Francis Bacon.

Advancement of learning and novum organum online

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ous zeal amount to this: — I. An iron bolt placed for a long
time towards the north and south acquires polarity from this
habit, without the touch of the magnet, as if the earth itself
operating but weakly from its distance (for the surface or outer
crust of the earth does not, in his opinion, possess the magnetic
power), yet, by long-continued motion, could supply the place
of the magnet, excite the iron, and convert and change it when
excited. 2. Iron, at a red or white heat, when quenched in a
direction parallel to the north and south, also acquires polarity
without the touch of the magnet, as if the parts of iron being
put in motion by ignition, and afterwards recovering themselves,
were, at the moment of being quenched, more susceptible and
sensitive of the power emanating from the earth, than at other
times, and therefore as it were excited. But these points, though
well observed, do not completely prove his assertion.

An instance of the cross on this point might be as follows :
Let a small magnetic globe be taken, and its poles marked, and
placed towards the east and west, not towards the north and
south, and let it continue thus. Then let an untouched needle
be placed over it, and suffered to remain so for six or seven
days. Now, the needle (for this is not disputed), whilst it re-
mains over the magnet, will leave the poles of the world and
turn to those of the magnet, and therefore, as long as it remains
in the above position, will turn to the east and west. But if the
needle, when removed from the magnet and placed upon a
pivot, be found immediately to turn to the north and south, or
even by degrees to return thither, then the presence of the earth
must be considered as the cause, but if it remains turned as at
first, towards the east and west, or lose its polarity, then that
cause must be suspected, and further inquiry made.

Again, let the required nature be the corporeal substance of
the moon, whether it be rare, fiery, and aerial (as most of the
ancient philosophers have thought), or solid and dense (as Gil-
bert and many of the moderns, with some of the ancients, hold).

4 2o BACON

The reasons for this latter opinion are grounded chiefly upon
this, that the moon reflects the sun's rays, and that light does
not appear capable of being reflected except by solids. The
instances of the cross will therefore (if any) be such as to ex-
hibit reflection by a rare body, such as flame, if it be but suffi-
ciently dense. Now, certainly, one of the reasons of twilight is
the reflection of the rays of the sun by the upper part of the
atmosphere. We see the sun's rays also reflected on fine even-
ings by streaks of moist clouds, with a splendor not less, but
perhaps more bright and glorious than that reflected from the
body of the moon, and yet it is not clear that those clouds have
formed into a dense body of water. We see, also, that the dark
air behind the windows at night reflects the light of a candle in
the same manner as a dense body would do. The experiment
should also be made of causing the sun's rays to fall through a
hole upon some dark and bluish flame. The unconfined rays
of the sun when falling on faint flames, do certainly appear to
deaden them, and render them more like white smoke than
flames. These are the only instances which occur at present of
the nature of those of the cross, and better perhaps can be found.
But it must always be observed that reflection is not to be ex-
pected from flame, unless it be of some depth, for otherwise it
becomes nearly transparent. This at least may be considered
certain, that light is always either received and transmitted or
reflected by an even surface.

Again, let the required nature be the motion of projectiles
(such as darts, arrows, and balls) through the air. The school,
in its usual manner, treats this very carelessly, considering it
enough to distinguish it by the name of violent motion, from
that which they term natural, and as far as regards the first
percussion or impulse, satisfies itself by its axiom, that two
bodies cannot exist in one place, or there would be a penetration
of dimensions. With regard to this nature we have these two
cross-ways : — The motion must arise either from the air carry-
ing the projected body, and collecting behind it, like a stream
behind boats, or the wind behind straws ; or from the parts of
the body itself not supporting the impression, but pushing them-
selves forward in succession to ease it. Fracastorius, and nearly
all those who have entered into any refined inquiry upon the
subject, adopt the first. Nor can it be doubted that the air has
some effect, yet the other motion is without doubt real, as is
clear from a vast number of experiments. Amongst others we
may take this instance of the cross, namely, that a thin plate or
wire of iron rather stiff, or even a reed or pen split in two, when
drawn up and bent between the finger and thumb, will leap
forward; for it is clear that this cannot be attributed to fhe
air being collected behind the body, because the source of


