There are many watering places in which fat people congregate every summer in order to undergo a reduction cure. In Europe Homburg, Carlsbad, Kissingen, Marienbad enjoy the greatest reputation. It is claimed for these waters that they "stimulate metabolism," in other words, increase the general metabolism, in particular, the combustion of fat. This problem is now amena ble to exact mensural control. The results obtained are very slight. It is true that within the first and second hour after the intake of mineral waters the output of energy increases by about 5 to 10%, but this is attributable more to the stimulation of the intestinal glands and musculature than to any other factor. Distributed over the whole day this increase in the total output of energy barely exceeds 1%. And not more than 2 to 3 g. of fat are consumed in order to furnish this amount of extra energy, certainly an exceedingly small quantity. In addition, one must remember that the intake of laxative mineral waters sometimes, although not always, somewhat impairs absorption. But not more than 3 to 4 g. of fat are withdrawn from assimilation in this way. Drinking cures are of great value for certain of the complications of obesity, as gastrointestinal disturbances, hepatic derangements, uric acid diathesis, etc. The undesirable reducing effect of such a cure, as it is carried out in the above-mentioned watering places, depends in its totality much more upon other factors than upon any specific properties of the waters (diet, exercise, hydrotherapy). Without these accessory factors the drinking cure per se is merely a drop on a hot stone.