Nitrogen in Urine. 363 



persons in normal health made with modern methods of analysis are of much 

 greater interest in connection with a discussion of the results obtained in 

 the Middletown experiments. 



The results of the more recent fasting experiments are given in table 196. 

 Although the nitrogen excretion per kilo of body-weight is not given in the 

 table, the data are readily obtained since the body-weight at the beginning of 

 the fast * 3 is given in the column headings. 



Eanke 44 made three experiments on himself while fasting. Each experiment 

 lasted one day. The amounts of nitrogen 45 eliminated were 10.4, 8.0, and 8.6 

 grams, respectively. In the last experiment no water was taken. 



Pettenkof er and Voit 4B reported three experiments, each continuing one day 

 in which the subject took no food other than a small amount of meat extract. 

 The extract contained 1.2, 1.3, and 1.7 grams of nitrogen on the three days. 

 The excretion of nitrogen in the urine was 12.5 (7.42 day, 5.09 night), 12.3 

 (6.72 day, 5.55 night) and 12.3 (5.55 day, 6.21 night) grams, respectively. 

 From 10 to 15 grams of common salt were taken in connection with the meat 

 extract. In the first two experiments the subject was resting, in the last he 

 performed considerable muscular work. In both Eanke's and Pettenkofer and 

 Yoit's experiments, the determination of nitrogen was made by the Liebig 

 method and hence did not represent the total urinary nitrogen. 



It is a matter of historic interest that the first experiment made with 

 Pettenkofer's respiration apparatus was that of Eanke studying the metabolism 

 during inanition. 



Likhachev " in a one-day fasting experiment found the total nitrogen output 

 to be 8. 5 2 grams. 



In a 2-day fast Eitter 48 found that the subject excreted 11.68 and 12.96 

 grams of nitrogen, respectively. 



In fasting experiments made in this laboratory and reported elsewhere, 49 the 

 nitrogen excretion on the first day of fast in four experiments was 11.5, 16.0, 

 14.1, and 11.7 grams, respectively. The experiments were all made with the 

 same subject. The first was after a carbohydrate diet during 4 days of rest; the 

 second after a 4-day work experiment, in which the diet consisted largely of 

 fats; the third likewise followed a 4-day work experiment with a fat diet; 

 and the fourth was the first day of a 2-day fast experiment following a day 

 of rest. On the second fasting day 12.2 grams of nitrogen were excreted. 



43 In computing the nitrogen excreted per kilo of body-weight the average body- 

 weight for each day of the fast should be used to secure the greatest accuracy. 

 These weights may be obtained by means of the daily losses shown in tables 184 

 and 185. 



44 Archiv Anat. u. Physiol. (1862), p. 340. 



45 The total nitrogen was computed from the weights of urea and uric acid found. 



49 Zeit. f. Biol. (1866), 2, p. 478. 



47 Dissertation St. Petersburg (1893). 



^Ritter, Miinchener medic. Wochenschr., 1893, Nos. 31 and 32. 



49 U. S. Dept. of Agr., Office of Expt. Sta. Bui. 136, p. 120 (1903). 



