Earths. MIN E R 
bluifti, exhibiting gold when fufed with lead. Found in 
the mines of Tranlyl vania, near Herczigan and Facebai. 
31. Argilla kollyrites, or kollyrite. Under this name 
an argillaceous fofiil is mentioned in Karlten’s Mineralo- 
gical Tables, which is found at Stephani-Schacht, near 
Schemnitz. Dr. Townfon, we luppofe, is one of the firft 
naturalifts who obferved it there. This fubftance, which 
was firft confidered as pure alumine, is light, very friable, 
and fnow-white ; it foils the fingers, and adheres ftrongly 
to the tongue, which laft property has procured it the 
name of kollyrite. According to Klaproth’s analyfis of 
the Hungarian kollyrite, it confifts of alumine 45, filex 14, 
water 41. 
This fubftance, which may be confidered as a purer 
variety of clay, has alfo been found, by Frieileben, at 
Weiffenfels, in Thuringia, in a ftratum of fand-ftone. 
According to Srongniart, it has a tolerable degree of te¬ 
nacity, and the water it abforbed is l'een to ooze out on 
the application of preffure ; but it retains the liquid with 
fuch force, that more than a month is required to dry 
qven a finall quantity of it. By deficcation, it feparates 
into bafaltic pril'ms, like ftarch, loles half of its weight, 
and becomes very light. 
C-ffiMENTUM. —Confifting of iron, alumine, a larger 
quantity of filex, and generally a finall proportion of 
carbonat of lime : hardifh, lighfcilh, porous, of an earthy 
texture, imbibing the water in which it is immerfed with 
a hilling noife, crackling when dried and prefled with the 
thumb; rough, without lultre: when powdered and beat 
up with water and quicklime, becoming fo hard as not 
to be penetrated by water; ealily melting in the fire into 
a black ficoria. There are two fpecies. 
1. Caementum tufa, or volcanic ftone : collected into 
entire cliffs and vaft ftrata about the volcanic mountains ; 
of a common form. Found in the neighbourhood of vol¬ 
canos, particularly in Italy, about Naples and Rome ; and 
confifts of compadl mafl'es of pozzolano, land, flag, pumice, 
and other ftones of volcanic origin : moftly fmoke-colour, 
cinereous, blackilh, brown, ochraceous, yeilowifli-grey, 
or brownilh-yellow, rarely reddilh, greenilh, or varie¬ 
gated : it is commonly magnetic, of an earthy fradlure, 
and not eafily decompofed by the adlion of the air: l'ome- 
times it has a finall mixture of bones, /hells, and other 
calcareous fubftances, and then effervefces a little with 
acids. 
2. Caementum trafs, or terras : forming large ftrata 
under the furface of the common foil; of a common form. 
This fubftance is met with in-the vicinity of the Rhine, 
near Frankfort and Cologne, &c. and is there called tuff- 
Jiein, which may be rendered tufa, or volcanic Jtone. It 
does not however appear to be a volcanic production, 
but derived from bafaltic rocks. From that part of the 
Rhine it is commonly imported into Holland, and from 
thence diltributed over Europe. It is much ul'ed as a 
l'ubftitute for pozzolana. 
“ The real Dutch terras (fays Mr. Phillips) is the king 
of all cements hitherto found out for ul'e under water. 
Its properties are fuch, that, a fhort time after two ftones, 
or the hardeft of bricks, are joined together by rubbing 
them clofe, like glue, between two joints of boards, and 
put into water, whether fea or frelh, you will find the 
brick, or ftone, fooner break than the cement. 
“ Neceflity, dire neceflity only, which is the mother of 
all inventions, was the original caule of the Dutch find¬ 
ing it neceffary, and firft uling of terras. Their inunenfe 
mounds and (luices to oppole the encroachments of the 
fea, they found, by experience, mull be built with fome- 
thing more durable than any cement or mortal - made with 
chalk or (hells; and, having no ftone in the country, they 
brought fome from a mountain, which, to all appearance, 
had been fome ages ago a volcano, the ftone of which was 
already partly pulverized, and which lay at a place called 
Audenach, in the country of Heffe, and bordering on 
the river Rhine, which runs partly through their coun- 
A L O G Y. Earths. 455 
try; and, being all brought by water-carriage, came very 
cheap. 
