12 VARIETY OF FORMS IN THE VEGETABLE AND ANIMAL KIMGDOMS. 
vreul has shown. For the most part they pre • 
sent solid combustible bodies, which strongly 
resist decomposition from the atmosphere. 
On the other hand, the ternary, the quaterna- 
ry, and even the more complex combinations 
of the organic kingdom, are less compact and 
less intimate ; they are the results of weaker 
affinities, which causes them to appear more 
unsettled and variable, because saturation in 
them is rarely perfected. The principle of 
combustion, oxygen, does not exist in sufficient 
quantities in them, to saturate the combustible 
elements and to prevent the possibility of 
their yielding to other affinities. This is the 
reason why all organic combinations are com- 
bustible. For they do not contain the proper 
quantity of oxygen to saturate their carbon 
and hydrogen. They buim, when heated, in 
contact with the atmosphere, and then absorb 
all the oxygen that is necessary to the satura- 
tion of the %drogen and carbon, 
XI. As the elements have a greater incli- 
nation to produce binary compounds than to 
continue in ternary and quaternary combina- 
tions, there is observed in organic substances 
a constant disposition to run into binary states 
of composition. Inorganic bodies having their 
elements in a kind of perfect equilibrium, 
these same elements are but little disposed to 
combine with surrounding matters, or in any 
other manner Such is'not the case with or- 
ganic matters, which are more complicated, 
and retained by less powerful affinities ; in 
them there is observed a constant tendency to 
resolve themselves. They are mostly com- 
posed of oxygen, hydrogen, nitrogen, and car- 
bon, the three first of which are gaseous 
when in a state of freedom, and sti'ive to 
abandon the solid form, a tendency which is 
still more increased by external heat and the 
heat peculiar to living bodies. The great 
affinity of the oxygen for the hydrogen and 
carbon causes it to combine easily with the 
first, whence results water, and with the se- 
cond, which produces carbonic acid. Nitro- 
gen, which has a great affinity for hydrogen , 
joins with it, and gives origin to ammonia. 
But, as the carbon and hydrogen do not find 
sufficient oxygen, in organic combinations, to 
form water and carbonic acid, they have a 
disposition to attract that of the atmospheric 
air. On these circumstances depends the 
facility with which plants and animals run 
into decomposition, and which rests on the 
constant tendency of their elements to con- 
tract binary combinations, and to quit a state 
in which they are maintained only by the 
powers acting in living bodies. Living bodies 
suffer, by the atmospheric influence remark- 
able changes, which induce the unfixed ele- 
ments of food, introduced and rendered fluid 
in their interior, to undergo, as well by the 
effect of a subtraction of the materials of the 
latter, as by an absorption of other princi- 
ples drawn from the air, a change in their 
respective proportions, designated under the 
name of respiration. The manifestations of 
activity of living bodies themselves, are in- 
cessantly modifying organic matters, the com- 
position of which is extremely variable and 
mobile, and cause them to pass sometimes to 
a more simple, sometimes to a more complex 
state, by changing the numerical relations of 
their elements in such a manner, that vegeta- 
ble combinations may become animal, and 
these resume the vegetable state. 
XII. There is this difference between liv- 
ing and inert bodies, relative to the connexion 
of the chemical composition with the configu- 
ration, that the former, although they resem- 
ble each other most in their composition, 
nevertheless present a much greater diversity 
in their forms. What an immense variety of 
forms the vegetable and animal kingdoms ex- 
hibit, notwithstanding the inconsiderable num- 
ber of elements which constitute living bodies 
in general. We even find that with an anala- 
gous composition, the parts of one and the same 
organic individual differ in a singular degree 
from each other in point of configuration. I ^vill 
mention, as an example, the diversity which 
petals often present in the same vegetable species 
and that which is remarked, among animals, in 
the configuration of the bones and muscles. In- 
organic bodies, on the contrary are remarkable, 
with very few exceptions, for their great an- 
alogy of form and crystallization, when their 
chemical composition is identical. 
There must be, therefore, in living bodies 
a peculiar power, differing from the chemical 
affinities which determines the forms of bo- 
dies not endued with life, and the action of 
which produces the diversity which organic 
forms with similar composition exhibit. Or, 
which expresses the same idea in a still more 
clear manner, the configuration of organic 
bodies is not only the effect of chemical affi- 
nity, as in bodies without life, but it is also 
that of a power of a special, or, it may be, 
a superior nature. 
XIII. Regarding the origin of organic com- 
binations, experience teaches us that they are 
only produced by the manifestations of activity 
of living bodies already existing. Albumen, ge- 
latin, mucus, gluten, starch, gum, sugar, &c., 
do not form spontaneously, by the union of 
elements, or binary compounds, according 
to the laws of chemical affinity, but only by 
the manifestations of activity of organic bodies 
already possessed of 1 fe. Organized beings 
are produced by their fellow-beings, or owe 
their origin to the matter of organized bodies 
in a state of decomposition. The production 
of organic combinations in these beings, takes 
the name of assimilation and nutrition, whilst 
the procreation of beings themselves is called 
generation. On the other hand, inorganic 
combinations and bodies never originate but 
from the remains of other more ancient bodies, 
fallen into dissolution, and the materials of 
which, under certain circumstances, re-unite 
to produce them, according to the laws of 
chemical and mechanical attraction alone. 
XIV. Even the most simple animal and 
vegetable forms, the infusoria, the green mat- 
ter of Priestley, the conserve, mouldiness, 
&c., in what is called spontaneous genera- 
tion, proceed, according to the observations 
and experiments undertaken by Needham, 
Priestley, Ingenhounz, Monti, Wrisberg, 
Muller, G. R. Treviranus, &c., not from inor- 
ganic matters, but from organic bodies and 
combinations passed into putrefaction or fer- 
