392 M A R 
Ipirit of wine, nor any lixivium, will do with it. There 
is another kind of fanguis draconis, called dragon’s blood 
in tears, which, mixed with urine alone, gives a very ele¬ 
gant colour. Phil. Tranf. N° 268. 
Befide thefe mixtures of colours and menftruums, there 
are fome colours which are to be laid on dry and unmix¬ 
ed. Thefe are, dragon’s blood of the pureft kind for a 
red ; gamboge for a yellow; green wax for a green ; com¬ 
mon brimftone, pitch, and turpentine, for a brown co¬ 
lour. The marble for thefe experiments muff be made 
confiderably hot, and then the colours are to be rubbed 
on dry in the lump. Some of thefe colours, when once 
given, remain immutable ; others are ealily changed or 
deftroyed. Thus the red colour given by dragon’s blood, 
or by a decoflion of logwood, will be wholly taken away 
by oil of tartar, and the polilh of the marble not hurt 
by it. 
A fine gold colour is given in the following manner: 
Take crude fal ammoniac, vitriol, and verdigris, of each 
equal quantities ; white vitriol fucceeds beft, and all mult 
be thoroughly mixed in fine powder. 
The ftaining of marble to all the degrees of red, or 
yellow, by folutions of dragon’s blood or gamboge, may 
be done by reducing thefe gums to powder, and grind¬ 
ing them with fpirit of wine in a glafs mortar; but, 
for fmaller attempts, no method is fo good as the mixing 
of a little of either of thefe powders with fpirit of wine 
in a filver fpoon, and holding it over burning charcoal. 
By this means a fine tindfure will be extracted, and with 
a pencil dipped in this, the fined traces may be made on 
the marble, while cold, which on the heating of it after¬ 
wards, either on fand, or in a baker’s oven, will all fink 
very deep, and remain perfectly diltinft in the done. 
It is very eafy to make the ground-colour of the 
the marble red or yellow by this means, and leave white 
veins in it. This is to be done by covering the places 
where the whitenefs is to remain with fome white paint, 
or even with two or three doubles only of paper, either 
of which will prevent the colour from penetrating in that 
part. All the degrees of red are to be given to marble 
by means of this gum alone ; a flight tindlure of it, with¬ 
out the affiftance of heat to the marble, gives only a pale 
flefh-colour; but the ftronger tindlures give it yet deep¬ 
er; to this the afiiltance of heat adds yet greatly; and 
finally, the addition of a little pitch to the tindiure gives 
it a tendency to blacknefs, or any degree of deep red 
that is defired. 
A blue colour may be given to marble by diffolving 
turnfol in a lixivium of lirne and urine, or in the volatile 
fpirit of urine ; but this has always a tendency to purple, 
whether made by the one or the other of thefe ways. A 
better blue, and ufed in an eafier manner, is furnifhed by 
the Canary turnfol, a fubftance well known among the 
dyers. This needs only to be difl'olved in water, and 
drawn on the place with a pencil; it penetrates very deep 
into the marble, and the colour may be increafed by draw¬ 
ing the pencil, wetted afrelh; feveral times over the fame 
lines. This colour is fubjedt to fpread and diffufe itfelf 
irregularly; but it may be kept in regular bounds, by 
circumfcribing its lines with beds of wax, or any other 
fuch fubftance. It is to be obferved, that this colour 
fhould always be laid on cold, and no heat given even af¬ 
terwards to the marble; and one great advantage of this 
colour is, that it is therefore eafily added to marbles al¬ 
ready ftained with any other colours, and it is a very beau¬ 
tiful tinge, and lalts a long time. Mem. Acad. Par. 1732. 
This art has in feveral people’s hands been a very lu¬ 
crative fecret, though there is fcarcely any thing in it 
that has not at one time or other been publilhed. Kircher, 
however, was one of the firft who publilhed any thing 
practicable about it. The author, meeting with ftones 
in forne cabinets fuppofed to be natural, but having 
• figures too nice and particular to be fuppofed to be na¬ 
ture’s making, and thefe not only on the furface, but 
funk through the whole body of the ftones, was at the 
M O R. 
pains of finding out the artift who did the bufinefs; and, 
on his refufing to part with the fecret on any terms, this 
author, with Albert Gunter, a Saxon, endeavoured to find 
it out; in which they fucceeded at length very well. 
