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To make purple.—Take the fineft gold, 
Giffulve it in aqua-regia, regulated with 
falammoniac; putit in a fand-heat for 
about forty eight hours to digeft the gold, 
collect the powder, grind it with fix times 
|. its weight of falphur, put it into a cru- 
e:ble on the fire tril the fulphur is evapo- 
rated, then amalgamate the powder with 
twice its weight ‘of mercury, put it into 
a mortar or other veflel, and rub it toge- 
ther for about ix hours, with a fmall 
quantity of water in the mortar, which 
change irequently, evaporate the remain- 
ing mercury in acrucible, and add to the 
powder ten times its weight of flux, or 
more or lefs as the hardnefs or foftne!s of 
the colour may require. 
To make rofe colour.—Take purple as 
prepared above, mix it with thirty times 
xts weight of fiux, and one hundredth 
part of its weight of filver leaf, or any 
preparation of hiver, or vary the prepor- 
tion of the flux and filver, as the quality 
of the colour may requiie; or any of the 
ether preparaticns-for purple will do, va- 
ryine the proportion of the flux and filver 
as above; or any mattrials, from which 
purple can be produced, will, with the 
addition of filver and flux, an{wer. 
Fo make brown.—TYake red lead one 
ounce, calcined iron one cunce, antimony 
two ounces, litharge.two ounces, zafier 
one ounce, fand two ounces, calcined, or 
neeited together, or uled raw, as may be 
maf expedient, or vary the proportions of 
any or ali the above as tint or quality may 
require. 
Meibod of afplication.—The aforefaid 
colours may be applied to veflels of giafs 
in the following manner: viz. by paint- 
ing, printing or transferring, dipping, 
floating, and grounding. 
Fo paint—Mix the colours (when re- 
éuced by grinding to a fine powder) with 
fpirits of turpentine, temper them with 
thick oj] of turpentine, and apply them 
with camel hair pencils, or any other thing 
theught proper; or mix them with nutor 
Monthly Retrefpee of the Fine-Arts. 
[May I, 
fpike oil, or any other effential or volatile 
oi], of with water, in which cafe ufe gum 
arabic, or any other gum that will dif 
folve in water, or with {pirits, varnifhes, 
gums of any kind, waxes, or refins: but 
the frft I conceive to be the bet. 
To print. —Take a glue bat, full fize, 
for tae fubje&t, charge the copper-plate 
with the oil or colour, and take the im- 
preflicn with the bat from the plate, whieh 
impreffion transfer on the gilafs: if the 
imprefiion be net ffrong enough, fhake 
fome dry colour on it, which will adhere 
to the moift colour; or take any engrav- 
ing or etching, or ftamp, or caft, and,. 
having charged it with the oil or colour, 
transfer it on the glafs by means of pre- 
pared paper, vellum, leather, or any 
other fublttance that will anfwer: but I 
think the firftthe beft. Any of the afore- 
{aid engravings, etchings, ftamps, cafis, 
or device, may be charged with wateis, 
oils, varnifhes, or glusinous matters of 
any kind, reduced to a proper ftate, as is 
neceflary in printing ia general; any cr, 
all of thefe may be ufed alone, or mixed 
with the colours. When ufed alone, the 
colour is to be applied in powder as be- 
fore- mentioned. 
Yo dip.—Mix the colour to about the 
coniiftency of a cream with any of the in-' 
gredients uied for printing, wherein dip 
the glafs veflel, keep it in motion till 
{mooth. 
To ground.—Fir& charge the glafs vet 
fel with oil ct-turpentine, with a camel- 
hair pencil, and while moift apply the co~ 
Jour in a dry powder, which will adhere 
to the oil, or, inftead of oi] of turpentine, 
ule any cf the materials ufed for printing ¢ 
but I think the firft the beft. 
To ficat.—Mix the colour with any of 
the ingredients ufed for printing, to a con- 
iftency acccrding tothe firength of ground 
required, float it throvgh a tube, or any 
other veffel, moving or fhaking the piece 
of glafs till the colour is fpread over the | 
perce required. : . 
Sr og ee eg eter reece eer 
MONTHLY RETROSPECT OF THE FINE ARTS. 
The Loan of all new Prints and Communications of Articles of Intelligence are requefied. 
EXHIBITION OF PAINTERS IN WATER 
COLOURS. 
| HE Society of Painters in Water 
%{ =©Colours commenced their fecond ex- 
hibition at No. 20, Lower Brook-ftreet, 
on Monday the 21ft of April, and fate, 
that the very flattering recestion which 
they met with laft year, encourages them — 
to praceed ‘in their plan; and they an- 
nounce, that for the better accommoda- 
tion of the public, they have engaged ° 
the Old Royal Academy Rooms, in Pall-> 
for thetr 
mall, which will be the place 
next and future exhibitions. 
There 
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