G 21 O 
GRO 
G R Y 
m 
sufficiently high. Tlie cattle that feed m the 
pastures through which this river runs have 
been known to die suddenly sometimes after a 
flood ; this is probably owing to the waters 
having been impregnated, either naturally or 
accidentally, with lead ore. 
Elden-hole is a huge profound perpendicu- 
lar chasm, three miles from Buxton, ranked 
among the natural wonders of the Peak. Its 
depth is unknown, and is pretended to be un- 
fathomable. Cotton tells us he sounded 884 
yards, yet the plummet still drew. But he 
might easily be deceived, unless his plummet 
was very heavy ; the weight of a rope of that, 
length might well make the landing of the 
plummet scarcely perceivable. 
Peak’s-hole, and PoolVhole, are two re- 
markable horizontal cavities under moun- 
tains ; the one near Castleton, the other 
just by Buxton. They seem to have owed 
their origin to the springs which have their 
current through them ; when the water had 
forced its way through the horizontal fis- 
sures of the strata, and had carried the 
loose earth away with it, the loose stones 
must fall down of course: and where the 
strata had lew or no fissures, they re- 
mained entire; and so formed these very ir- 
regular arches, which are now so much won- 
dered at. The water which passes through 
Pool’shole is impregnated with particles of 
limestone, and has incru.ted the whole ca- 
vern in such a manner that it appears as one 
solid rock. 
In grottos are frequently found crystals of 
the rock, stalactites, and other natural con- 
glaciations, and those often of an amazing 
beauty. M. Homberg conjectures, from se- 
veral circumstances, that the m rble pillars in 
the grotto of Antiparos vegetate or grow. 
That author looks on this grotto as a garden, 
in which the pieces of marble are the plants; 
and endeavours to show, that they could only 
be produced by some veg tative principle. 
At Koligno in Italy is another grotto, con- 
sisting of pillars and orders of architecture of 
marble, with their ornaments, &c. scarcely 
inferior to those of art ; but they all grow 
downwards: so that if this too is a garden, 
the plants are turned upside down. 
Grotto del Coni, is a little cavern near 
Pozzuoli, four leagues from Naples, the steams 
whereof are of a mephitical or noxious qua- 
lity ; whence also it is called boeca venenosa, 
the poisonous mouth. “ Two miles from Na • 
pies (says Dr. Mead), just by the Lago de 
Agnano, is a celebr .ted motet a commonly 
called La Grotta del Cani, and equally destruc- 
tive to all within the reach of its vapours. It 
is-a small grotto about eight feet high, twelve 
long, and fix broad ; from the ground arises a 
thin,, subtile, warm fume, visible enough to a 
discerning eye, which does not spring up- in 
little parcels here and there, but in one con- 
tinued stream, covering the whole 'surface of 
the bottom of the cave; having this remark- 
able difference from common vapours, that it 
does not, like smoke, disperse itself into the 
air, but quickly after its rise falls back again, 
and returns to the earth; the colour of tire 
sides of the grotto being the measure of its 
ascent: for so far it is of a darkish green, but 
higher only common earth. And as I mvself 
found- no inconvenience by standing in it, so 
no animal, if its head is above this mark, is 
the least injured. But when, as the manner 
is,, a dog, or any other creature, is forcibly 
kept below it; or, by reason of its Smallness, 
cannot hold its head above it, it presently 
loses all motion, falls down as dead, or in a 
a swoon ; the limbs convulsed and trembling, 
till at last no more signs of life appear than a 
very weak and almost insensible beating of 
the heart and arteries; which, if the animal 
is left a little longer, quickly ceases too, and 
then the case is irrevocable; but if it is 
snatched out and laid in the open air, it soon 
comes to life again, and sooner if thrown 
into the adjacent lake.” The steam or moe- 
fite of the grotto del cani is now well known 
to be carbonic acid gas. See Chemistry. 