Their method is this: Take aqua fortis and aqua regia 
of each two ounces, fal-ammoniac one ounce, fpirit of 
wine two drams, about twenty-fix grains of gold, and two 
drams of pure filver; let the filver be calcined and put 
into a phial, and pouf upon it the aqua fortis; let this 
ftand fome time, then evaporate it, and the remainder 
will firft appear of a blue, and afterwards of a black, co¬ 
lour; then put the gold into another phial, pour the aqua 
regia upon it, and, when it is difl'olved, evaporate it as the 
former; then put the fpirit of wine upon the fal-ammo¬ 
niac, and let it be evaporated in the fame manner. All 
the remainders, and many others made in the lame man¬ 
ner from other metals dilfolved in their proper acid men- 
Itrua, are to be kept feparate, and ufed with a pencil on 
the marble. Thefe will penetrate without the lealt aflift- 
ance of heat; and, the figure being traced with a pencil 
on the marble, the feveral parts are to be touched over 
with the proper colours, and this renewed daily till the 
colours have penetrated to the defired depth into the lione. 
After this the mafs may be cut into thin plates, and every 
one of them will have the figure exaffly reprefented on 
both furfaces, the colours never fpreading. The nicelt 
method of applying thefe, or the other tinging fubltances, 
to marble that is to be wrought into any ornamental 
works, and where the back is not expofed to view, is to 
apply the colours behind, and renew them fo often till 
the figure is fufficiently feen through the furface on the 
front, though it does not quite extend to it. This is the 
method that of all others brings the ftone to a nearer re- 
femblance of natural veins of this kind. 
The fame author gives another method to colour mar¬ 
ble by vitriol, bitumen, &c. forming a defign of what 
you like upon paper, and laying the laid defign between 
two pieces of polilhed marble ; then doling all the inter¬ 
laces with wax, you bury them for a month or two in a 
damp place. On taking them up, you will find that the 
defign you painted on the paper has penetrated the mar¬ 
bles, and formed exaffly the fame defign on them. 
Kirc/ier’s Mund. Subter. lib. viii. 9. Wallerius, in his Mine¬ 
ralogy, vol. ii. p. 128. recommends the laft method of 
Kircher; and the firft method is copied in the Phil. Tranf. 
vol. i. N° 7. where alfo we are told that the art was prac- 
tifed by Mr. Bird, a llone-cutter at Oxford, before the 
year 1666 ; but his method is not recorded. Mr. Robert 
Chambers, of Minching Hampton, in Gloucefterlhire, dif- 
covered and pra&ifed a method of colouring marble, 
which he kept a fecret. Mr. Da Cofta has publilhed an 
account of experiments made on feveral pieces of marble 
llained by this artift. Phil. Tranf. vol. li. p. 30. See alfo 
Phil. Tr. abr. i.44. iv. 533. xi. 324. 
In the year 1770, a patent was granted for a method 
of inlaying fcagliola or plalter, in and upon marble or 
metals, to imitate flowers, trees, fruit, birds, beads, land- 
fcapes, and all forts of ornaments. The procefs i3 as 
follows,—Firft, procure ftatuary marble, or metal, which 
mult be finely polilhed. Secondly, take fize-water, and 
mix the fame with common whiting; brulh this all 
over the polilhed marble, or metal. When the fame is 
dry, draw the defign thereon; and caufe that part within 
which is meant to be inlaid, to be cut out a quarter of 
an inch deep. Thirdly, take the fcagliola or plafter, 
which mult be finely fifted, and have all the neceffary co¬ 
lours finely ground, which mult be fuch as are ufed in oil 
by the painters. Mix the fcagliola or plafter into a pafte 
with lize-water ; add to the fame fuch colours as the de¬ 
fign requires ; then, with a finall trowel, lay the pafte into 
the cavities that are intended to be filled up, and let the 
fame remain until it becomes dry and hard; after which, 
level the fame, to the face of the marble, or metal, with 
a fmall plane or knife, which mult be very (harp. Gare 
mult be taken that the corners of the plane or knife do 
not 
