whereby it was
considered that an excess of any humour might be counteracted; moreover,
it was further assumed that four degrees of each property exist, and
that only those drugs are of use in curing a disease which contain the
necessary property or properties in the degree proportionate to that
in which the opposite humour or humours are in excess in the patient's
system.

PARACELSUS' views were based upon his theory (undoubtedly true in a
sense) that man is a microcosm, a world in miniature.(1) Now, all things
material, taught PARACELSUS, contain the three principles termed in
alchemistic phraseology salt, sulphur, and mercury. This is true,
therefore, of man: the healthy body, he argued, is a sort of chemical
compound in which these three principles are harmoniously blended (as
in the Macrocosm) in due proportion, whilst disease is due to a
preponderance of one principle, fevers, for example, being the result
of an excess of sulphur (_i.e_. the fiery principle), _etc_. PARACELSUS,
although his theory was not so different from that of GALEN, whose views
he denounced, was thus led to seek for CHEMICAL remedies, containing
these principles in varying proportions; he was not content with
medicinal herbs and minerals in their crude state, but attempted
to extract their effective essences; indeed, he maintained that the
preparation of new and better drugs is the chief business of chemistry.

(1) See the "Note on the Paracelsian Doctrine of the Microcosm" below.

This theory of disease and of the efficacy of drugs was complicated by
many fantastic additions;(1) thus there is the "Archaeus," a sort
of benevolent demon, supposed by PARACELSUS to look after all the
unconscious functions of the bodily organism, who has to be taken into
account. PARACELSUS also held the Doctrine of Signatures, according to
which the medicinal value of plants and minerals is indicated by their
external form, or by some sign impressed upon them by the operation of
the stars. A very old example of this belief is to be found in the use
of mandrake (whose roots resemble the human form) by the Hebrews and
Greeks as a cure for sterility; or, to give an instance which is still
accredited by some, the use of eye-bright (_Euphrasia officinalis_, L.,
a plant with a black pupil-like spot in its corolla) for complaints of
the eyes.(2) Allied to this doctrine are such beliefs, once held, as
that the lungs of foxes are good for bronchial troubles, or th