On Cases of Attraction in other Bodies.
Very often the herd of philosophizers and plagiarists repeat from the
records of others in natural philosophy opinions and errors about the
attractions of various bodies; as that Diamond attracts iron, and snatches
it away from a magnet; that there are various kinds or magnets, some which
attract gold, others silver, brass, lead; even some which attract flesh,
water, fishes. The flame of sulphur is said to seek iron and stones; so
white naphtha is said to attract fire. I have said above that {110}
inanimate natural bodies do not attract, and are not attracted by, others
on the earth, excepting magnetically or electrically. Wherefore it is not
true that there are magnets which attract gold or other metals; because a
magnetick substance draws nothing but magnetick substances. Though
Fracastorio says that he has shown a magnet drawing silver; if this were
true, it must have happened on account of iron skilfully mixed with that
silver or concealed in it, or else because nature (as she does sometimes,
but rarely) had mixed iron with the silver; iron indeed is rarely mixed
with silver by nature; silver with iron very rarely or never. Iron is mixed
with silver by forgers of false coin or from the avarice of princes in the
coining of money, as was the case with the denarius of Antony[189],
provided that Pliny is recording a true incident. So Cardan (perhaps
deceived by others) says that there is a certain kind of loadstone which
draws silver; he adds a most foolish test of this: "If therefore" (he says)
"a slender rod of silver be steeped in that in which a versatory needle has
stood, it will turn toward silver (especially toward a large quantity)
although it be buried; by this means anyone will be able easily to dig up
concealed treasures." He adds that "it should be very good stone, such as
he has not yet seen." Nor indeed will either he or anyone else ever see
such a stone or such an experiment. Cardan brings forward an attraction of
flesh, wrongly so named and very dissimilar from that of the loadstone; for
his _magnes creagus_ or flesh-magnet, from the experiment that it sticks to
the lips, must be hooted out from the assembly of loadstones, or by all
means from the family of things attractive. Lemnian earth, ruddle, and very
many minerals do this, and yet they are fatuously said to attract. He will
have it that there is another loadstone, as it were, a third species, into
which, if a needle is driven and afterwards stuck into the body, it is not
felt. But what has attraction to do with stupefaction, or stupor with a
Philosopher's intellect, when he is discoursing about attraction? There are
many stones, both found in nature and made by art, which have the power of
stupefying. Sulphur flame is said by some to attract, because it consumes
certain metals by its power of penetration. So white naphtha attracts
flame, because it gives off and exhales an inflammable vapour, on which
account it is kindled at some distance, just as the smoke of a recently
extinguished candle takes fire again from another flame; for fire creeps to
fire through an inflammable medium. Why the sucking fish Echineis or the
Remora should stay ships has been variously treated by Philosophers, who
are often accustomed to fit this fable (as many others) to their theories,
before they find out whether the thing is so in nature. Therefore, in order
that they may support and agree with the fatuities of the ancients, they
put forward even the most fatuous ratiocinations and ridiculous problems,
cliffs that attract, where the {111} sucking fish tarry, and the necessity
of some vacuum, I know not what, or how produced. Pliny and Julius Solinus
make mention of a stone Chatochitis[190]. They say that it attracts flesh,
and keeps hold of the hands, just as a loadstone does iron, and amber
chaff. But that happens only from a stickiness and from glue contained in
it, since it sticks more easily to the hands when they are warm. Sagda or
Sagdo[191], of the colour of a sard, is a precious stone mentioned by
Pliny, Solinus, Albertus, and Evax[192]; they describe its nature and
relate, on the authority of others, that it specially attracts wood to
itself. Some even babble that woods cannot be wrenched away except they are
cut off. Some also narrate that a stone is found which grows pertinaciously
into ships, in the same way as certain testacea on long voyages. But a
stone does not draw because it sticks; and if it drew, it would certainly
draw shreds electrically, Encelius saw in the hands of a sailor such a
stone of feeble virtue, which would hardly attract even the smallest twigs;
and in truth, not of the colour of the sard. So Diamond, Carbuncle,
Crystal, and others do attract. I pass over other fabulous stones;
Pantarbe, about which Philostratus writes that it draws other stones to
itself; Amphitane also, which attracts gold. Pliny in his origin of glass
will have it that a loadstone is an attractor of glass, as well as of iron.
For in his method of preparing glass, when he has indicated its nature, he
subjoins this about loadstone. "Soon (such is the astute and resourceful
craft) it was not content to have mixed natron; loadstone also began to be
added, since it was thought to attract to itself the liquor of glass (as it
does iron)." Georgius Agricola writes that to the material of glass (sand
and natron) one part also of loadstone is added. "Because that force is
believed, in our times just as in former times, to attract the liquor of
glass to itself, as it attracts iron to itself, purges it when drawn, and
makes clear glass from green or muddy; but the fire afterwards burns up the
loadstone." It is true indeed that some sort of _magnes_ (as the magnesia
of the glass-makers imbued with no magnetick virtues) is sometimes put in
and mixed with the material of the glass; not, however, because it attracts
glass. But when a loadstone is burnt, it does not lay hold of iron at all,
nor is iron when red-hot allured by any loadstone; and loadstone also is
burnt up by more powerful fires and loses its attractive potency. Nor is
this a function of loadstone alone in the glass furnaces; but also of
certain pyrites and of some easily combustible iron ores, which are the
only ones used by our glass-makers, who make clear, bright glass. They are
mixed with the sand, ashes, and natron (just as they are accustomed to make
additions in the case of metallick ores whilst they are smelted), so that
when the material slows down into glass, the green and muddy colour of the
glass may be purged by the penetrating heat. For no other material becomes
so hot, {112} or bears the fire for such a convenient time, until the
material of the glass is perfectly fluid, and is at the same time burnt up
by that ardent fire. It happens, however, sometimes, that on account of the
magnetick stone, the magnesia, or the ore, or the pyrites, the glass has a
dusky colour, when they resist the fire too much and are not burnt up, or
are put in in too great quantity. Wherefore manufacturers are seeking for a
stone suitable for them, and are observing also more diligently the
proportion of the mixture. Badly therefore did the unskilful philosophy of
Pliny impose upon Georgius Agricola and the more recent writers, so that
they thought the loadstone was wanted by glass-makers on account of its
magnetick strength and attraction. But Scaliger in _De Subtilitate ad
Cardanum_, in making diamond attract iron, when he is discussing
magneticks, wanders far from the truth, unless it be that diamond attracts
iron electrically, as it attracts wood, straws, and all other minute bodies
when it is rubbed. Fallopius reckons that quicksilver draws metals by
reason of an occult property, just as a loadstone iron, amber chaff. But
when quicksilver enters metals, it is wrongly called attraction. For metals
imbibe quicksilver, just as clay water; nor do they do this unless they are
touching, for quicksilver does not allure gold or lead to itself from afar,
but they remain motionless in their places.
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