CtiE 
lit. Secondary compounds, or cotnpdunds 
^ more than two simple principles. 
Though it cannot yet be determined 
Wliether the binary, and other compounds, 
enumerated in the last section, may exist as 
distinct principles in the combinations into 
which they may enter, it is nevertiieless cer- 
tain, that, either from this cause, or from the 
general predominance of the attractions to 
■Which they owe their formation, the appear- 
ances in composition and decomposition are 
such as admit of the affirmative supposition 
in by far the greater number of cases. This 
■was taken for granted by the earlier che- 
mists, and habit and convenience has conti- 
nued their language to the present time. 
The binary compounds, taken in the pre- 
ceding order, will indicate the following 
secondary combinations. 
1. Water combines with a great number 
of bodies, and in general may be separated 
by evaporation, congelation, or the effect of 
elective attraction, without any change in 
its own composition. It has been accord- 
ingly considered for a long time as a simple 
element, arid is even now very often disre- 
garded in its agency upon substances which 
it may hold in solution, (a) It absorbs very 
small portions of oxygen, hydrogen, or azote, 
arid emits them upon raising the tempera- 
ture, or lowering it to congelation. No 
proof has been given of its being capable of 
uniting in perfect combination with either 
of its component parts beyond the point of 
saturation. (6) It dissolves barytes plenti- 
fully, and strontites and linie sparingly; and 
it very actively takes up large proportions 
of the alkalies ; but from all these it may be 
separated without alteration by mere heat, 
(c) Its action upon carbon, sulphur, phos- 
phorus, or the metals, is not sufficient to pro- 
duce any sensible combination or decompo- 
sition, unless ata very ele vated temperatm’e, 
such as that of ignition, (d) The oxides are 
scarcely affected by it ; perhaps only when 
they approach the state of acidity, (e) Many 
of the acids unite strongly, and in all propor- 
tions, with it, and they are all more or less 
soluble. (/) The sulphurets and phospho- 
rets are suspended, and decomposition of 
the water takes place by disposing double 
affinity ; part of the sulphur taking oxygen 
from the water, and forming acid, which 
combines with the earth or alkali; and an- 
other part of the combustible uniting with 
the hydrogen of the decomposed water, and 
forming hydrosulphuret, part of which re- 
mains in solution, and part rises in form of gas. 
(g) The compounds of two or more com- 
CHE 
bustibles are not sensibly acted upon 
water. 
2. The alkalies combine (a) with all the, 
acids, and form compounds called neutral 
salts, more or less soluble in waiter; and 
also (6) with several of the earths and (c) 
of the metallic oxides; forming combina- 
tions, which, from the little attention yet 
paid to them,- have received no particular 
denominations. 
3. The eartlis also unite (a) with the acids, 
and form salts similar to those called neu- 
tral, and also for the most part soluble in 
water. Some of these likewise unite (6) 
with each other; and (c) with metallic ox- 
ides, by compound attraction duHng pre- 
cipitation in the humid way. 
4. Acids are the most powerful agents of 
combination with alkalies, earths, and metal- 
lic oxides, in the humid way, with Which, ds 
has been observed, they form salts. The 
earth silex is not taken up in any perceptible 
quantity by any acid but the fluoric, and this 
suspends it even in the form of gas. 
5. The compound of hydrogen and sul- 
phur acts in the manner of an acid upon the 
alkalies, earths, and metallic oxides. For 
which, and the effect of acids on the com- 
pound combustibles, reference must be 
made to the respective articles. 
It would carry us too far into the business 
of arrangement in this place, if we were 
not to adopt the same proceeding of refer- 
ring to the parts and products of Vege- 
table and Animal bodies ; we shall there- 
fore only mention five classes of the pro- 
ducts of organized substances, which, from 
their exclusive application to chemical ope- 
rations, cannot be passed without notice. 
These in the last results afford carbon and 
hydrogen, or carbon, hydrogen, and oxygen. 
They are, (a) alcohol, or spirit, ardent; 
(6) ether; (c) oils, volatile; (d) oils, fixed; 
(e) bitumens. 
CHENOLEA, in botany, a genus of the 
Pentandria Monogynia class and order : 
natural order of Holoraceae ; Atriplices, Jus- 
sieu. Essential character : calyx globular, 
one-leafed, five-parted ; capsule one-cel!ed, 
containing one smooth seed, bifid at the tip. 
There is but one species, viz. C. diffusa, 
which is a native of the Cape of Good Hope. 
CHENOPODIUM, in botany, English 
goose-foot, a genus of the Pentandria Digy- 
nia class and order : natural order of Holo- 
raceas : Atriplices, Jussieu. Essential cha- 
racter, calyx five-leaved, five-cornered; 
corolla none; seed one, centicular, supe- 
rior. There are twenty-three species. 
M2 
