The ancients, though ignorant of electricity, were acquainted with
the nature of amber, and knew that when rubbed it had the power
of attracting light bodies. In like manner they might have been
acquainted with the tourmaline, and might have known that it also,
when heated, attracted light bodies, and again repelled them; for had
they only bethought themselves, in order to search out the hidden
properties of this stone (which on account of its colour and hardness
is very remarkable), to put it into the fire, they would have then
seen it sport with the ashes. Some learned men have thought they
found traces of the properties of this stone, in what the ancients
tell us respecting the _lyncurium_, _theamedes_, and _carbunculus_.
The fruit of my researches respecting this subject I shall here lay
before the reader. All that we find in the ancients to enable us to
characterize the lyncurium is, that it was a very hard stone, which
could with difficulty be cut; that seals were formed of it; that it
was transparent, and of a fiery colour, almost like that of yellow
amber; that it attracted light bodies, such as chaff, shavings of wood,
leaves, feathers, and bits of thin iron and copper leaf, in the same
manner as amber; that the ancients procured it from Æthiopia, but that
in the time of Pliny no stone was known under that name[210].
This information proves, in my opinion, that the lyncurium cannot be
the belemnites, as some old commentators and Woodward have affirmed;
for the latter has not the celebrated hardness and transparency of the
former, neither has it the property of attracting light bodies, nor is
it fit for being cut into seals. That opinion probably has arisen in
the following manner:--the ancients supposed that the lyncurium was
the crystallized urine of the animal which we call the lynx. As some
belemnites contain bituminous particles which give them an affinity to
the swine-stone, naturalists, when they have rubbed or heated yellow
and somewhat transparent pieces of this fossil, have imagined that they
smelt the fabulous origin of the lyncurium.
Less ridiculous is the opinion of some old and modern writers, that
the lyncurium was a species of amber. Theophrastus, however, the
ablest and most accurate mineralogist of the ancients, would certainly
have remarked this and not have separated the lyncurium from amber.
Besides, the latter has not the hardness of the former, nor can it be
said that it is difficult to be cut; for at present it is often made
into various toys with much ingenuity. The opinion of Pliny is here of
little weight; for it is founded, as ours must be, on the information
of Theophrastus.
Epiphanius, who considered the Bible as a system of mineralogy, but
could not find the lyncurium in it, supposes that it may have been the
hyacinth[211]. However ridiculous the cause of this conjecture may be,
it must be allowed that it is not entirely destitute of probability;
and I say with John de Laet, “The description of the lyncurium does
not ill agree with the hyacinth of the moderns[212].” If we consider
its attracting of small bodies in the same light as that power which
our hyacinth has in common with all stones of the glassy species, I
cannot see anything to controvert this opinion, and to induce us to
believe the lyncurium and the tourmaline to be the same. The grounds
which Watson produces for this supposition, are more in favour of the
hyacinth than the tourmaline[213]. Had Theophrastus been acquainted
with the latter, he would certainly have remarked that it did not
acquire its attractive power till it was heated. At present, at least,
no tourmaline is known to attract until it is heated; though it would
not appear very wonderful if a stone like the magnet should retain its
virtue for a long time.
The duke of Noya Caraffa believes the theamedes of the ancients to
have been the tourmaline[214]. Of that stone we are told, by Pliny,
only that it possessed a power contrary to the power of the magnet;
that is, that it did not attract but repel iron. But this only proves,
that it had then been remarked that the magnet repelled the negative
pole of a piece of magnetic iron. This account has been thus explained
by Boot[215]. To induce us to consider the theamedes as the tourmaline,
Pliny ought to have said that it attracted iron and then repelled it.
With much greater probability may we consider as the tourmaline a
precious stone, classed by Pliny among the numerous varieties of the
carbuncle[216]; for however perplexed and unintelligible his account of
the carbuncles may be, and however much the readings in the different
copies may vary, we still know that he describes a stone which was very
hard; which was of a purple, that is a dark violet colour, and used for
seals; and which, when heated by the beams of the sun, or by friction,
attracted chaff and other light bodies. Had Pliny told us that it at
first attracted and then repelled them, no doubt would remain; but he
does not say so, nor do his transcribers Solinus and Isidorus[217].
A much later account of a stone that, when rubbed, is, like the magnet,
endued with an attractive power is to be found in a passage of John
Serapion, the Arabian, pointed out to me by Professor Bütner[218]. This
stone indeed cannot with much probability be taken for the tourmaline,
as all precious stones, when heated, have the same property; but it is
worthy of remark, that, like the lyncurium of the ancients, it belongs
to the hyacinths, the colour of which many of the real tourmalines
have; and among those of the island of Ceylon there are, perhaps, some
which ought to be classed among the hyacinths, rather than among the
schorls.
The real tourmaline was first brought from Ceylon, and made known
by the Dutch, about the end of the seventeenth or beginning of the
eighteenth century. It is commonly believed that the first account of
it ever published is that to be found in the Memoirs of the Academy of
Sciences at Paris for the year 1717; but it appears that fuller and
more accurate descriptions of the properties of that stone were given
in German works ten years before. The earliest information that I know
respecting it is in a book now almost and justly forgotten, entitled
Curious Speculations during Sleepless Nights[219]. In a passage, where
the author, speaking of hard and glassy bodies which attract light
substances, affirms that this property is not magnetic, he says, “The
ingenious Dr. Daumius, chief physician to the Polish and Saxon troops
on the Rhine, told me, that in the year 1703 the Dutch first brought
from Ceylon in the East Indies a precious stone called tourmaline, or
turmale, and named also _trip_, which had the property, that it not
only attracted the ashes from the warm or burning coals, as the magnet
does iron, but also repelled them again, which was very amusing; for as
soon as a small quantity of ashes leaped upon it, and appeared as if
endeavouring to writhe themselves by force into the stone, they in a
little sprang from it again, as if about to make a new effort; and on
this account it was by the Dutch called the _ashes-drawer_. The colour
of it was an orange-red heightened by a fire colour. When the turf
coals were cold, it did not produce these effects, and it required no
care like the magnet. I have considered whether it would not attract
and repel the ashes of other burning coals as well as those of turf;
and I have no doubt, that, if heated, it would attract other things
besides ashes.”