“ It is to be prefumed the Dutch had viiited Italy, and 
that fome of their builders or architects had been there, 
and noticed the works of the ancients at Venice, Naples, 
Rome, &c. and had obferved, that they had made ufe of, 
as a cement, the pozzolana-ftone, from the burning moun¬ 
tains of Vefuvius and Etna. This, I fuppole, induced 
them to fearch for, and bring their ftone from, the worn- 
out volcano before-mentioned in Heffe, to make their ce¬ 
ment or terras, for their water-works and foundations, 
which are chiefly under water. In time, the owner of 
the mountain, rinding the great demand of this ftone, 
railed the price. 
“ About the year 1750, an ingenious mechanic at Dort, 
a great part of which province was drowned by an inun¬ 
dation of the fea in the year 1446, and about 100,000 per- 
l'ons drowned ; (which country lies more expofed than 
any other of the.Seven Provinces, whofeimmenfe mounds 
and fluices confume vaft quantities of this cement called 
terras.) This ingenious mechanic tried an experiment of 
a l'ubftitute for this Heflian ftone, which he found to an- 
fwer to admiration. He then went to the owner of the 
Heflian Mountain, and told him he could make as good 
terras without his ftone, but offered to take all his ftone 
at about the then prefent price. The ftone-merchant, 
well knowing there was no ftone in Holland or any of the 
Seven Provinces, refilled his offer, and even made another 
advance on his ftone. The mechanic returned to Dort,. 
made terras of the l'ubftitute which he found at home, 
and obtained a patent of the Hates for fifteen years for no 
other terras to be ufed in any of the Dutch provinces ; he 
fold it cheaper, it was proved to be better, and the me¬ 
chanic made an immenle fortune. This l'ubftitute is to 
be found in every maritime country ; and the author of 
this work is able to point out the whole procefs of mak¬ 
ing it equal to the Dutch. To make terras properly for 
ufe, as a water-cement, mix frelh-burnt lime, not flacked 
too much (and if llone-lime the better), and to every 
bulhel of real Dutch terras add two of lime, as little water 
as pofiible, and well beat it with beaters, on a wood or 
ftone floor.” Crolby’s Builders’ Price-book, aoth edit. 
Cariosus. —Confifting of alumine, filex, and carbonat 
of lime, with a finall portion of iron ; light, loft, porous, 
falling to powder in water; effervefcing with nitric acid, 
hardening and growing a little red in the fire. 
Cariofus Anglicus, or Englilh rotten-llone, the only 
fpecies, is found in Derbylhire, Glamorganihire, and 
other coal-countries. It is evidently produced by the 
difintegration of our black limeftone, or marble, above 
which it is depolited, and not over coal, as Gmelin, we 
know not from what authority, has afferted. (Martin’s 
Outlines, p. 140.) Colour ifabella-yellow, dull-grey, or 
brown ; it eafily moulders, in the open air, and loon falls 
to powder in water, for which reafon it has been denomi¬ 
nated rotten-Jlone. It is principally ufed for polifliing 
metals and other fubftances. 
Ardesia. —Confifting of alumine and filex, with gene¬ 
rally a little oxyd of iron and carbonat of lime, and lome- 
times fome magnefia and petroleum ; loft, of a flaty tex¬ 
ture, generally breaking into difeoid fragments, opake, of 
a cqwunon form, imbibing water, but fo (lowly as not to 
be loftened ; and when moiftened exhaling an argillaceous " 
odour. Not effervefcing with nitric acid, melting into a 
turbid fcoria by a confiderable degree of heat; found in 
primitive as well as ftratified mountains, and when in the 
former of a grealy lullre; forming entire mountains, or 
their principal part. There are eleven fpecies. 
1. Ardefia novacula, or whetftone : a little polilhed, 
lliining within, lubopake, hardilh, greenilh-grey, makin<’ 
a whitilh mark. It is found in Ihiltofe mountains, form¬ 
ing confiderable layers, chiefly in the Levant, near Laue- 
ftein in Bareith, Siberia, and near Freyburg in Saxony. 
Fradture flaty, approaching to Ihiveryj does not adhere 
