303 
GEM. 
earths. Only no crucible or other receptacle is at all 
necelFary; the calls being formed like lb many fmall 
cakes half an inch thick, and thus put into the furnace 
with the bits of glafs upon them. The glafs, alter 
-coming to a proper heat, is preffed down upon the 
mould with an iron fpatula to receive the defired im- 
prelfion, thepreflTure requifite being more or lefs accord¬ 
ing to the fize of the Hone. 
Tlie art of taking iraprelfions of gems feems not to 
have been altog'etlier loft even in the Gothic ages; and 
it w^as revived in Italy in the time of Laurence of Medici 
and Pope Leo X. but it v/as not cultivated in an exten- 
ftve manner till the beginning of the eighteenth century, 
when M. Homberg reftored it, as,already mentioned. 
In this he is faid to have been greatly allifted and en¬ 
couraged by the then duke of Orleans regent of France, 
who ufed to amufe himfelf with that celebrated chemift 
in takingoffimprellions-in pafte from the king of France’s 
and hisowncolledlions of gems. M. Clachant the elder, 
an engraver of fome note, who died at Paris in 1781, 
alfo learned this 'art from his royal highnefs, to whofe 
houfehold his fatlter feems to have belonged. -Made- 
moifelle Feloix next cultivated this art. She had been 
taught by her father, who in quality of garcon de cham- 
bre to the regent had often allifted in the laboratory of 
his mailer, where he acquired this knowledge. Her 
collection confifted of 1800 choice imitations, with many 
originals, of the antique gems. 
Baron Stofch, a PrulTian, who travelled over Europe 
in quell of original engraved ftones and impreftions of 
ancient gems, for the elegant work which he pub.lilhed 
and Picart engraved, was w'ell acquainted with this art. 
He had taught it to hisfervant Chriftian Dehn, who fet¬ 
tled at Rome, where he made and fold his well known 
fulphur impreftions .and paftes. He liad collebted 2500 
articles. Dolce has arranged them in a fcientific order, 
and given a defcriptive catalogue of them. It was 
chiefly from Dehn’s eolleftion that the tafte for fulphurs 
and paftes has become lb univerfal. They are great 
objects of ftudy, and often require much learning to ex¬ 
plain them. I'hey have unqueftionably ferved to ex¬ 
tend and improve the art of engraving on ftones; and 
have been of infinite ufe to painters, to ftatuaries, and 
to other artilis, as well as to men of claftical learning 
and fine talle. 
It is. however very difficult to take off impreffions, and 
perfetlly to imitate various coloured cameos. It can¬ 
not be properly done in wax, fulphur, plafter, or glafs 
of one colour only. The difficulties ariling from their 
fize and form, and from tlie various nature of the differ¬ 
ent forts of glafs, which do not well unite into different 
llrata, are very numerous : nor could the completeft 
fuccefs in this chemical and mechanical branch of the 
art for a long time produce a tolerable cameo. Im- 
pivfiions or imitations, if unaflifted by the tool of the 
engraver, do not fucceed ; becaufe tlie undercutting and 
deep vrork of moft of the originals require to be filled 
up with clay or wax, tliat the moulds m.ay come off fafe 
without injuring tliem. Plence the impreftions from thel'e 
moulds come off hard and deftitute of delicacy, fliarp- 
Jiefs, and precifion of outline, till the underworking of 
tjie moulder is cut away. But Mr. Reiffenfteinat Rome, 
by his genius, perfeverance, and the afliftance of able 
artifts, at length overcame thefe difficulties ; and had 
the fatisfaction of fucceeding, and producing variegated 
cameos which can hardly be dillinguilhed from the ori¬ 
ginals. 
M. Lippart of Drefden, an ingenious glazier, and an 
entliufiaft in the fine arts, pradtiled this branch not un- 
fuccefsfully ; but not finding I'ufficient encouragement 
for his paftes of coloured glafs, or perhaps from local 
difficulties in making tliem well and cheap, he aban¬ 
doned the purfuit. He fubftituted in its place impref¬ 
fions of fine white alabafter orfelenite plafter. Such im- 
preliionsj when carefully foaked in a folution of white 
Caftile foap, then dried, and rubbed over with a foft 
brufti, take a very agreeable polilli. They ftiow the 
work perhaps to better advantage than red ox white ful¬ 
phurs do ; but they are not fo durable, and are liable 
to be defaced by rubbing. Of thefe impreffions M. 
