The works of Francis Bacon, lord chancellor of England.

386 NOVUM ORGANUM. Booir II.
nature of cold; whether its contraction be down- is very slow, and attacks very minute particles,
wards, as the expansion of heat is upwards. no heat is perceived.
Take, therefore, two iron rods or two glass tubes, It is also shown in a comparison of the disalike in other respects, and warm them a little, solution of iron and gold. For gold is dissolved
and place a sponge, dipped in cold water, or some without the excitement of any heat, but iron with
snow below the one and above the other. We a vehement excitement of it, although almost in
are of opinion that the extremities will grow cold the same time: because, in the former, the peneuin that rod first where it is placed beneath; as tration of the separating acid is mild, and gently
the contrary takes place with regard to heat. insinuates itself, and the particles of gold yield
III. The third difference is this. That heat is easily, but the penetration of iron is violent, and
not a uniform expansive motion of the whole, but attended with some struggle, and its particles are
of the small particles of the body; and this mo- more obstinate.
tion being at the same time restrained, repulsed, It is partially shown also in some gangrenes
and reflected, becomes alternating, perpetually and mortifications of flesh, which do not excite
hurrying, striving, struggling, and irritated by the great heat or pain from the gentle nature of the
repercussion; which is the source of the violence putrefaction.
of flame and heat. Let this suffice for a first vintage, or the comrnBut this difference is chiefly shown in flame mencement of the interpretation of the form of heat
and — boiling liquids, which always hurry, swell, by the liberty of the understanding.
and subside again in detached parts. From this first vintage, the form or true definiIt is also shown in bodies of such hard texture tion of heat (considered relatively to the universe
as not to swell or dilate in bulk, such as red-hot and not to the sense) is briefly thus. 4; Heat is
iron, in which the heat is most violent. an expansive motion, restrained and striving to
It is also shown by the fires burning most exert itself in the smaller particles.'" The expanbriskly in the coldest weather. sion is modified by "; its tendency to rise though
It is also shown by this; that when the air is expanding towards the exterior;" and the effort
dilated in the thermometer uniformly and equably, is modified by its not being sluggish, but active
-without any impediment or repulsion, the heat is and somewhat violent.
not perceptible. In confined draughts also, al- With regard to the operative definition, the
though they break out very violently, no remark- matter is the same. " If you are able to excite a
able heat is perceived, because the motion affects dilating or expansive motion in any natural body,
the whole, without any alternating motion in the and so to repress that motion and force it on itself
particles. For which reason try whether flame as not to allow the expansion to proceed equally,
do not burn more at the sides than in its centre. but only to be partially exerted, and partially
It is also shown in this, that all burning pro- repressed, you will, beyond all doubt, produce
cee by the minute pores of bodies, undermining, heat;" without any consideration as to whether
penetrating, plercl-ng, and pricking them as if the body be of earth (or elementary, as they term
with an infinite number of needlepoints. Hence it) or imbued with celestial influence, luminous or
all strong acids (if adapted to the body on which opaque, rare or dense, locally expanded or conthey act) exhibit tile ffects of fire from their tained within the bounds of its first dimensions,
corroding and pungent nature. verging to dissolution or remaining fixed, animal,
The difference of which we now speak is com- vegetable, or mineral, water, or oil, or air, or any
mon also to the nature of cold, in which the con- other substance whatever susceptible of such motracting motion is restrained by the resistance of tion. Sensible heat is the same, but considered
expansion, as in heat the expansive motion is relatively to the senses. Let us now proceed to
restrained by the resistance of contraction. further helps.
Whether, therefore, the particles of matter 21. After our tables of first review, our rejeepenetrate inwards or outwards, the reasoning is tion or exclusive table and the first vintage dethe same, though the power be very different, rived from them, we must advance to the remainbecause we have nothing on earth which is in- ing helps of the understanding with regard to the
tensely cold. interpretation of nature, and a true and perfect
IV. The fourth difference is a modification of induction; in offering which we will take the exthe preceding; namely, that this stimulating or amples of cold and heat where tables are necespenetrating motion should be rapid and never sary, but where fewer instances are required we
sluggish, and should take place not in the very will go through a variety of others; so as neither
minutest particles, but rather in those of some to confound investigation nor to narrow our doe.
t( lerable dimensions. trine.
It is shown by comparing the effects of fire In the first place, therefore, we will treat of
with those of time. Time dries, consumes, under- prerogative instances; 2. Of the supports of innkines, and reduces to ashes as well as fire, and, duction; 3. Of the correction of induction; 4. Of
perhaps, to a much finer degree, but as its motion1 varying the investigation according to the nature