H E L 
HEM 
906 
lay their eggs with great care in the earth, 1 
and the young ones are hatched with shells 
completely formed. Cutting off a snail’s 
head, a little stone appears, which is sup- 
posed to be a great diuretic, and good in all 
nephritic disorders. Immediately under this 
stone the heart is seen beating; and the au- 
ricles are evidently distinguishable, and are 
membranous, and of a white colour; as are 
also tire vessels which proceed from them. 
Snails discharge their excrements at a hole 
in their neck; they also breathe by this hole, 
and their parts of generation are situated 
very near it. 
So small an animal as the snail is not free 
from the plague of supporting other smaller 
animals on its body ; and as in other animals 
we find these secondary ones either living 
on their surface, as lice, &c. or only in 
the intestines, as worms, it is very remark- 
able that the snail is infested in both these 
manners, lice being found sometimes on the 
surface of its body, and worms sometimes 
within its intestines. There is a part of the 
common garden snail, and of other of the 
like kinds, commonly called the collar. This 
surrounds the neck of the snail, and is con- 
siderably thick, and is the only part that is 
visible when the animal is retired quietly into 
Sts shell. In this state of the animal these 
insects which infest it are usually seen in 
considerable numbers marching about very 
nimbly on this part; besides, the snail, every 
time it has occasion to open its anus, gives 
them a place by which to enter into its in- 
testines, and they often seize the opportunity. 
Snails are great destroyers of fruit in our 
gardens, especially the better sorts ot wall- 
fruit. Lime and ashes sprinkled on the 
ground where they most resort will drive 
them away, and destroy the young brood of 
them. It is a common practice to pull off 
the fruit they have bitten; but this should 
never be done, for they will eat no other till 
they have wholly eaten up this if it is left for 
them. See Plate Nat. Ilist. fig. 223. 
Helix. See Anatomy. 
HELLEBORUS, hellebore, a genus of the 
polygynia order, in the polyandria class of 
plants, and in the natural method ranking un- 
der the 26th order, multisiliquce. There is 
no calyx; but five or more petals; the nec- 
taria are bilabiated and tubular; the cap- 
sules polvspermous, and a little erect. There 
are seven species, the most remarkable of 
which is the niger, commonly called Christ- 
mas-rose. It has roots composed of many 
thick fleshy spreading fibres, crowned by a 
large cluster of lobed leaves, consisting each 
©f seven or eight obtuse fleshy lobes, united 
to one foot-stalk; and between the leaves 
several thick fleshy flower-stalks, three or 
four inches high, surmounted by large beau- 
tiful white flowers, of five roundish petals, 
and numerous filaments, appearing in win- 
ter, about or soon after Christmas. 
This plant may be propagated either by 
seeds or parting the roots, it prospers in 
the open borders, or may be planted in pots 
to move when in bloom, in order to adorn 
any particular place ; but it always flowers 
fairest and most abundantly in the front of a 
warm sunny border. The plants may be re- 
removed, and the roots divided for propaga- 
tion, in September, October, or November; 
but the sooner in autumn it is done, the 
H E t 
stronger will the plants flower at their proper 
season. 
The root of this plant was antiently used 
as a cathartic. The taste of it is acrid and 
bitter. Its acrimony, as Dr. Grew observes, 
is first felt on the tip of the tongue, and then 
spreads itself immediately to the middle, 
without being much perceived in the inter- 
mediate part. On chewing the root for a few 
minutes, the tongue seems benumbed, and 
affected with a kind of paralytic stupor, as 
when burnt by eating any thing too hot. The 
fibres are more acrimonious than the head of 
the root whence they issue. Black hellebore 
root, taken from 15 to 30 grains, proves a 
strong cathartic, and as such lias been ce- 
lebrated for the cure of maniacal disorders, 
and such also as were attributed to what the 
antients called the atra bilis. In mania, how- 
ever, this root appears by no means to be 
possessed of any specific power. It does not 
indeed appear that our black hellebore acts 
with so much violence as that of the an- 
tients, whence many have supposed it to 
be a different plant ; and indeed the de- 
scriptions which the antients have left us of 
their hellebore, do not agree with those of 
any of the sorts usually taken notice of by 
modern botanists. Another species has been 
discovered in the eastern countries, which 
Tournefort distinguishes by the name of hel- 
lebores niger orientalis, amplissimo folio, 
caule praealto, flore purpurascente, and sup- 
poses to be the true antient hellebore, from 
its growing in plenty about Mount Olympus, 
and in the island of Anticyra, celebrated of 
old for the production of this antimaniacal 
drug: he relates, that a scruple of this sort 
given for a dose, occasioned convulsions. 