This whole passage has been inserted word for word, without variation
or addition, and without telling the source from which taken, in a book
perhaps equally forgotten, called Observationes curioso-physicæ, or
Remarks and Observations on the great Wonders of the World, by Felix
Maurer, physician[220]. This thick volume is entirely compiled from a
number of works, the names of which are not mentioned.
In the Catalogue of the collection of natural curiosities belonging to
Paul Hermann, which were sold at Leyden in June 1711, I find, among the
precious stones, _Chrysolithus Turmale Zeylon_. Though no description
is added, it cannot be doubted that our tourmaline is meant. From this
however we learn that the name together with the stone came to us from
Ceylon, as Watson has remarked. We learn further, that the stone was
at first considered as a chrysolite, and perhaps it may be mentioned
under this name in the old accounts of Ceylon. Hermann, whose service
to botany is well known, was in that island from 1670 to 1677; and it
might be presumed, from his spirit of inquiry, that, had he known this
stone, he would somewhere or other in his works have taken notice of
its properties: but I find no mention of it either in his Cynosura
Materiæ Medicæ, or in Musæum Zeylonicum.
In the year 1719 the Academy of Sciences at Paris announced in their
memoirs for 1717, that in the latter year M. Lemery had laid before
them a stone found in a river in the island of Ceylon, which attracted
and repelled light bodies[221]. It is there called a small magnet,
though some difference between the two stones was admitted; but the
German naturalist before-mentioned, denies that the tourmaline is
endowed with magnetic virtue. It is however very remarkable, that
though it is said, in the Memoirs of the Academy, that it has the power
of attracting and repelling, no mention is made that it acquires that
property, only after it has been heated, which is expressly remarked
by the German. Those therefore who wish to ascribe to the ancients
a knowledge of the tourmaline may say, If the editor of the Memoirs
of the French Academy could forget this circumstance, is it not
highly probable that Theophrastus might have forgot it in describing
the lyncurium; Pliny, in describing the carbuncle; and Serapion, in
describing his hyacinth?
After this period the tourmaline must have been very scarce in Europe;
for when Muschenbroek made his well-known experiments with the
loadstone, and spared no labour to carry them to the utmost extent, he
was not acquainted with the nature of the tourmaline, which, according
to the account given of it by the Academy at Paris, he considered as a
magnet, as he himself says in the preface to his first dissertation,
published in 1724.
About the year 1740 however some German naturalists made experiments
with this stone, in order to discover the real cause of its attractive
property. These may be seen, under the article _Trip_, in the
well-known Dictionary of Natural History which is often printed with
Hübner’s preface; but I do not know to whom the honour belongs of
having first investigated the properties of this stone. As the above
dictionary is common, I shall give here only a very short extract
from it:--“This stone was brought to Holland by some persons who had
travelled in India, from the island of Ceylon, where it is found pretty
frequently among the fine sand near Columbo, and sold to the German
Jews. These caused it to be cut thinner, and the price of it soon rose
to eight and ten Dutch florins. It has been since much dearer; but at
present it is cheaper. It attracts not only ashes, but also metallic
calces: it however attracts more easily and with greater force those
which have been formed by means of sal-ammoniac, or the spirit of
that salt. It acquires its attractive power only after it has been
moderately heated; for when cold or heated to a greater degree it
produces no effect, which the author ascribes to its being united
with martial sulphur. The chrysolites and other precious stones of the
island do not possess the same property.” As the author quotes the
Laboratorium Zeylonicum, I consulted it, but found no information in it
respecting the tourmaline. The first person who thought of explaining
the property of the tourmaline by electricity was the great Linnæus,
who in the preface to his Flora Zeylanica[222], where he enumerates the
productions of the island, calls it the electrical stone; but at that
time, as he himself afterwards told me, he had not seen it.
What Linnæus only conjectured, Æpinus proved at Berlin in 1757 by
accurate observation and experiments, when endeavouring with Wilke
to investigate the secret of negative and positive electricity. The
history of their discoveries I shall here omit, as a better account of
them than I could give has been published in the Transactions of the
Swedish Academy by Wilke.
[The discovery by Huygens, in 1678, of the polarization of light
by double refraction, laid the foundation of a much more important
application of the tourmaline; for MM. Biot and Seebeck, in their
subsequent experiments, discovered that certain yellowish tourmalines,
that is, those which are yellowish by refracted light, possessed the
remarkable property of absorbing or checking one of the rays of a beam
of polarized light, and transmitting the others. This discovery led to
the use of tourmalines in most experiments which were subsequently made
with polarized light. For this purpose, the tourmaline, which generally
crystallizes in the form of a long prism, is cut lengthwise, that is,
parallel to the axis of the prism, into plates about the 30th of an
inch thick.
The invention of Mr. Nichol of a method of destroying one of the rays
of a polarized beam in a crystal of calcareous spar, has however in
later times entirely replaced the use of the tourmaline in optical
science, the colour of the tourmaline being a disadvantage which is
entirely removed in the use of Nichol’s prism[223].]