part
has towards each other, is the first bond of
beings, the ground of consistence and perma"
nency in Nature, and the support of harmony
in the universe. From these great combina-
tions the smaller relations are derived. The
earth moving on its own axis having separated
the portions of duration into day and night ;
all its animated inhabitants have their stated
periods of light and darkness, of their times of
waking and sleeping. The action of the
senses, and the motions of the members which
form a great part of the animal economy, arc

relat<.'d

NATURAL HISTORY. 349

related to this first combination; for in a
world where perpetual darkness reigned,
would there be senses alive to the enjoyment of
light.

As the inclination of the axis of the earth,
in its annual course round the sun, produces
considerable variations of heat and cold, which
we call seasons, all its vegetables have also,
either wholly or partially, their seasons of life
and death. The fall of the leaves, and the
decay of fruits, the withering of herbs aivd the
destruction of insects, depend entirely on this
second combination. In those climates where
there is not this variation, by the inclination
not being so material, the life of the vegetable
is not suspended, and every insect completeg
the stated period of its existence. Where the
four seasons, in fact, make but one, as under
the line, the surface of the earth is constantly
covered with flowers, the trees have a perpe-
tual foliage, and Nature seems to enjoy a con-
tinual spring.

Both in animals and plants, their particular
constitution is relatively to the general tempe-
rature of the earth, and which temperature de-?
pends upon its situation and distance from the
sun. If they were removed to a greater dis-
tance, neither our animals,nor our plant«,could
live or vegetate ; the water, sap, blood, and

all

5j0 buffon's

all their liquors, would lose their fluidity; if on
the contrary they were more near they would
vanish and dissipate in vapour. Ice and fire
are the elements of death, and temperate heat
the first support of life. The living particles
so generally diffused through all organized
bodies are related, not only by their activity
]but number, to the particles of light which
strike and penetrate almost all matter with
their heat ; for in every place where the sun
can heat the earth with its rays, the sur-
face will be covered with verdure, and peopled
with animals ; even ice is no sooner dissolved
into water tlian it swarms with inhabitants.
Water, indeed, is apparently more fertile than
the earth ; from heat it receives motion and life.
In one season the sea produces more animals
than the earth sustains ; but its production of
vegetables is infinitely less. And because
that the inhabitants of the oceqin have not a
a sufficient and permanent supply of vegeta-
bles, they are compelled to feed upon each
other ; and it is to this necessity that their
immense multiplication may be referred.
. As in the beginning every species was
created, the first individual of each has served
for a model to their descendants. The body
ef each animal or vegetable is a mould, to

which

NATURAL HISTORY* 351

>vliich are assimilated indifferently the organic
particles of all animals or vegetables which
have been destroyed by death, or consumed
by time. The brute particles, of which part
of their composition was formed, returned to
the common mass of inanimate matter; but
tlie organic particles, whose existence is per-
manent, are again resumed by organized bo-
dies : they are extracted at first from the earth
by vegetables, and then absorbed by animals
wlio feed thereon ; and thus serve for the sup-
port, growth, and expansion of both. By
this constant and perpetual circulation from
body to body, they serve to animate all orga-
nized beings. These living substances ia
quantity are always the same, and differ only
in form and appearance. In fertile ages, and
when population is the greatest, the whole sur-
face of the earth seems to be covered with men,
domestic animals, and useful plants. But in
the times of famine and depopulation, the fe-
rocious animals, poisonous insects, parasitical
plants, and useless herbs, resume, in their turn,
dominion over the earth. To man these changes
are material, but to Nature they are perfectly
indifferent. The silk worm so inestimable to
the former, is to the latter only a caterpillar
of the mulberry tree . Though this cater pillar,

which

S52 BUFFO n's

which so materially assists in the supply of our
luxuries, should disappear; though the plants,
from which our domestic animals procure their
nourishment, should be devoured by other ca-
terpillars ; though still others should destroy
the substance of our corn before the harvest ;
in short, though man and the larger animals
should be starved by the inferior tribes. Na-
ture would not be less abundant nor less alive ;
she never protects one at the expence of ano-
ther, but especially supports (he whole. As
to individuals she is regardless of number ; she
considers them only as successive images of
the same impression ; as passing shadows of
which the species is the substance.

