THA 
is God, because he is uncreated ; that no- 
thing is more beautiful than the world, be- 
cause it is the work of God ; nothing more 
extensive than space, quicker than spirit, 
stronger than necessity, wiser than time. 
He used to observe, that we ought never to 
say that to any one which may be turned to 
our prejudice : and that we should live with 
our friends as with persons that may be- 
come our enemies. In geometry he was a 
considerable inventor, as well as an im- 
prover, particularly in triangles ; and all 
the writers agree, that he was the first, even 
™ Egypt, who took the height of the pyra- 
mids by the shadoWi His knowledge and 
improvements in astronomy were very con- 
siderable. He divided the celestial sphere 
into five circles or zones ; the arctic and 
antarctic circles, the two tropical circles, 
and the equator. He observed the appa- 
rent diameter of the sun, which he made 
equal to Italf a degree ; and formed^ thq 
constellation of the Little Bear. He ob- 
served the nature and course of eclipses, 
and calculated them exactly ; one in parti- 
cular, memorably recorded by Herodotus, 
as it happened on a day of battle between 
the Medes and Lydians, which Thales had 
foretold ; and he divided the year into 365 
days. He died at the age of ninety years, 
leaving behind him an excellent character, 
as a mathematician, a philosopher, and mo - 
ralist. 
THALIA, in botany, so named in me- 
mory of John Thalius, a physician at Nord- 
huys, a genus of the Monandria Monogynia 
class and order. Natural order of Scita- 
mine®. Cann®, Jussieu. Essential cha- 
racter : calyx three leaved ; corolla five- 
petalled, two inner petals lessj nectary lan- 
ceolate, concave ; drupe with a one-celled 
hut. There are two species, viz. T. geni- 
culata, and T. cannmformis ; the former is 
a native of South America, the latter of 
Mallicollo, one of the New Hebrides, in 
Australasia ; it was also found in the Anda- 
man Isles, and Rangoon, in the kingdom of 
Regue, by Dr. Buchanan. 
THALICTRUM, in hotany, meadow I'ue, 
a genus of the Polyandria Polygynia class 
and order. Natural order of Multisilique. 
Ranunculace®,. Jussieu. Essential charac- 
ter: calyx none; petals four or five ; seeds 
tailless. There are twenty-two species. 
THALLITE, ,in mineralogy, a stone 
found in the fissures of mountains in Dau- 
phiny, and on Chamouni, in the Alps. iLis 
sometimes amorphous, and sometimes chrys- 
tallized. It is brittle. Specific gravity 
THE 
about 3.4. Before the blow-pipe it froths, 
and melts into a black flag : with borax it 
melts into a green bead. The constituent 
parts are. 
Silica 
Alumina 
Oxide of Iron 
Lime 
Oxide of manganese....... 
96.5 
Loss 
100.0 
THAPSIA, in botany, a genus of the 
Pentandria Digynia class and order. Natu- 
ral order of Umbellat®, or Umbellifer®. 
Essential character : fruit oblong, surround- 
ed by a membrane. There are six species. 
THEA, in botany, tea-tree, a genus of the 
Polyandria Monogynia class and order. 
Natural order of Coluranifer®. Aurantia, 
Jussieu. Essential character : corolla six 
or nine-petalled ; calyx five or six-leaved 
capsule tricoccous. 
The tea plant is a native of Japan, China, 
and Tonquin, and has not been found grow- 
ing spontaneously in any other part of the 
world. 
Linn® us says that there are two species 
of the tea plant ; the bohea, the corolla of 
which has six petals; and the viridis, or 
green tea, which has nine petals. Thunberg 
makes only one species, the bohea, consist- 
ing of two varieties: the one with broad 
and the other with narrow leaves. This 
botanist’s authority is decisive respecting 
the Japanese, tea plants ; but as China has 
not yet been explored, we cannot' deter- 
mine what number of species there are in. 
that country. The tea-tree, however, is 
nowr common in the botanical gardens in 
this country ; and it is evident that there 
are two species, or, at least, permanent va- 
rieties of it ; one with a much longer leaf 
than the other, which our gardeners call the 
green tea ; and the other with shorter 
leaves, which they call the bohea. The green 
is by much the hardiest plant, and with very 
little protection will bear the rigour of our 
winters. 
This plant delights in valleys, and is fre- 
quent on tlie sloping sides of mountains and 
the banks of rivers, where it enjoys a 
southern exposure. It flourishes in the 
northern latitudes of Pekin as well as round 
Canton ; but attains the greatest pefection 
in the mild temperate regions of Nankin, 
It is said only to be found between the 30th 
