Ultramarine is a very fine blue powder, almost of the colour of the
corn-flower or blue-bottle, which has this uncommon property, that,
when exposed to the air or a moderate heat, it neither fades nor
becomes tarnished. On this account it is used in painting; but it was
employed formerly for that purpose much more than at present, as smalt,
a far cheaper article, was not then known. It is made of the blue parts
of the lapis lazuli, by separating them as much as possible from the
other coloured particles with which they are mixed, and reducing them
to a fine powder. The real lapis lazuli is found in the mountains of
that part of Tartary called Bucharia, which extends eastwards from
the Caspian sea, and particularly at Kalab and Budukschu. It is sent
thence to the East Indies, and from the East Indies to Europe. The
Bucharians also carry fragments of it, weighing sometimes a pound and
more, to Orenburg, though less frequently than some years ago. As large
pieces of a pure and beautiful colour are scarce even in that distant
country, and as they are employed for making ornaments and toys, the
rough stone itself is costly; and this high price is increased in the
ultramarine by its laborious preparation, though in later times the
process has been rendered much easier[1443].
On account of the scarcity and great value of the lapis lazuli, other
stones, somewhat like it only in colour, have been substituted in its
stead; and hence have arisen the many contradictions to be found in the
works of different authors, particularly those of the ancients, where
they speak of the properties and country of this species of stone.
Many have considered the Armenian stone, which is a calcareous kind of
stone tinged with copper; many the mountain blue or malachite, and many
also blue sparry fluor, and blue jasper, as the lapis lazuli[1444];
and ultramarine of course is not always what it ought to be. At
present, smalt of a good colour is often purchased therefore at a dear
rate; and it is in greater request, as it is certain that its colour
is more durable in fire than even that of the lapis lazuli. Good
ultramarine must be of a beautiful dark colour, and free from sand as
well as every other mixture. It must unite readily with oil; it must
not become tarnished on a red-hot tile or plate of iron, and it ought
to dissolve in strong acids, almost like the zeolite, without causing
any effervescence. In the year 1763, an ounce of it at Paris cost
four pounds sterling, and an ounce of _cendre d’outremer_, which is
the refuse, two pounds. At Hamburg, Gleditsch sold fine real Oriental
ultramarine for a ducat per ounce, and warranted it to stand proof by
fire; but whether it would stand proof by acids also, I do not know.
From what has been said, a question arises, whether ultramarine was
known to the ancient Greeks and Romans? And this gives occasion to
another, whether they were acquainted with lapis lazuli? The name lapis
lazuli no one indeed can expect to find among them; for it is certain
that we received it from the Arabians; and the word _ultramarinum_ is
altogether barbarous Latin. Some centuries ago, many foreign articles,
brought from beyond sea, had a name given them from that circumstance;
and the ancients applied the epithet _marinum_ to various productions
on the like account. Hence, in the decline of the Roman language was
formed _ultramarinum_, which some have endeavoured to improve by
changing it into _transmarinum_, but this among the ancients never
signified a colour.
Though the ancient names of precious stones have neither been examined
with sufficient accuracy nor distinguished with the greatest possible
certainty, I think I can discover among them the lapis lazuli. I
consider it as the sapphire of the ancients, and this opinion has been
entertained by others; but I hope to render it more probable than it
has hitherto appeared. In the first place, the sapphire of the Greeks
and Romans was of a sky-blue colour with a violet or purplish glance;
and sometimes it had a very dark or almost blackish-blue colour.
Secondly, this stone was not transparent. Thirdly, it had in it a great
many gold points, or golden-yellow spots, but that which had fewest was
most esteemed. Fourthly, it was polished and cut; but when it was not
perfectly pure, and had mixed with it harder extraneous particles, it
was not fit for the hands of the lapidary. Fifthly, it appears that it
was procured in such large pieces that it could be employed for inlaid
or mosaic-work. Sixthly, it was often confounded with, or compared to,
copper-blue, copper-ore, and earth and stones impregnated with that
metal. Seventhly, such medicinal effects were ascribed to it as could
be possessed only by a copper salt; and lastly, it formed veins in
rocks of other kinds of stone, as we are informed by Dionysius[1445].
That a stone with these properties cannot be the sapphire of our
jewellers is beyond all doubt. Our real sapphire does not form veins in
other fossils, but is found among sand in small crystals, shaped like
diamonds; though they sometimes have rather the figure of columns. Like
other precious stones, they are always transparent; they have never
gold points in them; their blue colour resembles more or less that of
blue velvet, and it is often very pale, and approaches seldom, or very
little, to purple. Powder of sapphire appears like fine pounded glass,
exhibits no traces of copper, and can in no manner produce a blue
pigment, or be confounded with mountain-blue.