in earth, air, and water, then, there exists a
certain quantity of organic matter which can-
not be destroyed, but which is constantly assi-
milated in a certain number of moulds, that arc
perpetually undergoing destruction and re-
newal : these moulds, or rather individuals, tho'
varying in number in every species, are never-
theless always the same, that is, proportioned to
the quantity of living matter ; and this appears
to be absolutely the case, for if there wore any
redundance of this matter, or if it were not at
all times fully occupied by the individuals of

tli€

NATURAL HISTORY. 353

the species which exist, it would, most assur-
edly, form itself into new species, for being
alive it would not remain without action ; and
once uniting with brute matter is sufficient to
form organized bodies ; and it is by this con-
stant combination, and invariable proportion,
that Nature preserves her form and consistence.
The laws of Nature, both with respect io
the number of species and of tl>eir support and
equilibrium, being fixed and constant, she
would invariably have the same appearance,
and be in all climes absolutely the same, if her
complexion did not so completely vary in
almost every individual form. The figure of
each species is an impression, in which the
principal characters are so strongly engraven as
never to be effaced ; but the accessory parts and
shades are so greatly varied that no two indi-
viduals have a perfect resemblance to each
other ; and in all species there are a number
of varieties. The human species, which has
such superior pretensions, varies from white to
black,from small to great, &c. The Laplander,
the Patagonian, the Hottentot, the European,
the American, and the Negro, though the off-
spring of the same parents, have by no means
the resemblance of brothers.
TOL, X. Z z It

tt is evident, therefore, that every species U
subjectfo individual difFerenccs,but thateacli!
ofthem does not equally possess the constant
varieties \^'hich are perpetuated fhrouj^b succes*
si vr generations* themoredignifiedthespecies,
the less changeable is its figure, and the less are
the varieties of it. The multiplication of ani-
mals being inversely in proportion to their
magnifudc, as the possibility of variation must
be in exact proportion to the numbers they
produce, there consequently must be more va-
rieties among the small than the large animals ;
and also, for the same reason, there \>ill be a
greater number of species which seem to ap-
proacli each other ; for the unity of the spe-
cies in the large animals IS more fixed, and the
nature of their separation more extended.
What a number of various and similar spe-
cies surround those of the squirrel, the rat,
and other small quadrupeds, while the massy
elephant stands alone, without a compeer,
and at the head of the whole.

The brute matter, of which the body
of the earth is principally composed, is
a substance that has not undergone many
alterations, thongh the whole has more
than once been disturbed and put in mo-

tioB

NATURAL HISTORY. 355

Cion by the hand of Nature. The globe of the
eartli has been penetrated by fire, and after-
wards covered and disordered by water. The
sand, which occ^ipies the interior parts of th^
earth, is a vitrified matter ; and the layers of
clay, by which its surface is covered, are no-
thing but the same sand having been decora^
posed by tlie operation ofthe waters. Granite,
free-stone, flint, nay, all mjetals, are compos-
ed of this same vitrified matter, whose parti-
cles have been condensed or sepa rated, accord^
ing io the laws of their affinity. These sub*
stances are totally destitute of animation ;
they exists and will continue to do so, inde-
pendently of animals and vegetables. There
are, however, many other substances, which,
although they have the appearance of l)eing
equally inanimate, orijrinate from organized
bodies; and of this description are marble,
lime-stone, chalk, and marl ; they being com5-
posed of the fragments of shells, and of those
small animals which by transforming the wa-
ter of the sea into stone, produce coral, and all
the madrepores, whose varieties are numberless,
and whose quantity are almost immense. Pit-
coal, turf, and many other substancts found in
the upper strata, are also of this nature, they
being only the residue of vegetables which
have been wore or less corrupted or consumed.