motion is in the centre of the plate or pen, and not in its ex-

Again, let the required nature be the rapid and powerful mo-
tion of the explosion of gunpowder, by which such vast masses
are upheaved, and such weights discharged as we observe in
large mines and mortars, there are two cross-ways before us
with regard to this nature. This motion is excited either by
the mere effort of the body expanding itself when inflamed, or
by the assisting effort of the crude spirit, which escapes rapidly
from fire, and bursts violently from the surrounding flame as
from a prison. The school, however, and common opinion
only consider the first effort ; for men think that they are great
philosophers when they assert that flame, from the form of the
element, is endowed with a kind of necessity of occupying a
greater space than the same body had occupied when in the
form of powder, and that thence proceeds the motion in ques-
tion. In the mean time they do not observe, that although this
may be true, on the supposition of flame being generated, yet
the generation may be impeded by a weight of sufficient force
to compress and suffocate it, so that no such necessity exists as
they assert. They are right, indeed, in imagining that the ex-
pansion and the consequent emission or removal of the opposing
body, is necessary if flame be once generated, but such a neces-
sity is avoided if the solid opposing mass suppress the flame
before it be generated ; and we in fact see that flame, especially
at the moment of its generation, is mild and gentle, and requires
a hollow space where it can play and try its force. The great
violence of the effect, therefore, cannot be attributed to this
cause ; but the truth is, that the generation of these exploding
flames and fiery blasts arises from the conflict of two bodies of a
decidedly opposite nature — the one very inflammable, as is the
sulphur, the other having an antipathy to flame, namely, the
crude spirit of the nitre ; so that an extraordinary conflict takes
place whilst the sulphur is becoming inflamed as far as it can
(for the third body, the willow charcoal, merely incorporates
and conveniently unites the two others), and the spirit of nitre
is escaping, as far also as it can, and at the same time expanding
itself (for air, and all crude substances, and water are expanded
by heat), fanning thus, in every direction, the flame of the sul-
phur by its escape and violence, just as if by invisible bellows.

Two kinds of instances of the cross might here be used — the
one of very inflammable substances, such as sulphur and cam-
phor, naphtha and the like, and their compounds, which take
fire more readily and easily than gunpowder if left to themselves
(and this shows that the effort to catch fire does not of itself
produce such a prodigious effect) ; the other of substances which
avoid and repel flame, such as all salts ; for we see that when



'they are cast into the fire, the aqueous spirit escapes with a
crackling noise before flame is produced, which also happens in
a less degree in stiff leaves, from the escape of the aqueous part
before the oily part has caught fire. This is more particularly
observed in quicksilver, which is not improperly called mineral
water, and which, without any inflammation, nearly equals the
force of gunpowder by simple explosion and expansion, and is
said, when mixed with gunpowder, to increase its force.

Again, let the required nature be the transitory nature of
flame and its momentaneous extinction ; for to us the nature of
flame does not appear to be fixed or settled, but to be generated
from moment to moment, and to be every instant extinguished ;
it being clear that those flames which continue and last, do not
owe their continuance to the same mass of flame, but to a con-
tinued succession of new flame regularly generated, and that
the same identical flame does not continue. This is easily
shown by removing the food or source of the flame, when it at
once goes out. We have the two following cross-ways with
regard to this nature : — This momentary nature either arises
from the cessation of the cause which first produced it, as in
light, sounds, and violent motions, as they are termed, or flame
may be capable, by its own nature, of duration, but is subjected
to some violence from the contrary natures which surround it,
and is destroyed.

