CHEMISTRY. 
335 
oxide. The charcoal, by combining with 
the oxygen and caloric, escapes under the 
form of carbonic acid gas, and the metal re- 
mains pure and revived. 
All combustible substances may be oxyge- 
nated also by combining them either with the 
nitrate of potash, or that of soda, or with the 
oxygenated muriate of potash. At a certain 
degree of heat the oxygen abandons the ni- 
trate or the muriate, and combines with the 
combustible body, but with great violence. 
Lead 
1 , 
Mercury 
The reason is as follows. 1 he oxygen, ui 
J. lie m ' , 
combining with the nitrates, and particulai ly 
with the oxygenated muriates, enters along 
with a quantity of caloric almost, equal to 
that necessary for constituting it oxygen gas. 
At the moment of its combination with the 
combustible body, ail this caloric becomes 
suddenly tree, and produces terrible detona- 
tions. This method of oxygenation, there- 
fore, must not be attempted but with the ut- 
most caution, and when very small quantities 
of matter are employed. 
There are did. rent degrees of oxygena- 
tion : the first degree forms oxides, the second 
forms weak acids, the third strong acids, and 
the fourth hyperoxygenated acids. 
The combination of oxygen with 
r Cal :.ric forms oxygen gas 
1 Hydrogen — water 
Degrees, 
of oxy- 
genation 
r 1 , — base of atmospheric 
\ air. 
Azote <2, — nitrous oxide 
) 3, — nitrous gas 
( 4,. — .nitric acid 
{ 1 , — oxide of carbon 
\2, — carbonic acid 
/ 1, — oxide of sulphur, 
) soft sulphur 
b 2, — sulphurous acid 
( 3, — sulphuric acid 
n, — oxide of phosphorus 
Phosphorus \ 2, — phosphorous acid 
l 3, — phosphoric acid 
/ 1, — muriatic acid 
The muria- ) 2, — oxymuriatic acid 
tic radical ) 3, — hyperoxy muriatic 
( acid 
I he fluoric ) , — fluoric acid 
radical > 
d he boracic > , — boracic acid, 
radical 5 
L 
Bismuth 
Colxilt 
N ickel 
Zinc 
Antimony 
Arsenic 
Manganese 
Tungsten 
Molybdena 
Titanium 
Chrome 
grey oxide of lead 
yellow and red oxide 
of lead 
black oxide of mer- 
cury 
vellow and red oxide 
’ of mercury 
grey r oxide of bis- 
muth 
\ 2, — white oxide of bis- 
(_ muth 
1 1 — grey oxide of cobalt 
1, — oxide of nickel 
^ 1 , — grey oxide of zinc 
(2, — white oxide of zinc 
/ 1, — grey oxide of anti- 
' mony 
2, — white oxide of anti- 
\ mony 
/ 1 , — grey oxide of arsenic 
j 2, — • white oxide of arse- 
j nic 
(3, — arsenic acid 
r 1 , — black oxide of man- 
) ganese 
4 2, — white oxide of man- 
{_ ganese 
(1, — oxide of tungsten 
( 2, tungstic acid 
< 1, oxide of molybdena 
( 2, molybdic acid 
1, oxide of titanium 
( 1 , oxide of chrome 
1 2. chromic acid. 
certain portion of oxygen, which reduces 
them to the state of oxide, or to the acid 
state, according to the degree ot oxygena- 
tion. 
The nature of animal matters, theiefore, 
may vary, like that of vegetable matters, 
three ways: 1st, By the number of the sub- 
stances which enter into the combination ot 
their radicals; 2d. By tire difference in the 
proportion of these substances ; od. By the 
different degrees of oxygenation. 
The combination ot azote with 
forms azotic gas 
Degrees 
of oxy- 
genation 
/ 1, the base . of atmo- 
\ spheric air 
< 2, nitrous oxide 
) 3, nitrous gas 
F 4, nitric acid 
ammonia 
f Caloric 
y Oxygen 
< 
-animal matters. 
