The phenomena of undernutrition occurring either independently or as a complication of a variety of diseases are often overlooked, or if discovered at all, are commonly misinterpreted. Hence chronic undernutrition is frequently allowed to persist to the great detriment of the organism. Three fundamental rules must be fulfilled in feeding patients, especially individuals afflicted with chronic disorders, viz.: 1. The diet must incorporate a caloric value sufficient to maintain adequate nutrition, for otherwise the body cannot put forward its best endeavors to combat the disease. 2. The diet must be so composed that it spares the diseased organ, i. e., imposes no excessive tasks upon parts that are already functionally or organically impaired. 3. The diet must neither directly nor indirectly injure or overtax any portion of the body. Regulations both of a qualitative and a quantitative character, must therefore, be formulated; and these rules should be based upon physiologic reasoning, and only when this fails upon empiricism. Routine of any sort is to be condemned. The peculiar nutritional demands of each patient should be carefully studied. Accordingly, "not only must the patient be instructed by the physician, but the physician must also learn from each patient." Sanatoria and watering places should learn this lesson more thoroughly.

The rules in regard to the quality of the diet that patients suffering from different diseases should have are more easy to understand than the rules in regard to the total quantity of food that is permissible and advisable. There is a normal state of nutrition, a maximum and a minimum compatible with safety and well-being. Above and below these levels lies dangerous territory. In order to understand the regulation of these limits the mathematics of the normal, expressed in calories and energy equivalents, must be understood.

The two lectures published herewith do this in a masterful manner. The conception of the "maintenance diet" (Erhaltungskost) is formulated and made the basis of all nutritional studies; the effects of deviations from this standard (acutely or chronically--fasting or undernutrition) upon the fats, the carbohydrates, the proteids of the body are clearly and concisely delineated; the most important urinary phenomena that are the direct result of general undernutrition or of one-sided feeding are described and their diagnostic significance interpreted.

In the second lecture the treatment of chronic undernutrition is given, i. e., the raising of the state of nutrition from the sub-normal to the normal, or from the normal to the maximum. Especially instructive, from a practical standpoint, are the rules in regard to the increase of active, breathing, energyproducing muscle protoplasm on the one hand; of inactive, storage-or reserve-material, chiefly represented by fat, on the other. It is particularly refreshing, in this lecture, to read the criticism of innumerable dietetic fads and fallacies. Iconoclasm of this kind is of the greatest practical use provided something of value is erected in the place of the fallen idols. This requirement the author of these lectures has fulfilled to a pre-eminent degree.

Alfred C. Croftan.

April 25th, 1910.

100 State Street, Chicago.