We may therefore adopt the following instance of the cross.
We see to what a height the flames rise in great conflagrations ;
for as the base of the flame becomes more extensive, its vertex
i<i more lofty. It appears, then, that the commencement of the
extinction takes place at the sides, where the flame is com-
pressed by the air, and is ill at ease ; but the centre of the flame,
which is untouched by the air and surrounded by flame, con-
tinues the same, and is not extinguished until compressed by
degrees by the air attacking it from the sides. All flame, there-
fore, is pyramidal, having its base near the source, and its vertex
pointed from its being resisted by the air, and not supplied from
the source. On the contrary, the smoke, which is narrow at the
base, expands in its ascent, and resembles an inverted pyramid,
because the air admits the smoke, but compresses the flame ;
for let no one dream that the lighted flame is air, since they are
clearly heterogeneous.

The instance of the cross will be more accurate, if the ex-
periment can be made by flames of different colors. Take,
therefore, a small metal sconce, and place a lighted taper in it,
then put it in a basin, and pour a small quantity of spirits of
wine round the sconce, so as not to reach its edge, and light
the spirit. Now the flame of the spirit will be blue, and that of
the taper yellow ; observe, therefore, whether the latter (which


can easily be distinguished from the former by its color, for
flames do not mix immediately, as liquids do) continue pyra-
midal, or tend more to a globular figure, since there is nothing
to destroy or compress it. If the latter result be observed, it
must be considered as settled, that flame continues positively
the same, whilst inclosed within another flame, and not exposed
to the resisting force of the air.

Let this suffice for the instances of the cross. We have dwelt
the longer upon them in order gradually to teach and accustom
mankind to judge of nature by these instances, and enlighten-
ing experiments, and not by probable reasons.

37. We will treat of the instances of divorce as the fifteenth
of our prerogative instances. They indicate the separation of
natures of the most common occurrence. They differ, how-
ever, from those subjoined to the accompanying instances ; for
the instances of divorce point out the separation of a particular
nature from some concrete substance with which it is usually
found in conjunction, whilst the hostile instances point out the
total separation of one nature from another. They differ, also,
from the instances of the cross, because they decide nothing,
but only inform us that the one nature is capable of being sep-
arated from the other. They are of use in exposing false forms,
and dissipating hasty theories derived from obvious facts ; so
that they add ballast and weight, as it were, to the understand-

For instance, let the required natures be those four which
Telesius terms associates, and of the same family, namely, heat,
light, rarity, and mobility, or promptitude to motion ; yet many
instances of divorce can be discovered between them. Air is
rare and easily moved, but neither hot nor light ; the moon is
light but not hot ; boiling water is warm but not light ; the
motion of the needle in the compass is swift and active, and
yet its substance is cold, dense, and opaque; and there are
many similar examples.

Again, let the required natures be corporeal nature and nat-
ural action. The latter appears incapable of subsisting with-
out some body, yet may we, perhaps, even here find an instance
of divorce, as in the magnetic motion, which draws the iron to
the magnet, and heavy bodies to the globe of the earth ; to
which we may add other actions which operate at a distance.
For such action takes place in time, by distinct moments, not
in an instant ; and in space, by regular degrees and distances.
There is, therefore, some one moment of time and some inter-
val of space, in which the power or action is suspended betwixt
the two bodies creating the motion. Our consideration, then,
is reduced to this, whether the bodies which are the extremes
of motion prepare or alter the intermediate bodies, so that the



power advances from one extreme to the other by succession
and actual contact, and in the mean time exists in some inter-
mediate body ; or whether there exists in reality nothing but
the bodies, the power, and the space ? In the case of the rays
of light, sounds, and heat, and some other objects which oper-
ate at a distance, it is indeed probable that the intermediate
bodies are prepared and altered, the more so because a quali-
fied medium is required for their operation. But the magnetic
or attractive power admits of an indifferent medium, and it is
not impeded in any. But if that power or action is independent
of the intermediate body, it follows that it is a natural power
or action existing in a certain time and space without any body,
since it exists neither in the extreme nor in the intermediate
bodies. Hence the magnetic action may be taken as an in-
stance of divorce of corporeal nature and natural action ; to
which we may add, as a corollary and an advantage not to be
neglected, that it may be taken as a proof of essence and sub-
stance being separate and incorporeal, even by those who phi-
losophize according to the senses. For if natural power and
action emanating from a body can exist at any time and place
entirely without any body, it is nearly a proof that it can also
emanate originally from an incorporeal substance; for a cor-
poreal nature appears to be no less necessary for supporting
and conveying, than for exciting or generating natural action.