Carbon 
Sulphur 
Gold 
Platina 
Silver 
5 l > 
The combination of oxygen with 
Degrees 
of oxy- 
genation 
1, forms yellow oxide of 
gold 
2, — red oxide of gold, 
precipitate of Cas- 
sius 
yellow oxide of pla- 
tina 
1, — oxide of silver 
1 } — reddish-brown oxide 
•of copper 
2, — green and blue oxide 
of copper 
] j — black oxide of iron 
2, — yellow and red oxide 
of iron 
1, — grey oxide of tin 
2, — white oxide of tin 
In the mineral kingdom almost all the ox- ! 
idable and acidiliable radicals sebm to be 1 
simple substances; but in the vegetable king- 
dom there are scarcely any which are not j 
composed of two substances, hydrogen and 
carbon. Azote and phosphorus are often 
joined with them, and the result is radicals 
with four bases. 
From these observations, it appears that 
the oxides and the animal and vegetable 
acids may differ from each other three ways. 
1st. By the number of acidiliable principles 
which' constitute their base; 2d, By the dif- 
ference in the proportions ot these principles , 
3d, By the different degrees of oxygenation. 
This is more than sufficient to account for the 
great number ot varieties which nature ex- 
hibits to us. It thence appears, therefore, 
that some of the vegetable acids can be con- 
verted into each other. Nothing is neces- 
sary for this purpose but to change the pro- 
portion of carbon and hydrogen, and to oxy- 
genate them more or less. Carbon and hy- 
drogen, by the first degree of oxygenation, 
oive tartareous acid; by. a second degree 
oxalic acid; and by a third the acetous, or 
acetic acid. 
( 
Copper 
Iron 
Tin 
Of azote or nitrogen. Azote is a principle 
diffused in great abundance throughout na- 
ture : when combined with caloric, it forms 
azotic or mephitic gas, which in volume is 
three fourths of the atmosphere, and in weight 
somewhat less than atmospheric air. It al- 
ways remains in the state of gas at the tempe- 
rature and pressure of the atmosphere which 
we experience; and we are unacquainted with 
any' degree ot compression or cold capable of 
reducing it to the solid, or even to the liquid 
state. Azote is one of the essential constituent 
parts of animal matter ; it is combined in them 
with carbon and hydrogen, and sometimes with 
phosphorus ; the whole being-connected by a 
Hydrogen 
Carbon 
Hydrogen 
and sometimes 
Phosphorus 
„ Oxygen 
Of hydrogen . Hydrogen is one of the 
constituent principles of water, and thence it 
has received its name. It forms in the com- 
position of water fifteen hundredth parts ot its 
weight, while oxygen forms the other eighty- 
rive 3 parts. The affinity of hydrogen for ca- 
loric is so great, that it constantly remains in 
the state of gas at the degree ot heat and 
pressure in which we live; it is impossible, 
therefore, to procure it free from all combi- 
nation, and consequently we are unacquaint- 
ed with the nature of this-- principle, it is 0113 
of the most abundant principles in nature ; 
for besides entering into the composition of 
water, which is itsed so abundant 011 the 
earth, it is one of those principles which act 
the most conspicuous part in the vegetable 
and animal kingdoms,, by combination with 
different substances. 
Having already referred to the production 
of hydrogen gas, (seeAiR, p.31) we shall now 
shew the means of obtaining it by experi- 
ment. 
Exp. Let the gun-barrel x y (fig. 21) pass 
through a furnace F, and adjust to one extre- 
mity of it the bent tube A, and let the 
other extremity terminate in the tube B, car- 
ried under the receiver C. \\ hen the appa- 
ratus is thus disposed, and the several parts 
luted together, the gun-barrel must be 
brought to a red heat, and the water poured 
in drop by drop through A ; and when it 
comes in contact with the gun-barrel, it. is 
decomposed; the iron seizes on the oxygen 
of the water, and the hydrogen escapes 
through B in a state of gas. 
This gas may also be obtained by pouring 
a solution of sulphuric acid over filings of iron 
or zinc. 
Exp. Put iron filings into the jar A with 
two tubulures a and b, adjust to h the small 
glass tube ending in a capillary bore, and 
through a pour the diluted sulphuric acid : 
the cr-1 s will speedily be disengaged ; and if a 
taper is applied to x, it will continue to burn 
with a fine blue flame as long as the decom- 
position goes on. L his is called the philo- 
sophipal caudle , 
