A. Muller, 1911

Five years later A. Muller2 from the same clinic reported two researches, likewise with the Zuntz-Geppert apparatus, one with a subject who was perfectly healthy and the other with a greatly emaciated subject. In the first case, in an experimental period of about 2 months, 210 grams of nitrogen were added to the body during a period of surfeit feeding of 28 days. During this time there was an increase of 4 kg. in the body-weight, but the oxygen consumption rose only from 228 to 234 c.c. per minute. There was a slight decrease in the oxygen consumption per kilogram, ranging from 4.2 c.c. in the preliminary period to 4.0 c.c. in the surfeit feeding period. Muller concludes that when a marked storage of nitrogen is produced in a normal man by surfeit feeding with excess of both nitrogen and calories, the increase in the oxygen consumption is practically insignificant. On this point the experiment confirms fully the findings of Dengler and Mayer. Muller concludes that the absence of an increase in oxygen consumption argues against a storage of active protoplasmic tissue and bears out the contention of von Noorden that the nitrogenous substance added to the body did not have the same biological properties as the original protoplasm.

1 Dengler and Mayer, Zentralbl. f. d. ges. Physiol, u. Pathol, d. Stoffw., 1906, N. F., 1, p. 228. 2 A. Muller, Zentralbl. f. d. ges. Physiol, u. Pathol, d. Stoffw., 1911, N. F., 6, p. 617.

With the second subject, who was much emaciated, with a height of 175 cm. and a body-weight of 46 kg., a storage of 198 grams of nitrogen was found 23 days after an operation for gastroenteritis. The increase in the oxygen consumption after the operation was very pronounced, rising from 180 to 231 c.c. The body-weight increased 5.5 kg. Since this increase in oxygen consumption took place a relatively few days after the operation and before there was a great storage of nitrogen in the body or appreciable increase in body-weight, the author argues that this was not caused by an addition of active protoplasmic tissue. He assumes that the increase in the oxygen consumption may be due to two possibilities: one, that during the hunger period the body was forced to limit its energy exchange and that with renewed feeding the energy thus s ved was expended; the other, that the transition from chronic undernutrition to normal conditions, especially to protein plethora, might lead to a temporary condition of stimulus to the cells and a transitory increase in metabolism. The first experiment of Muller is extremely difficult to understand. To secure so large a storage of nitrogen in the body with an apparently normal individual without altering the basal metabolism in the slightest is a striking observation. It is to be regretted that this experiment could not have been repeated under uniform conditions and thorough control.

Zuntz And Schirokich, 1912

A series of experiments made by Zuntz and Schirokich1 with Horace Fletcher, after a diet of potatoes and butter, has already been discussed in connection with experiments on this subject made at Wesleyan University and the Nutrition Laboratory. (See pages 7 to 10).

Zuntz, 1913

Zuntz,2 in studying an animal that was underfed for a period of 13 months, found that the heat production per square meter of body-surface per 24 hours as computed on the Meeh formula (a method of computation that Zuntz himself considers somewhat doubtful) showed a falling off in metabolism from 931 calories when the dog weighed 10 kg. to 631 calories when the dog weighed one-half this amount. In spite of this fact, and in all probability because later when the body-weight had been reduced to 4.1 kg., the heat production per square meter of body-surface rose to 921 calories, Zuntz concludes that the theory of an adjustment of metabolism to an insufficient intake is not here substantiated. On the contrary, the opposite was demonstrated in the last few weeks of life, when there was a great rise in the metabolism.

1 Zuntz and Schirokich, Separate from Med. Klinik, 1912, No. 32, 5 pp. 2 Zuntz, Biochem. Zeitachr., 1913, 55, p. 341.

Morgulis, 1914

Morgulis,1 carrying out the theories of Zuntz with whom he had worked in Berlin, reports results of an experiment on a dog which was given about one-third of the maintenance requirement in the diet. Prior to the reduction in the diet, the energy requirement was computed from the respiratory exchange to be 39.3 calories per kilogram per 24 hours. As a matter of fact, after the dog had lost 42.35 per cent of his original weight, the energy requirement was 43.6 calories, or 11 per cent more. Wholly inexplicable increases and decreases in metabolism were reported with the resumption of excess feeding.

Hari, 1914

In a carefully planned series of experiments designed to eliminate the question of too low a temperature, Hari,2 employing all of the usual Budapest accuracy of technique, studied the influence of chronic undernutrition on the metabolism, measuring the heat directly by means of the Rubner calorimeter. Although the experiments were somewhat complicated by the fact that, in the first place, the basal value was obtained in several days of complete fast, that milk was administered at times cold and at times warm, and that the actual amount of energy ingested averaged in all the series about 70 per cent of the maintenance need, Hari has drawn some important conclusions. Of special significance to us in this discussion, however, is the clear relationship he notes between metabolism and loss in nitrogen. The irregularity of his results he explains in part on the ground of individuality. The feeding experiments are usually of such short duration that it is difficult to distinguish between true starvation and the period of chronic undernutrition which in no case continued more than 9 days. Using the fasting days as basal values, Hari notes that when insufficient food is given, there is either a slight increase or a very slight tendency to a decrease in metabolism.