Our hellebore is looked upon principally as 
an alterative; and is sometimes employed in 
small doses for promoting the uterine and 
urinary discharges, &c. It proves a power- 
ful emmenagogue in plethoric habits, where 
steel is ineffectual or improper. In some 
parts of Germany a species of black hellebore 
has been made use of, which frequently pi-o- 
duced violent, and sometimes deleterious, 
effects. It appears to be the fetid kind of 
Linnseus, called in English settlewort, setter- 
wort, or bastard hellebore. The roots of this 
may be distinguished from those of the true 
kind, by their being less black. 
2. The hyemalis, with a beautiful yellow 
flower, which is the common harbinger of 
spring. 
HELM of a ship, is a piece of timber 
fastened into the rudder, which comes for- 
ward into the steerage, or place where the 
person at the helm steers the ship, by hold- 
ing the whipstaff in his hand, which is joined 
to the helm. They begin, however, to be 
left off, steering-wheels being used in their 
room. 
There are several terms in the sea language 
relating to the helm: as, bear up the helm; 
that is, let the ship go more large before the 
wind: helm a mid-ship or right the helm; 
tlrat is, keep it even with the middle of the 
ship : port the helm, put it over to the left side 
of the ship: starboard the helm, put it on the 
right side of the ship. See Ship-building. 
HELMET, an antient defensive armour 
worn by horsemen both in war and in ts or- 
naments. It covered both the head and face, 
only leaving an aperture in the front secured 
by bars, which was called the visor. 
It is still used in heraldry by way of crest 
over the shield or coat of arms, in order to 
express the different degrees of nobility by 
the different manner in which it is borne. 
Thus a helmet in profile is given to gentle- 
men and esquires: to a knight, the helmet 
standing forward and the beaver a little open ; 
the helmet in profile and open, with bars, 
belongs to all noblemen under the degree of 
a duke; and the helmet forward and open, 
with many bars, is assigned to kings, princes, 
and dukes. There is generally but one hel- 
met upon a shield ; but sometimes there are 
two, and even three : it there are two, they 
ought to face each other ; and if three, the 
middlemost should stand directly forward, 
and the other two on the sides facing towards 
it. 
HELMINTH OLITHUS, in natural his- 
tory, a name given by Linnaeus to petrified 
bodies resembling worms. Of these he reck- 
ons four genera. 1. Petrified lithophyta, 
found in the mountains of Sweden. 2. Pe- 
trified shells. 3. Petrified zoophytes. 4. Pe- 
trified reptiles. See Lithophyta, &c. 
HELONIAS, a genus of the trigynia or- 
der, in the bexandria class of plants, and in 
the natural method ranking under the I Oth 
order, coronariae. The corolla is hexapeta- 
lous ; there is' no calyx ; and the capsule is 
trilocular. There are two species, herbs of 
America. 
HELVETIA, a genus of the class and or- 
der cryptogamia fungi. There are two spe- 
cies, natives of this country. 
HELXINE. See Polygonum. 
HEMATOPUS, in ornithology, a genus 
of the grallae order. The generic character 
is: the bill compressed, the lip an equal 
wedge; nostrils linear ; tongue a third part 
as long as the bill ; feet formed for running, 
three-toed, cleft. 
The H. ostrolegus, or oyster-catcher, in- 
habits almost every sea-shore, is sixteen and 
a half inches long, feeds on marine worms 
and insects, but chiefly on oysters and lim- 
pets, which it extracts from the shell with 
great dexterity. Eggs, four to five; colour, 
olive-yellow, with irregular purplish spots. 
This is the only species. See Plate Nat, 
Hist. fig. 219. 
HEMEROBIUS, in zoology, a genus of 
insects of the neuroptera order, the charac- 
ters of which are these : the mouth is furnish- 
ed with two teeth ; the palpi are four ; the 
wings are deflected but not plaited ; and the 
aiitenn® are bristly and longer than the breast. 
There are 15 species, principally distinguish- 
ed by their colours. This insect takes the 
name of hemerobius from the shortness of its 
life, which, however, continues several days. 
In the state of larva it is a great devourerof 
plant-lice, for which it has had bestowed 
upon it the appellation of lion of the plant- 
lice. The hemerobii, even after their trans- 
formation, preserve their carnivorous inclina- 
tion. Not satisfied with making war upon 
the plant-lice, who tamely let themselves be 
devoured, they do not spare each other. Tire 
eggs of this insect are borne upon small pe- 
dicles, which are nothing but a gum spun 
out by the hemerobius by raising up the 
hinder part of its abdomen, and by that means 
the egg remains fastened to the upper part 
of the thread. Those eggs are deposited 
upon leaves, and set in the form of bunches. 
They have been taken for parasitic plants. 
11 
