was at least intelligible. It associated itself, too, with the pious utterances so frequent among the mediæval teachers and practitioners of medicine. The theory was that the Creator in providing herbs for the service of man had stamped on them, at least in many instances, an indication of their special remedial value. The adoption of ginseng root by the Chinese as a remedy for impotence, and of mandrake by the Hebrews and Greeks in the treatment of sterility, those roots often resembling the male form, have been often cited as evidence of the antiquity of the general dogma.... But isolated instances of that kind are very far from proving the existence of systematic belief. Hippocrates states that diseases are sometimes cured by the use of “like” remedies; but he was not the founder of homœopathy.
It is likely that the belief in a special indication of the virtues of remedies grew up slowly in the monasteries, and was originated, perhaps, by noticing some curious coincidences. It found wide acceptation in the sixteenth century, largely owing to the confident belief in the doctrine expressed in the writings of Paracelsus. Oswald Crollius and Giovanni Batista Porta, both mystical medical authors, taught the idea with enthusiasm. But it can hardly be said that it maintained its influence to any appreciable extent beyond the seventeenth century. Dr. Paris describes the doctrine of signatures as “the most absurd and preposterous hypothesis that has disgraced the annals of medicine”; but except that it may have led to experiments with a few valueless herbs, it is difficult to see sufficient reason for this extravagant condemnation of a poetic fancy.
The signatures of some drugs were no doubt observed after their virtues had been discovered. Poppy, for instance, under the doctrine was appropriated to brain disorders, on account of its shape like a head. But its reputation as a brain soother was much more ancient than the inference.
It is only necessary to give a few specimens of the inductive reasoning involved in the doctrine of signatures as revealed by the authors of the old herbals. The saxifrages were supposed to break up rocks; their medicinal value in stone in the bladder was therefore manifest. Roses were recommended in blood disorders, rhubarb and saffron in bilious complaints, turmeric in jaundice, all on account of their colour. Trefoil “defendeth the heart against the noisome vapour of the spleen,” says William Coles in his “Art of Simpling,” “not only because the leaf is triangular like the heart of a man, but because each leaf contains the perfect icon of a heart and in the proper flesh colour.” Aristolochia Clematitis was called birthwort, and from the shape of its corolla was believed to be useful in parturition. Physalis alkekengi, bladder wort, owed its reputation as a cleanser of the bladder and urinary passages to its inflated calyx. Tormentilla officinalis, blood root, has a red root, and would therefore cure bloody fluxes. Scrophularia nodosa, kernel wort, has kernels or tubers attached to its roots, and was consequently predestined for the treatment of scrofulous glands of the neck. Canterbury bells, from their long throats, were allocated to the cure of sore throats. Thistles, because of their prickles, would cure a stitch in the side. Scorpion grass, the old name of the forget-me-not, has a spike which was likened to the tail of a scorpion, and was therefore a remedy for the sting of a scorpion. [The name forget-me-not was applied in England, until about a century ago, to the Ground Pine (Ajuga Chamœpitys), for the unpoetical reason that it left a nauseous taste in the mouth.]
Oswald Crollius, who describes himself as Medicus et Philosophus Hermeticus, in his “Tractatus de Signatures,” writes a long and very pious preface explaining the importance of the knowledge of signatures. It is the most useful part of botany, he observes, and yet not a tenth part of living physicians have fitted themselves to practise from this study to the satisfaction of their patients. His inferences from the plants and animals he mentions are often very far-fetched, but he gives his conclusions as if they had been mathematically demonstrated. Never once does he intimate that a signature is capable of two interpretations. A few illustrations not mentioned above may be selected from his treatise.
Walnuts have the complete signature of the head. From the shell, therefore, a salt can be made of special use for wounds of the pericranium. The inner part of the shell will make a decoction for injuries to the skull; the pellicle surrounding the kernel makes a medicine for inflammation of the membrane of the brain; and the kernel itself nourishes and strengthens the brain. The down on the quince shows that a decoction of that fruit will prevent the hair falling out. So will the moss that grows on trees. The asarum has the signature of the ears. A conserve of its flowers will therefore help the hearing and the memory. Herb Paris, euphrasia, chamomile, hieracium, and many other herbs yield preparations for the eyes. Potentilla flowers bear the pupil of the eye, and may similarly be employed. The seed receptacle of the henbane resembles the formation of the jaw. That is why these seeds are good for toothache. The lemon indicates the heart, ginger the belly, cassia fistula the bowels, aristolochia the womb, plantago the nerves and veins, palma Christi and fig leaves the hands.
The signatures sometimes simulate the diseases themselves. Lily of the valley has a flower hanging like a drop; it is good for apoplexy. The date, according to Paracelsus, cures cancer; dock seeds, red colcothar, and acorus palustris will cure erysipelas; red santal, geraniums, coral, blood stones, and tormentilla, are indicated in hæmorrhage; rhubarb in yellow bile; wolves’ livers in liver complaints, foxes’ lungs in pulmonary affections, and dried worms powdered in goats’ milk to expel worms. The fame of vipers as a remedy was largely due to the theory of the renewal of their youth. Tartarus, or salt of man’s urine, is good against tartar and calculi.
Colour was a very usual signature. Red hangings were strongly advocated in medical books for the beds of patients with small-pox. John of Gaddesden, physician to Edward II, says, “When I saw the son of the renowned King of England lying sick of the small-pox I took care that everything round the bed should be of a red colour, which succeeded so completely that the Prince was restored to perfect health without the vestige of a pustule.”