HER 
well luted ; or by covering the vessel with 
another ovum philosophical)!. 
HERNANDIA, juck-in-a-box-tree, a ge- 
nus of the triandria order, belonging to the 
monoecia class of plants, and in the natuial 
method ranking under the 38th order, tri- 
cocca 2 . The male calyx is tripartite ; the co- 
rolla tripetalous ; the female calyx is trun- 
cated, quite entire; the corolla hexapeta- 
lous ; the plum hollow, and open at the 
mouth or upper part, with a loose kernel. 
The species are, 
] . The sonora, or common jack-in-a-box, a 
native of both the Indies. It grows 20 or 30 
feet high, with broad peltated leaves, and 
monoecious flowers, succeeded by a large 
swollen hollow fruit formed of the caiy x ; hav- 
ing a hole or opening at the end, and a hard 
-nut within. I he wind blowing into the ca- 
vity of this fruit makes a very whistling and 
rattling noise, whence comes the name. 
2. 't he ovigera grows many feet high, with 
large oval leaves not peltated ; and monoe- 
cious flowers, succeeded by a swollen fruit 
open at the end, and a nut within. It is 
said the sonora in Java affords a sure antidote 
against poison, if you either put its small 
roots on the wounds, or eat them ; as was 
discovered to Rumphius by a captive woman 
in the war between the people of Macassar 
and the Dutch, in the year 1667. The sol- 
diers of the former always carry this root 
about them, as a remedy against wounds with 
poisoned arrows. Both these plants being 
tender exotics, must be planted in pots of 
rich earth, and always kept in a hot-house ; 
in which, notwithstanding all the care that 
can be taken, they seldom flower, and never 
grow beyond the height of common shrubs, 
though in the places where they are natives 
they arrive at the height of trees. They are 
propagated by seeds procured from the W est 
Indies. 
HERNIA. See Medicine and Sur- 
gery. , 
HERNIARIA, rupture-wort, a genus of 
the digynia order, in the pentandria class of 
plants, and in the natural method ranking 
under the eleventh order, holoraceae. The 
calyx is quinquepartite there is no corolla ; 
there are flve barren stamina, and a monos- 
permous capsule. There are four species, of 
which the only remarkable one is the glabra, 
■ or smooth rupture-wort, a native of many 
parts of England. It is a low trailing plant, 
with leaves like the smaller duckweed ; the 
flowers come out in clusters from the side of 
the stalks at the joints, and are of a yellowish 
green colour. I his plant is a little saltish 
and astringent. The juice is useful to take 
away specks in the eye. Cows, sheep, and 
horses, eat the plant ; goats and swine refuse 
it. „ . 
HERON, in ornithology. See Ardea. 
HERRING, in ichthyology. See Clu- 
pea and Fishery. 
HERRINGS, it is unlawful to buy or sell 
herrings at sea before the fishermen come into 
the haven, and the cable of the ship be drawn 
to the land. 31 Ed. III. c. 2. 
No herrings shall be sold in any vessel but 
where the barrel contains 32 gallons, and 
half barrel and firkin accordingly ; and they 
must be well packed, of one time’s packing 
and salting, and be as good in the middle as 
at the ends; on pain of forfeiting 3s. 4d. a 
barrel. 
Vol. I. 
II E T 
Vessels with herrings are to be marked 
with the quantity and place where packed ; 
and packers are ’to be appointed and sworn 
in all fishing ports, and under the penalty of 
100/. 
IiERSE, in fortification, is a lattice or 
portcullice, made in the form of a harrow, and 
stuck full of iron spikes. See Fortifica- 
tion. 
HESPERIS, dame's violet, or queen's gil- 
lifiotver, a genus of the siliquosa order, in the 
tetradvnamia class of plants, and in the na- 
tural method ranking under the 39th order, 
siliquosa’. The petals are turned obliquely ; 
there is a glandule within the shorter stami- 
na; the siliqua almost upright; the stigma 
forked at the base, connivent, or closing at 
the top. There are seven species, the most 
remarkable are, 
1. The matronalis, or common sweet-scent- 
j ed garden rocket, having fibrous roots, 
crowned with a tuft of long, spear-shaped, 
rough, leaves ; upright, single, hairy stalks, 
two feet high, terminated by large and long 
spikes of sweet-scented flowers of different 
colours and properties in the varieties, of 
which there is a great number. All the va- 
rieties of this species are so remarkable for 
imparting a fragrant odour, that the ladies 
were fond of having them in their apart- 
ments. Hence they derived the name of 
dame’s violet ; and bearing some resemblance 
to a stock-gilliflower were sometimes called 
queen’s gilliflower, but are now most com- 
monly called rocket. 
