It is a curious fact that the irritation or puncture of a very circumscribed area in the floor of the fourth ventricle in the medulla is followed by the appearance of sugar in the urine. This spot is called the " diabetic centre," and it is in close relation with the sympathetic and vasomotor nerves that control the capacity of the hepatic blood vessels. In animals in which fatty degeneration of the liver cells has been artificially produced by metallic poisoning, puncture of the diabetic centre produces glycosuria. Glycosuria is also observed in men after the inhalation of chloroform and in animals after the inhalation of irritant vapours and after stimulation of the pneumogastric nerve. Schiff produced glycosuria experimentally by the removal of the spleen from animals, but it does not follow this operation in man. He also tied off successive portions of the liver from connection with the circulation, and found the production of sugar proportionately decreased. The frog is capable of surviving extirpation of the liver for three weeks, and at the end of this time no sugar is found in the blood (Schiff). If the vagus nerve is divided in the neck, or if the spinal cord be divided above the origin of the great sympathetic nerve, diabetes may result.

Bernard suggested that glycosuria might be cured if it were possible to galvanise the sympathetic nerves. The foregoing experiments demonstrate that glycosuria may be caused by a variety of nerve lesions and irritations. It is also frequently associated with modifications in the activity of the hepatic circulation.