Besides

S55 buffon's

Besides these, there are other substances "vihiGll
have been produced by the second action of
fire upon original matter ; these are but few
in number, and consist of such as pumice*
stones, sulphur,the scoria of iron, asbestos, and
lava. To one or other of these three great
combinations may be referred all the relations
of brute matter, and all the substances of the
mineral kingdom.

The laws of affinity, by which the various
particles of these different substances separate
from each other, in order (o unite among them-
selves and form homogeneous masses, are per-
fectly similar to that general law by which
the celestial bodies act upon each other; in both
cases their exertions are the same. Globules
of water, of sand, or of metal, have the same
influence, and act upon each other as the earth
acts upon the mmxi ; and if the laws of affinity
have hitherto been deemed different from
those of gravity, it is because the subject has
been considered in a very confined point of
view. The mutual action of celestial bodies iii
very little influenced by figure; their distance
from each other is so very great, that this is
necessarily the case ; but when they are not fat
asunder, then the effect of figure is considerable.
For instance, if the earth and moon, instead
af spherical figures, were both short cylinders,

an4

NATURAL HISTORY. 357

and exactly equal throughout in their diame"*
ters, their reciprocal action would be very lit-
tle varied from what it is at present, because
the distances of all their parts irom each otlier
would be very little changed. But it' these
two globes were cyliiiders of great extent,
and approached near to each otiier, the law of
their reciprr.cal action would seem to be dif^
ferent, inasmuch as the distances of their
parts would be greatly varied ; and hence
whenever figure becomes a principle in dis-
tance the law will appear to vary, although in
fact it is always the same.

The human intellect guided by this prin-
ciple, may advance one step further in pene-
trating into the operations of nature. The
figure of the constituent particles of bodies still
remains unknown ; we cannot entertain the
smallest doubt that water, air, earth, metals,
and all homogeneous particles, are compo-^ed
of elementary particles, v>hich are perfectly
similar, although we are s'ill ignorant of their
figure. By the aid of calculition this at pre-
sent unknown field of knowled-^e may be dis-
closed by {.O'-terity, and the figure of the ele-
mentary bodies be ascertained with tolerable
precision. They may take the principle W6
have established as the basis of their enquiry ;

namely,

558 buffon's

namely, '' that all matter is attracted in the
*' inverse raiio of ihe square of the distance ;
^' and this law >eems to admit of no variation
^' in I articular at(ractionsbuiTvh?it arises from
^' the figure of the con^tiiueut particles of each
*^ substance, because this figure enters as an
'* element or principle into the distance ;"and
having once discovered, by repeated experi-
ments, the law ofattraciion in any particular
substance, they may then, by the aid of calcu-
lation, be able to trace the figure of its consti-
tuent particles. To render this point more
clear, let us suppose, that by placing mercury
on a perfectly jjolished surface, repeated expe-
riments prove that this fluid metal is always
attracted in the inverse ratio of the cubeof the
distance ; it will then become necessary to in^
vestigate what figure gives this expression ;
and this figure will be certainly thatof thecon^-
stitucnt particles of mercury. If it should ap-
pear, by such experiments, that the attraction
of mercury was in the inverse ratio of the
square of tlie distance, it would be clearly de^
TOonstratcd that its constituent particles were
spherical, because a sphere is the only figure
which observes this law, and at whatever dis-r
lance globes are placed the law of their attrac?
tion is always the same.

Newton

BfATUllAL lilSTTORY. 25^

Newton had some idea that chemical affini-
ties (which are nothing more in fact thanthe.se
particular attractions which we have men-
tioned) were produced by the same kind of
laws as those of gravitation; but he does not
appear to have perceived <hat all those parti-
cular laws were merely simple modificationg
of the general one, and that their apparent dif-
ference arose solely from the circumstance of
(he figure of the atoms, which attract each
other, having, when at small distances, a
greater influence upon the force of this law
than the mass of matter.