38. Next follow five classes of instances which we are wont
to call by the general term of instances of the lamp, or of im-
mediate information. They are such as assist the senses ; for
since every interpretation of nature sets out from the senses, and
leads, by a regular fixed and well-established road, from the
perceptions of the senses to those of the understanding (which
are true notions and axioms), it necessarily follows, that in
proportion as the representatives or ministerings of the senses
are more abundant and accurate, everything else must be more
easy and successful.

The first of these five sets of instances of the lamp, strengthen,
enlarge, and correct the immediate operations of the senses ;
the second reduce to the sphere of the senses such matters as
are beyond it ; the third indicate the continued process or series
of such things and motions, as for the most part are only ob-
served in their termination, or in periods ; the fourth supply the
absolute wants of the senses ; the fifth excite their attention and
observation, and at the same time limit the subtilty of things.
We will now proceed to speak of them singly.

39. In the sixteenth rank, then, of prerogative instances, we
will place the instances of the door or gate, by which name
we designate such as assist the immediate action of the senses.
It is obvious, that sight holds the first rank among the senses,


with regard to information, for which reason we must seek
principally helps for that sense. These helps appear to be
threefold, either to enable it to perceive objects not naturally
seen, or to see them from a greater distance, or to see them
more accurately and distinctly.

We have an example of the first (not to speak of spectacles
and the like, which only correct and remove the infirmity of a
deficient sight, and therefore give no further information) in the
lately invented microscopes, which exhibit the latent and in-
visible minutiae of substances, and their hidden formation and
motion, by wonderfully increasing their apparent magnitude.
By their assistance we behold with astonishment the accurate
form and outline of a flea, mo? and animalculae, as well as
their previously invisible color a**d motion. It is said, also,
that an apparently straight line, drawn with a pen or pencil, is
discovered by such a microscope to be very uneven and curved,
because neither the motion of the hand, when assisted by a
ruler, nor the impression of ink or color, is reaily regular, al-
though the irregularities are so minute as not to be perceptible
without the assistance of the microscope. Men have (as is
usual in new and wonderful discoveries) added a superstitious
remark, that the microscope sheds a lustre on the works of nat-
ure, and dishonor on those of art, which only means that the
tissue of nature is much more delicate than that of art. For
the microscope is only of use for minute objects, and Demo-
critus, perhaps, if he had seen it, would have exulted in the
thought of a means being discovered for seeing his atom, which
he affirmed to be entirely invisible. But the inadequacy of
these microscopes, for the observation of any but the most
minute bodies, and even of those if parts of a larger body, de-
stroys their utility ; for if the invention could be extended to
greater bodies, or the minute parts of greater bodies, so that a
piece of cloth would appear like a net, and the latent minutiae
and irregularities of gems, liquids, urine, blood, wounds, and
many other things could be rendered visible, the greatest ad-
vantage would, without doubt, be derived.

We have an instance of the second kind in the telescope, dis-
covered by the wonderful exertions of Galileo ; by the assistance
of which a nearer intercourse may be opened (as by boats or
vessels) between ourselves and the heavenly objects. For by
its aid we are assured that the Milky Way is but a knot or con-
stellation of small stars, clearly defined and separate, which
the ancients only conjectured to be the case ; whence it appears
to be capable of demonstration, that the spaces of the planetary
orbits (as they are termed) are not quite destitute of other stars,
but that the heaven begins to glitter with stars before we arrive
at the starry sphere, although they may be too small to be


visible without the telescope. By the telescope, also, we can
behold the revolutions of smaller stars round Jupiter, whence
it may be conjectured that there are several centres of motion
among the stars. By its assistance, also, the irregularity of
light and shade on the moon's surface is more clearly observed
and determined, so as to allow of a sort of selenography. By
the telescope we see the spots in the sun, and other similar
phenomena ; all of which are most noble discoveries, as far as
credit can be safely given to demonstrations of this nature,
which are on this account very suspicious, namely, that experi-
ment stops at these few, and nothing further has yet been dis-
covered by the same method, among objects equally worthy of

