And these classes have been subdivided into many varieties, but it is enough, in a treatise on the feet and their covering, to allude to the cause of torment generally, as a hard substance and a soft one, pressing into the foot, as the Roman name emphatically describes it, “clavus dura”--a small tack. The approach of a corn, as all who ever felt it know, commences with a slight inflammatory smart on the prominent part of the little toe; then comes on the excessive burning, the throbbing, the stabbing: “a little longer, yet a little longer;” and then the point of the tack begins to enter, the outer skin is penetrated, the next membrane becomes inflamed, and, from the delicate “network” of the rete mucosum, an increased quantity of secretion is poured out: gradually a substance is formed, hard, horny, and with a sharp point, that descends deeper and deeper into the foot, until not unfrequently it reaches and enters the blood-vessels and very joints themselves. All attempts at cure must be directed to the point of the corn. It has been usual to salve and plaster and cut the head of this tack, generally with little or no success--call it a thorn in the foot, “spina pedum,” a name given to it by some practitioners; and how absurd this palliative treatment appears--every one knows that the thorn must immediately be extracted, and if we delay, great pain is the consequence, and soon nature expels it herself. Some balsams and tinctures have been much spoken of by the older writers on the different excrescences, but modern practice has very judiciously excluded them, from their insufficiency to produce any good effect. The radical cure is more dependent upon surgical than medical means. “Although I have devoted,” says Mr. Durlacher, “nearly thirty years practical experience to the investigation, and have tried various chymical and other remedial agents, yet I have never been able to discover any certain cure for corns. Nevertheless, men are found bold enough in their ignorance and presumption, to assert, by public advertisement, that they possess an infallible nostrum, capable of thoroughly eradicating corns; and others who pretend to extract them, seek to aid their trickery and charlatanry by exhibiting small spiculæ as the roots of the corns they have extracted, although it is a positive fact from the structure of the skin, that such an assertion must be false, and the whole proceeding the veriest imposition imaginable.”