If the pain and tenderness be located on the _under_-surface of the os calcis, there are several misconceptions possible. (1) Careful examination may reveal a tendency to flatfoot, the pain being referable to strain on the posterior insertion of the plantar fascia. (2) The root of the trouble may be a gonococcal inflammation of the plantar fascia, or of the periosteum covering the os calcis. (3) A skiagram may show the existence of a bony spur on the inferior surface of the os calcis. (4) The bursa under the os calcis may be inflamed. (5) Also, as Tubby has pointed out, pain in the heel may be referable to shortening of one leg or constant standing, and more rarely to tuberculous disease of the os calcis. If the pain and tenderness be located on the _posterior_ surface of the os calcis, or in the tendo Achillis, the following should be excluded before assigning the trouble to “gout”:— (1) _Post-calcaneal Bursitis._—Inflammation of the bursa lying between the os calcis and the tendo Achillis is not uncommon. It may be uni- or bi-lateral, and in the majority of instances is attributable to violent exercise, or chafing of the heel by ill-fitting boots. The local swelling and tenderness at the site of the inflamed bursa and its aggravation by plantar flexion of the foot will afford a clue to its true nature. (An exostosis projecting from the hinder surface is sometimes a cause of post-calcaneal bursitis.) (2) _Synovitis of the Tendo Achillis._—Symptoms very similar to those above described have been met with in a teno-synovitis of the tendo Achillis, as evidenced by swelling of the sheath, tenderness, and silky crepitus. GOUT IN THE SOLE There is a wide disposition to regard all painful or unpleasant sensations in the sole of the foot as evidences of “goutiness.” It may be recalled that Strabo, according to Plutarch, apostrophised heat or itching of the feet at night as “the lisping of the gout.” Duckworth, too, emphasised the frequency of this symptom in the gouty, and Sir Charles Scudamore also held heat and dryness of the sole as frequent harbingers of acute attacks. Now, did we but confine our hazards as to gout only to cases marked by heat or itching in the sole, possibly little harm might result; but unfortunately there is a flippant readiness to relegate all obscure pains or abnormal sensations in the sole to the “gouty” category. Needless to say, this is quite unjustifiable. We need not reiterate the bounden necessity of excluding all static foot deformities, but we should in addition recall the various types of _plantar neuralgia_.