Lippart publiftied three different collections, each of 
them containing one thoufand articles ; and to the merit 
of having increafed tlie number of Mademoifelle Feloix 
and Clirirtiano Dehn’s colledtions, wliich are all inferted 
in his, he added that of employing two learned Germans 
to arrange and defcribe them. The firft thoufand were 
arranged and d’efcribed by the late profeffor Chrift at 
Leiplic, and the fecond and third thoufand by profeffor 
Heine at Goettingen. Nor did M. Lippart flop here: 
but to make the ftudy of antiquity. more eafy and ac¬ 
ceptable to artifts, he felcfted out of the whole coUec- 
tion of three thoufand, a fmaller one of two thoufand of 
the bell and moft inftruttive fubjecds, of w'hich he him¬ 
felf drew up and publiftied a defcription in Germany. 
But of all the ingenious men who have taken impref¬ 
fions of engraved gems in fulphur and in pafte, no one 
has carried that art to fuch perfection as Mr. James 
Taffie of Leicefter-fquare, London. His knowledge in 
various branches of the fine arts, particularly in tliat ot 
drawing, naturally led him to it. The elegant portraits 
which he models in wax, and afterwards mould.s and 
cafts in pafte, which entirely refemble cameos, are higlily 
efteemed by the public. Mr. Taffie, profiting ot all 
the former publications of this fort, and by expence, 
induftry, and accefs to many cabinets in England and 
other kingdoms to wliicli former artifts had not obtained 
admiffion, has now increafed his colleftion of impreffions 
of ancient and modern gems to the number of upwards 
of fixteen thoufand articles. It is the greateft colleTion 
of tills kind that ever exifted ; and ferves for all the pur- 
pofes of artifts, antiquaries, ftudents, men ot tafte, and 
even philofophers. The great demand for his paftes 
was perhaps at firft owing to the London jewellers, who 
introduced them into faihion by fetting them in rings, 
feals, bracelets, necklaces, and other trinkets. The 
reputation of this collection having reached the late 
emprels of Rullia, fiie was pleafed to order a complete 
fet; which being executed in the beft ftyle, were arranged 
in elegant cabinets, and placed in the noble apartments 
of the fuperb palace at Czarlko Zelo. 
Mr. Taflie, in executing this commiffion, availed him¬ 
felf of all the advantages which the improved ftate of 
chemiftry, the various ornamental arts, and the know¬ 
ledge of the age, feemed to afford. The impreffions 
were taken in a beautiful white enamel compofition, 
whicli is not fubjeCt to Ihrink or form air-bladders; 
wliich emits fire when itruck with fteel, and takes a fine 
polilli ; and wliich fhows every ftroke and touch of the 
artift in higher perfeCIion than any other fubftaiicc. 
When the colours, mixed colours, and nature of tiie re- 
fpeiJive originals, could be afcertained, they were imi¬ 
tated as completely as art can imitate them ; infomuch 
that many of the pafte intaglios and cameos in this coi- 
leCfion are fuch faithful imitations, that arti.fts tliem- 
felves have owned they could hardly be diltinguiftied 
from the originals. And when tlie colour andTiature 
of tlie gems could not be autlienticated, the paftes W'ere 
executed chiefly in tranfparent colours ; coiiftant atten¬ 
tion being beftowed to preferve the outlines, attributes, 
and infcriptions. And it is to this valuable collection 
of Mr. Taffie’s antique gems, that the editors of the 
Encyclopaedia Londinenfis are indebted for moft of the 
fcnrce and valuable ancient portraits given in this ela¬ 
borate work. 
In the liope of inviting into more general notice this 
interefting, but negle6i;ed, branch of the fine arts, we 
are furtlier induced to give fome engravings of curious 
antique and other Gems, feleCied and copied from the 
choicelf cafts in the valuable collettion of Mr. Taflie, 
above-mentioned. The fubjeits in Plate I. are as fol¬ 
low s 