We have instances of the third kind in measuring-rods, astro-
labes, and the like, which do not enlarge, but correct and guide
the sight. If there be other instances which assist the other
senses in their immediate and individual action, yet if they add
nothing further to their information they are not apposite to
our present purpose, and we have therefore said nothing of

40. In the seventeenth rank of prerogative instances we will
place citing instances (to borrow a term from the tribunals),
because they cite those things to appear, which have not yet
appeared. We are wont also to call them invoking instances,
and their property is that of reducing to the sphere of the senses
objects which do not immediately fall within it.

Objects escape the senses either from their distance, or the
intervention of other bodies, or because they are not calculated
to make an impression upon the senses, or because they are not
in sufficient quantity to strike the senses, or because there is not
sufficient time for their acting upon the senses, or because the
impression is too violent, or because the senses are previously
filled and possessed by the object, so as to leave no room for
any new motion. These remarks apply principally to sight,
and next to touch, which two senses act extensively in giving
information, and that too upon general objects, whilst the re-
maining three inform us only, as it were, by their immediate
action, and as to specific objects.

There can be no reduction to the sphere of the senses in the
first case, unless in the place of the object, which cannot be per-
ceived on account of the distance, there be added or substituted
some other object, which can excite and strike the sense from a
greater distance, as in the communication of intelligence by
fires, bells, and the like.

In the second case we effect this reduction by rendering those
things which are concealed by the interposition of other bodies,
and which cannot easily be laid open, evident to the senses by


means of that which lies at the surface, or proceeds from the
interior ; thus the state of the body is judged of by the pulse,
urine, etc.

The third and fourth cases apply to many subjects, and the
reduction to the sphere of the senses must be obtained from
every quarter in the investigation of things. There are many
examples. It is obvious that air, and spirit, and the like, whose
whole substance is extremely rare and delicate, can neither be
seen nor touched — a reduction, therefore, to the senses becomes
necessary in every investigation relating to such bodies.

Let the required nature, therefore, be the action and motion
of the spirit enclosed in tangible bodies ; for every tangible body
with which we are acquainted, contains an invisible and in-
tangible spirit, over which it is drawn, and which it seems to
clothe. This spirit being emitted from a tangible substance,
leaves the body contracted and dry ; when retained, it softens
and melts it ; when neither wholly emitted nor retained, it
models it, endows it with limbs, assimilates, manifests, organ-
izes it, and the like. All these points are reduced to the sphere
of the senses by manifest effects.

For in every tangible and inanimate body the enclosed spirit
at first increases, and as it were feeds on the tangible parts
which are most open and prepared for it ; and when it has
digested and modified them, and turned them into spirit, it
escapes with them. This formation and increase of spirit is
rendered sensible by the diminution of weight ; for in every
desiccation something is lost in quantity, not only of the spirit
previously existing in the body, but of the body itself, which
was previously tangible, and has been recently changed, for
the spirit itself has no weight. The departure or emission of
spirit is rendered sensible in the rust of metals, and other putre-
factions of a like nature, which stop before they arrive at the
rudiments of life, which belong to the third species of process.
In compact bodies the spirit does not find pores and passages
for its escape, and is therefore obliged to force out, and drive
before it, the tangible parts also, which consequently protrude,
whence arises rust and the like. The contraction of the tan-

Online LibraryFrancis BaconAdvancement of learning and novum organum → online text (page 45 of 51)