The question, whether the ancients were acquainted with our sapphire,
and whether it may not belong to their amethysts or hyacinths, I shall
not here examine. I am inclined rather to decide in the negative than
the affirmative; and at any rate the proof will always remain dubious.
It might perhaps be difficult also to determine whether every modern
mineralogist who has spoken of the sapphire was acquainted with, and
alluded to, the real stone of that name.
On the other hand, we can affirm with the greatest certainty, that
the sapphire of the ancients was our lapis lazuli. The latter is of a
blue colour, which inclines sometimes to violet or purple, and which
is often very dark. It is altogether opake, yet its colour will admit
of being compared to a sky-colour; in mentioning of which Pliny had no
idea of transparency, for he compares the colour of an opake jasper
to a sky-blue[1446]. The lapis lazuli is interspersed with small
points, which were formerly considered as gold, but which are only
particles of pyrites or marcasite. It can be easily cut and formed
into articles of various kinds, and at present it is often used for
seals. Pliny, however, informs us that it was not fit for this purpose
when it was mixed with hard foreign particles, such as quartz; and
that which was of one colour was therefore much more esteemed[1447].
Many cut stones of this kind, which are considered as antiques, may be
found in collections. I remember to have seen several works of this
sort in the excellent collection of the duke of Brunswick, which, in
all probability, are Egyptian, and which are worthy of an accurate
description. That lapis lazuli was used formerly for inlaid works
I am well convinced, though at present I can produce no proofs. In
how beautiful a manner it is employed for that purpose in Florentine
works, is well known. The largest and most magnificent squares of
lapis lazuli which I ever saw, are in the apartments at Zarskoe-Selo,
a summer palace near Petersburg, belonging to the empress of Russia,
the walls of which are covered with amber, interspersed with plates
of this costly stone. I was informed that these plates were procured
from Thibet. The doubt expressed by Epiphanius concerning stairs
overlaid with lapis lazuli, respects only the great expense of it, and
he perhaps imagined that the steps were entirely cut from the solid
stone. The confounding the sapphire with the _cyanus_, or comparing it
to it, of which several instances occur, proves that the former must
have had a great resemblance to copper-ore; for that the _cyanus_ is
a kind of mineral or mountain blue, tinged with copper, I have proved
already[1448]. The blue colour of lapis lazuli has always been supposed
to be owing to copper; but according to the latest discoveries it
originates from iron[1449]. The medicinal effects which the ancients
ascribed to their sapphire could be produced only from a mixture of
copper, as they considered the Armenian stone, or false lapis lazuli,
to be the real kind. They recommended copper ochre for an inflammation
of the eyes[1450]. In the last place it agrees with what Dionysius
says, that the sapphire or lapis lazuli was produced in veins among
other kinds of stone[1451]. The sapphire also mentioned in the oldest
writings of the Hebrews, appears to be no other than the sapphire
of the Greeks, or our lapis lazuli; for it was said likewise to be
interspersed with gold points[1452].
The ancients therefore were acquainted with our lapis lazuli; but the
question whether they used it as a paint, or prepared ultramarine from
it, I cannot answer with sufficient certainty. It is possible that
their _cæruleum_ sometimes may have been real ultramarine; but properly
and in general it was only copper ochre[1453]. The objection that the
ancients made blue glass and blue enamel, and if they had not smalt
they could use no other pigment that would stand fire but ultramarine,
I shall answer in the next article.
Before I proceed to the oldest information with which I am acquainted
respecting ultramarine, or the blue colour made from lapis lazuli, I
shall communicate what I know of the origin and antiquity of the name
commonly given to this stone. That I might be able to offer something
more on the subject than what has been said by Salmasius[1454],
I requested the opinion of Professor Tychsen, which, with his
permission, I have here subjoined[1455]. It is, in the first place,
certain that the word is of Persian derivation, and the stone, as I
have already remarked, has hitherto been brought to us from Persia.
Secondly, it signifies a blue colour. It was at first also the common
name in Europe for blue stones and blue colours used in painting;
and it was a long time used to express mountain-blue impregnated
with copper. The modern systematic mineralogists, it appears, first
appropriated the corrupted Persian word to the present lazur-stone,
properly so-called; and those therefore would commit an error in
mineralogy who should now apply this name to the Armenian stone,
mountain-blue, or any other blue mineral containing copper.
