GYP 
shock, and in which they were rendered 
motionless, and to all appearance dead by 
it. It appears that the electrical fish has 
no teeth, and the most minute examination 
of the fishes contained in their stomachs 
could discover no marks of laceration, even 
in the slightest degree. Gymnotes of three 
feet in length are incapable of swallowing 
any fish larger than three inches and a half. 
It appears that the strength of their pecu- 
liar talent is in proportion to their magni- 
tude, and it is stated that there are some in 
Surinam river, whose length is twenty feet, 
and whose shock is followed by immediate 
death to any human being, who is so unfortu- 
nate as to be exposed to it. It is observed, 
that even after the electrical fish is dead, it 
retains, for a considerable time, more or 
less of this singular property. It is a. fish 
greatly and justly dreaded by the inhabi- 
tants of those countries, the rivers of which 
it frequents ; it is however, notwithstanding 
this circumstance, used by them for food, 
and even by some, considered as a capital 
delicacy. For a representation of the 
gynmotus electricus, see Pisces, Plate IV. 
fig. 5. 
GYNANDRIA, in botany, the name of 
the twentieth class in the Liunasan system. 
It consists of plants with hermaphrodite 
flowers, in which the stamina are placed 
upon the style, or upon a pillar-shaped re- 
ceptacle resembling a style, which rises in 
the middle of the flower, and hears both 
the stamina and pointal. There are seven 
orders in this class, each of which is founded 
on the number of the stamina in the plants 
which compose it. See Botany. 
GYNOPOGON, in botany, a genus of 
the Pentandria Monogynia class and order. 
Natural order of Apocinete, Jussieu. Es- 
sential character : calyx half five-cleft-, in- 
ferior, permanent ; corolla five-parted, tube 
ventricose below the tip, throat contract- 
ed ; stigma globular, two-lobed ; berry pe- 
dicelled, sub-globular ; seed cartilaginous, 
sub-bilocnlar. There are three species, na- 
tives of the islands in the South Seas. 
GYPSIES. There are several statutes 
against them, by which they are treated as 
rogues and vagabonds. 
GYPSOPHILA, in botany, a genus of 
the Decandria Digynia class and order. Na- 
tural order of Caryophyllei. Essential cha- 
racter : calyx one-leafed, bell-shaped, an- 
gular ; petals five, ovate, sessile ; capsule 
globular, one-celled. There are twelve 
species. 
GYR 
GYPSUM, a substance well known to 
the ancients, and one that is very abundant 
in nature, and is now denominated, accord- 
ing to the new chemical arrangement, the 
sulphate of lime. It forms immense strata, 
composing entire mountains ; it is found in 
almost every soil, either in greater or less 
quantities ; it is contained in the waters of 
the ocean, and in almost all river and 
spring water. In these its presence is the 
cause of the quality termed hardness, which 
may be known by the water being incapa- 
ble of forming a solution of soap, the sul- 
phuric acid seizing on the alkali of the soap, 
and the oil forming a compound with the 
lime. Sulphate of lime is insipid, white, 
and soft to the touch. Water will not 
hold a 500th part of it in solution. Ex- 
posed to heat it appears to effervesce, which 
phenomenon is caused by the expulsion of 
water. It becomes opaque, and falls into 
powder. This powder, when its water has 
been driven off" by the application of a red 
heat, absorbs water rapidly, so that if it be 
formed into a paste with water, it dries in a 
few minutes. In this state it is called 
plaster of Paris, and is employed for form- 
ing casts, and for a variety of purposes in 
the art of statuary. 
GYRINUS,in natural history, water-flea, 
a genus of insects of the order Coleoptera. 
Antennas cylindrical ; jaws horney, one- 
toothed, sharp-pointed ; eyes four, two 
above and two beneath ; thorax and shells 
margined, the latter shorter than the body ; 
legs formed for swimming. The insects of 
this genus are to be found on the surface of 
waters, on which they run, and describe 
circles with a great degree of swiftness ; 
when attempted to be taken, they plunge to 
the bottom, drawing after them a bubble 
very similar to a globule of quicksilver. 
Eleven species of the gyrinus have been 
described, of which one only is found in 
Europe, viz. G. natator, a small insect, hot 
more than a quarter of an inch long, of a 
blackish colour, but with so bright a surface 
as to shine like a mirror in the sun. The 
larva is of a very singular aspect, having a 
lengthened body, furnished with many late- 
ral appendages down the body, exclusively 
of six legs. Dr. Shaw says, its motions are 
extremely agile, swimming in a kind of ser- 
pentine manner, and -preying on the smaller 
and weaker water-insects, minute worms, 
&c. It is a highly curious object for the 
microscope. When its change arrives, it 
farms for itself a small oval cell or case on a 
