THE 
eaufe them to decay. The plants being thus ma- 
naged, will continue feveral years, and produce 
flowers and feeds annually, from which new plants 
may be raifed. They delight in a foft loamy foil, 
and if they are expofed only to the morning fun, 
they will thrive better than if they have a warmer fitu- 
ation, for they endure the cold of our winters very well. 
The roots of the third fort were formerly ufed in me- 
dicine, but are now never ordered, being fuppofed to 
have a poifonous quality. Boerhaave fays it has much 
the fame qualities as Euphorbium, it burns the bowels 
and produces a diarrhoea. 
THELIGONUM. Lin. Gen. Plant. 947. Cyno- 
crambe. Tourn. Cor. 52. tab. 485. Dogs Cabbage. 
The Characters are, 
It has male and female flowers on the fame plant. The 
male flowers have a turbinated empalement of one leaf., cut 
into two fegments which turn backward. It has no pe- 
tal, but feveral eredt ftamina the length of the empale- 
ment, terminated by flngle fummits. The female flowers 
have a fmall bifid empalement of one leaf , which is per- 
manent. It has no petals , but has a globular germen , fup- 
porting a Jhort ftyle crowned by an obtufe fligrna. The 
germen afterward becomes a thick globular capfule with 
one cell , inclofing one globular feed. 
This genus of plants is ranged in the eighth fedlion 
of Linnteus’s twenty-firft clafs, which includes the 
plants whole flowers have male and female flowers on 
the fame plant, and the flowers have many ftamina. 
We have but one Species of this genus, viz. 
Theligonum ( Cynocrambe .) Sauv. Monfp. 129. Cyno- 
crambe Diofcoridis. C. B. P. 122. Dogs Cabbage of 
Diofcorides. 
This plant grows naturally in the fouth of France, in 
Italy, and Tartary. It is an annual plant, which de- 
cays as foon as me feeds are ripe. The ftalks trail on 
the ground like thofe of Chickweed ; they grow about 
a foot long their joints are pretty dole ; thefe are 
garnifhed with oval acute-pointed leaves, Landing on 
pretty long foot-ftalks which are bordered. At each 
joint is placed one of thefe leaves, and from the fame 
point come out feveral fmaller leaves of the lame 
fhape on flhorter foot-ftalks. The flowers are pro- 
duced from the wings of the ftalk in clufters, fitting 
very clofe ; they are fmall, of an herbaceous white 
colour, fo make no great appearance. The male and 
female flowers grow from the fame joint. The female 
flowers are fucceeded by a Angle roundifh feed, which 
ripens in autumn. 
It is preferved in botanic gardens for the fake of va- 
riety. The feeds of this muft be fown in autumn, in 
the place where the plants are to remain •, for when 
they are fown in the fpring, the plants rarely come up 
the fame year. They require no other culture but to 
keep them clean from weeds, and thin them where 
they are too clofe. 
THEOBROMA. Lin. Gen. Plant. 806. Guazuma. 
Plum. Nov. Gen. 36. tab. 18. Baftard Cedar. 
The Characters are, 
The empalement of the flower is compofed of three oval con- 
cave leaves which arc reflexed. The flower has five oval 
petals which fpread open , and are hollowed like a fpoon \ 
from the top of each petal comes out a bifid briftly ligula , 
divided like two horns. It has a great number of fhort 
ftamina joined in five bodies, and are the length of the 
petals, which are terminated by roundifh fummits, and a 
roundifh germen fupporting a flngle ftyle the length of 
the petals , crowned by a flngle ftigma. The germen af- 
terward turns to a roundifh fruit with five angles, open- 
ing in five cells, each containing feveral feeds. 
This genus of plants is ranged in the ftrft feftion of 
Linnaeus’s eighteenth clafs, which includes thofe 
plants which have many ftamina joined in flve bodies. 
We have but one Species of this genus, viz. 
Theobroma ( Guazuma ) foliis ferratis. Hort. Cliff. 379. 
Theobroma with flawed leaves. Guazuma arbor ulmi- 
folia, fruftu ex purpura nigro. Plum. Nov. Gen. 36. 
Tree Guazuma with an Elm leaf, and a black purple fruit. 
This grows naturally in moft of the iflands in the 
Weft-Indies, where it rifes to the height of forty or 
\ 
fifty feet, having a trunk as large as a middle-fized 
man’s body, covered with a dark brown, furrowed 
bark, fending out many branches toward the top, 
which Ipread out wide on every hand, and are gar- 
nifhed with oblong heart-fhaped leaves placed alter- 
nate, which are near four inches long, and two broad 
near their bale, ending in acute points, of a bright 
green on their upper fide, and pale on their under, 
fawed on their edges, with a ftrong midrib, and fe- 
veral tranfverfe veins, and ftand upon fhort foot-ftalks. 
The flowers come out in bunches from the wings of 
the leaves ; they are fmall and of a yellow colour, 
having five concave petals which fpread open circu- 
larly, with a great number of ftamina, which at their 
bale are joined in five bodies, terminated by roundifh 
fummits. In the center is fituated a roundifh ger- 
men, fupporting a flender ftyle the length of the fta- 
mina, crowned by a Angle ftigma. The germen af- 
terward turns to a roundifh warted fruit having five 
obtufe angles, and five cells which contain feveral ir- 
regular feeds. 
The wood of this tree is white and ductile, fo is fre- 
quently cut into Laves for calks. The fruit and leaves 
are good fodder for cattle, therefore- when the planters 
clear the land from wood, they leave the trees of this 
fort Landing for food for their cattle, which is of great 
uie in dry leafons, when the common fodder is fcarce. 
There are fome plants of this fort preferved in the 
gardens of fome curious perfons ; it is propagated by 
feeds, which muft be procured as frelh as poffible 
from the countries where the plants grow naturally. 
Thefe fhould be fown upon a good hot-bed in the 
fpring, and when the plants are fit to remove, they 
fhould be each planted in a feparate fmall pot, and 
plunged into a hot-bed of tanners bark, obferving to 
Ihade them from the fun till they have taken new root ; 
then they fhould be treated in the fame way as the 
Coffee-tree, keeping them always in the tan-bed in 
the Love. 
THERMOMETER, [Oe^y-bf/sr^ov, of heat, 
and {ABTfico, to meafure.] An mftrument fhewing, or 
rather meafuring, the increafe and decreafe of the 
heat, and cold of the air. 
Of which there are various kinds ; the conftrudtions, 
defeats, theories, &c. whereof are as follow. 
The confer ullion of a Thermometer, depending on the 
rarefaction of the air. 
In the tube C F, to which is 
faftened a glafs ball A, is put 
a quantity of common water, 
mixed with aqua regia, to pre- 
vent its freezing ; and the mix- 
ture tinged with a folution of 
vitriol, to give it a greennefs. 
In filling the tube, care is tak- 
en that there be fo much air 
left in the ball and tube, as 
that when at its greateft con- 
denfation in the middle of win- 
ter, it may juft fill the ball ; 
and yet in its greateft rarefac- 
tion in fummer, may not drive 
all the liquor out of the tube. 
To the other extreme of the 
tube is faftened another glafs 
ball E F, open to the air at 
F. On each fide the tube is 
applied the fcale B D, divided 
into any number of equal 
parts. 
Now as the ambient air be- 
comes warmer, the air in the 
ball and the top of the tube 
expanding, would drive the li- 
quor into the lower ball, and 
confequently its furf'ace will 
defeend ; on the contrary, as the 
ambient air grows colder, that 
in the ball becoming condenfed, the liquor will afeend. 
The 
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