2. The inodora, or scentless rocket, has 
upright stalks two feet high, all the branches 
terminated by large spikes of scentless flow-- 
ers, with obtuse petals, of different colours 
and properties in the varieties. v 
3. Thetristis, or duli-flowered night-smell- 
ing rocket, has upright, bristly stalks, two 
feet high, spear-shaped pointed leaves, and 
spikes of pale purple flowers, of great fra- 
grance in the evening. 
w All the species are hardy, especially the 
first and second, which prosper in any of the 
open borders, and any common garden soil ; 
but the third, being rather impatient of a se- 
vere frost, and of much moisture in winter, 
should have a dry warm situation, and a few 
may be placed in*pots, to be sheltered in case 
of inclement weather. They may be propa- 
gated either by seeds, by offsets, or by cut- 
tings off the stalks. 
HESSIAN Ely. See Tenti-iredo. 
HETEROGENEOUS Numbers, mix- 
ed numbers, consisting of integers and frac- 
tions. 
Heterogeneous Quantities, are 
those which are of such different kinds, as 
that one of them taken any number of times, 
never equals or exceeds the other. 
Heterogeneous Surds, are such as have 
different radical signs, as ^ aa, \/bb,^J 9, ^/18, 
&c. See Surd. 
If the indices of the powers of the heteroge- 
neous surds be divided by their greatest com- 
mon divisor, and the quotients be set under the 
dividends; and those indices be multiplied cross- 
wise by each others quotients ; and before the 
products be set the common radical sign ^ , 
with its proper index ; and if the powers of the 
given roots be involved alternately, according 
to the index of each others quotient, and the 
common radical sign be prefixed before those 
products, then will those two surds be reduced 
5 
H I B 913 
to others, having but one common radiealsign. 
As to reduce 
aa and bb 
2 V "< 2 v'" 'pd V .. M 
HETEROSCII. See Geography. 
FIETEROUSIANS, a sect of Arlans, who 
did not believe that the Son of God was of a 
substance like to that of die Father. 
HEUCHERA, in botany, a genus of the 
pentandria digynia class of plants, the corolla 
whereof consists of live petals ; the fruit is 
an ovato-accuminated capsule ; semibifid, 
terminating in two reflex po.nts, and contain- 
ing two ceils. There are two species. 
HEXACHORD, in antient music, a con- 
cord t ailed by the moderns a sixth. 
HEXAEDRON, or Hexahedron, one of the 
five regular or Platonic bodies ; befog indeed 
the game as the cube ; and is so called from it* 
having 6 faces. — The square of the side or edge 
of a hexahedron, is one-third of the square of 
the diameter of the circumscribing sphere ; and 
hence the diameter of a sphere is to the side of 
its inscribed hexahedron, as ^/3 to 1. 
In general, if A, B, and C, be put to denote 
respectively’ the linear side, the surface, and the 
solidity of a Hexahedron, or cube, also r the ra- 
dius of the inscribed sphere, and R the radius 
of the circumscribed One ; then we have these 
general equations or relations : 
1. A = 2 /■ = f R^/3 = a/| b 
= ^0. 
2. B = 24 r 2 — 8R 2 = BA 1 
= 6l/C\ 
3. C = 8r 3 = |RV 3 = A* 
= |V| B - 
4. R = V 3 = iA^/3 = Wi B 
= w 3 X^C. 
5. r = = rA — 
= W c - 
HEXAGON, in geometry, a figure of six 
sides and angles ; and if these sides and angle* 
be equal, it is called a regular hexagon. 
The side of every regular hexagon, inscribed 
in a circle, is equal in length to the radius of 
that circle. Hence, it is easy, by laying off the 
radius six times upon the circumference, to in- 
scribe an hexagon fox a circle. 
To describe a regular hexagon on a given 
right line AB (plate Miscel. fig. 123,) draw an 
equilateral triangle ACB, and the vertex C will 
be the centre of a circle which rviU circumscribe 
the hexagon required ABDEFG. 
As 1 is to 1 .672, so is the square of the side of 
any regular hexagon to the area thereof, nearly. 
Or the side of a hexagon being s, its area will 
be = 2.5980762 j 2 == IT X tang. 60° = -f^/ 3 - 
Hexagon, in fortification, is a place defended 
by six bastions. 
HEXAMETER, in antient poetry, a kind of 
verse consisting of six feet ; the first four of 
which may be indifferently, either spondees or 
dactyls; the fifth is generally a dactyl, and the 
sixth always a spondee. Such is the following 
verse of Horace : 
1 2 3 4 5 6 
Aut pro | desse vo | lunt, aut | delec | tare po j eta, 
HEXANDRIA, in botany, a class of 
plants, the sixth in order, comprehending all 
those plants which have hermaphrodite flow- 
ers, and six stamina in each. 
HIBISCUS, St/rian mallow, a genus of 
the pol yandria order, in the monadelphia 
class of* plants, and in the natural method 
ranking under the 37th order, columniferx. 