It is, notwithstanding, upon this theory that
the perfect knowledge of brute matter depends.
The basis of all matter is the same, and its
form throughout would be perfectly similar, if
the figures of its constituent particles wer? not
different ; and th us it is that one hoTiogeneous
substance can differ from another only in pro-
portion to the difference of their original par-
ticles. A body composed of spherical particles
ought to be one half specifically lighter than
that whose particles are cubical, because as the
first only touch each other by their points,
they leave intermediale spaces equpl to what
they occupy, whereas the cubical particles
join without leaving the smallest interval, and
must consequently form a matter half as heavy

a£:ain.

§60 BUFFOM*fi

again. Although the figures are considerably
varied, that varialioii is by no means so great
as we might imagine, since Nature has fixed
the limits of lightness and gravity. Gold and
air, with respect to density, are the two ex*
tremes, and therefore all the figures in Nature
must be comprehended as coming between
those two ; such as would have produced
heavier or lighter substances have been re*
jected.

In speaking of figures, as employed by Na*
turp, I do not mean to imply that they must
be necessarily, or are exactly, similar to those
geometrical figures which we form in our
imagination. We form laws by supposition)
and then endeavour to rendpr them simple by
abstraction. It is very possible that there are
neither exact cubes nor perfect spheres in the
universe; but as nothing certainly exists with*-
out form, and as from the variation of subr
stances the figures of the elements are differ-
ent, some of them most undoubtedly must ap"
proach to ihe sphere, the cube, and all the
other regular figures which we have conceived.
The precise, absolute, and abstract figures
which our minds are so frequently induced to
admit, cannot have any existence, because
all objects are related, and differ only by al*
most imperceptible shades. It is by the

same

NATURAL HISTORY. S6l

same ruk tbat when I speak of one substance
as being entirely full, because composed of cu-
bical particles, and another as being not more
than half full, because its parts are spherical,
I mean only comparatively, and not that such:
substances really exist ; for experience has
fully informed usj that in transparent bodies^
such as glass, which is both dense and heavy,
there is but a small quantity of matter in pro-
portion to the extent of the intervals ; nay, as
we have before observed, it might be demon-
strated that even gold, Mhich is the most dense
species of matler, has more vacuities than
sub&tance.

To investigate the powers of Nature is the
object of rational mechanics, while active me-
chanics is solely confined to a combination of
particular po^vers, and consequently the art of
constructing machines. This art has at all
times been certain of cultivation from necessity
and convenience; and both ancients and mo-
derns have equall}^ excelled in it. But rational
mechanics is a- science invented in our days ;
for, from the days of Aristotle to those of Des-
cartes, even the philosophers have reasoned no
better upon the nature of motion^. than uni-
formly to mistake the effect for tlie ca\ise. Im*
pulsion was the only force with which they
VOL X. A a a were

S62 BUFF0!^8

were acquainted; to it they attributed the
effects of others, and all the phenomena of the
universe. If this idea of theirs had been pro-
bable, or even possible, impulsion, which they
regarded as the sole cause, must have been a
general effect, which equally belonged to all
matter, and which equally exerted itself in all
places, and at all times ; but every day demon-
strated the contrary to be the fact ; for they
must have perceived that this force had no ex-
istence in bodies at rest ; that it had but a
short subsistence in projected bodies, being
soon destroyed by resistance ; that a fresh im-
pulse was absolutely necessary for its renewal,
and that, consequently, so far from being a
general cause, it was only a particular effect
produced by others more general.