Without pretending to have discovered the first mention of the name
lazuli in those writings which have been handed down to us, I shall
here offer, as the oldest with which I am acquainted, that found
in Leontius[1456], who, where he gives directions for colouring a
celestial globe, speaks of _lazurium_. If Fabricius be right, Leontius
lived in the sixth century[1457]. Among the receipts for painting,
written in the eighth century, which Muratori[1458] has made known,
we find an unintelligible account how to make _lazuri_, for which
_cyanus compositus_, perhaps a prepared kind of mountain-blue, was to
be employed. There is also another receipt which orders blue-bottles
to be pounded in a mortar. It appears therefore that this word was
used in the corrupted Latin of that period to signify a blue colour
for painting. The same word, formed after the Greek manner, seems
to have been used for blue by Achmet, the astrologer, who lived
in the ninth century[1459], and by Nonus in the tenth for a blue
earth[1460]. Of still more importance is a passage of Arethas, who
lived in the following century, and who, in his exposition of a verse
in the book of Revelation[1461], says, the sapphire is that stone,
of which _lazurium_, as we are told, is made[1462]. This, therefore,
is a strong corroboration that the sapphire of the ancients was our
_lapis lazuli_, and appears to be the first certain mention of real
ultramarine. The word however occurs often in the succeeding centuries
for blue copper-ochre. Constantinus Africanus, a physician of the
eleventh century, ascribes to lapis lazuli the same medicinal qualities
as those of copper-ochre[1463]; as do also Avicenna, Averroes, and
Myrepsius. The first, under the letter _lam_, gives a chapter entitled
_lazuard_, to which the translator has prefixed “De azulo, id est, de
lapide Armenio;” and the last says expressly, that the _lapis lazuli_
of the Latins is the _lazurios_ of the Greeks[1464]. The words _azura_,
_azurum_, _azurrum_, occur often also in that century for _blue_.
The name _ultramarine_, or, as it was first called, _azurrum
ultramarinum_, I have not yet found in any writer of the fifteenth
century. But it appears that it must have been common about the end
of that century, as it was used by Camillus Leonardus in 1502[1465].
It is probable that it originated in Italy. In the first half of the
sixteenth century Vanuccio Biringoccio gave directions for preparing
the real ultramarine, which he distinguishes with sufficient accuracy
from copper azur[1466], or, as he calls it, the _azurro dell’
Alemagna_. At that period, however, the best method of preparing it
must have been doubtful as well as little known, and on that account of
no great benefit; for, in the beginning of the sixteenth century, the
father of the celebrated Giambatista Pigna, an apothecary at Modena,
was in possession of the secret for making the best ultramarine, by
which he acquired more riches than would have arisen from a large
estate[1467]. It is not, therefore, altogether true that Alexius
Pedemontanus, as Spielmann relates[1468], was the first person who
mentioned ultramarine. I am of opinion that this Alexius, or Hieronymus
Ruscellai concealed under that name, who wrote in the beginning of
the sixteenth century, only first published a complete account of the
method of preparing it. At any rate, his receipt was long followed as
the best and the most certain[1469]. But on what information is that
assertion founded, which we read in English and French authors[1470],
that the preparation of ultramarine was found out in England, and
that a servant of the East India Company disclosed it, in order to be
revenged for some injury which he had sustained?
[The following is the method of making ultramarine from lapis lazuli.
The finest mineral is selected, heated to a dull red heat, and quenched
in water; it is thus rendered friable, and is ground down into an
impalpable powder. This is then mixed with a tenacious paste made
of linseed oil, wax, resin, turpentine and mastic; and the mixture
being kneaded in warm water gives out the blue particles, which are
afterwards collected by subsidence.
Chemists are not agreed concerning the cause of the colour of
ultramarine. Dr. Eisner considers it to arise from sulphuret of sodium
and of iron, the former being a higher sulphuret than the latter. MM.
Clement and Desormes show that the iron is not essential, either to the
lapis lazuli, or to the pigment made from it.
An artificial method of making ultramarine was discovered in 1828
by M. Guimet; the process has been kept secret. Processes have also
been discovered by M. Gmelin of Tübingen, M. Persoz of Strasburg, and
others. M. Gmelin’s process consists in fusing a mixture of two parts
of sulphur and one of dry carbonate of soda in a Hessian crucible, and
then sprinkling into it by degrees another mixture of silicate of soda
and aluminate of soda. The crucible must be exposed to the fire for
an hour after this. The ultramarine thus prepared contains a little
sulphur, which can be separated by means of water.
Some valuable observations on this subject have lately been published
by M. Prückner[1471]. He states that the materials required in the
preparation of ultramarine are alumina, sulphate of soda, sulphur,
charcoal and a salt of iron, the common sulphate or green vitriol being
the best. The alumina is supplied in white bole, or a very pure white
clay. The sulphate of soda is reduced by charcoal and heat to the
state of sulphuret, and its solution thus obtained afterwards boiled
with sulphur so as to form a persulphuret (penta-sulphuret, Berz.).
The solution is then mixed with the dried clay and stirred; during
the mixing a solution of green vitriol is added and mixed. It is then
dried and very finely powdered as rapidly as possible. It is afterwards
heated in a muffle; then washed, drained and again heated in a muffle;
finally it is again washed, dried and powdered.]