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 that the heart of a lion will endow one with courage; as CORNELIUS AGRIPPA put it, "It is well known amongst physicians that brain helps the brain, and lungs the lungs."(3) (1) The question of PARACELSUS' pharmacy is further complicated by the fact that this eccentric genius coined many new words (without regard to the principles of etymology) as names for his medicines, and often used the same term to stand for quite different bodies. Some of his disciples maintained that he must not always be understood in a literal sense, in which probably there is an element of truth. See, for instance, _A Golden and Blessed Casket of Nature's Marvels_, by BENEDICTUS FIGULUS (trans. by A. E. WAITE, 1893). (2) See Dr ALFRED C. HADDON'S _Magic and Fetishism_ (1906), p. 15. (3) HENRY CORNELIUS AGRIPPA: _Occult Philosophy_, bk. i. chap. xv. (WHITEHEAD'S edition, Chicago, 1898, P. 72). In modern times homoeopathy--according to which a drug is a cure, if administered in small doses, for that disease whose symptoms it produces, if given in large doses to a healthy person---seems to bear some resemblance to these old medical theories concerning the curing of like by like. That the system of HAHNEMANN (1755--1843), the founder of homoeopathy, is free from error could be scarcely maintained, but certain recent discoveries in connection with serum-therapy appear to indicate that the last word has not yet been said on the subject, and the formula "like cures like" may still have another lease of life to run. To return to PARACELSUS, however. It may be thought that his views were not so great an advance on those of GALEN; but whether or not this be the case, his union of chemistry and medicine was of immense benefit to each science, and marked a new era in pharmacy. Even if his theories were highly fantastic, it was he who freed medicine from the shackles of traditionalism, and rendered progress in medical science possible.