the same mega as is, also, the milky juice of the fig, 
ost all the fruit trees yield some sort 
acia tree, in Arabia, 
yields the Gum Arabic, which is the chief nourishment 
of the nations of those parts, who obtain it in great 
quantities from i incisions which they make in the trees. 
This Gu ¢ is now in frequent use in our own 
country; an as: pao a good aliment for young children; 
particularly when on a sea voyage, where milk cannot 
e comman 
Another ierstiel is Caoutchoue, or Indian rubber, 
species of trees in South 
The botanic names of 
South Auerica, is one of the principal trees from 
which the Caoutchouc is now procured. The fluid is 
collected from the tree by incision; the color is, at 
first, a yellowish white, but, by exposure to the air, it 
becomes dark. Moulds made of clay, in the form of 
bottles, shoes, &c. are dipped into it repeatedly, and 
afterwards dried, and, when of a sufficient thickness, the 
clay moulds are easily crushed, and the pieces emptied 
out. 
The natives make vessels of it for cohtaining water 
and oiia: liquids; and, while soft, all sorts of designs 
are traced uponit. On unt of its inflammability, it 
is used at Cayenne, for ara, When warmed, it gives 
out a peculiar odor, but not an unpleasant one; from 
its smoke, a considerable quantity of very fine lamp 
black may be collected. 
Rectified oil of turpentine, at common temperature, 
will afford a » complete solution of it; and, when mixed 
tae be applied to a variety of useful 
siete 
The fresh cut surface of the Caoutchouc will unite 
wee by simple contact, and, by a proper pressure, 
y be brought so completely in union, as to be no 
more liable fe Separate in t 
The & 
resu 
¢ its extension, a very sensible warmth is 
me as fon be discovered by applying it between 
the lips. 
Another secretion to be found in vegetable, in ina 
greater or less degree, is sugar: but gene ly mixed 
with gum, sap, or other ingredients. Ita most 
roots—as the beet, carrot, &c. but, more 
particularly in “ee Saccharum, or sugar cane. 
The odor of plants, is a volatile oil of a resinous nature 
3 
namon 
their oils in the stem and leaves; Elicampane, and the 
emary and Thyme in 
calyx of their flowers; Chamomile, Lemon and Orange 
Trees, in the petals. Many fruits contain it through 
their whole substance, such as eit msg &e. 
Oranges and Lemons, in the zest or peeling whic 
encloses them, &c. 
Fecula is the ening ge given to the farinaceous 
substance contained in all seeds, and in some roots— 
as Wheat, Indian corn, oer Potato, Parsnip, &c. it is 
intended by Nature for the first aliment of the young 
plant. 
olor.—The fixed colors of opaque bodies are, in 
all probability, owing to their absorbing some vb the 
olored parts of white light, or rays of the sun, and 
reflecting others; their immense variety arising from a 
mixture of the reflected primitive colors, in various 
number and proportion. It is impossible to say upon 
what cause the disposition of brine Bs certain colors 
in p' ce to others, may depend. The probability 
is, ay a arises from the dificent Pies! of the surfaces. 
ere are some flowers, the petals of which are in 
different ET of the same leaf, of dierent colors; as 
examin 
a 
texture of the blue and Pee® parts. en texture, also, 
of the white and red Rose is 
It is from reflected rays me we judge st the color of 
&c. is occasioned by 
has pera ms many e owned on the refraction of 
light, in a more accurate manner that t had been pre- 
viously ei confines them to four colors only—red, 
green, blue, and violet. 
me philosophers say there are only three ori, riginal 
and cule distinct colors, viz: the red, yellow, and blue. 
Providence seems to have decorated Nature with an 
enchanting diversity of colors, for the purpose of beau- 
as thatg 
the colo most grateful and beneficial to i cye, should 
predominate. 
9 
