24 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



Hunt, 1910. The effect of a restricted diet upon the resistance 

 of animals to certain poisons was studied by Hunt^ in an extensive 

 series of experiments on mice and guinea-pigs. The author assumes 

 that acetonitrile exerts its toxic effects only, or largely, after under- 

 going changes due to the processes of metabolism, the intensity of 

 the processes of oxidation determining the intensity of the toxic effect. 

 The diet given the experimental animals, while qualitatively the 

 same, was less than that of the animals on the unrestricted diet. The 

 dose of acetonitrile dissolved in water was injected subcutaneously; 

 the amount used was proportional to the body-weight. Only those 

 experiments in which the dose was nearly fatal are cited. It was 

 ascertained as typical of these experiments, that with equal doses of ace- 

 tonitrile the animal on an unrestricted diet died, while that on the 

 restricted diet recovered. This was interpreted as showing a diminu- 

 tion in the intensity of the processes of metabolism with restricted 

 diet. 



Grafe, 1910. — In his first publication on metabolism during katatonia, 

 Grafe^ points out that in spite of what he considers sufficient food, 

 namely, 1,400 calories per day, the body-weight remained constant at 

 47.5 kg. as compared with an initial weight of approximately 55 kg. 

 He concludes that the body does not exhibit a tendency to increase in 

 weight, and considers this as possibly a peculiarity of katatonia. We 

 have here one of the earliest suggestions in Grafe's writings of the 

 conception of an adjustment of metabolism to food intake, viz., that 

 with increased food intake there is increased energy expenditure. 



Grafe, 1911. — In a special search for pathological conditions in which 

 a retardation of basal metabolism would be noted, Grafe,^ in a carefully 

 planned series of experiments, studied the metabolism of patients in 

 psychiatric coma. Obtaining his subjects from the Psychiatric Insti- 

 tute in Heidelberg, he placed them in the Jaquet respiration cham- 

 ber in the Clinic for experiments lasting from 3 to 12 hours or 

 more. If we consider only those experiments in which the subjects 

 remained very quiet, we find in certain cases of mental disturbance 

 accompanied by stupor that the basal metabohsm, either per kilogram 

 of body-weight or per square meter of body-surface (using the Meeh 

 formula), is extraordinarily low. In one case it was 39 per cent below 

 the value selected by Grafe as a normal, namely, 800 calories per square 

 meter per 24 hours. 



Grafe finds it difficult to explain this depression in metabolism as 

 being caused by chronic undernutrition. Grafe's patients, although 

 admittedly somewhat undernourished when compared with the aver- 

 age of normal people of the same age, were far from being ema- 



^Hunt, Public Health and Marine-Hospital Service of the U. S., Hygienic Laboratory Bull. 

 No. 69, 1910. 



2 Grafe. Zeitschr. f. physiol. Chem., 1910, 65, p. 45. 



3 Grafe, Deutsch. Arch. f. klin. Med., 1911, 102, p. 15. 



