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temperature, hydrogen in its turn decomposes oxide of iron. What signi-
fies, in this case, any order of affinity that we may ascribe to iron and
hydrogen with oxygen? If we make the order vary with the temperature,
we have a merely verbal, and therefore pretended explanation. Chemis-
try affords us now many such cases, apparently contradictory, indepen-
dently of the long series of decisive considerations that have made us
reject absolute affinities, the only ones, after all, that have any scien-
tific consistency whatever. The old habit is, however, so strong that
even Berthollet, in the very work in which he overthrows the old doc-
trine of invariable or elective affinities, proposes vague affinities under
many modifications. The strange doctrine of predisposing affinity is to
be found in the work, among others, of the most rational of recent chem-
ists, the illustrious Berzelius. When, for instance, water is decomposed
by iron through the action of sulphuric acid, so as to disengage the
hydrogen, this remarkable phenomenon is commonly attributed to the
affinity of the sulphuric acid for the oxide of iron which tends to become
formed. Now, can anything be imagined more metaphysical, or more
radically incomprehensible, than the sympathetic action of one substance
upon another which does not yet exist, and the formation of the last by
virtue of this mysterious affection? The strange fluids of physicists are
rational and satisfactory in comparison with such notions These consid-
erations justify the desire that chemists should have a sufficient training
in mathematical, astronomical, and then in physical philosophy, which
have already put an end to such chimerical researches within their own
domain, awl would discard them speedily from the more complex parts
of natural philosophy. It is only by having witnessed the purification in
the anterior sciences that chemists could realize it in their own: and
there could not be complete positivity in chemistry if metaphysics lin-
gered in astronomy or physics. This, again, justices the place assigned
to chemistry among the sciences. The individual must follow the general
course of his race in his passage to the positive state. He must kind that
true science consists, everywhere, in exact relations, established among
292/Auguste Comte
observed facts, allowing the deduction of the most extensive series of
secondary phenomena from the smallest possible number of original
phenomena, putting. aside all vain inquiry into causes and essences.
And this is the spirit which has to be made preponderant in chemistry,
dissolving for ever the metaphysical doctrine of affinities.
The inferiority of chemistry to physics, in regard to method and
doctrine, explains its relative imperfection with regard to actual sci-
ence. We have only to compare with the formula which told us what
chemistry ought to be, what it actually is, to see that it is at an immense
distance much further than physics from its true scientific aim.
Chemical facts are at this day essentially incoherent, or, at best, feebly
coordinated by a small number of partial and insufficient relations, in-
stead of those certain, extended, and uniform laws of which physics is
so justly proud. As for prevision, if it is imperfect in physics in com-
parison with astronomy, it can hardly be said to exist in chemistry at all:
the issue of each chemical event being usually known only by specially
consulting the immediate experiment, when, as it were, the event is al-
ready accomplished.
Imperfect as chemistry is, in regard to method and doctrine it is yet
superior to physiology, and still more, to social science, not only be-
cause, from the comparative simplicity of its phenomena, the facts and
investigations are clearer and more decisive, but because it has a few,
though very few, real theories, capable of affording complete previsions;
a thing as yet impracticable, except in a general manner, with living
bodies. We shall have occasion to notice the theory of proportions, the
equivalent of which is not, in any sense, to be looked for in physiology.
We must remember, while estimating the comparative imperfection of
the sciences, that the importance to us of their perfection is in propor-
tion to their simplicity; our available means being always found to cor-
respond with our reasonable wants. I hope, too, that this severe estimate
of the actual state of each science will stimulate rather than discourage
the student; for it is more gratifying to our human activity to conceive of
the sciences its susceptible of vast, varied, and indefinite progress, than
to suppose them perfect, and therefore stationary, except in their sec-
ondary developments.
This leads us to consider the function of Chemistry in the education
of the human mind.
It may be said to train us in the great art of experimentation: not as
being our exclusive teacher, for, as we have seen, physics is superior to
Positive Philosophy/293
it in this: and it is more. the art of observing than of experimenting that
Chemistry is chiefly distinguished for. But there is an important part of
the positive method which chemistry seems destined to carry to the highest
perfection. I do not mean the theory of classifications, of which chem-
ists know too little at present, but the art of rational nomenclatures,
which is quite unconnected with classifications. Since the reform in chemi-
cal language, attempts have been incessantly made, to this hour, to form
a systematic nomenclature in anatomy, in pathology, and especially in
zoology: but these endeavours have not had, and never can have, any
success to compare with that of the reformers of chemical language; for
the nature of the phenomena does not admit of it. It is not by accident
that the chemical nomenclature is alone in its perfection. The more com-
plex phenomena are, and the more varied and less restricted the com-
parisons of objects, the more difficult it becomes to subject them to a
system of denominations, at once rational and abridged, so as to facili-
tate the habitual combination of ideas. If the organs and tissues of the
living body differed only from one point of view; if maladies were suffi-
ciently defined by their seat. if, in zoology, genera, or at least families
could be estate fished by a homogeneous the corresponding sciences
might at once admit of systematic nomenclatures as rational and as effi- [ Pobierz całość w formacie PDF ]