It is clear, though Paracelsus long antedated Hahnemann, the founder of Homœopathy, that much of his medical teaching is what we should now call Homœopathic. Hahnemann, in fact, borrowed extensively from Paracelsus. Take, for instance, Paracelsus’s teaching with regard to the quintessence or virtue of each substance. This, he taught, though infinitesimal in quantity, even in large bodies, had none the less the power to affect the mass through and through, as a single drop of gall embitters, or a few grains of saffron colour a large quantity of water. The application of homœopathic cures by those ignorant of homœopathic principles has frequently led to mistakes in this connection; as, for instance, the administration of doses many times in excess of what the complaint requires, the result being the entire failure of the medicine to produce the intended effect. “There are wide differences,” says Paracelsus, striking again a very homœopathic note, “between what the ancient doctors taught and what we here teach, and therefore our healing art differs widely from theirs. For we teach that what heals a man also wounds him, and what wounded will also heal him. For the nettle can be so changed that it cannot burn, the flame so that it does not scorch, and the chelidony so that it does not cicatrize. Thus similars are good in healing, such and such a salt to such and such a sore. And the things which heal a wound in Nature heal the same sort of wound in man.” “Many kinds of rust,” says Paracelsus again, “occur in the minerals; for each mineral has its own peculiar nature.” This rust is in the form of a disease, and iron has one disease, while copper has another. In a similar way a man has a sore and it is healed by treatment. The metal, too, has a sore, and can be healed by treatment. “Metallic bodies,” says Paracelsus, long antedating the discoveries of the present day, “are as liable to death as the others, for their salt is arsenic.” The whole earth is linked together, and the life that passes through the bodies of men passes also through the bodies of minerals. Paracelsus had no patience with those who taught of a panacea that would heal all diseases. He described them as people who “rode all horses with one saddle,” through whom more harm than good was effected. He maintained that a doctor must know the sick and all matters appertaining to their state “just as a carpenter knows his wood.” He mentions six essential qualifications for the practical physician. (1) A doctor (he says) must know how many kinds of tissue there are in the body, and how each kind stands in relation to the man. (2) He must know all the bones, such as the ribs and their coverings, the difference between one and another, their relations to each other and their articulations. (3) He must know all the blood-vessels, the nerves, the cartilages and how they are held together.