Grotta del Serpi, is a subterraneous ca- 
vern near the village of Sassa, eight miles 
from the city of Braccano in Italy, described 
by Kircher thus: “The grotta del serpi is 
big enough to hold two persons. It is per- 
forated with several fistular apertures, some- 
what in the manner of a sieve ; out ol which, 
at the beginning of the spring season, issues 
a numerous brood of young snakes of divers 
colours, but all free from any particular 
poisonous quality. In this cave they expose 
their lepers, paralytics, arthritics, and ele- 
phantine patients, quite naked; where, the 
warmth of the subterraneous steams resolv- 
ing them into a sweat, and the serpents 
clinging variously all around, licking and 
sucking them, they become so thoroughly 
freed of all their vicious humours, that upon 
repeating the operation for some time, they 
become perfectly restored.” T his cave Kir- 
cher visited himself ; and found it warm, and 
every way agreeable to the description given 
of it. lie saw the holes, and heard a mur- 
muring hissing noise in them. Though he 
missed seeing the serpents, it not being the 
season of their creeping out, yet he saw a 
great number of their exuviae or sloughs, and 
an elm growing hard by laden with them- 
The discovery of the virtues of this cave was 
by the cure of a leper going from Rome to 
some baths near this place. Losing his way, 
and being benighted, he happened upon this 
cave. Finding it very warm, he pulled off 
liis clothes ; and being weary and sleepy, had 
the good fortune not to feel the serpents 
about him till they had wrought his cure 
G rotto. Milk v, Crypta Lactea, a mile 
distant from the antient village of Bethlehem, 
is said to have been, thus denominated on 
occasion of the Blessed Virgin, who let fall 
some drops of milk in giving suck to Jesus in 
this grotto- And hence it has been com- 
monly supposed, that the earth of this cavern 
has tne virtue of restoring milk to women 
that are gro.vn dry, and even of curing fe- 
vers- Accordingly, they are always digging 
in it, and the earth is sold at a good rate to 
such as have folly enough to give credit to 
the fable. An altar has been built on the 
place, and a church just by it. 
• Grotto is also used for a little artificial 
edifice Tirade in a garden, in imitation of a 
natural grotto. The outsides of these grottos 
are usually adorned with rustic architecture, 
and their inside with shell-work, fossils, &c. 
finished likewise with jets-d’eau or fountains, 
&c. A cement for artificial grottos may be 
made thus : Take 2 parts of white rosin, melt 
it clear, and add to it 4 parts of bees’ -wax ; 
when melted together, add 2 or 3 parts of 
the powder of the stone you design to ce- 
ment, or so much as will give the cement 
(lit; colour of the stone. With this cement, 
the stones, shells, &c. after being well dried 
before the fire, may be cemented. Artificial 
red coral branches, for the embellishment 
of grottos, may be made in the following, 
manner: Take clear rosin, dissolve it in a 
brass-pan, to every ounce of which add two 
drams of the finest vermilion; when you 
have stirred them well together, and have 
chosen your twigs and branches, peeled and 
dried, take a pencil and paint the branches 
all over whilst the composition is warm ; 
afterwards shape them in imitation of natural 
coral. This done, hold the branches over a. 
gentle coal-fire, till all is smooth arrd even 
as if polished. In the same manner white 
coral may be prepared with white lead, and 
black coral with lamp-black. A grotto may- 
be built with little expence, of glass, cinders,, 
pebbles, pieces of large hint, shells, moss, 
stones, counterfeit coral, pieces of chalk, &c. 
all bound or cemented together with the 
above-described cement. 
GROUND, in painting, the surface upon 
winch the figures and other objects arc repre- 
sented. See Painting-. 
Ground-tackle, a ship’s anchors, cables, 
and in general whatever is found necessary to 
make her ride safe at anchor. 
Ground-tv y, in botany. See Glechovia.. 
GROUND-P/'ne. See Teucrium. 
GROUNDAGE, a custom or tribute paid, 
for the ground on which a ship stands in 
port. 
GROUNDSEL, in botany, &c. See 
Senecio. 
GROUP, in painting and sculpture, is an 
assemblage of two or more figur.es of men, 
beasts, fruits, & c. which have some apparent 
relation to each other. See Painting. 
G ROUSE, or Growse. See Tetrao. 
GROWAN, among the miners of Corn- 
wall, a coarse gritty stone, of a greyish co- 
lour, which they are often obliged to dig 
through before they can reach the ore. 
GRUNSTEIN, primitive, is a mixture of 
hornblende and felspar ; and is divided into 
different varieties, according as its texture is 
granular or compact. See Rocks primi- 
tive. 
GRY, a measure containing one-tenth of 
a line. A line is one-tenth of a digit, and a 
digit one-tenth of a foot, and a philosophical 
foot one-third of a pendulum whose dia— 
dromes, or vibrations, in the latitude of 45 
degrees, are each equal to one second of 
time, or one-sixleenth of a minute. 
GRYGALLUS, in ornithology, a name 
given to the urogallus, or tetrao. See 
Tetrao. 
GRV LLUS, the locust, grasshopper, anri~ 
cricket, in entomology, a genus of bisects 
belonging to the order hemiptera. The 
generic character is, head inflected, armed 
with jaws, and furnished with feelers,. An- 
tenna-, in most species,. either, filiform or se- 
taceous. Wings four, deflex, convoluted : 
lower wings pleated. Ilind legs formed for 
leaping : claws double on all the feet. There 
are 61 species, of which the following are 
most worthy of notice : 
1. Among the most numerous species is 
the grylius migratorius of Linnaeus, or com- 
mon migratory, locust, which of ail the in- 
sects ca|>able of injuring mankind seems to 
possess the most dreadful powers of destruc- 
tion. Legions of these animals are from 
time to time observed in various parts of the 
