(14) Robert Fludd, the Mystical Physician, British Medical
     Journal, London, 1897, ii, 408.

The doctrine of contraries drawn from the old Greek philosophy, upon which a good deal of the treatment of Hippocrates and Galen was based—­dryness expelled by moisture, cold by heat, etc.—­was opposed by Paracelsus in favor of a theory of similars, upon which the practice of homeopathy is based.  This really arose from the primitive beliefs, to which I have already referred as leading to the use of eyebright in diseases of the eye, and cyclamen in diseases of the ear because of its resemblance to that part; and the Egyptian organotherapy had the same basis,—­spleen would cure spleen, heart, heart, etc.  In the sixteenth and seventeenth centuries these doctrines of sympathies and antipathies were much in vogue.  A Scotchman, Sylvester Rattray, edited in the “Theatrum Sympatheticum"(15) all the writings upon the sympathies and antipathies of man with animal, vegetable and mineral substances, and the whole art of physics was based on this principle.

     (15) Rattray:  Theatrum Sympatheticum, Norimberge, MDCLXII.

Upon this theory of “mumia,” or magnetic force, the sympathetic cure of disease was based.  The weapon salve, the sympathetic ointment, and the famous powder of sympathy were the instruments through which it acted.  The magnetic cure of wounds became the vogue.  Van Helmont adopted these views in his famous treatise “De Magnetica Vulnerum Curatione,"(16) in which he asserted that cures were wrought through magnetic influence.  How close they came to modern views of wound infection may be judged from the following:  “Upon the solution of Unity in any part the ambient air . . . repleted with various evaporations or aporrhoeas of mixt bodies, especially such as are then suffering the act of putrefaction, violently invadeth the part and thereupon impresseth an exotic miasm or noxious diathesis, which disposeth the blood successively arriving at the wound, to putrefaction, by the intervention of fermentation.”  With his magnetic sympathy, Van Helmont expressed clearly the doctrine of immunity and the cure of disease by immune sera:  “For he who has once recovered from that disease hath not only obtained a pure balsaamical blood, whereby for the future he is rendered free from any recidivation of the same evil, but also infallibly cures the same affection in his neighbour . . . and by the mysterious power of Magnetism transplants that balsaam and conserving quality into the blood of another.”  He was rash enough to go further and say that the cures effected by the relics of the saints were also due to the same cause—­a statement which led to a great discussion with the theologians and to Van Helmont’s arrest for heresy, and small wonder, when he makes such bold statements as “Let the Divine enquire only concerning God, the Naturalist concerning Nature,” and “God in the production of miracles does for the most part walk hand in hand with Nature.”