It is true, however, that we ought to consi-
der a general effect as a cause, for we cannot
become acquainted with the real cause of thig
effect, because all our knowledge is derived
from comparison, and as there is not any
thing to which we can compare an effect,
which is supposed general, and equally belong-
ing to every thing, we can know it only by
the fact. According to this view, attraction,
or gravity, being a general effect common to
all matter, and clearly evinced by the fact,

ought

NATtJRAL HISTORY. 363

ought io be considered as a cause; and to
which all particular causes should be referred,
nay even that of impulsion, since it is less ge-
neral and less constant ; and the principal dif-
ficulty is to perceive how impulsion can be an
effect of attraction ; for if we rest on the com-
munication of motion by impulse, we are then
persuaded that it can only be transmitted from
one body to another by elasticity, and that all the
hypotheses, which suppose a communication
of motion in hard bodies, are mere ideal fan-
cies, which do not exist in Nature. A per-
fectly hard or a perfectly elastic body is en-
tirely imaginary, as neither of them really eX'
ist ; for it is certain tliat nothing exists ab-
solutely or in extreme; and the idea ofper-
tion must suppose one or the other.

It is certain that if there were no elasticity
in matter there would be no impulsive force ;
for instance, if we throw a stone, the motion it
acquires is communicated by the elasticity of
the arm. When motion is communicated by
one body in action encountering another at
rest, how can we possibly suppose it to be done
otherwise than by compressing the spring of
the elastic particles it contains, which recover-
ing itself almost immediately after, gives to the
whole mass a force equal to that which it re-
ceived ^

S64: BUFFON^S

ceived ? How a perfectly hard body sbouid
admit this force, or receive rootion, is beyond
comprehension ; and the enquiry is uniaeces-
^ary, since no such body exists ; for, all bodies
areendwved with elasticity. The force of elec-
tricity is proved by experiments to be elastic,
and to belong to matters in general ; and there-
fore, if no other eiasticity existed in the interior
parts of bodies but that of this eJectrieal mat-
ter, that would be sufficient for the comraunica*-
tion of motion ; and consequently to this great
spring, aR a general effect, the particular cause
of impulsion must be attributed.

A little reflection on the mechanism of elasti-
city will convince us that its force depends on
that of attraction. To have a still more clear
idea of this subject, let ois suppose a spring
the most simple, such as of a solid angle of
iron, or of any other hard substance, and then
see what will be the result of compressing it.
By compression we oblige the parts adjacent
to the top of the angle to liend, or to separate
a little from each other ; bsit the pressure being
removed they again approach as luear as they
had done before. Their adhesion, from which
the cohesion of bodies results, is clearly an ef-
fect of their mutual attraction. Upon the
spring beitig pressed this adhesion is nr»t de-
stroyed,

NATURAL HISTORY. 26&

stroyed, because, althoiigh the particles are
separated, they are not removed bejoud the
sphere of their mutual attraction; consequently
the moment the pressure is taken away the
force is renewed, the separated parts draw
near, and their spring is restored. Bvit if the
pressure be too violent, they will, in that case,
be removed beyond the sphere of their attrac*
tion, and the spring will break, because the
compressing force will be greater than that of
cohesion, or that of mutual attraction, by
which the particles are kept together. This
proves that elasticity can only exert itself in
proportion to the cohesion of the particles of
matter, tliat is^ in proportion as they are united
by the force of their mutual attraction ; from
which it results, that elasticity in general,
which alone can produce impulsion, and im-
pulsion itself, are owing to the force of attrac-
tion, and are only particular eifects which de-
pend on that general one.

Notwithstanding that these ideas appear to
be perfectly clear to me, 1 do not expect to see
them adopted. People in general reason only
from their sensations, and natural philosophers
determine from their prejudices ; as, therefore,
both these must be set aside, very few will re-
main to form a proper judgment; but such

is

B66 bufpon's natural history,

is the dignity of Truth , that she is content
"with a few admirers, and is always lost in a
crowd ; she is at all times august and majestic,
notwithstanding which she is frequently ob-
scured by fantastic opinions, and obliterated by
fanciful chimeras. I, however, view and un-
derstand Nature in this manner, and am almost
induced to believe that she is still more simple ;
the phenomena exhibited by brute matter is
caused by a single force, and from this force,
combined with that of heat, originate those
living particles which gave rise to, and sup-
port all, the various effects of organized bo-*
dies.

FJNIS.
l^g^KMTY UBRART

H. C. State Colkti

T. Gillet, Crown-court, Fleet-street.

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