THR 
CottHS 
Echineis 
Gasterostens 
Gobius 
Labrns 
Lonchiiirus 
Mulbis 
Perea 
Plenronecte* 
Scams 
Sciaana 
Scomber 
Scorpoena 
Spams 
Trachychtbys 
Trigla. 
THRASHING, or Threshing, in agri- 
e\i]tiire, the art of beating the corn out of 
the ears. There are several ways of separat- 
ing corn from the ear; the first by beating it 
with a flail, which is properly what is called 
thrashing. The other method, still prac- 
tised in several countries, is to make mules, 
or horses, trample on it, backwards and for- 
wards ; this is properly what the ancients 
called tritura and trituratio. The Hebrews 
used oxen therein, and sometimes yoked four 
together for this purpose. Another way 
among the ancients was with a kind of 
sledge, made of boards joined together, and 
loaden with stones or iron, upon which a 
man was mounted, and the whole drawn 
over the corn by horses : this instrument 
was called traha or tribula. It is a rule 
among husbandmen, that the season for 
thrashing is as soon as tlie corn has sweated 
in the heap or mow. Thrashing machines 
are now much in use with the farmers on a 
large scale. 
THREAD, a small line, made np of a 
number of fine fibres of any vegetable or 
animal substance, such as flax, cotton, or 
silk thread. 
THREATENING letter. If any per- 
son shall send any letter threatening to ac- 
cuse any other person of a crime punishable 
with death, transportation, pillory, or otlier 
infamous punishment, with a view to extort 
money from him, he shall be punished at 
the discretion of the court, with fine, im- 
prisonment, pillory, whipping, or trans- 
portation : SO. G. II. c. 24 . And if the 
writer of a threatening letter deliver it him- 
self, and do not send it, he is guilty of fe- 
lony under this act. 
THRINAX, in botany, a genus of the 
Appendix Palm® class and order. Natural 
order of Palms. Essential character : calyx 
six-toothed; corolla none; stigma fuimel- 
forin, oblique ; berry one-seeded. There is 
only one species, ciz. T. parviflora, palmeto 
royal, or palmeto-tliatch, a native of Ja- 
maica and Hispaniola. 
THRUSH. See Tordhs. 
THU 
THRYALLIS, in botany, a genus of the 
Decandria Menogynia class and order. Na- 
tural order of Tricocc®. Acera, Jussieu. 
Essential character : calyx five-parted ; pe- 
tals five ; capsule tricoccous. '1 here is but 
one species, viz. T. brasiliensis, a little 
shrab, with round jointed branches ; small 
yellow flowers ; fruits tricoccous, or three- 
grained ; it is a native of Brasil. 
THUJA, in botany, arbor vita, a genus 
of the Monoecia Monadelphia class and or- 
der. Natural order of Conifer®. Essential 
character : male, calyx scale of an ament ; 
corolla none ; stamina four ; female, calyx 
of a strobile, with a two-flowered scale; 
corolla none ; pistil one ; nut one, girt with 
a membranaceous wing. There are four 
species. We shall notice the T. occidentalis, 
American, or common, arbor vit® ; this tree 
I'.as a strong woody trunk, rising to the height 
of forty feet ; the bark, while young, is 
smooth, and of a dark brown colour, but as 
the trees advance, the bark becomes cracked, 
and !e.ss smooth, the branches are produced 
irregularly on every side, standing almost 
horizontal, the young slender shoots fre- 
quently hang dbwn; the young branches 
are flat, and the small leaves are placed 
over each other like the scales of fish; the 
flowers are produced from the side of the 
young branches, very near to the foot stalk; 
the males grow in oblong catkins, betw'een 
these the females are collected in form of 
cones ; w'hen the former have shed their 
farina, they soon drop otT, the latter are suc- 
ceeded by oblong cones, or strobiles, hay- 
ing obtuse smooth scales, containing one or 
tw'o oblong .seeds. 
THUMERSTONE, in mineralogy, a spe- 
cies of the flint genus: common colour is 
brown of various degrees of intensity ; it is 
seldom found massive, often disseminated, 
but most frequently crystallized. Specific 
gravity about 3 . 3 , It melts easily before 
the blow pipe, without addition, into a 
greenish, white, semi-transparent glass. The 
constituent parts are. 
®''‘ca 52 7^0 
Alumina S5.79 
J-'rae ■ 
Oxide of iron g gg 
ofmangancse i.oo 
Loss 2.49 
100.00 
It appears to be peculiar to the primi- 
tive mountainis, is found in many parts of 
